Oral History Transcript — Dr. Robert H. Thomas
This transcript may not be quoted, reproduced or redistributed in whole or in part by any means except with the written permission of the American Institute of Physics.
This transcript is based on a tape-recorded interview deposited at the Center for History of Physics of the American Institute of Physics. The AIP's interviews have generally been transcribed from tape, edited by the interviewer for clarity, and then further edited by the interviewee. If this interview is important to you, you should consult earlier versions of the transcript or listen to the original tape. For many interviews, the AIP retains substantial files with further information about the interviewee and the interview itself. Please contact us for information about accessing these materials.
Please bear in mind that: 1) This material is a
transcript of the spoken word rather than a literary product; 2) An interview
must be read with the awareness that different people's memories about an event
will often differ, and that memories can change with time for many reasons
including subsequent experiences, interactions with others, and one's feelings
about an event. Disclaimer: This transcript was scanned from
a typescript, introducing occasional spelling errors. The original typescript
Access form | Project support | How to cite | Print this page
See the catalog record for this interview and search for other interviews in our collection
Robert Thomas; January 27, 2009
ABSTRACT: This interview was conducted as part of a series documenting the history of scientific work on the West Antarctic Ice Sheet (WAIS). Robert Thomas discusses his education in physics at the University of Liverpool, and his entry into glaciology through the Falkland Islands Dependencies Survey/British Antarctic Survey, and his subsequent education at the Scott Polar Research Institute in Cambridge under Charles Swithinbank. There is detailed information on his employment on the Ross Ice Shelf Geophysical and Glaciological Survey with Charles Bentley, and subsequent appointments at the University of Maine with Terry Hughes and George Denton, at Cambridge, and National Aeronautics and Space Administration (NASA) Goddard. The interview also covers his subsequent work for NASA on radar and laser altimetry in Greenland and Antarctica (separate from the main research group focusing on ice stream behavior), and discussion of the Intergovernmental Panel on Climate Change process.
W. Thomas: This is Will Thomas. I’m speaking with Bob Thomas (who is of no relation of mine) concerning the West Antarctic Ice Sheet research project. We are in Bethesda, Maryland on what I believe is January 27th, 2009. So I guess to get started, could you maybe tell me a little bit about your background, where you grew up, how you got interested in science, if your parents were involved in science at all or if it was your own initiative — that sort of thing.
B. Thomas:I originally came from England and grew up in a place called Hoylake near Liverpool on the west coast. And did all of my schooling in England through what was then the grammar school system in Britain, and was an attempt to bring a more egalitarian level of education so that the people at the bottom could creep up to the top. And it worked very well and enabled me to get to university at the University of Liverpool, which is where I studied physics. I found that after a while I wasn’t desperately interested in physics as it was then — it would probably be more exciting today. But I did a bit of geology and things like metallurgy and logic as well, and I found that those were more interesting, and particularly the field sciences. So that when I left University, and I was looking for a job —
W. Thomas: This is the 1950s?
B. Thomas:This was in 1959. So when I left Liverpool, I was looking for a job that really would give me an opportunity to do those kinds of things. I didn’t have a desperately good degree, having lost interest in physics, and I was quite pleased when someone from what was then known as the Falkland Islands Dependencies Survey came to the University looking for people to go to the Antarctic. Specifically they were looking for geologists, and I wasn’t really a geologist, so they weren’t terribly interested in me as a geologist. But they figured I’d studied physics, and they let me interview to become an ionosphericist, because they used to do that as well in the Antarctic. And they didn’t want me for that either, but they sort of crept down the ladder, and what they always wanted was weathermen — meteorologists, so they sent me on a course to learn how to make weather observations. And I spent a few months at the Met Station at Birmingham Airport learning how to do that, and then off we went to the Antarctic and in those days we went by ship, and I was employed as a meteorologist.
It took us about two months to get down there. We went by the Falkland Islands where we’d get all our equipment, and then we were dumped off for a couple of years at a base. This was on the west side of the Antarctic Peninsula, a place called Galindez Island, around about the Antarctic Circle, just north of the Antarctic Circle — delightful place on the small island with a little ice cap on it. And that gave me the chance to pursue glaciology really as a hobby, because I didn’t have much in the way of equipment. But fortunately, some surveyors came through and taught me how to survey with a theodolite, and I started surveying ice stakes and just measuring anything that I could see, more or less. After two years of doing that, I was able to put together a paper when I came back to England. And then after an interval of about two years during which I traveled in South America and did things like that, I went again to the Antarctic, but this time professionally. They actually paid me to be a glaciologist, and I went to a place called Halley Bay, which was a base, built on an ice shelf just east of the Filchner Ice Shelf in the Weddell Sea. That was quite a bit further south, and it was floating ice that flows off the continent. It was maybe 30 or 40 kilometers seaward of the place.
W. Thomas: And this is still with the Falkland Islands Dependencies Survey?
B. Thomas:Well, it was then called the British Antarctic Survey and it was under Sir Vivian Fuchs. And we spent a couple of years in a base that was being progressively buried, so that it was about 30 feet below the snow by the time I got there. During the two years we built another base on the top. But I did a lot of fieldwork and traveled here, there, and everywhere measuring things on the ice shelf, primarily motion schemes, so that I could measure how fast the ice was moving and how fast it was stretching. Again, when I came back, I was able to mesh that into a thesis. When I came back, I worked in Cambridge at the Scott Polar Research Institute.
W. Thomas: Do you have kind of the years that this is taking place?
Oh, yes. The first time I was there in 1960 and 1961 at Galindez Island. The second time I was down there I was down from 1966 and 1967.
W. Thomas: Oh, okay. What were you doing in between?
B. Thomas:I traveled in South America and took any old job I could get in between. It was really just fooling around I suppose [laughs]. At that age, you know, you like to do different things. So when I came back the second time and BAS, as it then was, British Antarctic Survey, had its sort of scientific center was in Cambridge, or what little glaciology they did was based in Cambridge. So I went to the Scott Polar Research Institute and worked on a thesis. I was very lucky there, because that was a place where a lot of glaciologists from throughout the world used to come and spend their sabbaticals. It was a nice place to be. And while I was there, Bill Budd came through, and Jensen, who was the modeler who worked with Budd, and also Hans Weertman came through, and Colin Bull from Ohio State, and I think a couple of Russians came. I mean it was a very lively place to meet people and get ideas. And of course, Weertman was the fellow who did the early work on ice shelves in terms of their creep. About then he was working on the paper which tested the idea that Mercer had put forward that if the ice shelves break away, then the ice sheet might collapse into the sea. And so he wrote a paper looking at the theoretical side of that. And it was a timely occasion I picked to be there.
W. Thomas:You’re talking about the 1974 paper by Weertman?
I think that’s right, yeah, on the stability of the grounding line. Because I was in Cambridge from 1968 until ’73, I think, and so he was in Cambridge thinking about these things before he’d written that paper, and he would give talks about it and this, that, and the other. And of course, he’d written his ice shelf paper. So part of my thesis essentially was to use the data I’d collected to apply the Weertman equations and infer the properties of ice.
At the same time, it was clear that parts of the ice shelf weren’t behaving like a freely floating ice shelf and that the ice was being banged up against an area where the ice shelf ran aground, and that strongly affected its stress, the stress distribution within the ice shelf. And the creep rates, which I’d measured the creep rates, so I worked everything backwards to figure out what the impact of this little grounded area was on the ice shelf. And it was clear that the grounding point was acting like a sort of buttressing point and transmitting like a back pressure on the ice shelf from the entire width of the ice shelf right to the grounding line. So it was clear that ice shelves can have quite a strong stress impact on anything flowing into the ice shelves.
W. Thomas:So now we’re talking about these papers here on the creep of ice shelves?
B. Thomas:That’s right, and the interpretation of behavior.
W. Thomas:Okay. So these are in the Journal of Glaciology, right.
B. Thomas:So the interpretation of behavior looks at the stress distribution associated with the grounding point. So that was quite closely related to what Weertman had been doing. Now Weertman’s analysis considered a freely floating ice shelf and what happens to the grounding line for a freely floating ice shelf. So when I later wrote a paper which looked at the effect of a bounded ice shelf on a glacier, that took advantage of what I had learned on the Brunt Ice Shelf [near Halley Research Station] because then you are no longer just considering the effect of the water pressure, you’ve got all these other back pressures that are applied ultimately to the glacier. The approach I took was that that back pressure would be felt far, far inland, not just at the grounding line. That became a point of contention with theoreticians later on who proved to their own satisfaction that this couldn’t happen. You know, that there would only be a few ice thicknesses inland of the grounding line that the glacier would give a damn about an ice shelf. You know, you take an ice shelf away and the ice up here doesn’t care. And so that was the only way that we could check that out really was by observation. As you probably know, more recently the observations are coming through that show that indeed the ice does feel the ice shelf a long, long way inland.
So that early work fortuitously on the Brunt Ice Shelf, because it turned out to have this little grounding point, fed into a lot of the things that I did later and was highly related to the stuff that Weertman was working on and the stuff that Terry Hughes had proposed, Terry and John Mercer.
W. Thomas:How aware were you, especially before you kind of came to Cambridge — I guess what I want to ask is you’d sort of taken up field study after you’d become disinterested in physics, and then you take up glaciology as a sort of a hobby. Based on my understanding of it, there’s not a huge glaciological community at the time. So is it really only once you come to Cambridge that you become aware of the theoretical work, and before it’s mostly sort of measurements?
B. Thomas:More or less, yeah. When I did the work on Galindez, glaciology was essentially a dilettante kind of a hobby for people on holiday in the Alps, and they’d see a glacier and they’d go and put a boulder on it and realize it was moving. It was at more or less that level. There was not a lot of hard backing to it. People like Nye and Glen already existed, and they’d been considering glacier dynamics in a very sort of simple way. But, you know, it was all good sound stuff. And I was aware of that when I went to Halley Bay. Certainly when I went to Galindez, I mean I just measured things. I didn’t know what I was doing. Obviously you’d be interested to know if the ice was moving, so I put stakes in and learned how to survey and all that kind of thing. And measured temperatures, measured snowfall — you know, anything I could. And to some extent, it wasn’t exactly that crude when I went to Halley Bay, and I did have in mind the idea of measuring a strain that worked, measured at creep rates because I was aware of some of these.
W. Thomas:So you’d become more aware of Glen and Nye.
B. Thomas:So I knew the kind of parameters that would be important to know if you were going to do anything. But at the same time, I didn’t really know where to do it, so I would measure things wherever I went. If I went on a trip, I’d put stakes in, even though I didn’t know whether I was ever going to get back there. Most of them turned out that, even if I didn’t get back there, someone did, and so we were able to learn quite a bit about the ice shelf over a bigger area than just my main survey area… So there was an area of low ice shelf, for instance, where the ice shelf had split apart. And we had no idea — there were no aerial photographs or anything of that place then, and so you’d travel somewhere and you’d find that you had no idea what was going on.
W. Thomas:Right. So it’s mostly a matter of measuring the distance between the stakes, for example, because you wouldn’t know your precise position.
B. Thomas:That’s right. We didn’t have absolute position; everything was relative. In those days, the velocity had been inferred by measuring or mapping the magnetic field. Because the magnetic field, if you map it in detail, has little bumps in it. And those stay the same, but the ice shelf is moving over these bumps, so you could infer speeds. It was as crude as that. Similarly star observations, we used to do star observations and repeat those over many years. So we had a rough idea how fast the ice was moving. And similarly, when we went far away on the ice shelf, we only had sun observations to fix things on. So it needed a big time separation to infer anything. But a lot of that fortuitously turns out to have been useful, because then when you put all the numbers together, you see how they relate. So then after Cambridge —
W. Thomas:Sorry, if we can just kind of go back just too sort of fill in some details on these kind of first two trips to the Antarctic. How long were the trips and about how many people were with you?
B. Thomas:Well, in each case it was two years. In those days the British went by ship, and they needed overlap, so everyone, or nearly everyone, went for two years, and part of the base would be replaced every year so there was a continuity. At Galindez, there were 13 of us, and at Halley, 36. Both times I went down we still used dogs for transport, so it was good old explorer stuff. We also started using little, like snowmobiles, those kind of things, Skidoos and the like. Some of the longer trips they used big tractors. But all the trips I went on were with small vehicles or dogs. It was more like a Boy Scout camp in those days. Very different from conditions now.
W. Thomas:Was it sort of, and I’m not entirely sure how to phrase it, but I sort of get the sense that after the International Geophysical Year [1957-58], there’s sort of a central sort of concerted program like what Charlie Bentley would have been on to sort of do these maps of just what was there on the ice. [Yes.] And RIGGS, of course, has sort of been that tradition. What this sort of more just, I don’t want to say side project necessarily, but it might be…
B. Thomas:The British didn’t do anything very ambitious. The only large-scale survey they did with seismic and magnetics and the like was when they crossed the Pole, and the quality of the work wasn’t very good. Colin Bull was I think on that trip doing some of that work. And earlier there had been the Maudheim exhibitions that Charles Swithinbank and Gordon Robin were on. That was in the 1940s. That was fairly solid science and well thought out. But the Falkland Islands Dependencies and BAS work essentially was what you could do with whatever resources you could scrape together. I even had to make a big case and go and see Vivian Fuchs before I went the second time to justify the number of aluminum poles and bamboo sticks I wanted. And so it was an uphill battle to get anything done, because they didn’t want to spend any money. The facilities, the logistics were pretty crude.
But on the other hand, you had plenty of time. And you also had total freedom in those days. Often on trips the first thing that you dumped was the radio because it was heavy and it didn’t work very well, and so you were totally on your own, and you could plan whatever you wanted. So it was really a matter of a reconnaissance kind of survey. You’d go somewhere; you’d think this is interesting, as we did with the low ice shelf. When the ice shelf was split open, there was a region of low ice shelf. And we leveled across it, and I did a little bit of strain work on it. Plus, we had hand drills that would drill down ten meters, so we drilled into it. And we found a layer of brine in there. So I drilled at a number of places and was able to get the slope of this brine. And I didn’t know what I was doing. But then later on there was a paper about brine infiltration somewhere, and I think I wrote a paper about…yeah, I was taking advantage of the fact that I knew the slope of the brine layer and the temperatures, so I was able to figure out something about the penetration of the brine into the ice shelf.
But this is all sort of fortuitous stuff. You don’t know at the time…there’s no plan to it.
Except the main strain network, which basically the main reason I had originally put that in was to actually measure precisely what the velocity was. So I wanted to go back onto the inland ice where the ice was moving fairly slowly, and do a triangulation to figure out what the speed is really here. That turned out to be quite an exciting sort of survey problem because everything is moving while you are making the survey, and it takes you many months to make it. It was also exciting because getting from the ice shelf to the grounded ice was quite dangerous — there were lots of crevasses and all that kind of stuff. So the first opportunity when I left BAS and finished my Ph.D., just fortuitously they were thinking about the RIGGS [Ross Ice Shelf Geophysical and Glaciological Survey].
W. Thomas:Who did you do your Ph.D. under at Cambridge?
B. Thomas:Charles Swithinbank. But he’s not really a physicist. He’s a very good sort of descriptive glaciologist, has some very good ideas, but not the sort of mathematical approach that — Gordon Robin was also at the Institute, and he’s got a solid background in — And of course, I came across people like Weertman, and I learned a lot from the people who were visiting. But also with Cambridge in those days, it was a very free business doing a dissertation. You sort of went wherever you wanted to go, and that was beneficial.
W. Thomas:[John] Nye had been away from there for quite some time at that point.
B. Thomas:He was at Bristol, so I came across him. I mean, I saw him in meetings and all that kind of thing. John Glen was one of my examiners. And Collins, I think, was the other one, more of a mathematician kind. He made Nye’s equations more rigorous, I think, Collins.
And I’m trying to remember what happened about the Ross Ice Shelf. I think Charles Swithinbank worked in America, and he still had contacts over there, and I think he told me about the fact that they were thinking of doing this survey on the ice shelf. Or Charlie Bentley was doing the geophysical part. He suggested that I write and suggest doing some glaciology. So I put together actually a handwritten proposal. It was just a long letter proposing essentially to do the same kind of thing that I’d done on the Brunt Ice Shelf going from down, I think I was going to go down Ice Stream B or C onto the ice shelf.
W. Thomas:Were there a lot of other people doing that sort of thing?
B. Thomas:No. I mean there was no one else doing glaciology, as far as I was aware, on the RIGGS. And Charles had suggested, “Well, why don’t you put forward whatever you want to do?” So I did. But it would have involved quite a bit of logistics, you know. Depots and all that kind of thing to get me from the inland ice right onto the ice shelf… it would have been, I don’t know, 800 kilometers, a major — I was thinking that it would be done the way the British did it, you know, with fairly low cost, simple depots and very small groups. But that’s not the way they tend to do things. I forget who contacted me; maybe it was Rutford already, but someone indicated, “Look, this is interesting stuff. But you’re going to have to fit in with the logistics that Charlie Bentley has.” And what he’s got in mind is he wants to do a grid of stations all over the ice shelf. So I figured, well, that sounds fine. I mean if the logistics are there to do that ambitious a project, then, all the better. So I adapted things, essentially measuring strain rates wherever we had a station, every 50 kilometers. They were also just starting to use geoceivers in those days, which give you an absolute position — a sort of GPS of the day, and it would give you a position to within ten meters perhaps. But you’d get an absolute velocity. And I figured if I’ve got lots of absolute velocities plus strain rates, I’ve essentially got everything. I can interpolate whatever else I need. Charlie was measuring the ice thickness, and also the depth of the seabed where he could, looking through the ice. So we were going to very well describe the biggest ice shelf in the world, and it was well worth doing.
And indeed, I think it turned out to be one of the most successful major field experiments ever achieved, the RIGGS, with the extensive measurements that Charlie made just about everywhere. And it gave birth really to the West Antarctic Ice Sheet project, which in part, what I had originally proposed included bits of the Ice Sheet. But of course, only along one line, so I was very pleased to see him extending inland, where they had a lot more information now. You know where the ice was coming from right along the coast from RIGGS, because the velocities from RIGGS and the thickness gave them a big head start. So that started in 1973, and it went on until about 1978 I think, didn’t it, the RIGGS? It was several years anyway. And there was one year we actually went down, two of us, to do glaciology when the plane had crashed up at Dome C, and they figured, well, it doesn’t look as if we can support you this year, because we’re short a C-130. But they were going to use a helicopter. They were even talking about using one of these great big Army helicopters with two or three rotors. So we can probably do a bit of glaciology. So they were going to helicopter us around reasonably close to McMurdo to put in some more stations. But they gave that up. So we went all the way to McMurdo and then all the way back. I forget what year that was. That was about the third year into RIGGS when —
W. Thomas:Charlie Bentley, I think, mentioned that, that there were safety problems with helicopters or something to that effect.
B. Thomas:Oh, yeah. I mean, it would have been a disaster if we’d actually done it! [Laughter] I worked within a radius planting these stations every 50 kilometers. And then only the glaciologists have to go back. The geophysicists had done what they had wanted to do. So two of us would go and try and find these stations after a year. That was often very frustrating because in those days, of course, there was no GPS. The planes were using INS (Inertial Navigation System). It didn’t work all that well.
I think the worst year of doing this was when it was further south. We had a British group, came in from British Antarctic Survey, and we used their plane and their pilot. He was extremely good. He was accustomed to driving without very good navigations, so he would dead reckon. As he was flying, he would use whatever information he had so he’d know roughly where he was. Which if you are too dependent upon automatic systems, you get lost very quickly if the systems go out. But he would always dead reckon, so he would know reasonably well where he was. And then he would do a grid search to find these damn stations, because we’d leave behind a bamboo pole, really, with a flag on it, and often we’d build a cairn. Now, whether the cairn survived for year is touch and go. So we’d be looking for a little glint in the snow, flying back and forth with binoculars. And we found just about every one of them — it’s amazing.
And then sometimes they would drop us, the plane would, and go on to work with the geophysicists. They would drop us with a Skidoo, what they call a banana sledge, which is a plastic sled about the length of this table, very light with a canvas cover on it. That would have our equipment in it, and it would have a tent, basic life support system, and we would drive around, because we hadn’t seen the damn thing. The pilot would assure us it’s somewhere within so many kilometers of here. But we would just drive around searching continuously. And again, I think there was one station we didn’t find. But sometimes we were out hours looking for the bloody thing. And then they could find us when we came back because, of course, our tent was up and they would be able to see us. But that was frustrating —. And I can tell you, being dragged along on a banana sled because you are wedged in with everything else, they bounce over the hard — it’s an extremely painful way of traveling. [Laughter]
W. Thomas:You know, I was speaking with Doug MacAyeal, and he joined up with RIGGS the last couple of years, was it?
B. Thomas:Yeah, that’s right.
W. Thomas:He was telling me about how the planes would drop equipment without really even stopping.
B. Thomas:Yeah, oh yeah. And you never knew when they were coming, because we’d be doing our station, because they were trying to service several stations, and we’d finish, and then there was nothing to do but wait. The obvious thing to do is to crawl into your sleeping bag. There was one time I was happily sleeping away, and the way the pilot would wake you, right over there and suddenly this screaming noise, and you’d think your end is come, you know. You’d have to struggle out of your sleeping bag. But it is a surprise we got them all done. Of course, when we finally assembled all the data, it’s amazing how much we learned from RIGGS.
W. Thomas:I think Charlie Bentley was mentioning some dispute over calling away an airplane or something like that as well. I think you had called away an airplane?
B. Thomas:I remember Charlie got extremely annoyed about some station, because we were working at the very first place that we went to. I think we called that one Base Camp, but it was in the southeast part, near Crary Ice Rise. Not far from there, I think it’s the region between Ice Stream C (they’ve renamed all these things) and Ice Stream B. Ice Stream B is going fast, C is going slow, so you’ve got these quite big shear crevasses. According to the grid there was a station in there, and I tried to figure out a region that we could visit without having cracks going through. Because I’d put a rosette out, you know a station here, and three stations out here, each a kilometer away, so you would need a bit of ice solid enough so that when cracks going through it when you are driving around in the Skidoo. I think we’d found one and put a station in there, and Charlie was irate that we had gone there because it was so dangerous. To this day I don’t think it was terribly dangerous, but looking from the sky it certainly looked dangerous, so he was quite annoyed about that. I can’t remember any other big… I can’t remember diverting a plane [laughs]. Maybe I did; I can’t remember.
W. Thomas:I’d have to go back over the interview or something. I don’t think he wanted to make a big deal of it or anything; it just was an interesting story.
B. Thomas:That was maybe the most interesting station, because we were close to Crary Ice Rise, and I put stations on Crary Ice Rise. And that was an interesting place to go to because you could get a feel for what the ice shelf was doing to it by looking at it from the sky. And also we landed and traveled up and down it. And I think I did a level line right along Crary Ice Rise. And then we visited what we call the “dirty ice area”, because we went off Crary Ice Rise onto the ice shelf, which was shearing past all this, so there were crevasses everywhere. But we tied ourselves together with ropes and all that kind of thing and went in. And we actually collected some of this muck. It’s where the ice had scraped along the seabed and been churned over, so the ice shelf was bringing up seabed to the surface, so we thought we’d sample it. And I forget even what happened. We gave it to one of the oceanographers or something; I don’t know what ever came of it. But it was an exciting trip.
W. Thomas:And then I think the only other thing I can remember off the top of my head is the inability to locate the grounding line.
B. Thomas:Oh, the grounding line. Yeah, that’s very difficult because, again, we had stations that went up into the mouth of Ice Stream B. And you know, traveling through that area it becomes very undulating. And you don’t really know whether these places where the ice is scraping on the bottom or just because there’s a lot of pressure there, and it sort of gets squashed into folds. So again, it made it very difficult to find stations, because these ridges were between you, and you would have to drive around until, hopefully, you’d find a flag waiting for you. So it was really like looking for a needle in a haystack sometimes. There was one place I think we ended up camping for about three days. This was actually on the inland ice in the mouth of Ice Stream C, which I think they may call Kamb Ice Stream now. It’s the slowest. And we had geoceiver stations, a few of them in there, and they later on showed that the ice was going very slowly. I think we actually ended up driving the skidoo up onto the inland ice, because there the ice was moving slowly, and it was fairly benign. You know, there weren’t crevasses. And we were able to put a station actually on the inland ice. It also gave us an opportunity to do a level line and a strain line that went right across the grounding line. And that was one place where the grounding line was very obvious: where the slow moving ice came into the ice shelf, because it came in moderately steeply. And we were able to get quite a bit of detail there because I had strains going right across this little hinge line. So we spent a few days at that station.
W. Thomas:Okay. So I know you end up at Maine not too long after RIGGS or maybe towards the end of it.
B. Thomas:I’ll tell you, it was during RIGGS, because I started off in 1973 at The University of Nebraska, which is where Bob Rutford was, the manager for RIGGS, and then later on he became the head of what used to be the OPP, The Office of Polar Programs. And John Clough took over. He had been one of Charlie Bentley’s Ph.D students. John Clough. And when he got his Ph.D., he started to manage the RIGGS.
About a year after that, I think it was 1976, was it that I moved up to Maine? Because Terry Hughes and George Denton had come down to Maine to give talks about Terry’s ideas.
W. Thomas:Come down to?
B. Thomas:To Nebraska, I think to talk with RIGGS. I’m trying to remember. About that time I was working on, and maybe they had invited me up to Maine to give a talk on the ideas that I had that a bounded ice shelf would have a different effect than Weertman had shown. That is that if the ice shelf can’t move very easily, then its removal is going to have a more profound effect on the inland ice. And so they were interested in that because that was the kind of thing that they were then working on…
W. Thomas:They had this CLIMAP Project.
B. Thomas: …CLIMAP reconstruction. And part of that was the retreat of the Ross Ice Shelf, which left behind all sorts of moraines. That’s the kind of thing that George Denton was looking at and trying to date the retreat and reconstruct the glaciology that has to go with it. So all this was interrelated, really.
W. Thomas:But you weren’t at all interested in the CLIMAP?
B. Thomas:No, I wasn’t involved with CLIMAP at all. But the glaciology I was doing was very closely related to the kind of thing that they were interested in and Terry was pursuing. And shortly after that I…
W. Thomas:Were you aware of his ISCAP bulletin things, or was it after that?
B. Thomas:Oh, yeah. His ISCAP bulletins were reasonably fresh then. They were the ones that suggested that you’ve got the situation where, because of the concave downward slope of the West Antarctic Ice Sheet, the basal friction is clearly getting lower there. And so you’ve got a situation where potentially you could get a major retreat. That sort of meshed very well with the kind of thing that I was doing. And I think it was about then that I had a paper in Canada where I looked at the retreat of the Laurentide Ice Sheet up the St. Lawrence valley…
W. Thomas:This one?
B. Thomas:That’s right, yeah. …Which was a similar kind of situation to the retreat of the ice streams that must have flowed across what is now the Ross Ice Shelf. So it’s the same kind of glaciology that comes into it. [Part 2] So it must have been ’76 that I went to Maine and continued working on the RIGGS. And it was in Maine that Doug MacAyeal became the student who was working with RIGGS.
W. Thomas:Who had you been working with before on RIGGS?
B. Thomas:There was a student from Nebraska. His name was David Gaylord. He was a geologist. I think he’d come with Rutford from Minneapolis or wherever Rutford had been before that. Then there was a local student called David Eilers. But they weren’t students in the sense of studying glaciology. They were students from the student body who came to go to the Antarctic. So they were essentially labor.
W. Thomas:Assistants, right?
B. Thomas:But they were competent labor. But Doug was actually working on his masters at Maine.
W. Thomas:Yeah, according to him, he’d worked on a catastrophe theory of ice ages, and so they said, “You’d better go up to Maine” [Laughs]
B. Thomas:Yeah. I think that he was the only one who actually pursued it into a career. There were another two or three students at Maine who came really for the adventure. So there was probably another three years’ worth of RIGGS still to go at that stage.
W. Thomas:This was in seasons, right, where you’d go down for…
B. Thomas:Oh, yeah. The earliest we ever went down was the second year and that was in 1974. Because, of course, the glaciologists had to re-measure last year’s plus go on and establish new stations. Whereas the geophysicists only had to do the latter. So we would tend to have to go down before them to try and mop up what was left over, and then go on to work on the other stuff. And I was over-ambitious the first time of re-measuring and we went down in October. Normally you start working in November. And it was bloody cold. The instruments started to break and all because of the cold. We had tellurometers in those days for measuring distance. These are radio wave machines rather than lasers. They came in a little suitcase, so they are not terribly small. And they were susceptible to the cold. So we had a lot of problems apart from the unpleasantness. But, you know, we were able to get the measurements made.
And then move up to Roosevelt Island, or near Roosevelt Island, where the next stage of measurements was made. But, typically, we’d go for probably almost three months: November, December and part of January, so it would be a long season. I forget how many stations we’d get done in a year, but it was quite a lot of stations. We were limited also by the radius that the Twin Otter could fly comfortably. So I think we ended up with four major stations. There was the one I think we called Base Camp in the southeast; and then there was Roosevelt Island and then Q-13, which was further west towards McMurdo; and then C-16 or something like that down in the southwest of the ice shelf, which more or less mopped everything up. There was a little bit that we never got done, but not a lot.
So it really was quite an extensive experiment. You know, it’s very difficult to get long-term experiments like that supported. The WAISP, the West Antarctic Ice Sheet Project was essentially the same kind of longevity, even more so. But I think in terms of coverage, the RIGGS probably exceeds even that.
W. Thomas:So it was pretty much the same sort of thing from year to year.
B. Thomas:Oh yeah. It was essentially the same measurements every year, just in different places. Charlie would hone his skills and probably improve his techniques each year, but the objective was the same. And it was all pre-GPS, so velocity was a painful thing to acquire with the geoceivers. That was done by the USGS. They sent a couple of people down each year to operate that.
W. Thomas:We were talking a little bit about calving bay dynamics and ice sheet retreat up the St. Lawrence Valley system. So this, I take it, is sort of an amalgamation of your previous work on kind of the theoretical side of glaciology with sort of the paleoclimatic models that they are working on at Maine.
B. Thomas:Yeah, I used whatever was available regarding understanding of when this happened and what sea level was at the time and those kinds of things. As the boundary conditions, if you like. But there was very little hard paleoclimatology, but I just knew that the ice had retreated from that so, you know, it had to retreat. So this was just a way of explaining…
W. Thomas:Creating a model of the process?
B. Thomas:Yeah. And taking a value. You know, knowing what the topography is now gives you an indication of what the bed topography was then.
W. Thomas:So looking at it from sort of a geohistorical standpoint wasn’t a major leap then from the previous thinking.
B. Thomas:Oh no, no. It was just a mechanism that ice behavior could explain the rapid retreat. And then we did the same kind of thing with the Ross Ice Shelf, Charlie Bentley and I. I think before that I’d done a paper on the thickening of the ice shelf using our data to infer that the ice was thickening in the southeast corner. And as Charlie built up a better idea of the basal topography of the ice shelf, or the ocean bed beneath the ice shelf, it was possible to apply the same kind of approach as I’d done with the St. Lawrence to the several ice streams that presumably crossed the Ross Ice Shelf.
W. Thomas:So this is really, as near as I can tell, the first attempt to sort of tie fieldwork into the sort of theoretical model of Hughes and Weertman.
B. Thomas:Yeah. And also to take into account the drag on the sides of these ice streams. Because the Weertman approach has no restraint on the ice shelf, whereas each of these is shearing past its sides. And that slows the ice shelf down and that retards the glaciers that flow into it. So this takes that into account. That slows down the retreat, but it also accentuates the amount of retreat that’s potential, once you get rid of those or float the ice shelf free.
W. Thomas:To what extent is there a sort of — I mean, within just a few years after this, the question of WAIS collapse becomes very prominent in all the conferences in the 1980s and so forth. Whereas even here in 1978, I’m sort of under the impression that it’s just sort of a very localized concern, and that your attempt to kind of see whether this jibes with the observations that you are making of whether or not the shelf is an equilibrium.
B. Thomas:Yeah, this predates the concern about what might be happening now. And I think it was Mercer’s paper that sort of brought that to the fore.
W. Thomas:This was the ’78 one on CO2?
B. Thomas:That’s right. The potential for loss of some ice shelves and what that might do. You know, this was done before that, because the actual work for this was done probably, I don’t know, in ’77. Then when Mercer’s paper came along, there was the opportunity of looking at, well, just how feasible is that? I’m trying to remember. I mean we looked at the ice shelves, at the Ross Ice Shelf, I think, in the paper on greenhouse warming. I should have read this to remind me! [Chuckles] I think we looked at what happens if the Ross Ice Shelf goes and just how fast the — There should be a Nature paper on that. [Looks through documents.] That’s the one that addresses the Mercer — [W. Thomas: Thomas, Sanderson and Rose, ’79]. I don’t actually have copies of lots of these papers. I think we consider what happens if the Ross Ice Shelf goes, which would end up having a very dramatic effect. We’ve got these very, very rapid rates of retreat. That’s right; this is the Ice Stream B. So it considers the sort of worst-case scenario of the loss of the… that’s right, the complete removal of the ice shelves. You get a five-meter rise in less than 100 years! Which is probably true, but of course, you can’t remove the Ross Ice Shelf. And the other thing we looked at is this leakage out the north through Pine Island region, through here, which is far more vulnerable and which has turned out to be the major concern. This is something that I think Terry was looking at at the same time.
W. Thomas:Yeah, because they came out with that “weak underbelly” paper, right?
B. Thomas:Yeah. And we all had a bit of a “set to” about that, because they figured that I’d been sort of poaching their ideas, I think. There was a big kafuffle about that. I don’t know whether Terry talked to you about it.
W. Thomas:No. When I was up at Maine, I didn’t quite feel that that was the time and place to broach the issue, but it’s been sort of mentioned to me as to what happened at Maine in ’79 and ’80, and I think Denton kind of alluded to it, that there were people working on ice.
B. Thomas:Yeah, I think Denton was the one who was most offended. You know, I think it was a storm in a teacup, but it definitely soured the situation considerably. Terry and I have survived it quite well, but I’m not sure what Denton feels about it still to this day. But that was a clumsy thing. I should have been more… in retrospect, you know. I think I wrote the paper in England, which is where I was working with Sanderson. So I should have been communicating more closely with Terry and company while I was doing that. But it’s water under the bridge; there’s nothing can be done about it.
W. Thomas:Right. This is just kind of one of the periods that I want to understand most closely, because within just a very short time, the idea of having to set a firmer sort of knowledge on the collapse process enters into the assessment process. Whereas here, I get the sense that there’s a little bit less of a need for closure there. It’s just sort of setting bounds.
W. Thomas:For example, this five meters in 100 years figure is sort of, I get the sense that Hughes just kind of throws it out there because he has the sense that at the end of the last glacial maximum, it went very quickly. And so it would stand to reason that it would happen again, if it’s because these ice sheets are below sea level. And then you are sort of trying to say, “Well, there are extenuating factors that would prevent that, so let’s explore those.”
B. Thomas:Yeah, I mean, particularly, you know, the five-meter figure is totally extreme. I hope we mentioned in there that you would have to remove the ice shelves instantly to do that, and there’s no way you can do that. The big issue then becomes how long does it take to carve away a big ice shelf? I think that’s where the work since then has focused, is to try to put some time constraints on all this stuff. I think we have to remember that all of this was done before there were any observations to suggest that anything was happening. It’s only in the late ’90s that we started to see glaciers actually responding to weakening of the ice shelf and we could start to test some of the ideas. Because basically you’ve got a big force balance with these glaciers that flow into an ice shelf. Or anywhere on the glacier. You’ve got the hydrostatic forces that are trying to spread the ice, and you’ve got basal friction, you’ve got lateral drag, and you’ve got water pressure pushing backwards. And you’ve got weight forces trying to push the glacier downhill. It’s the balance between those things that decides what’s going to happen. Basically you’ve got like four huge numbers, two of them fighting the other two. Clearly if you take one of those big numbers away, all hell breaks loose. That’s more or less what this [paper] does, it takes one of the big numbers away, but you can’t do that in real life. Not for a big ice shelf. But for a little ice shelf, you can. And that’s what happened with Larsen B, almost overnight: you took one of those big numbers away. And that big number is the number associated with drag of the ice shelf past its sides and going over a bumpy bed. You don’t take the water pressure away; that’s still there even if you rip the ice shelf away. But you take a big part of the ice shelf restraint away, and we see how dramatic the glacier can behave. And that’s a small ice shelf. So it highlights the fact that this is probably right — if you did take the Ross Ice Shelf away, there’s nothing to stop it. And particularly because of the bed shape.
But the far more difficult problem is what happens in real life. In real life, you’re going to thin the ice shelf and you’re going to weaken it, and then you have all feedbacks coming in. You’ve got other feedbacks because, as the ice starts to accelerate, the basal and the lateral drag increase because of the way ice behaves. The faster it goes, the bigger the shear stresses, etc. And those all feedback. And then you’ve got other feedbacks because your hydrostatic forces, as the glacier thins, get less and less. So all this has to be rolled up. It’s easy to roll them into equations, but putting values into those equations becomes the very difficult part. And so to my view, the biggest constraint we’ve got is the fact that we lack enough observations to put bounds on some of these components that are in the equations. And to some extent, you can dress up your ignorance by making your model overly elaborate. The elaborateness of the model gives the impression that we know more about the situation than we really do. And I think that’s the danger we got into before 2000, and even right up to the most recent IPCC report, is that the models are highly sophisticated for what they do, but they tend to sweep under the rug the things that they don’t do. And so until recently, we’d been using surface mass balance models, which we can do pretty well — the Huybrechts kind of thing — to figure out what will happen to an ice sheet when you heat it up. All you are doing is doing a surface balance between melting and snowfall for the most part, because the ice dynamics in the models are constrained so they can’t respond fast. So you’re taking away the biggest component of the response. Making your model very elaborate, three dimensional and this, that and the other, conceals the fact that there is all this stuff that you don’t know how to model. And well, I think it’s improving now. You know, the modelers are finally admitting the things that they haven’t done very well.
W. Thomas:Now the impression that I get is Mercer sort of comes almost out of nowhere with this ’78 paper. Of course, he has the work in ’68. What’s kind of your perspective on that? You’re really one of the only people, I think, who can really tell me, because you were the first to respond really. What was the deal with Mercer ’78? Were you aware of it in process? Was Mercer sort of there in the background all along? Because there’s this ten year gap.
B. Thomas:No, I mean, I wasn’t really aware of what Mercer was doing. I was aware of the ISCAP bulletins, and I suspect that Mercer was influenced by those. And his 1968, I think I may have read at some stage, but I can’t remember the details of it. What…?
W. Thomas:Well, that’s the one where he links the Sangamon sea levels with just sort of this —essentially is looking for a source of the sea level rise 100,000 years in the past, six meters above the present. And so he suggests the West Antarctic Ice Sheet because it had been sort of buzzing around that it’s special because it’s a marine ice sheet. And then he actually mentions the possibility of human-induced global warming right at the end of ’68 piece. But it’s just a quick mention, and there’s absolutely nothing on it for another ten years. And I get the sense that Hughes is the one who really takes it to town with the ISCAP bulletins. And so then all of a sudden, Mercer reappears. This is a big mystery to me because in sort of review article history, Mercer appears to be very prominent because he is always suggesting the right thing at the right time. And yet, he’s totally removed from everything else. And this is the thing that I most want to understand.
B. Thomas:Yeah, to be honest with you, I cannot give you much insight into that. I assume that he was following up on Terry’s papers, because they were both at Ohio State at that time, weren’t they? So it would make sense. And certainly at that stage, I had no idea. He was probably — I think I actually read Mercer’s paper and that’s what — And probably also, based upon…Weertman had given these talks at Cambridge when I was there, so that must have been in the early ’70s. But it wasn’t concerning the idea of greenhouse warming; it was just the relationship between an ice shelf and…so it was more of an academic problem in those days, things that may have happened, you know, thousands of years ago, but certainly not something that may happen anytime soon. [Chuckles]
W. Thomas:It’s not really something you can attach a number to, right?
W. Thomas:So who are Sanderson and Rose?
B. Thomas:They were both, I think, Ph.D. students at that stage in Cambridge, and they were working on, I think, the ice thickness measurements that the Scott Polar had made with Robin and Evans and all those kind of people. One of them, I think Sanderson, had probably written a paper on a bounded ice shelf. I think it was probably like “The equilibrium profile of a bounded ice shelf.” So that was taking into account the same kind of things that I’d been concerned about with the Brunt Ice Shelf in a more rigorous manner. Primarily it was the bounds of the ice shelf, the lateral drag, which we took, or tried to take, into account in this paper. Rose, I think, was probably a radio echo sounding person. I can’t remember what in detail that he used to do.
W. Thomas:Okay. And you’d gone over to Cambridge?
B. Thomas:Yeah, I was in Cambridge for about several… My wife at that time was expecting a baby, so I’d gone over there.
W. Thomas:Sorry, just to kind of throw it into the record, at what point did you get married?
B. Thomas:Oh, 1972, I think. ’71 or ’72.
W. Thomas:Okay, right before RIGGS.
B. Thomas:Yeah. Oh yeah, before RIGGS, yeah. I mean, I didn’t even know about RIGGS at that stage. I was still working on my Ph.D. That was a previous wife, not the one I’ve got here. So we were expecting our son at that stage, and he was going to be born in England. So I went and spent several months over there and worked, you know, sat in the Scott Polar Research Institute while I was working. So it was an easy place to work. These people were involved in the same kind of work.
W. Thomas:Okay. So this is primarily your work then, with contributions in a sense?
B. Thomas:Yeah, it’s primarily mine, and probably Sanderson provided the biggest contribution in terms of what the others did because there were some details about the lateral drag when the ice is diverging that gets a bit complicated, so he was able to provide insight on that. But it was mainly stuff that I’d built out of the other paper from the calving bay and the one I did with Charlie [Bentley]. Which, again, Charlie essentially provided me the bed topography, and I more or less wrote the other paper, the one on the Ross Ice Shelf retreat.
W. Thomas:Yeah, he mentioned that his name just kind of got stuck on the second paper because of the first paper that you did with him.
B. Thomas:The one on the thickening of the Ross Ice Shelf, was it?
W. Thomas:Yeah, the model for Holocene retreat of the West Antarctic Ice Sheet, I think is the one.
B. Thomas:That’s right. That was the one that took a lot of work. Yeah, he provided me with the thicknesses on that one. But was there another paper that we shared? I can’t remember.
W. Thomas:These are the only two that I have with…
B. Thomas:Oh, yeah, that one. That one as well, because again, he had all the thicknesses.
W. Thomas:Right. Well, I think that was the one that he expected to be on. When his name appeared on that one, I think he was a little bit surprised, on the Holocene retreat one.
B. Thomas:Yeah, well, he had all the thicknesses, so I figured it was appropriate. So it really wasn’t until the late ’90s probably that we started to see things like this happening, which it became more than just an academic issue. Because again, the Nature paper was really talking about what potentially could happen…
W. Thomas:Yeah, scenario building.
B. Thomas: …not in a real world. You know, maybe a few thousand years ago something traumatic happened that suddenly removed the ice shelf. But it was extremely improbable that it could have happened very quickly. But it gives you an upper bound as to what can happen. But, you know, now our job is to flesh in those [chuckles] somewhere in that range.
W. Thomas:Right. Well, this is around 1980, and it seems to me that there’s just sort of a bursting point here sort of where — I mean, Bentley, for example, decides to become involved in glaciology. To that point it was all field geophysics.
B. Thomas:That’s right, yeah.
W. Thomas:And you sort of get this notion that there’s a spectrum of views, for example. So Hughes gets into like the most radical camp, and then there are a lot of people who see you as sort of in the radical side of things. But versus Hughes, of course, you’re quite conservative, as you point out in this paper, with the extenuating feedback mechanisms. And I think the first conference is in Maine in 1980?
B. Thomas:I can’t remember that.
W. Thomas:Okay. It was, I think, a Department of Energy conference.
B. Thomas:Oh that, yeah! No, I think that was in Seattle, wasn’t it, or something?
W. Thomas:Well, there were a few. I’d have to look through my notes.
B. Thomas:But, yeah. Actually the Environmental Protection Agency got involved. They were sponsoring some effort to consider how fast the glaciers could retreat and we produced some kind of a scientific report. I think Bindschadler was involved with that as well. He was looking at the melt from Greenland. And I was reconstructing what Antarctica could do based upon really extrapolating from just one ice stream, Ice Stream B I took as my test case, and then concerning what might happen if that happened in several places around the Antarctic Ice Sheet, came up with some projected sea level curve. So I think you’re right, there were a number of efforts to reconstruct sea level. In fact, I think I may have a sort of synopsis of all those kind of things somewhere in here. [Leafs through papers] Yeah, this is a history of the sea level rise predictions versus the date when they were published. I think some of these are DOE kind of things. EPA is around about here. Well, this was in the days when we were in meters. I don’t know who did this one, but it was probably a DOE. And the NRC did things. As we got a little bit more sophisticated, the predictions dropped and the IPCC comes in somewhere here.
W. Thomas:Okay. What document are we looking at right now?
B. Thomas:Well, this is something I’m writing at the moment, so it’s not — this is a synopsis of all the predictions that I could find.
W. Thomas:Yeah, the sort of the progression of predictions.
B. Thomas:Yeah, exactly.
W. Thomas:The sort of thing that Michael Oppenheimer is really interested in for various reasons.
B. Thomas:And you can see there is a tendency to drop. And also that the error bounds get smaller. The uncertainty limits are, in fact, they’re pretty good. If you go to the lower uncertainty, they’re still the same. But the IPCC, as I said earlier: basically surface mass balance predictions, even the most recent one, they put a little bit of a token for dynamic impacts. This is the IPCC. But their error bounds are very small, unrealistically small. And then, of course, based upon observations, Rahmstorf gets almost double the IPCC. So clearly they’re missing something. And it sort of reinforces what I’m convinced is that we’re really short of observations — we’re not short of models; we’re short of observations to constrain these models. So there again is the IPCC. This is what it’s based empirically on.
So what’s kind of your impression then, getting into the 1980s when there’s sort of this pile on into the — I mean, it’s around that time that you really get what we can think of as the WAIS problem as when will it collapse, when will it collapse, and you get graphs like the one you just showed me. But of course, there are all sorts of different perspectives. I mean, Oerlemans starts in quite early in the 1980s, I think. But he’s more of a climate modeler versus a modeler of dynamic processes. And so he tends to discount a lot of these other models and his own models. And it’s sort of difficult to —
B. Thomas:Does Oerlemans look at the ice sheets or just the… I can’t remember.
W. Thomas:Well, I think it’s mostly — There are several different models, and I haven’t mastered them all, by any means. But, in a lot of cases, because they are climate models, it’s a question of melt versus accumulation and that sort of thing. So it doesn’t even include the issues that you’re interested in.
B. Thomas:Well, that’s what I was thinking. It’s more of a sort of surface mass balance approach, which is primarily what everyone has done. And they may give it a sort of superficial coat of dynamics by including a background ice sheet dynamic model. But it’s so somnolent, this model, that it doesn’t matter. You might as well just look at the surface. And that, I think, is what the problem is. It’s all in the dynamics.
W. Thomas:Right. There’s no way to put in…
B. Thomas:We’re polishing the camel’s tail, and we’re forgetting about the rest of its body is basically with most of the modeling that’s been going on. I think there has to be, certainly for the future, a far heavier emphasis on key observations. The problem with observations, unless you focus them, they can totally consume you. You’ve got to decide what is the important stuff to measure. And we’re sufficiently ignorant that we really need those measurements. All of these things are variations on models and, inevitably, they’re going to give you almost any answer you want.
W. Thomas:Well, this is sort of a nice segue way into the Siple Coast project into the 1980s that sort of gets extended into the WAIS Initiative project. To what extent are you involved in that then?
B. Thomas:Very little.
W. Thomas:Right. You moved to NASA.
B. Thomas:Yeah, I originally started working for NASA looking at the potential applications of laser altimetry data, because they were considering launching a satellite laser to look at ice sheets. And since, they have done that, of course. But this was way back in, I think the late ’70s they started looking into it. So they had working groups that would come up with all sorts of scientific reports and the like. And I was involved with that. And that was certainly a fully exciting way of looking at the ice sheets.
W. Thomas:Were you involved with them sort of in a consultative aspect before you actually moved there?
B. Thomas:Yeah, just as a member of a working group. And I think I wrote something for one of the reports. Having spent many, many years doing field work, starting with a small ice cap, a very small ice cap, and then expanding to the Ross Ice Shelf, it was very apparent to me that this way of doing things — although it’s exciting, it’s interesting — is never going to give you any big answers. At best you will know something about a component of the ice sheet in your lifetime. And the potential of remote sensing was so enormous, in my view at that time, which the altimetry that a satellite could achieve looks as if it could be an enormous source of information. So I got really quite excited about it. Jay Zwally was able to get me working with him at [NASA] Goddard [Space Flight Center], initially as a contractor really, to work on preparing for the laser altimetry and also applying the radar altimetry. So we wrote a number of papers primarily on the radar altimetry applications. After a year or two I think, I got the opportunity of working at NASA Headquarters with Stan Wilson, who ran the Oceans and Ice Program, primarily Oceans program. But they had an ice component. And Frank Carsey had managed the ice component before that, which is from JPL.
Frank originally was under the physicists, but he was working on sea ice. And he had been at Goddard and working with the ice group, which I think at that time was under Jay Zwally. And Jay brought a number of people in, and Frank was one of them I think, to work on sea ice.
W. Thomas:How sort of recent was NASA’s program in all of this when you joined up?
B. Thomas:NASA, for a number of years, had been developing some sensors for looking at the Earth. And they were primarily driven by engineers. You know, they didn’t say, “Well, let’s go and measure this. How do we measure it?” The engineers would come up with some new way of measuring, let’s say radar back scatter or passive microwave radiation or whatever, and they’d try it out. And they were surprisingly successful. They’d make lots of measurements of many things. But then they didn’t really know what to do with them. They didn’t really have any branch of NASA to figure out what to do with them.
W. Thomas:Instrumentation development.
B. Thomas:Instrumentation, yeah. And they were very good at it. They were way ahead of the science really. And then sometime during the ’70s, NASA figured, well, you know, we’ve got to change this. So they set up a science division, if you like. They probably had one in the space sciences before that, but this is for Earth science. They decided on a number of sub-disciplines, and there was solid Earth science, oceans, and biology, one or two others, atmosphere of course, and the ozone was included in there somewhere. In fact, the ozone hole was one of the mandates, for NASA to look at the ozone hole just as NSF has the mandate to look at the Antarctic.
So there was some order put into the science objectives. They were able to get working groups together to figure out what were the important things to measure. And are any of these sensors that we’ve already got, and producing data, any use to doing that? The oceans group, under Stan Wilson, had all of the oceans thrown to them. There was a climate branch as well as everything else, and they supposedly should have had responsibility for ice, but they didn’t want it, or the program manager at the time didn’t want it. So Stan took it under his wing. And of course, sea ice is relevant to the oceans, so it made sense from that point of view. But the ice sheets were an orphan, really, and glaciers were covered by the land program, small glaciers and ice caps. But the ice sheets were left out there hanging. Meanwhile, they’d had Seasat, which had many very successful sensors aboard measuring ocean color, measuring passive microwave, measuring radar altimetry, and measuring ocean winds. Just an amazingly successful satellite. It had synthetic aperture radar onboard as well produced an enormous amount of data. Just for three months it was going, and the data were just piling up. And in many ways, it would have been an embarrassment if it had kept going because it would have had a huge amount of data.
But, anyway, one of the requirements on each of the science groups was to show what could be done with these various data that had already been collected by Seasat. And Seasat, most of the sensors were relevant to the oceans as well as everything else, and so Stan had quite a big job on assessing Seasat. It did a very good job with sea ice. Passive microwave would map the sea ice and tell us quite a lot about it. But ice sheets remained more or less an orphan. It didn’t have much money spent on it. And Frank Carsey was able to get something going. Then when I came in, one of the options, they used to go through an exercise of what will happen if Congress gives us 10% more or 10% less funds? And the option for 10% less was they would close down the ice program. [Chuckles] So it was on a tightrope. But I was able to continue the sea ice, anyway, because we didn’t get a 10% cut. And fortuitously, someone else in the branch had a little bit of money left over and I was able to spend that on ice sheets because I was managing the program.
W. Thomas:Do you remember the year that you went to NASA?
I think I first went; I was trying to remember this, probably 1983. Actually worked at Headquarters. But I was working with Jay [Zwally] at Goddard probably from 1981. So Stan was able to show applications for the oceans. But it was clear, also, that there were some very powerful applications on the ice sheets. And particularly so because they are so bloody inaccessible for ordinary ways of looking at — And it turned out that the synthetic aperture radar was very powerful because there were people starting to figure out how to use the data to actually measure ice sheet velocities, which are very difficult to measure without going down there and putting things on the ice. And that’s an incredibly powerful technique to measure how fast the ice is moving. And the altimetry tells you the shape of the ice sheet and how it’s changing. The passive microwave tells you a lot about the surface of the ice sheet, how the melt is changing. Scatterometer also tells you a lot about the surface of the ice sheet. So almost everything that Seasat had on board was very, very powerful for the ice sheets.
And then another opportunity came along at NASA in that the Canadians were launching Radarsat. Meanwhile, the Europeans had launched ERS-1, which had some sensors on it similar to Icesat, so it was able to continue the time series, if you like. And the Navy had launched Geosat, which was an altimeter. So there were time series of important data sets being compiled. And because the Canadians wanted to launch Radarsat, they wanted NASA to actually launch it and they would provide the sensor. And NASA said, “Well, that’s all well and good. But what do we get for it?” So they asked the oceans branch, and Stan and I and a fellow called Bill Townsend, who was from altimetry, what became the TOPEX altimeter, and he later had a very senior position at NASA. Anyway, we sat down and haggled about what could we ask the Canadians to do. And one of the things was, not just to provide us with data free, but also to turn the satellite around so that they could look at the Antarctic. Because its SAR looks off to the side, and it was designed to look northwards so that they could do the sea ice around, kind of, Canada very well. So we asked them to turn it around for a few weeks so that it could map all of the Antarctic Ice Sheet. So that started to increase the importance of ice within NASA.
And the Europeans were taking notice as well, because they had their own satellite and they started applying satellite data to ice. And it turns out to have been extremely fruitful, that whole approach to doing things that the Canadians, the Europeans, and NASA all were awakening to what you could do over ice with satellite data.
Then in the early ’90s, GPS came along, and for the first time we knew where an airplane was. Before that we could fly very sophisticated sensors on an airplane. But because we didn’t really know where the airplane was, a lot of the data, its value dropped almost to zero. For instance, very accurate altimetry from an airplane, it’s a waste of time if you don’t know how high the airplane is. GPS changed all that overnight. There was a group at [NASA] Wallops [Island Facility] that had an airborne laser altimeter, which was primarily used for looking at the ocean. It had a mode in which it could be used to get ocean color, which tells you about the productivity of the ocean. They also started experimenting with using GPS kinematically, that is, while the aircraft is moving, so that you can calculate exactly where the airplane is to within, you know, five or ten centimeters. So that was an incredible breakthrough. And we were able to start a program surveying Greenland from an airplane, measuring its shape very accurately. We started that in the early ’90s while I was still at Headquarters. So we started quite a lively Greenland program, and I was able to get a lot of other work related to that going. I had people drilling holes in the ice to get past accumulation rates, and people on the ice measuring strain rates, and quite a lot of work that NASA was supporting. And at that time, NSF wasn’t supporting very much in Greenland except up at Summit. That NASA program was the first to show that the ice sheet was thinning, and primarily around the edges because of dynamic effects. And it did highlight the importance of dynamics. And essentially that program has continued until now.
W. Thomas:So it’s essentially sort of a building survey programs there?
B. Thomas:It was built around an aircraft survey program that measured very accurately the shape of the ice sheet. If you do that repeatedly, you can measure how it’s changing. But to try and understand that, we had surface programs. For instance, driving a scatterometer around to understand better the penetration of radar waves into the ice, so that we could better interpret the satellite data. We had people with bases on the ice at different camps looking at how the surface changed as it melted and how that would affect the passive microwave signal. We had people drilling into the ice to try and find out how accumulation rates in the past related to things that you could see from space. We did one traverse all the way around the ice sheet on the surface that I was involved with. We started on the surface putting GPS stations every 30 kilometers all the way around the ice sheet to measure the velocity at high elevation — about 2,000 meter elevation — to find out how fast the ice was spreading outwards from the center. And the satellite methods of measuring velocity don’t work very well at high elevations — they need surface characteristics to be able to track things. So this complemented what the satellites could do. The synthetic aperture radar data were used extensively to measure the outflow of the actual glaciers, where they enter the sea. So there were many components of this program. We pulled them all together, made a fairly complete assessment of the mass balance of the ice sheet and, to some extent, the reasons that were driving the mass balance, why it was thinning in some places, thickening in others.
W. Thomas:So all these projects are coordinated then at Headquarters?
B. Thomas:Yeah, I was essentially coordinating at Headquarters.
W. Thomas:So you were the coordinator then?
W. Thomas:Okay. Is there a group name or something?
B. Thomas:It was called PARCA: the Program for Arctic Regional Climate Assessment. [Discussion of taking notes versus the purpose of the recording] Its first achievement was to show that the Greenland Ice Sheet was thinning at the edges and actually thickening in the middle. The climate models had said that as climate gets warmer, it should be thickening in the middle, and that’s why even the recent IPCC claims that Antarctic would actually grow bigger as climate grows warmer. And it should because it’s cold and there’s more water in the atmosphere. But it tends to be more than balanced by what’s happening at the edges. Certainly in Greenland, there’s a huge wastage at the edges. And it turns out that the signals are so big that many, many different remote sensing capabilities can measure them.
We used to bother about… When the satellite laser altimeter was first mooted, it was considered, “well, we’re going to have to be able to measure the elevation to an accuracy of like 1 centimeter per year averaged over 10,000 square kilometers,” or numbers like that. Because the total accumulation in the Antarctic is only ten or fifteen centimeters a year; you want to know how that changes to within 10 percent — well, so you are driven down to these small numbers of accuracy. But it turns out that where things are changing, they’re changing by meters per year, and the job becomes a lot easier. We can structure our program in such a way, for instance, with the ice sheets; you have some fairly simple, crude way of identifying where these big changes are taking place. They locate the hot spots, and then you isolate where you really need the information, and so you can home in on those regions and use more sophisticated ways of measuring them and understanding them better. Instead of having to do everything, you target those areas which are really important. And there are a limited number of hot spots in the ice sheets that we really need to know more about.
So the whole remote sensing approach allows you to do things in a far more cost-effective way than we used to do things when we were working totally from ignorance. We didn’t really know where anything was going to change, so we had to look everywhere. We thought we had to look with a very, very detailed microscope, but those small changes of a few centimeters per year don’t matter. They’re irrelevant compared to the important things. So it’s totally revolutionized ice sheet science.
The stuff that was pulled together by Stan Wilson way back in the ’80s, he went there in the late ’70s from the Office of Naval Research where he had managed their ocean program. So he had quite the experience of the community. And he is an oceanographer. He came out of Johns Hopkins, I think. So he was very effective in promoting not only the ice work, but the whole ocean sciences have been transformed by the stuff that he started in those days, during the ’80s. It was a very lively time to be in NASA.
W. Thomas:So what’s the relationship between this and the sort of thing that, say, Bob Bindschadler would have been working on in the same period, is it the same program, just different branches of it?
B. Thomas:Not really. Bob has worked primarily with NSF support, although he’s a NASA employee. When I was at Goddard, this must have been the early ’80s while I was still at Goddard, and we had the idea of proposing to do some work in the Antarctic to extend from RIGGS onto the ice sheet. So I was involved with writing that proposal that ended up getting Bob to the Antarctic. And I think Jay [Zwally] was involved as well; he was a co-investigator, I think. And we put together this proposal which turns out was very successful, but I didn’t go for family reasons or something. I dropped out of actually being involved. So I was involved to that extent with the West Antarctic Ice Sheet Project. You know, I had ideas of what needed to be done based upon what I learned from RIGGS. So I was very interested in it. But then shortly after that, I got this job at Headquarters. Plus, I didn’t really want to be trekking down to the Antarctic for extended periods. Well, obviously once I got that job, I couldn’t be taking huge chunks of time, so I dropped out of the WAISP, the WAI, whatever it is. It changed its name every… I think it was called the Siple Coast Project in those days.
W. Thomas:Yeah, in the 1980s, I think Siple Coast Project, then briefly SeaRise. And then they thought that they would presuppose the conclusions so it became WAIS Initiative.
B. Thomas:And then we had WAISP. I remember I used to go to Polar Research Board meetings as a NASA representative. And they were discussing presumably when they were starting to call it; I think they called it West Antarctic Ice Sheet Project in those days, WAISP. And I couldn’t resist it. I put together a view graph while Bob was presenting a summary of what WAISP was going to be, I came up with these other acronyms. One of them was the Filchner-Ronne Under-Ice Antarctic…and there was a “D” in there, and I’m trying to remember the other one. Oh, yeah, the Above — the acronym was ABUSE, so it came up as WAISP, FRAUD and ABUSE for these three Antarctic projects, because I figured, and to some extent I still do, that WAISP had become a waste of money. Because those kind of projects, they tend to become Christmas trees and everyone hangs their pet project onto them and they do a little bit of everything. Some of it is going to pay off. But, for the most part, it becomes unfocused, and it’s not the way I think science should be done. It’s too broad. It achieved things, but I don’t think it achieved anything like, for instance, [what] RIGGS achieved, which was far more focused. It was a comparatively short project. I mean WAISP has been going on for 20-odd years. I really was —
W. Thomas:And that’s all NSF then?
Yeah, it’s all NSF. I mean NASA paid Bob’s salary, is basically it. It grew out of RIGGS, so it made sense you were looking at these ice streams. But I think if someone had stood back and looked at the whole thing; the West Antarctic Ice Sheet is more than just the ice streams that are flowing into the Ross Ice Shelf. If you look at it objectively, you would say to yourself, “Well, there’s three sides to the ice sheet: one flows into the Filchner-Ronne Ice Shelf, one flows into the Ross Ice Shelf — These are huge ice shelves. They are pretty big and solid and, okay, they may change, but they’re not likely to change very dramatically. So you’ve got two big, solid front doors on the West Antarctic Ice Sheet. They even went through the sea rise name. So they were aware that sea level was important. What about the back door? The bit that opens directly northwards.
W. Thomas:Pine Island?
B. Thomas:Yeah, that whole coast, the Amundsen Coast is open. So scientifically, if you’re really interested in the dynamics of the West Antarctic Ice Sheet, you would at least spend a lot of time looking at that lot. It was totally ignored. And partly it’s the NSF approach. You know, logistics drives things. If we’re going here, everyone has to go here. They talked about it. They started having science working groups talking about the Amundsen Bay area a hell of a long time ago. I mean, probably in the early ’90s. And they never did anything about it. It wasn’t until NASA went and worked with the Chileans and actually made some measurements down there and showed that it could be done that NSF, within a year, acted upon what they had been talking about doing for a decade. And I’m sure that if we hadn’t done that work over Pine Island and Thwaites etc., with the Chilean airplane to show that things were changing fairly rapidly, that they would have continued to talk about going down there. So I think there’s a fundamental problem with the way we do science.
W. Thomas:When is it that that work gets done?
B. Thomas:That was in 2002 that we flew with the Chileans. And then I think we flew again in 2004, and that was when the NSF and The University of Texas and the British went down and did an extensive survey over the whole region with Twin Otters. But it could have been done anytime. It only required the will to do it. I think there’s a major problem with science now is we’re going more to that mode, that is, the science working group. You’ll get the people who are burned out planning the future. You don’t get the young scientists doing things in a small way with the bright ideas making things happen. They have to jump on a Christmas tree that is being driven by people, who were good 30 years ago, but they are set in their ways, and they’re not going to do things in an innovative way anymore. These big programs are not really productive, I don’t think.
W. Thomas:And it’s funny, because I was sort of, obviously from a much different angle but, it’s sort of the same view that I got from Hughes and Denton up at Maine, which is that you get a lot of sort of nice detailed knowledge about the way these ice streams work. But Hughes especially says, “Well, I just kind of forgot about the Ross Ice Shelf after 1980 and concentrated on other things.” And he essentially referred to it in the same sort of Christmas tree sort of way. And it’s like people have made their careers based on the notion that this is going to tell us whether or not the West Antarctic Ice Sheet is going to collapse.
B. Thomas:Yeah. And it just didn’t. It proved what was almost obvious. But now NSF has finally thrown its hat in the ring, and Amundsen Sea is going to be the focus. Which is okay, but again, I think it’s going to be everything. And the reality is there are huge areas in the East Antarctic that we should be looking at. So smaller projects with diverse objectives, I think, is the way to go. It’s very difficult to do that because we also have become far more security conscious and all that kind of thing, and safety conscious. So it’s very difficult to do cheap, small projects anymore. And that’s why the British were able to achieve things even at very low cost. They essentially had to be involved with the Amundsen Sea work that Texas got involved with. It was Twin Otters and a fairly small logistic component, because —
W. Thomas:Sorry. You got involved with Texas?
B. Thomas:University of Texas provided one of the radars that they use for measuring thickness. The British Antarctic Survey provided a plane and their radar. I think The University of Texas had a laser onboard, but it wasn’t a very good laser. I mean, again, with a little bit of organization they could have had a better approach to doing things with the right equipment onboard. I think NSF chartered another Twin Otter. So there were two Twin Otters involved. But there were many, many issues with that. We had flown many lines with the Chileans. And the surveys that were done by the British and The University of Texas did not take advantage of repeating some of those lines. You know, it’s like money in the bank: if you survey something accurately, you can always go back and do it again; you don’t have to wait. You’ve got that initial measurement to compare with. And we’re all looking at changes. So not repeating old lines, I think, is bad planning.
W. Thomas:You know, I just read kind of an overview by David Vaughan. It sounds like its related, sort of the renewed attention now to the Amundsen Sea area. It’s like, well, hey, we need to do this.
B. Thomas:Well, we certainly do. It’s a very important area, and it needs to be monitored. There’s no doubt about that. But I’m concerned with the fact that it…
W. Thomas:Well, that it just sort of hops from problem to problem every 10 or 15 years rather than taking a spread out approach.
B. Thomas:That’s right. And it’s region. And my impression is they — I was amazed when I went to work on RIGGS. To get a team into the field, there weren’t many of us actually working on the ice. You know, we had to have a big camp with little houses, and we had to have big generators and a huge fuel bladder. It becomes a major enterprise. Then if you’ve got air crew there, you’ve got to have showers, you’ve got to have a kitchen, you’ve got to have… And it’s a total contrast. That’s all well and good, but that’s not actually getting the work done. And that’s where nearly all the money goes. And it becomes a major embarrassment for NSF. They’ve got to ship all this stuff in, devote C-130s to it, and an enormous amount of fuel. I’m sure there are easier…well, there are definitely cheaper ways of doing it and quicker ways of doing it. The trouble is once you’ve got a big camp, you feel obliged to bring everyone and his auntie down, because we’ve got to justify this huge camp. So we’ll do a little bit of this, we’ll do… You get many, many groups. Whereas, in fact, I think we should, particularly sea level rise, we need to address it as an engineering problem now. We know what’s happening. We know the ice sheet is thinning and in danger of thinning fast. So let’s design our approach around the problem and forget the rest. It would be nice to measure these other things while we are there, but this is an important problem. You know, if you have a leak, you get the plumber. You don’t, “Well, while we’re here, let’s get the carpenter and decorate the ceilings and do this, that and the other.” We could have far more focused programs if we take it that way. We’re going to do science as we do it, but it’s going to be targeted science. And I think we have to go to that mode if we’re seriously going to address the sea level rise problem.
W. Thomas:Just to make sure that I can have it straight, so we’re talking about thinning versus learning everything there is to know about ice stream dynamics.
B. Thomas:Well, I think, certainly we don’t want everything there is to know. But there are certain things we need to know about ice stream dynamics that are clearly related to the issue of sea level rise. Those can be spelled out fairly clearly, and we can target those things. And if it requires measurements of depth, whatever it is, let’s identify what those are and maybe. It would be nice to do some magnetometry while we’re at it and this, that and the other, since the logistics are there. But they are going to slow everything down. They are going to make the logistics that much bigger. And then you lose the priority sets. You know, if there is a delay on the magnetometry, which can hold everything up. And that’s the kind of things — You know, WAISP or whatever it is these days has been going for what, 25 years? It’s an incredible length of time. And it would be nice to get them to list what they see as their key findings from 25 years of expensive science.
What is the size of, say, the Siple Coast WAISP project versus say what you had been doing with the altimetry in the [inaudible]?
B. Thomas:I have no idea in terms of money. It’s many, many millions per year, the WAISP, it had to be. And it’s probably difficult to pin it down, because the NSF bookkeeping often only books as part of the project the support of the individual PIs. So you get maybe ten universities being supported. That’s dwarfed by the cost of the airplanes and the logistics needed to support the airplanes, ba-da, ba-da. That runs it up into the tens of millions per year. When I was doing the PARCA project, I think we would be hovering for everything — because we paid for the airplanes, we paid for everything — something between one and two million a year for the whole Greenland Ice Sheet, and we learned an enormous amount about the Greenland Ice Sheet from that.
W. Thomas:See, that was what was not clear to me, because when I imagined satellites and all that sort of thing, must be more expensive.
B. Thomas:Oh, well, yeah, I mean satellites obviously those —
W. Thomas:But those are used for other things. It’s like getting time on the satellites?
B. Thomas:Yeah. And in fact, most of what we learned from Greenland, we learned from the aircraft program. I mean, the satellite data were there, but we did not use — In fact part of what I worked on, once we had the advantage of having the aircraft data, I showed to my own satisfaction that the satellite radar altimetry data aren’t much use.
W. Thomas:Right. But that starts to be the case once the GPS system makes the air —
B. Thomas:Well, the big problem with radar is that it penetrates the ice, and so it reflects — You know, if you want to know how far and fast this table is going up and down, you measure the height of the top, don’t you, with respect to something. If, however, the thing you’re measuring with actually penetrates the wood a little bit, that’s all right as long as the amount it penetrates is always the same. But the properties of the surface snow, the dielectric properties, are strongly affected by how wet they are, how much wind has blown on them. And so that surface is going up and down. So you don’t know what you are measuring. In some cases, as the surface gets wetter, the radar reflecting horizon actually goes up towards the surface. So it looks as if the ice sheet is thickening, and in many cases it really is. But it’s thickening maybe only 20% as fast as you think it is. So it’s a very misleading tool, and one has to be very, very careful. To some extent, the satellite laser altimetry can be misleading. But there are some things that are very, very powerful. And particularly the synthetic aperture radar from space, because that does give you a measure of ice velocities. It has its problems, because they tend to be snapshots, temporal snapshots, and the velocity can change with a seasonal cycle. So you may be looking at the velocity here and, if you come six months later it will be different. But there are ways of getting around that. So one has to understand the constraints on everything you measure and, to some extent, use other things to try and bound those errors that are implicit. But certainly in costs, if you really put the price of a satellite in, you’re dwarfing everything else. And that’s another thing one has to be careful about. But some of these satellites serve many, many disciplines. And to some extent, I tend to regard them as like the roads. You know the roads have to be built. But they’re there, we use them, we don’t pay —
W. Thomas:They’re not on your ledger. Right.
B. Thomas:Yeah. And that’s what I think of as satellites. But, certainly to the taxpayer [chuckles] they are part of the balance sheet. But they’re there, anyway. And a lot of these are foreign, the synthetic aperture radar, European is most of what we use, and Canadian. And we can buy the data; it’s still cheaper than actually going down there and making measurements.
W. Thomas:It wasn’t clear to me initially that all the WAIS project things were that much more expensive than what you were doing.
B. Thomas:Yeah. Well, the field components of them were certainly a lot more expensive, and probably a lot more expensive than RIGGS. RIGGS was comparatively cheap. It only took about four or five years. It was basically supplying a camp for that year and one or two resupplies of fuel, and that would be it. I suppose to a large extent, the Siple Coast was somewhat similar, but the camps seemed to be bigger, because they had far more people on the ground than we seemed to have during RIGGS. But it is a major problem, I think, now with science is that there’s a possibility that we’re going to go somewhere, and everyone comes out of the woodwork with their ideas, and NSF feels obliged to respond to all that stuff.
W. Thomas:Now they’re the ones who probably have the closest relationship with this whole IPCC process? I know you mentioned a year ago that you were a reviewer for those reports.
B. Thomas:Well, I don’t think NSF does. IPCC takes scientists from everywhere. Now the agencies can recommend people to participate in the authorship of these different documents. I was on the last one actually; I was one of the, they call them lead authors, on the ice chapter [Chapter 4 of Assessment Report 4]. And they came from all over the place. I think actually EPA, because I’d worked with them on sea level rise way back, they recommended that I — Because on the previous one I’d reviewed it, and I had a lot of concerns that I’d sent in because I was convinced they were underestimating the dynamic potential. And at that time, of course, the whole history of this ice shelf glacier stability, it went through an interesting phase. It was the early days when everyone jumped on it and thought, “Oh, yeah, the ice shelves might go and sea level will shoot up.” And those estimates of sea level rise, the early ones, were based upon those ideas. And that lasted for two or three years. And then the theoreticians came in and started to prove it was all wrong — that this simply couldn’t happen, that glaciers just a few ice thicknesses inland cannot feel what’s happening downstream… And it depends how you think ice is, or how ice really is. You know, if it was squishy like water, what they say is true. But if it’s stiff like — you know, you push on this end of the table, the other end moves. It depends what it is. And so they had room to say this, but they couldn’t prove it. Just like we couldn’t prove the opposite.
But what bothers me is that they did prove it. They couldn’t prove it, but they did prove it. But if you examine closely what they did, they made some assumptions early in the game which made it impossible for the other end of the table to feel it. And so it was a totally circular argument. “We assume it can’t be so, therefore it mustn’t be so,” is basically what they said. And this happily persisted right through glaciology for over a decade, and it was washed out. It used to be sort of laughed out of court, the idea that the ice shelves… You know, “That was yesterday; people don’t believe that anymore.” And this continued, right? It continued into the IPCC, and the IPCC made some grudging possibilities. This was not the most recent one, the previous one. The 2000 one or whenever it was.
W. Thomas:Oh, the third one. [IPCC Assessment Report 3]
B. Thomas:Not the first one, by any means. The third one. Yes, that’s the one I reviewed, I think. And they made grudging concessions to “Well, maybe — But, you know, modern glaciologic —” like I don’t know the quotes, but it’s all to say that this is considered extremely unlikely. And so my review obviously didn’t agree with that. And I think they made some slight concessions in the final write up. And the EPA people that I’d worked with earlier were still about, and they were eager to make the point that really we needed to take account of these things. And so they recommended me as a lead author, and I think NASA did as well. So I ended up in on that. But even with this one, I mean the chapter that we wrote took account of these things well. But then there is another group in the IPCC who does the actual predictions. And there isn’t a hell of a lot of communication between the different groups. They meet at different times, and it becomes an email thing. When we first got the predictions that these people made, a number of us expressed concern about this, the fact that the dynamic still wasn’t included, in that it was still essentially a surface mass balance estimate. As far as I could make out, the rationale was, “Well, we don’t have a model for that, so we have to use the models we’ve got.” That seemed to be an incredible approach. If we’re ignorant about something, let’s forget it.
But they did put some weasel words in there. They’ve got, I forget what it is, “ten centimeters of the increase in sea level over 100 years may possibly…you might add on ten centimeters for the possibility that the dynamics might come in.” So they added on a little bit.
W. Thomas:Right, sort of an expectation value or something like that.
B. Thomas:Yeah. And it was based upon the most simplistic and obviously incorrect… What basically they said was that, “Okay, we know there’s a dynamic signal. And it’s during a time period when the global temperature (I assume it was global) rose by a tenth of a degree, let’s say. So let’s assume it’s linear. So if the temperature rises by three degrees, the dynamic signal will be thirty times as big.” And everything we know about the signal is that it’s totally non-linear, and it probably has nothing to do with temperature. This was pointed out to them, but they still…I mean, that’s all they were able to do. And it’s fair enough — you can’t do it. But the best thing to do when you can’t do it is to say you can’t do it and indicate that there’s a big uncertainty. They didn’t shrink their uncertainty values, except to say those weasel words that were in there. But the numbers that you see when the IPCC is quoted is their very conservative numbers, and the possibility of the great big numbers has been thrown out the window. Now there have been a lot of papers since then, too, to highlight this. So I think it will slowly be corrected. But it is a concern about the way science is done.
W. Thomas:So the people who are trying to take into account the dynamic processes in very, sort of, largely arbitrary ways are mostly climate modelers then I take it?
B. Thomas:They’re generally modelers, yeah. You know, it’s neat for a modeler, I think, to have a model that produces a result. So you can see, I suppose, what’s driving them. And it is a horrendous problem, you know, the modeling issue.
W. Thomas:So in the fourth one then, when you’re an author, are there, kind of, meetings then?
B. Thomas:Oh, yeah, there was a series of meetings. There were three or four meetings spread over a couple of years. There was one in Italy, there was one in China (I didn’t go to the China one), there was one in New Zealand, and then there was one in Norway. It was a lot of work; I mean it’s an enormous amount of work. So the different chapters get together and you have plenaries every now and then. But there were different working groups, and so we were in the science rationale working group or whatever it is. I think they’ve got three or four working groups, and they all meet at different times.
W. Thomas:And how many people are there with you?
B. Thomas:Oh, hundreds! They’re not all ice, obviously. This is for everything.
W. Thomas:But then when you’re talking with people like — Oppenheimer was involved with that, right? [Oppenheimer was involved in AR3, not AR4 with R. Thomas]
W. Thomas:So there’s you, there’s him, as far as the West Antarctic Ice Sheet is concerned?
B. Thomas:Oh, well, I don’t think he was in the ice group. No. The ice group was glaciologists. There were about ten or fifteen of us. Richard Alley was in it for instance, and Ian Allison from Australia. There was a Chinaman in it, and I’ve forgotten his name. [Coordinating lead author Jiawen Ren, and lead author Tingjun Zhang] There was someone from Chile in there. [Jorge Carrasco] I’m trying to remember his name from Germany who chaired it [Peter Lemke, coordinating lead author]; he’s an oceanographer, but he’s sort of a sea ice person as well. But, I mean, it was a very good group, very fruitful. I think our chapter is reasonably good. But most of the time is spent, the chapter group works together and then maybe once, every other day you all get together as a group to discuss overlapping issues. And we have side meetings with other chapters where there is some overlap. So it’s quite a rigorous process.
W. Thomas:Was there general agreement, like, within your chapter group?
B. Thomas:Oh, yeah.
W. Thomas:Because you just were figuring out things that needed to be taken into account?
B. Thomas:Oh, yeah. We went through very thoroughly, and every writing bit is interchanged between us all. And as I say, meetings with other groups, with other chapters. But we didn’t have cross-meetings with other working groups, like the prediction people, who were different people, and they were primarily modeling people. A lot of modelers have very little sort of personal awareness of the stuff they model, so they can go off at a tangent.
W. Thomas:So once you get to the point where you have to sort of consolidate these things it becomes just sort of…?
B. Thomas:Well, we get to see what they have concluded, but at a fairly late stage. And then we get some feedback, as we did, to try and… And they did put some words in there, and this rather simplistic approach to putting something in it. They wanted to have something they could put in a model that would yield a number. So they put this temperature-related dynamic instability which is based on zero physics, but it comes up with a number [chuckles].
W. Thomas:So I guess it’s just fair to say, then, that the way they put these things together is…
B. Thomas:There are weaknesses, serious weaknesses. And they are aware of it. I think there have been meetings since then where the IPPC is trying to reconsider how better to do these things. I mean it’s a big, cumbersome process, and it’s very difficult to get around that because you know how a desire for democracy means that we have to represent everyone. You know, science doesn’t necessarily work that way, but we like to feel that it does.
W. Thomas:Is it a question of not being able to put something legitimately into a model and not being able to legitimately leave it out, and so the consolidation process…?
B. Thomas:Yeah. There’s an urgency on all these things for us to produce some numbers for the policymakers. Because if you just say words, well, they’ll say, “We’re not listening to you.” But if you give them numbers, maybe they’ll carry more weight. But you’ve got to be very careful when you do that.
W. Thomas:Okay. I think we’ve kind of come up to the present time, I suppose. Is there something else that we should be looking at?
B. Thomas:Well, I’m getting back to sort of the progression of what I’ve done. You know, my sort of final effort while I was at NASA Headquarters was to put together this Greenland program. At the same time, I was on the Icesat science team, which is the laser satellite that NASA finally launched in 2003. So by 1998 I was actually doing things on the Greenland Ice Sheet as well as managing the program. I was on that traverse, for instance. So that was getting far more interesting to me than managing programs. Also, the spirit at NASA was somewhat changing. There used to be a lot of independence for each program, and there was an allocation of money, but you were more or less left to do with the money whatever you liked. It was somewhat different from the NSF model, because you could set clear objectives and you could sort of manage the science to address those objectives. So you didn’t have to have an open wide proposal process, because you knew what you wanted to achieve. You knew what kind of science was needed, so you could actually contact people, see if they were interested. Everyone had to write a proposal, but you didn’t necessarily even have to send it out for review. It had to relate to the objectives of the project.
W. Thomas:This is NASA?
B. Thomas:At NASA, yeah. So it was a very effective way of — I mean you could be in a mess that way as well. But assuming that you had a reasonably good program manager, you could get things done in a far more focused and a rapid way than the NSF model. So it was a very satisfying place to be. But they had started to change that with multiple reorganizations as time went by, and they started to go in for bigger programs. They brought in EOS, which is the Earth Observing System, so that was having working group after working group, and it became cumbersome and top heavy to really get things done. So I was quite happy to focus on actually doing some science.
W. Thomas:This is in ’98?
B. Thomas:In ’98. And I started working with one of the contractors and focusing on the PARCA results and preparing for Icesat. And then they launched Icesat in 2003, so I spent more time on that. Since then I’ve worked on some Icesat data, and also analyzing the stuff we acquired in the Antarctic from the work with the Chileans. And also Greenland. We continue to acquire data over Greenland, so that’s a continual source of more ideas.
W. Thomas:So the increased flexibility is because you go to the contractor rather than...
B. Thomas:Oh, yeah. I mean, I was doing the same thing at NASA —
W. Thomas:That’s the point when you leave Headquarters?
B. Thomas:Yeah. It was becoming very difficult. In fact, the last time that I went to Greenland, they had totally reorganized yet again. And they had different senior managers in. And Stan Wilson had been sort of edged out, and had gone to NOAA. And the new bosses were more or less telling me that, “Well, you know, if you’re not here to defend your budget, it may go away.” So it was getting extremely difficult to rationalize going to Greenland for two or three weeks, and so it was better to obtain the greater freedom.
So anyway, that continues more or less through to today. And most recently, I’ve been looking at Icesat data and the most recent aircraft data. Certainly from my perspective, the aircraft data is giving us far more detailed information. We’re reaching the stage where we know when Greenland — Certainly there are like three glaciers that are changing most rapidly, you know, tens of meters per year thinning, and in some cases, there’s a doubling of velocity within a very short space of time. These are very fast glaciers, so they go at more than ten kilometers a year. So understanding these is key to any prediction. And the best way to understand them is to get detailed information, particularly of the bed topography, and where they speed up, the spatial patterns and how that relates to bed topography — all those kind of things. They feed you back the information that you have to have to constrain the models. And so that’s where, certainly for me, that the most interest is at the present.
So I think that’s about up to date.
W. Thomas:Yes. I suppose that I don’t have any more immediate questions. I think it seems like a pretty good overview. So do we just want to call it there then?
B. Thomas:Yeah, if you’re happy, I’m happy (laughs).