90.	GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS (for more detailed headings, see the Geophysics Appendix)
	91.	Solid Earth physics
S	91.10.-v	Geodesy and gravity
M	91.10.-v	Geodesy and gravity (see also 91.50.Kx Gravity and isostasy—in Marine geology and geophysics; 91.45.gh—in geophysics appendix)
	91.10.By	Mathematical geodesy; general theory
	91.10.Da	Cartography
S	91.10.Fc	Space geodetic surveys
M	91.10.Fc	Space and satellite geodesy; applications of global positioning systems
	91.10.Jf	Topography; geometric observations
S	91.10.Kg	Crustal movements
M	91.10.Kg	Crustal movements and deformation
	91.10.Lh	Photogrammetry
S	91.10.Nj	Rotational variations; polar wobble
M	91.10.Nj	Rotational variations; polar wobble (see also 92.10.Iv Ocean influence of Earth’s rotation)
N	91.10.Op	Gravity anomalies; time variable gravity
S	91.10.Pp	Gravimetric measurements and instruments
M	91.10.Pp	Geodetic techniques; gravimetric measurements and instruments
S	91.10.Qm	Harmonics of the gravity potential field
M	91.10.Qm	Harmonics of the gravity potential field; geopotential theory and determination
	... ... ...	Rheology of lithosphere and mantle, see 91.32.De, 91.32.Gh
D	91.10.Rn	Rheology of lithosphere and mantle (Use 91.32.De)
	91.10.Sp	Satellite orbits
	91.10.Tq	Earth tides
S	91.10.Vr	Ocean/Earth/atmosphere interaction
M	91.10.Vr	Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions; mass balance
	91.10.Ws	Reference systems
N	91.10.Xa	Global change from geodesy
S	91.25.-r	Geomagnetism and paleomagnetism; geoelectricity
M	91.25.-r	Geomagnetism and paleomagnetism; geoelectricity (see also 91.50.Iv Marine magnetics and electromagnetics)
	91.25.Cw	Origins and models of the magnetic field; dynamo theories
	91.25.Dx	Archeomagnetism
	91.25.Ey	Interactions between exterior sources and interior properties
N	91.25.F-	Rock and mineral magnetism (see also 91.60.Pn Magnetic and electrical properties—in Physical properties of rocks and minerals)
N	91.25.fa	Biogenic magnetic minerals
N	91.25.fd	Environmental magnetism
N	91.25.G-	Spatial variations in geomagnetism
N	91.25.ga	Harmonics and anomalies
D	91.25.Ga	Spatial variations: all harmonics and anomalies (Use 91.25.ga)
N	91.25.gj	Attributed to seafloor spreading
D	91.25.Jc	Spatial variations attributed to sea floor spreading (Use 91.25.gj)
S	91.25.Le	Time variations: diurnal to secular
M	91.25.Le	Time variations in geomagnetism
S	91.25.Mf	Reversals
M	91.25.Mf	Magnetic field reversals: process and timescale
	91.25.Ng	Paleomagnetism
	91.25.Ph	Magnetostratigraphy
S	91.25.Qi	Geoelectricity; electromagnetic induction and conductivity (magnetotelluric effects)
M	91.25.Qi	Geoelectricity, electromagnetic induction, and telluric currents
N	91.25.Rt	Magnetic anomalies; modeling and interpretations
N	91.25.St	Magnetic fabrics and anisotropy
N	91.25.Th	Reference fields: regional; global
N	91.25.Ux	Remagnetization
N	91.25.Wb	Geomagnetic induction
N	91.25.Xg	Geomagnetic excursion
N	91.25.Za	Core processes
	91.30.-f	Seismology
N	91.30.Ab	Theory and modeling, computational seismology
	91.30.Bi	Seismic sources (mechanisms, magnitude, moment frequency spectrum)
N	91.30.Cd	Body wave propagation
S	91.30.Dk	Seismicity: space and time distribution
M	91.30.Dk	Seismicity (see also 91.45.gd—in geophysics appendix)
S	91.30.Fn	Surface and body waves
M	91.30.Fn	Surface waves and free oscillations
N	91.30.Ga	Subduction zones (see also 91.40.Rs—in Volcanology; 91.45.Hc—in Tectonophysics; 91.50.Wy—in Marine geology and geophysics; 91.67.fc—in geophysics appendix)
N	91.30.Hc	Mid-ocean ridges (see also 91.40.St—in Volcanology; 91.50.Rt—in Marine geology and geophysics; 91.67.ff—in geophysics appendix)
N	91.30.Iv	Transform faults
N	91.30.Jk	Tomography in seismology (see also 91.35.Pn Tomography of the Earth's interior)
D	91.30.Ks	Free oscillations (periods less than 12 hours) (Use 91.30.Fn)
	91.30.Mv	Strong motions and shock waves
S	91.30.Nw	Tsunamis
M	91.30.Nw	Tsunamis (see also 92.10.hl—in geophysics appendix)
S	91.30.Px	Phenomena related to earthquake prediction
M	91.30.Px	Earthquakes
S	91.30.Rz	Explosion seismology
M	91.30.Rz	Nuclear explosion seismology
	91.30.Tb	Volcano seismology
N	91.30.Uv	Core and mantle seismology
	91.30.Vc	Continental crust seismology
N	91.30.Wx	Lithosphere seismology (see also 91.45.gf—in geophysics appendix)
	91.30.Ye	Oceanic crust seismology
N	91.30.Za	Paleoseismology
N	91.32.-m	Rheology of the Earth
N	91.32.Ac	General aspects
N	91.32.De	Crust and lithosphere
N	91.32.Gh	Mantle
N	91.32.Jk	Friction of fault zones
	91.35.-x	Earth's interior structure and properties
	91.35.Cb	Models of interior structure
S	91.35.Dc	Heat flow; geothermy
M	91.35.Dc	Heat flow; geothermy (see also 91.50.Ln Heat flow (benthic)—in Marine geology and geophysics)
	91.35.Ed	Structure of the Earth's interior below the upper mantle
	91.35.Gf	Structure of the crust and upper mantle
S	91.35.Lj	Composition of Earth's interior
M	91.35.Lj	Composition and state of the Earth's interior (see also 91.67.gb—in geophysics appendix)
	... ... ...	Geochronology, see 91.80.+d; 91.80.-d in geophysics appendix
D	91.35.Nm	Geochronology (Use 91.80.+d)
	91.35.Pn	Tomography of the Earth's interior (see also 91.30.Jk Tomography in seismology)
S	91.40.-k	Volcanology
M	91.40.-k	Volcanology (see also 91.30.Tb Volcano seismology)
N	91.40.Ac	Geochemical modeling
S	91.40.Bp	Ash deposits
M	91.40.Bp	Tephrochronology; ash deposits
	91.40.Dr	Atmospheric effects (see also 92.60.Mt Particles and aerosols—in Meteorology)
S	91.40.Ft	Eruptions
M	91.40.Ft	Eruption mechanisms
N	91.40.Ge	Hydrothermal systems (see also 91.67.Jk—in Geochemistry; 92.05.Lf—in oceanography)
S	91.40.Hw	Lava
M	91.40.Hw	Lava rheology and morphology
N	91.40.Jk	Magma migration
N	91.40.La	Physics and chemistry of magma bodies
N	91.40.Pc	Thermodynamics in volcanology
N	91.40.Qa	Reactions and phase equilibria (see also 91.67.De—in Geochemistry)
N	91.40.Rs	Subduction zone processes (see also 91.30.Ga—in Seismology; 91.45.Hc—in Tectonophysics; 91.50.Wy—in Marine geology; 91.67.fc—in geophysics appendix)
N	91.40.St	Mid-oceanic ridge processes (see also 91.30.Hc—in Seismology; 91.50.Rt—in Marine geology; 91.67.ff—in geophysics appendix)
N	91.40.Ta	Intra-plate processes (see also 91.50.Tb—in Marine geology; 91.67.fh—in geophysics appendix)
N	91.40.Uc	Volcanoclastic deposits
N	91.40.Vg	Volcanic gases
N	91.40.Wx	Calderas
N	91.40.Yt	Remote sensing of volcanoes (see also 93.85.Pq)
N	91.40.Zz	Volcano monitoring; volcanic hazards and risks
	... ... ...	Planetary volcanism, see 96.12.Xy
S	91.45.-c	Physics of plate tectonics
M	91.45.-c	Tectonophysics
N	91.45.Bg	Planetary interiors (see also 96.12.Pc—in Planetology of solid surface planets; 96.15.Nd—in Planetology of fluid planets)
S	91.45.Cg	Continental margins
M	91.45.Cg	Continental tectonics
	91.45.Dh	Plate tectonics
	... ... ...	Neotectonics, see 91.45.ch—in geophysics appendix
D	91.45.Ei	Neotectonics (Use 91.45.Cg)
S	91.45.Fj	Convection currents
M	91.45.Fj	Convection currents and mantle plumes
N	91.45.Ga	Dynamics and mechanics of tectonics
N	91.45.Hc	Subduction and obduction zone processes (see also 91.30.Ga—in Seismology; 91.40.Rs—in Volcanology)
N	91.45.Jg	Hot spots, large igneous provinces, and flood basalt volcanism
N	91.45.Kn	Core processes
N	91.45.Nc	Evolution of the Earth
D	91.45.Pt	Slow vertical crustal movements (including isostasy and postglacial phenomena) (Use 91.45.Ga)
S	91.45.Qv	Tomography of plate tectonics
M	91.45.Qv	Tomography of plate tectonics (see also 91.30.Jk—in Seismology)
N	91.45.Rg	Heat generation and transport
	... ... ...	Folds and folding, see 91.55.Hj
	... ... ...	Fractures and faults, see 91.55.Jk
D	91.45.Sx	Relations of gravity observations to tectonics and isostasy (Use 91.10.Pp)
D	91.45.Ty	Folds and Folding (Use 91.55.Hj)
D	91.45.Vz	Fractures and faults (Use 91.55.Jk)
N	91.45.Wa	Volcanic arcs
N	91.45.Xz	Stresses in tectonophysics
	... ... ...	Hydrothermal systems, see 91.40.Ge
	... ... ...	Planetary tectonics, see 96.12.Xy
	... ... ...	Pluton emplacement, see 91.55.Sn
	... ... ...	Rheology of the Earth, see 91.32.-m
D	91.45.Yb	Pluton emplacement (Use 91.55.Sn)
	91.50.-r	Marine geology and geophysics
N	91.50.Ac	Back-arc basin processes
N	91.50.Bd	Continental shelf and slope processes
S	91.50.Cw	Beach, coastal, and shelf processes
M	91.50.Cw	Beach and coastal processes
S	91.50.Ey	Ocean bottom processes
M	91.50.Ey	Seafloor, morphology, geology, and geophysics (see also 92.10.Oc Benthic boundary layers, ocean bottom processes—in oceanography)
S	91.50.Ga	Bathymetry and noncoastal underwater morphology
M	91.50.Ga	Bathymetry, seafloor topology
N	91.50.Hc	Gas and hydrate systems (see also 92.20.Uv—in oceanography)
N	91.50.Iv	Marine magnetics and electromagnetics
S	91.50.Jc	Turbidity currents, sedimentation
M	91.50.Jc	Marine sediments, turbidity currents—processes and transport (see also 91.65.Ti—in petrology; 91.67.Ty—in Geochemistry; 92.10.Wa and 92.20.Vn—in oceanography; 92.40.Gc—in hydrology; 91.80.Wx—in geophysics appendix)
N	91.50.Kx	Gravity and isostasy
N	91.50.Ln	Heat flow (benthic)
N	91.50.Nc	Littoral processes
N	91.50.Ps	Marine hydrogeology
N	91.50.Qr	Micropaleontology
N	91.50.Rt	Mid-ocean ridge processes (see also 91.30.Hc—in Seismology; 91.40.St—in Volcanology; 91.67.ff—in geophysics appendix)
N	91.50.Sn	Ocean drilling (see also 93.85.Tf Oil prospecting, pipelines, and conduits)
N	91.50.Tb	Oceanic hotspots and intra-plate volcanism (see also 91.40.Ta—in Volcanology; 91.67.fh—in geophysics appendix)
N	91.50.Uv	Oceanic plateaus and fracture zone processes
N	91.50.Vx	Ophiolites
N	91.50.Wy	Subduction zone processes
N	91.50.Xz	Submarine landslides
N	91.50.Yf	Submergence instruments, ROV, AUV, Submersibles, and ocean observatories
N	91.55.-y	Structural geology
N	91.55.Ax	Mechanics, theory and modeling
N	91.55.Bc	Continental neotectonics
N	91.55.De	Diapir and diapirism
N	91.55.Fg	Dynamics and mechanics of faulting (see also 91.32.Jk Friction of fault zones, rheology of)
N	91.55.Hj	Folds and folding
N	91.55.Jk	Fractures and faults (see also 91.50.Uv Oceanic plateaus and fracture zone processes)
N	91.55.Ln	Kinematics of crustal and mantle deformation
N	91.55.Mb	High strain deformation zones
N	91.55.Nc	Local crustal structure; regional crustal structure
N	91.55.Pq	Melanges
N	91.55.Qr	Mesoscopic fabrics
N	91.55.Sn	Pluton emplacement
N	91.55.Tt	Role of fluids
N	91.55.Uv	Remote sensing in structural geology
	... ... ...	Rheology of the Earth, see 91.32.-m
	91.60.-x	Physical properties of rocks and minerals (for rheological properties of geological materials, see 83.80.Nb)
	91.60.Ba	Elasticity, fracture, and flow
S	91.60.Dc	Creep and deformation
M	91.60.Dc	Plasticity, diffusion, and creep
S	91.60.Ed	Crystal structure and defects
M	91.60.Ed	Crystal structure and defects, microstructure
	91.60.Fe	Equations of state
	91.60.Gf	High-pressure behavior
	91.60.Hg	Phase changes
	91.60.Ki	Thermal properties
	91.60.Lj	Acoustic properties
	91.60.Mk	Optical properties
N	91.60.Np	Permeability and porosity
S	91.60.Pn	Magnetic and electric properties; environmental magnetism
M	91.60.Pn	Magnetic and electrical properties (see also 91.25.F- Rock and mineral magnetism)
	... ... ...	Environmental magnetism, see 91.25.fd
N	91.60.Qr	Wave attenuation
N	91.60.Tn	Transport properties
N	91.62.+g	Biogeosciences (see also 91.67.Uv Organic and biogenic geochemistry; 92.20.Jt Biology of the ocean; 91.80.Kc—in geophysics appendix)
S	91.65.-n	Geophysical aspects of geology, mineralogy, and petrology
M	91.65.-n	Mineralogy and petrology
N	91.65.An	Mineral and crystal chemistry
	... ... ...	Geochemical cycles, see 91.67.Nc
D	91.65.Br	Geochemical cycles (Use 91.67.Nc)
N	91.65.Cq	Igneous petrology
S	91.65.Dt	Isotopic composition/chemistry
M	91.65.Dt	Isotopic composition (see also 91.67.Qr Radiogenic isotope geochemistry; 91.67.Rx Stable isotope geochemistry)
N	91.65.Ej	Extrusive structures and rocks
	... ... ...	Low temperature geochemistry, see 91.67.Vf
D	91.65.Fw	Low-temperature geochemistry (Use 91.67.Vf)
N	91.65.Gk	Intrusive structures and rocks
	... ... ...	Organic geochemistry, see 91.67.Uv
D	91.65.Hy	Organic geochemistry (Use 91.67.Uv)
N	91.65.Jn	Layered magma chambers
N	91.65.Kf	Metamorphic petrology
N	91.65.Lc	Pressure-temperature-time paths
N	91.65.My	Fluid flow
	... ... ...	Trace elements, see 91.67.Pq
D	91.65.Nd	Trace elements (Use 91.67.Pq)
N	91.65.Pj	Ultra-high pressure metamorphism
N	91.65.Qr	Ultra-high temperature metamorphism
	91.65.Rg	Mineral occurrences and deposits
N	91.65.Sn	Meteorite mineralogy and petrology
S	91.65.Ti	Sedimentary petrology
M	91.65.Ti	Sedimentary petrology (see also 91.50.Jc—in marine geology; 91.67.Ty—in Geochemistry; 92.10.Wa and 92.20.Vn—in oceanography; 92.40.Gc—in hydrology; 91.80.Wx—in geophysics appendix)
	... ... ...	Major element composition, see 91.67.Pq
D	91.65.Vj	Major element composition (Use 91.67.Pq)
N	91.67.-y	Geochemistry (see also 92.20.Cm Chemistry of the ocean; 92.40.Bc Chemistry of fresh water; 92.60.Ls Ion chemistry of the atmosphere; 91.62.Kt, 91.80.Kc, and 92.20.C- in geophysics appendix)
N	91.67.Bc	Geochemical modeling
N	91.67.De	Reactions and phase equilibria (see also 91.40.Qa—in Volcanology)
N	91.67.Fx	Geochemical processes
N	91.67.Gy	Chemical composition
N	91.67.Jk	Geochemistry of hydrothermal systems (see also 91.40.Ge—in Volcanology; 92.05.Lf—in oceanography)
	... ... ...	Physics and chemistry of magma bodies, see 91.40.La
N	91.67.Nc	Geochemical cycles (see also 92.20.Sg Biogeochemical cycles—in oceanography; 92.60.hn—in meteorology; 92.30.Gh—in geophysics appendix)
N	91.67.Pq	Major and trace element geochemistry (see also 92.20.Wx Trace elements—in chemical and biological oceanography)
N	91.67.Qr	Radiogenic isotope geochemistry (see also 91.65.Dt Isotopic composition—in Mineralogy and petrology; 92.20.Td Radioactivity and radioisotopes—in oceanography)
N	91.67.Rx	Stable isotope geochemistry (see also 91.65.Dt Isotopic composition—in Mineralogy and petrology)
N	91.67.St	Fluid and melt inclusion geochemistry
N	91.67.Ty	Sedimentary geochemistry (see also 91.50.Jc—in marine geology; 91.65.Ti—in Mineralogy and petrology; 92.10.Wa and 92.20.Vn—in oceanography; 92.40.Gc—in hydrology; 91.80.Wx—in geophysics appendix)
N	91.67.Uv	Organic and biogenic geochemistry
N	91.67.Vf	Low-temperature geochemistry
	91.70.-c	Information related to geologic time
	91.70.Bf	Cenozoic
	91.70.Dh	Mesozoic
	91.70.Fj	Paleozoic
	91.70.Hm	Precambrian
N	91.80.+d	Geochronology (see also 92.30.Hj—in geophysics appendix)
	91.90.+p	Other topics in solid Earth physics (restricted to new topics in section 91)
	92.	Hydrospheric and atmospheric geophysics
N	92.05.-x	General aspects of oceanography
N	92.05.Bc	Analytical modeling and laboratory experiments
N	92.05.Df	Climate and inter-annual variability (see also 92.60.Ry Climatology, climate change and variability—in meteorology; 92.70.Gt Climate dynamics—in Global change)
N	92.05.Ek	Long term variability; Heinrich events
N	92.05.Fg	Diurnal, seasonal and annual cycles
N	92.05.Hj	Physical and chemical properties of seawater (salinity, density, temperature)
N	92.05.Jn	Ocean energy extraction
N	92.05.Lf	Hydrothermal systems (see also 91.40.Ge—in Volcanology; 91.67.Jk—in Geochemistry)
S	92.10.-c	Physics of the oceans
M	92.10.-c	Physical oceanography
N	92.10.A-	Circulation and currents
N	92.10.ab	General circulation
N	92.10.ad	Deep water formation and circulation
N	92.10.af	Thermohaline convection
N	92.10.ah	Ocean currents; Eastern boundary currents, Western boundary currents
N	92.10.ak	Eddies and mesoscale processes
N	92.10.am	El Nino Southern Oscillation (see also 92.30.La—in Paleoceanography)
	... ... ...	Physical properties of seawater, see 92.05.Hj
	... ... ...	Capillary waves, see 92.10.hd—in geophysics appendix
D	92.10.Bf	Physical properties of seawater (Use 92.05.Hj)
D	92.10.Cg	Capillary waves (Use 92.10.Hm)
S	92.10.Dh	Dynamics of the deep ocean
M	92.10.Dh	Deep ocean processes
	92.10.Ei	Coriolis effects
S	92.10.Fj	Dynamics of the upper ocean
M	92.10.Fj	Upper ocean and mixed layer processes
D	92.10.Gk	El Nino (Use 92.10.am)
S	92.10.Hm	Surface waves, tides, and sea level
M	92.10.Hm	Ocean waves and oscillations
N	92.10.Iv	Ocean influence of Earth's rotation
	... ... ...	Seiches, see 92.10.hk—in geophysics appendix
D	92.10.Jn	Seiches (Use 92.10.Hm)
S	92.10.Kp	Sea-air energy exchange processes
M	92.10.Kp	Sea–air energy exchange processes (see also 92.60.Cc—in meteorology)
S	92.10.Lq	Turbulence and diffusion
M	92.10.Lq	Turbulence, diffusion, and mixing processes in oceanography
D	92.10.Mr	Thermohaline structure and circulation (Use 92.10.af)
S	92.10.Ns	Fine structure and microstructure
M	92.10.Ns	Fine structure and microstructure in oceanography
N	92.10.Oc	Benthic boundary layers, ocean bottom processes (see also 91.50.Ey Sea floor, morphology, geology, and geophysics—in marine geology)
D	92.10.Pt	Optical properties of sea water (Use 92.05.Hj)
	... ... ...	Optical properties of seawater, see 92.05.Hj
S	92.10.Rw	Sea ice
M	92.10.Rw	Sea ice (mechanics and air/sea/ice exchange processes)
S	92.10.Sx	Coastal and estuarine oceanography
M	92.10.Sx	Coastal, estuarine, and near shore processes (see also 91.50.Cw Beach and coastal processes—in marine geology)
	92.10.Ty	Fronts and jets
N	92.10.Ua	Overflows
S	92.10.Vz	Underwater sound
M	92.10.Vz	Underwater sound (see also 43.30.+m; 43.30.-k—in acoustics appendix)
S	92.10.Wa	Sediment transport
M	92.10.Wa	Sediment transport (see also 91.50.Jc—in marine geology; 91.65.Ti—in Mineralogy and petrology; 91.67.Ty—in Geochemistry; 92.20.Vn in Chemical oceanography; 92.40.Gc—in Hydrology; 91.80.Wx—in geophysics appendix)
N	92.10.Xc	Ocean fog
	92.10.Yb	Hydrography (for ocean parameter estimation by acoustical methods, see 43.30.Pc—in acoustics appendix)
N	92.10.Zf	Upwelling and convergences (see also 92.30.Vn—in geophysics appendix)
	... ... ...	Marine geology and geophysics, see 91.50.-r
S	92.20.-h	Interdisciplinary aspects of oceanography
M	92.20.-h	Chemical and biological oceanography
S	92.20.Bk	Aerosols
M	92.20.Bk	Aerosols (see also 92.60.Mt—in meteorology; 91.67.gp and 92.30.Ef—in geophysics appendix)
	92.20.Cm	Chemistry of the ocean
	... ... ...	Photochemistry; photosynthesis, see 92.20.ch—in geophysics appendix
	... ... ...	Ocean energy extraction, see 92.05.Jn
D	92.20.Gr	Ocean energy extraction (Use 92.05.Jn)
S	92.20.Hs	Anoxic environments
M	92.20.Hs	Anoxic environments (see also 91.62.+g Biogeosciences; 91.62.De—in geophysics appendix)
N	92.20.Iv	Benthic processes, sea-bottom processes (see also 91.50.Ey—in marine geology; 92.10.Oc—in oceanography; 92.40.Gc—in hydrology)
S	92.20.Jt	Biological aspects of oceanography
M	92.20.Jt	Biology of the ocean (see also 91.62.+g Biogeosciences; 92.40.vu Cryobiology—in geophysics appendix)
D	92.20.Kv	Photochemistry (Use 92.20.Cm)
D	92.20.Lw	Photosynthesis (Use 92.20.Cm)
D	92.20.Mx	Physicochemical properties (Use 92.20.Cm)
	92.20.Ny	Marine pollution
N	92.20.Ox	Hypoxic environment (see also 91.62.De—in geophysics appendix)
	... ... ...	Bacteria, see 92.20.jb—in geophysics appendix
	... ... ...	Plankton, see 92.20.jf and 92.20.jh—in geophysics appendix
D	92.20.Pz	Bacteria (Use 92.20.Jt)
D	92.20.Rb	Plankton (Use 92.20.Jt)
N	92.20.Sg	Biogeochemical cycles (see also 91.67.Nc—in Geochemistry; 92.60.hn—in meteorology; 92.30.Gh—in geophysics appendix)
S	92.20.Td	Radioactivity
M	92.20.Td	Radioactivity and radioisotopes (see also 91.65.Dt Isotopic composition—in Mineralogy and petrology; 91.67.Qr Radiogenic isotope geochemistry)
N	92.20.Uv	Gases in chemical oceanography (see also 91.50.Hc Gas and hydrate systems—in marine geology)
N	92.20.Vn	Sedimentation (see also 91.50.Jc—in marine geology; 91.65.Ti—in petrology; 91.67.Ty—in Geochemistry; 92.10.Wa—in oceanography; 92.40.Gc—in hydrology; 91.80.Wx—in geophysics appendix)
N	92.20.Wx	Trace elements (see also 91.67.Pq Major and trace element geochemistry)
N	92.20.Xy	Carbon cycling (see also 91.62.La—in geophysics appendix)
N	92.30.+m	Paleoceanography
S	92.40.-t	Hydrology and glaciology
M	92.40.-t	Hydrology and glaciology; cryosphere (see also 92.70.Ha—in Global change)
N	92.40.Aa	Anthropogenic effects (see also 92.30.De—in geophysics appendix)
N	92.40.Bc	Chemistry of fresh water
	92.40.Cy	Modeling; general theory
N	92.40.De	Drought
S	92.40.Ea	Precipitation
M	92.40.Ea	Precipitation (see also 92.60.jf—in geophysics appendix)
	... ... ...	Rivers, runoff, and stream flow, see 92.40.qh and 92.40.qp—in geophysics appendix
D	92.40.Fb	Rivers, runoff, and streamflow (Use 92.40.Qk)
S	92.40.Gc	Erosion and sedimentation
M	92.40.Gc	Erosion and sedimentation; sediment transport (see also 91.50.Jc—in marine geology; 91.65.Ti—in Mineralogy and petrology; 91.67.Ty—in Geochemistry; 92.10.Wa and 92.20.Vn—in oceanography; 91.80.Wx—in geophysics appendix)
N	92.40.Ha	Debris flow and landslides
N	92.40.Iv	Desertification
S	92.40.Je	Evaporation
M	92.40.Je	Evapotranspiration (see also 92.60.jc Evaporation—in geophysics appendix)
	92.40.Kf	Groundwater
S	92.40.Lg	Soil moisture
M	92.40.Lg	Soil moisture and temperature
	... ... ...	Limnology, see 92.40.qj—in geophysics appendix
D	92.40.Ni	Limnology (Use 92.40.Qk)
N	92.40.Oj	Eco-hydrology; plant ecology
N	92.40.Pb	Geomorphology
S	92.40.Qk	Water quality and water resources
M	92.40.Qk	Surface water, water resources
	... ... ...	Water quality, see 92.40.kc and 92.40.qc—in geophysics appendix
	... ... ...	Snow, see 92.40.ed—in geophysics appendix
D	92.40.Rm	Snow (Use 92.40.Ea)
D	92.40.Sn	Ice (Use 92.40.Vq)
S	92.40.Vq	Glaciers
M	92.40.Vq	Glaciology (see also 92.30.Mc—in geophysics appendix)
	... ... ...	Ice, see 92.40.vx—in geophysics appendix
N	92.40.We	Hydrologic cycles and budgets
N	92.40.Xx	Irrigation; dams
N	92.40.Yy	Wetlands
N	92.40.Zg	Hydrometeorology, hydroclimatology
S	92.60.-e	Meteorology
M	92.60.-e	Properties and dynamics of the atmosphere; meteorology (see also 92.40.Zg Hydrometeorology, hydroclimatology)
N	92.60.Aa	Modeling and model calibration (see also 92.70.Np Global climate modeling)
	92.60.Bh	General circulation
N	92.60.Cc	Ocean/atmosphere interactions, air/sea constituent fluxes (see also 92.10.Kp—in oceanography)
D	92.60.Dj	Gravity waves, tides, and compressional waves (Use 92.60.hh)
D	92.60.Ek	Convection, turbulence, and diffusion (Use 92.60.hk)
	92.60.Fm	Boundary layer structure and processes
	92.60.Gn	Winds and their effects
N	92.60.H-	Atmospheric composition, structure, and properties
N	92.60.ha	Exospheric composition and chemistry
N	92.60.hb	Thermospheric composition and chemistry, energy deposition
N	92.60.hc	Mesospheric composition, energy deposition, constituent transport and chemistry
N	92.60.hd	Stratospheric composition and chemistry
N	92.60.hf	Tropospheric composition and chemistry, constituent transport and chemistry
N	92.60.hg	Constituent sources and sinks
N	92.60.hh	Acoustic gravity waves, tides, and compressional waves
N	92.60.hk	Convection, turbulence, and diffusion (see also 92.30.Ef—in geophysics appendix)
N	92.60.hn	Geochemical cycles (see also 91.67.Nc—in Geochemistry; 92.20.Sg—in oceanography; 92.30.Gh—in geophysics appendix)
D	92.60.Hp	Chemical composition and chemical interactions (Use 92.60.H-)
N	92.60.hv	Pressure, density, and temperature
N	92.60.hw	Airglow and aurorae (see also 94.20.Ac Auroral ionosphere; 94.30.Aa Auroral phenomena in magnetosphere)
N	92.60.hx	Other upper atmospheric phenomena: red sprites; blue jets; atmospheric gamma ray and intense VHF emissions
N	92.60.Iv	Paleoclimatology (see also 92.70.Gt Climate dynamics—in Global change)
S	92.60.Jq	Water in the atmosphere (humidity, clouds, evaporation, precipitation)
M	92.60.Jq	Water in the atmosphere
N	92.60.Kc	Land/atmosphere interactions
S	92.60.Ls	Ionic interactions and processes
M	92.60.Ls	Ion chemistry of the atmosphere
	92.60.Mt	Particles and aerosols (see also 92.20.Bk—in oceanography; 91.67.gp and 92.30.Ef—in geophysics appendix)
S	92.60.Nv	Cloud physics; stratus and cumulus clouds
M	92.60.Nv	Cloud physics and chemistry
N	92.60.Ox	Tropical meteorology
S	92.60.Pw	Atmospheric electricity
M	92.60.Pw	Atmospheric electricity, lightning
	92.60.Qx	Storms
S	92.60.Ry	Climatology
M	92.60.Ry	Climatology, climate change and variability (see also 92.70.Gt and 92.70.Kb—in Global change; 92.30.Bc—in geophysics appendix)
S	92.60.Sz	Air quality and air pollution
M	92.60.Sz	Air quality and air pollution (see also 07.88.+y Instruments for environmental pollution measurements)
S	92.60.Ta	Interaction of atmosphere with electromagnetic waves; propagation
M	92.60.Ta	Electromagnetic wave propagation
N	92.60.Uy	Polar meteorology
S	92.60.Vb	Solar radiation
M	92.60.Vb	Radiative processes, solar radiation
	92.60.Wc	Weather analysis and prediction
N	92.60.Xg	Stratosphere/troposphere interactions
N	92.60.Zc	Volcanic effects
S	92.70.-j	Global change
M	92.70.-j	Global change
N	92.70.Aa	Abrupt/rapid climate change
N	92.70.Bc	Land/atmosphere interactions
	92.70.Cp	Atmosphere
	92.70.Er	Biogeochemical processes
S	92.70.Gt	Climate dynamics
M	92.70.Gt	Climate dynamics (see also 92.60.Ry—in meteorology; 92.30.Bc—in geophysics appendix)
N	92.70.Ha	Cryospheric change
N	92.70.Iv	Geomorphology and weathering (see also 92.40.Gc Erosion and sedimentation; sediment transport; 92.40.Pb—in hydrology; 92.40.P- in geophysics appendix)
S	92.70.Jw	Oceans
M	92.70.Jw	Oceans, sea level change (see also 92.10.hp—in geophysics appendix)
N	92.70.Kb	Regional climate change (see also 92.60.Ry—in meteorology; 92.30.Bc—in geophysics appendix)
	92.70.Ly	Water cycles
N	92.70.Mn	Impacts of global change; global warming (see also 92.30.Np—in geophysics appendix)
N	92.70.Np	Global climate modeling
N	92.70.Pq	Earth system modeling
N	92.70.Qr	Solar variability impact
N	92.70.St	Land cover change
	92.90.+x	Other topics in hydrospheric and atmospheric geophysics (restricted to new topics in section 92)
	93.	Geophysical observations, instrumentation, and techniques
	93.30.-w	Information related to geographical regions
	93.30.Bz	Africa
	93.30.Ca	Antarctica
	93.30.Db	Asia
	93.30.Fd	Australia
	93.30.Ge	Europe
	93.30.Hf	North America
	93.30.Jg	South America
	93.30.Kh	Large islands (e.g., Greenland)
	93.30.Li	Arctic Ocean
	93.30.Mj	Atlantic Ocean
	93.30.Nk	Indian Ocean
	93.30.Pm	Pacific Ocean
	93.30.Qn	Southern Ocean
	93.30.Rp	Regional seas
	93.30.Sq	Polar regions
	93.30.Tr	Temperate regions
	93.30.Vs	Tropical regions
	93.55.+z	International organizations, national and international programs
	... ... ...	Data acquisition and storage, see 93.85.Bc
D	93.65.+e	Data acquisition and storage (Use 93.85.Bc)
D	93.85.+q	Instrumentation and techniques for geophysical research (Use 93.85.-q)
N	93.85.-q	Instruments and techniques for geophysical research: Exploration geophysics (see also 91.50.Ga Bathymetry, seafloor topology; 91.50.Yf Submergence instruments, ROV, AUV, submersibles, and ocean observatories—in marine geology; 92.10.Yb Hydrography—in oceanography)
N	93.85.Bc	Computational methods and data processing, data acquisition and storage
N	93.85.De	Exploration of continental structures
N	93.85.Fg	Downhole methods
N	93.85.Hj	Gravity methods
N	93.85.Jk	Magnetic and electrical methods
N	93.85.Ly	Exploration of oceanic structures
N	93.85.Np	Radioactivity methods
N	93.85.Pq	Remote sensing in exploration geophysics (see also 91.40.Yt—in Volcanology; 91.55.Uv—in Structural geology)
N	93.85.Rt	Seismic methods
N	93.85.Tf	Oil prospecting, pipelines, and conduits (see also 91.50.Sn Ocean drilling)
N	93.90.+y	Other topics in geophysical observations, instrumentation, and techniques (restricted to new topics in section 93)
S	94.	Aeronomy and magnetospheric physics
M	94.	Physics of the ionosphere and magnetosphere
N	94.05.-a	Space plasma physics (see also 96.50.-e Interplanetary physics)
N	94.05.Bf	Plasma interactions with dust and aerosols
N	94.05.Dd	Radiation processes
N	94.05.Fg	Solitons and solitary waves
N	94.05.Hk	Spacecraft/atmosphere interactions
N	94.05.Jq	Spacecraft sheaths, wakes, and charging
N	94.05.Lk	Turbulence
N	94.05.Pt	Wave/wave, wave/particle interactions
N	94.05.Rx	Experimental techniques and laboratory studies (see also 52.72.+v in physics of plasmas)
N	94.05.Sd	Space weather
	... ... ...	Convection, diffusion, and turbulence, see 92.60.Hk
	... ... ...	Physics of the neutral atmosphere, see 92.60.-e
	... ... ...	Absorption and scattering of radiation, see 92.60.Ta and 92.60.Vb
	... ... ...	Atmospheric tides, waves, and winds, see 92.60.hh Acoustic gravity waves, tides, and compressional waves. See 92.60.Gn Winds and their effects
	... ... ...	Cosmic dust, see 96.50.Dj Interplanetary gas and dust; 98.38.Cp Interstellar dust grains; diffuse emission; infrared cirrus
D	94.10.-s	Physics of the neutral atmosphere (for atmospheres of the planets, see 96.35.Hv) (Use 92.60.-e)
D	94.10.Bw	General properties of the high atmosphere (Use 92.60.hd)
	... ... ...	Atmospheric composition and structure, see 92.60.H-
D	94.10.Dy	Atmospheric structure, pressure, density, and temperature (stratosphere, mesosphere, thermosphere, exosphere) (see also 92.60.-e Meteorology and 92.70.-j Global change) (Use 92.60.hv)
D	94.10.Fa	Atmospheric composition (atomic or molecular), chemical reactions and processes (see also 82.33.Tb Atmospheric chemistry in physical chemistry and chemical physics) (Use 92.60.H-)
D	94.10.Gb	Absorption and scattering of radiation (Use 92.60.Ta)
	... ... ...	Absorption and scattering of radiation, see 92.60.Ta and 92.60Vb
D	94.10.Jd	Tides, waves, and winds (Use 92.60.Gn)
	... ... ...	Atmospheric tides, waves, and winds, see 92.60.hh Acoustic gravity waves, tides, and compressional waves. See 92.60.Gn Winds and their effects
D	94.10.Lf	Convection, diffusion, mixing, turbulence, and fallout (Use 92.60.hk)
	... ... ...	Convection, diffusion, and turbulence, see 92.60.Hk
D	94.10.Nh	Cosmic dust (Use 98.38.Cp)
	... ... ...	Cosmic dust, see 96.50.Dj Interplanetary gas and dust; 98.38.Cp Interstellar dust grains; diffuse emission; infrared cirrus
D	94.10.Rk	Aurora and airglow (Use 92.60.hw)
	94.20.-y	Physics of the ionosphere (for ionospheres of the planets, see 96.35.Kx; for radiowave propagation, see 41.20.Jb in electromagnetism; see also section 52 Physics of plasmas and electric discharges)
N	94.20.Ac	Auroral ionosphere (see also 92.60.hw Airglow and aurorae—in meteorology; 94.30.Aa Auroral phenomena in magnetosphere)
S	94.20.Bb	Wave propagation
M	94.20.Bb	Wave propagation (see also 94.30.Tz—in Physics of the magnetosphere)
N	94.20.Cf	Ionospheric modeling and forecasting
N	94.20.D-	Ionospheric structure, composition
D	94.20.Dd	Ionospheric structure (D, E, F, and topside regions) including steady-state ion densities and temperatures (Use 94.20.D-)
N	94.20.de	D region
N	94.20.dg	E region
N	94.20.dj	F region
N	94.20.dk	Polar cap ionosphere
N	94.20.dl	Topside region
N	94.20.dm	Mid-latitude ionosphere
N	94.20.dt	Equatorial ionosphere
N	94.20.dv	Ion chemistry and composition; ionization mechanisms
D	94.20.Ee	D region (Use 94.20.de)
N	94.20.Fg	Plasma temperature and density
	... ... ...	Plasmasphere, see 94.30.cv
D	94.20.Gg	E region (Use 94.20.dg)
D	94.20.Ji	F region (Use 94.20.dj)
D	94.20.Kj	Polar cap ionosphere (Use 94.20.dk)
D	94.20.Lk	Topside region (Use 94.20.dl)
D	94.20.Mm	Plasmasphere (Use 94.30.cv)
D	94.20.Pp	Plasmapause (Use 94.30.ch)
S	94.20.Qq	Particle precipitation
M	94.20.Qq	Particle precipitation (see also 94.30.Ny—in Physics of the magnetosphere)
	... ... ...	Interactions between waves and particles, see 94.20.W-
D	94.20.Rr	Interactions between waves and particles (Use 94.20.wj)
S	94.20.Ss	Electric fields
M	94.20.Ss	Electric fields; current system
S	94.20.Tt	Ionospheric soundings
M	94.20.Tt	Ionospheric soundings; active experiments
S	94.20.Vv	Ionospheric disturbances and modifications
M	94.20.Vv	Ionospheric disturbances, irregularities, and storms
N	94.20.W-	Ionospheric dynamics and interactions
N	94.20.wc	Plasma motion; plasma convection; particle acceleration
N	94.20.wf	Plasma waves and instabilities
N	94.20.wg	Ionosphere/atmospheric interactions
N	94.20.wh	Ionosphere/magnetosphere interactions
N	94.20.wj	Wave/particle interactions
N	94.20.wl	Plasma interactions with dust and aerosols
N	94.20.wq	Solar radiation and cosmic ray effects
N	94.20.ws	Electromagnetic wave propagation
D	94.20.Ww	Plasma motion, convection, or circulation (Use 94.20.wc)
N	94.20.Xa	Meteor-trail physics
D	94.20.Yx	Interaction between ionosphere and magnetosphere (Use 94.20.wh)
S	94.30.-d	Physics of the magnetosphere
M	94.30.-d	Physics of the magnetosphere
N	94.30.Aa	Auroral phenomena in magnetosphere (see also 94.20.Ac Auroral ionosphere)
S	94.30.Bg	Magnetic coordinate systems
M	94.30.Bg	Magnetospheric modeling and forecasting
N	94.30.C-	Magnetospheric configuration and dynamics
N	94.30.cb	Inner magnetosphere
N	94.30.cf	Outer magnetosphere
N	94.30.cg	Magnetospheric cusp
N	94.30.ch	Magnetopause
D	94.30.Ch	Magnetospheric configuration (Use 94.30.C-)
N	94.30.cj	Magnetosheath
N	94.30.cl	Magnetotail
N	94.30.cp	Magnetic reconnection
N	94.30.cq	MHD waves, plasma waves, and instabilities
N	94.30.cs	Plasma motion; plasma convection
N	94.30.ct	Plasma sheet
N	94.30.cv	Plasmasphere
N	94.30.cx	Polar cap phenomena
D	94.30.Di	Magnetopause (Use 94.30.ch)
D	94.30.Ej	Magnetic tail (Use 94.30.cl)
D	94.30.Fk	Plasma motion, convection, or circulation (Use 94.30.cs)
D	94.30.Gm	Plasma instabilities (Use 94.30.cq)
S	94.30.Hn	Trapped particles
M	94.30.Hn	Energetic trapped particles
D	94.30.Jp	Ring currents (Use 94.30.Kq)
S	94.30.Kq	Electric fields
M	94.30.Kq	Electric fields, field-aligned currents and current systems, and ring currents
	94.30.Lr	Magnetic storms, substorms
	94.30.Ms	Magnetic pulsations
N	94.30.Ny	Energetic particle precipitation (see also 94.20.Qq—in Physics of the ionosphere)
S	94.30.Tz	Waves: propagation and excitation
M	94.30.Tz	Electromagnetic wave propagation (see also 94.20.Bb—in Physics of the ionosphere)
S	94.30.Va	Magnetosheath; interaction with interplanetary space (including solar wind)
M	94.30.Va	Magnetosphere interactions
N	94.30.Xy	Radiation belts
S	94.80.+g	Instrumentation for aeronomy and magnetospheric studies
M	94.80.+g	Instrumentation for space plasma physics, ionosphere, and magnetosphere
S	94.90.+m	Other topics in aeronomy and magnetospheric physics (restricted to new topics in section 94)
M	94.90.+m	Other topics in space plasma physics, physics of the ionosphere and magnetosphere (restricted to new topics in section 94)
	95.	Fundamental astronomy and astrophysics; instrumentation, techniques, and astronomical observations
	95.10.-a	Fundamental astronomy
	95.10.Ce	Celestial mechanics (including n-body problems) (see also 45.50.Pk in classical mechanics of discrete systems)
	... ... ...	Dynamics and kinematics of stellar systems, see 98.10.+z
	95.10.Eg	Orbit determination and improvement
S	95.10.Fh	Chaotic dynamics
M	95.10.Fh	Chaotic dynamics (see also 05.45.-a Nonlinear dynamics and chaos)
	95.10.Gi	Eclipses, transits, and occultations
	95.10.Jk	Astrometry and reference systems
	95.10.Km	Ephemerides, almanacs, and calendars
S	95.30.-k	Fundamental aspects of astrophysics
M	95.30.-k	Fundamental aspects of astrophysics (see also section 26 Nuclear astrophysics; section 32 Atomic properties and interactions with photons; section 34 Atomic and molecular collision processes and interactions; section 33 Molecular properties and interactions with photons)
S	95.30.Cq	Elementary particle processes
M	95.30.Cq	Elementary particle processes
S	95.30.Dr	Atomic processes and interactions
M	95.30.Dr	Atomic processes and interactions
S	95.30.Ft	Molecular and chemical processes and interactions
M	95.30.Ft	Molecular and chemical processes and interactions
	95.30.Gv	Radiation mechanisms; polarization
	95.30.Jx	Radiative transfer; scattering
S	95.30.Ky	Atomic and molecular data, spectra, and spectral parameters (opacities, rotation constants, line identification, oscillator strengths, gf values, transition probabilities, etc.)
M	95.30.Ky	Atomic and molecular data, spectra, and spectral parameters (opacities, rotation constants, line identification, oscillator strengths, gf values, transition probabilities, etc.)
	95.30.Lz	Hydrodynamics
	95.30.Qd	Magnetohydrodynamics and plasmas (see also 52.30.Cv and 52.72.+v in physics of plasmas)
	95.30.Sf	Relativity and gravitation (see also section 04 General relativity and gravitation; 98.80.Jk Mathematical and relativistic aspects of cosmology)
S	95.30.Tg	Thermodynamic processes, conduction, convection, equations of state
M	95.30.Tg	Thermodynamic processes, conduction, convection, equations of state
	95.30.Wi	Dust processes (condensation, evaporation, sputtering, mantle growth, etc.)
S	95.35.+d	Dark matter (stellar, interstellar, galactic, and cosmological)
M	95.35.+d	Dark matter (stellar, interstellar, galactic, and cosmological) (see also 95.30.Cq Elementary particle processes; for brown dwarfs, see 97.20.Vs; for galactic halos, see 98.35.Gi or 98.62.Gq; for models of the early Universe, see 98.80.Cq)
N	95.36.+x	Dark energy (see also 98.80.-k Cosmology)
	95.40.+s	Artificial Earth satellites (for lunar and planetary probes, see 95.55.Pe; see also 07.87.+v in instruments, apparatus, and components common to several branches of physics and astronomy)
	95.45.+i	Observatories and site testing
S	95.55.-n	Astronomical and space-research instrumentation
M	95.55.-n	Astronomical and space-research instrumentation (see also 94.80.+g Instrumentation for space plasma physics, ionosphere, and magnetosphere; 07.87.+v Spaceborne and space research instruments, apparatus, and components)
	95.55.Aq	Charge-coupled devices, image detectors, and IR detector arrays (see also 85.60.Gz Photodetectors)
	95.55.Br	Astrometric and interferometric instruments
	95.55.Cs	Ground-based ultraviolet, optical and infrared telescopes
	95.55.Ev	Solar instruments
	95.55.Fw	Space-based ultraviolet, optical, and infrared telescopes
	95.55.Jz	Radio telescopes and instrumentation; heterodyne receivers
	95.55.Ka	X- and gamma-ray telescopes and instrumentation
	95.55.Pe	Lunar, planetary, and deep-space probes
S	95.55.Qf	Photometric, polarimetric, and spectroscopic instrumentation
M	95.55.Qf	Photometric, polarimetric, and spectroscopic instrumentation
S	95.55.Rg	Photoconductors and bolometers
M	95.55.Rg	Photoconductors and bolometers
	95.55.Sh	Auxiliary and recording instruments; clocks and frequency standards
	95.55.Vj	Neutrino, muon, pion, and other elementary particle detectors; cosmic ray detectors (see also 29.40.-n Radiation detectors-in nuclear physics)
	95.55.Ym	Gravitational radiation detectors; mass spectrometers; and other instrumentation and techniques (see also 04.80.-y Experimental studies of gravity in general relativity and gravitation)
	95.75.-z	Observation and data reduction techniques; computer modeling and simulation
	95.75.De	Photography and photometry (including microlensing techniques)
	95.75.Fg	Spectroscopy and spectrophotometry
	95.75.Hi	Polarimetry
	95.75.Kk	Interferometry
	95.75.Mn	Image processing (including source extraction)
	95.75.Pq	Mathematical procedures and computer techniques
	95.75.Qr	Adaptive and segmented optics (see also 42.68.Wt Remote sensing; LIDAR and adaptive systems in atmospheric optics)
	95.75.Rs	Remote observing techniques
	95.75.Tv	Digitization techniques (see also 07.05.Pj Image processing in instruments)
	95.75.Wx	Time series analysis, time variability
	95.80.+p	Astronomical catalogs, atlases, sky surveys, databases, retrieval systems, archives, etc.
	95.85.-e	Astronomical observations (additional primary heading(s) must be chosen with these entries to represent the astronomical objects and/or properties studied)
	95.85.Bh	Radio, microwave (>1 mm)
	95.85.Fm	Submillimeter (300 mum-1 mm)
	95.85.Gn	Far infrared (10-300 mum)
	95.85.Hp	Infrared (3-10 mum)
	95.85.Jq	Near infrared (0.75-3 mum)
	95.85.Kr	Visible (390-750 nm)
	95.85.Ls	Near ultraviolet (300-390 nm)
	95.85.Mt	Ultraviolet (10-300 nm)
	95.85.Nv	X-ray
	95.85.Pw	gamma-ray
	95.85.Ry	Neutrino, muon, pion, and other elementary particles; cosmic rays
	95.85.Sz	Gravitational radiation, magnetic fields, and other observations
	95.90.+v	Historical astronomy and archaeoastronomy; and other topics in fundamental astronomy and astrophysics; instrumentation, techniques, and astronomical observations
S	96.	Solar System
M	96.	Solar system; planetology
S	96.10.+i	General, solar nebula, and cosmogony
M	96.10.+i	General; solar nebula; cosmogony
N	96.12.-a	Planetology of solid surface planets (see also 96.15.-g Planetology of fluid planets; 96.30.Bc Comparative planetology)
N	96.12.Bc	Origin and evolution
N	96.12.De	Orbital and rotational dynamics
N	96.12.Fe	Gravitational fields
N	96.12.Hg	Magnetic field and magnetism
N	96.12.Jt	Atmospheres
N	96.12.Kz	Surfaces
N	96.12.Ma	Composition
N	96.12.Pc	Interiors
N	96.12.Qr	Polar regions
N	96.12.St	Heat flow
N	96.12.Uv	Rings and dust
N	96.12.Wx	Interactions with particles and fields
N	96.12.Xy	Tectonics, volcanism
N	96.15.-g	Planetology of fluid planets (see also 96.12.-a Planetology of solid surface planets; 96.30.Bc Comparative planetology)
N	96.15.Bc	Origin and evolution
N	96.15.De	Orbital and rotational dynamics
N	96.15.Ef	Gravitational fields
N	96.15.Gh	Magnetic field and magnetism
N	96.15.Hy	Atmospheres
N	96.15.Kc	Composition
N	96.15.Lb	Surfaces
N	96.15.Nd	Interiors
N	96.15.Pf	Physical properties of materials
N	96.15.Qr	Impact phenomena
N	96.15.St	Tori and exospheres
N	96.15.Uv	Rings and dust
N	96.15.Vx	Interactions with particles and fields
N	96.15.Wx	Tidal forces
N	96.15.Xy	Polar regions
	96.20.-n	Moon
S	96.20.Br	Origin, formation, and age
M	96.20.Br	Origin and evolution
S	96.20.Dt	Features, landmarks, mineralogy, petrology, and atmosphere
M	96.20.Dt	Features, landmarks, mineralogy, and petrology
S	96.20.Jz	Gravitational field, selenodesy, magnetic fields
M	96.20.Jz	Gravitational field, selenodesy, and magnetic fields
S	96.20.Ka	Cratering
M	96.20.Ka	Impacts, cratering
N	96.25.-f	Planetology of comets and small bodies
N	96.25.Bd	Origin and evolution
N	96.25.De	Orbital and rotational dynamics
N	96.25.Fx	Atmospheres
N	96.25.Hs	Composition
N	96.25.Jz	Ionospheres
N	96.25.Ln	Magnetic fields and magnetism
N	96.25.Nc	Gravitational fields
N	96.25.Pq	Impact phenomena
N	96.25.Qr	Interactions with solar wind plasma and fields
N	96.25.St	Plasma and MHD instabilities
N	96.25.Tg	Radiation and spectra
N	96.25.Vt	Satellites
N	96.25.Xz	Volcanism
S	96.30.-t	Planets, their satellites and rings; asteroids
M	96.30.-t	Solar system objects
N	96.30.Bc	Comparative planetology (see also 96.12.-a Planetology of solid surface planets; 96.15.-g Planetology of fluid planets)
N	96.30.Cw	Comets (see also 96.25.-f Planetology of comets and small bodies)
	96.30.Dz	Mercury
	96.30.Ea	Venus
	96.30.Gc	Mars
N	96.30.Hf	Martian satellites
	96.30.Kf	Jupiter
N	96.30.L-	Jovian satellites
N	96.30.lb	Io
N	96.30.ld	Europa
N	96.30.lf	Ganymede
N	96.30.lh	Callisto
	96.30.Mh	Saturn
N	96.30.N-	Saturnian satellites
N	96.30.nd	Titan
	96.30.Pj	Uranus
N	96.30.Qk	Uranian satellites
	96.30.Rm	Neptune
	96.30.Sn	Pluto
N	96.30.Td	Neptunian satellites
N	96.30.Up	Plutonian satellites
N	96.30.Vb	Dust, extraterrestrial materials
	96.30.Wr	Planetary rings
N	96.30.Xa	Kuiper belt, trans-Neptunian objects
S	96.30.Ys	Asteroids (minor planets)
M	96.30.Ys	Asteroids, meteoroids
N	96.30.Za	Meteors, meteorites and tektites (see also 91.65.Sn Meteorite mineralogy and petrology; 94.20.Xa Meteor-trail physics; 91.67.gn—in geophysics appendix)
	... ... ...	Planetary, asteroid, cometary, and satellite characteristics and properties, see 96.12.-a, 96.15.-g, and 96.25.-f
	... ... ...	Cosmic rays, see 96.50.S-
D	96.35.-j	Planetary, asteroid, cometary, and satellite characteristics and properties (see also 97.82.-j for extrasolar planetary systems) (Use 96.12.-a)
D	96.35.Cp	Origin, formation, evolution, and ages (Use 96.12.Bc)
D	96.35.Er	Chemical composition (Use 96.12.Ma)
D	96.35.Fs	Mass, size; gravitational fields; rotation; orbits (Use 96.12.Fe)
D	96.35.Gt	Surface features, cratering, and topography (Use 96.12.Kz)
D	96.35.Hv	Neutral atmospheres (Use 96.12.Jt)
D	96.35.Kx	Ionospheres; magnetospheres (Use 96.12.Jt)
D	96.35.Mz	Interiors (Use 96.12.Pc)
D	96.35.Na	Volcanism and tectonics (Use 96.12.Xy)
D	96.35.Pb	Electric and magnetic fields (Use 96.12.Hg)
D	96.35.Se	Interplanetary comparisons (Use 96.30.Bc)
D	96.40.-z	Cosmic rays (for cosmic rays outside the Solar System, see 98.70.Sa; for cosmic-ray interactions, see 13.85.Tp in hadron-induced high- and super high-energy interactions) (Use 96.50.S-)
D	96.40.Cd	Interplanetary propagation and effects (Use 96.50.sh)
D	96.40.De	Composition, energy spectra, and interactions (Use 96.50.sb)
D	96.40.Fg	Energetic solar particles and photons (Use 96.50.Vg)
D	96.40.Kk	Solar modulation and geophysical effects (Use 96.50.S-)
D	96.40.Pq	Extensive air showers (Use 96.50.sd)
D	96.40.Tv	Neutrinos and muons (Use 96.50.S-)
D	96.40.Vw	Cosmic-ray effects in meteorites and terrestrial matter (Use 96.50.sf)
S	96.50.-e	Interplanetary space
M	96.50.-e	Interplanetary physics (see also 94.05.-a Space plasma physics)
S	96.50.Bh	Solar and interplanetary electric and magnetic fields (including solar wind fields)
M	96.50.Bh	Interplanetary magnetic fields
S	96.50.Ci	Solar wind plasma
M	96.50.Ci	Solar wind plasma; sources of solar wind
S	96.50.Dj	Interplanetary gas and dust (including gegenschein and zodiacal light)
M	96.50.Dj	Interplanetary dust and gas
S	96.50.Ek	Solar wind interactions with planets, satellites, and comets (for interactions with Earth, see 94.30.Va)
M	96.50.Ek	Heliopause and solar wind termination
S	96.50.Fm	Shock waves
M	96.50.Fm	Planetary bow shocks; interplanetary shocks
	... ... ...	Comets, see 96.30.Cw; 96.30C- in geophysics appendix
D	96.50.Gn	Comets (Use 96.30.Cw)
	96.50.Hp	Oort cloud
	... ... ...	Kuiper belt, see 96.30.Xa
	... ... ...	Meteors, meteoroids, and meteor streams, see 96.30.Za
	... ... ...	Meteorites, micrometeorites, and tektites, see 96.30.Za
D	96.50.Jq	Kuiper belt (Use 96.30.Xa)
D	96.50.Kr	Meteors, meteoroids, and meteor streams (Use 96.30.Za)
D	96.50.Mt	Meteorites, micrometeorites, and tektites (Use 96.30.Za)
	96.50.Pw	Particle acceleration
S	96.50.Qx	Stream-stream interactions
M	96.50.Qx	Corotating streams
S	96.50.Ry	Waves and discontinuities
M	96.50.Ry	Discontinuities
N	96.50.S-	Cosmic rays (see also 94.20.wq Solar radiation and cosmic ray effects)
N	96.50.sb	Composition, energy spectra and interactions
N	96.50.sd	Extensive air showers
N	96.50.sf	Interactions with terrestrial matter
N	96.50.sh	Interplanetary propagation and effects
N	96.50.Tf	MHD waves; plasma waves, turbulence
N	96.50.Uv	Ejecta, driver gases, and magnetic clouds
N	96.50.Vg	Energetic particles
N	96.50.Wx	Solar cycle variations
N	96.50.Xy	Heliosphere/ interstellar medium interactions
N	96.50.Ya	Pickup ions
N	96.50.Zc	Neutral particles
N	96.55.+z	Astrobiology and astrochemistry of the Solar system and interplanetary space (see also 91.62.Fc—in geophysics appendix)
	96.60.-j	Solar physics
S	96.60.Bn	Diameter, figure, rotation, mass
M	96.60.Bn	Diameter, rotation, and mass
S	96.60.Fs	Chemical composition
M	96.60.Fs	Composition
S	96.60.Hv	Electric and magnetic fields
M	96.60.Hv	Electric and magnetic fields, solar magnetism
N	96.60.Iv	Magnetic reconnection
S	96.60.Jw	Solar interior
M	96.60.Jw	Solar interior
S	96.60.Ly	Oscillations and waves; helioseismology
M	96.60.Ly	Helioseismology, pulsations, and shock waves
S	96.60.Mz	Photosphere, granulation
M	96.60.Mz	Photosphere
S	96.60.Na	Chromosphere and chromosphere-corona transition; spicules
M	96.60.Na	Chromosphere
N	96.60.P-	Corona
D	96.60.Pb	Corona; coronal loops, streamers, and holes (Use 96.60.P-)
N	96.60.pc	Coronal holes
N	96.60.pf	Coronal loops, streamers
N	96.60.ph	Coronal mass ejection
N	96.60.Q-	Solar activity (see also 92.70.Qr—in Global change)
D	96.60.Qc	Sunspots, faculae, plages (Use 96.60.qd)
N	96.60.qd	Sun spots, solar cycles
N	96.60.qe	Flares
N	96.60.qf	Prominence eruptions
D	96.60.Rd	Flares, bursts, and related phenomena (Use 96.60.qe)
D	96.60.Se	Prominences (Use 96.60.qf)
S	96.60.Tf	Solar electromagnetic radiation
M	96.60.Tf	Solar electromagnetic emission
N	96.60.Ub	Solar irradiance
S	96.60.Vg	Particle radiation, solar wind, and solar neutrinos
M	96.60.Vg	Particle emission, solar wind (see also 94.30.vf—in geophysics appendix)
D	96.60.Wh	Coronal mass ejection (Use 96.60.ph)
N	96.60.Xy	Transition region
	96.90.+c	Other topics on the Solar system and planetology (restricted to new topics in section 96)
	97.	Stars
	97.10.-q	Stellar characteristics and properties (see also 04.40.Dg Relativistic stars in general relativity and gravitation and section 26 Nuclear astrophysics)
	97.10.Bt	Star formation
	97.10.Cv	Stellar structure, interiors, evolution, nucleosynthesis, ages
	97.10.Ex	Stellar atmospheres (photospheres, chromospheres, coronae, magnetospheres); radiative transfer; opacity and line formation
	97.10.Fy	Circumstellar shells, clouds, and expanding envelopes; circumstellar masers (for interstellar masers, see 98.38.Er or 98.58.Ec)
	97.10.Gz	Accretion and accretion disks
	97.10.Jb	Stellar activity
	97.10.Kc	Stellar rotation
	97.10.Ld	Magnetic and electric fields; polarization of starlight
	97.10.Me	Mass loss and stellar winds
	97.10.Nf	Masses
	97.10.Pg	Radii
	97.10.Qh	Surface features (including starspots)
	97.10.Ri	Luminosities; magnitudes; effective temperatures, colors, and spectral classification
	97.10.Sj	Pulsations, oscillations, and stellar seismology
	97.10.Tk	Abundances, chemical composition
	97.10.Vm	Distances, parallaxes
	97.10.Wn	Proper motions and radial velocities (line-of-sight velocities); space motions (see also 95.10.Jk Astrometry and reference systems)
	97.10.Xq	Luminosity and mass functions
	97.10.Yp	Star counts, distribution, and statistics
	97.10.Zr	Hertzsprung-Russell, color-magnitude, and color-color diagrams
	97.20.-w	Normal stars (by class): general or individual
	97.20.Ec	Main-sequence: early-type stars (O and B)
	97.20.Ge	Main-sequence: intermediate-type stars (A and F)
	97.20.Jg	Main-sequence: late-type stars (G, K, and M)
	97.20.Li	Giant and subgiant stars
	97.20.Pm	Supergiant stars
	97.20.Rp	Faint blue stars (including blue stragglers), white dwarfs, degenerate stars, nuclei of planetary nebulae (for planetary nebulae, see 98.38.Ly or 98.58.Li)
	97.20.Tr	Population II stars (horizontal branch, metal poor, etc.)
	97.20.Vs	Low luminosity stars, subdwarfs, and brown dwarfs
	97.20.Wt	Population III stars
	97.21.+a	Pre-main sequence objects, young stellar objects (YSO's) and protostars (T Tauri stars, Orion population, Herbig-Haro objects, Bok globules, bipolar outflows, cometary nebulae, etc.) (see also 98.38.Fs and 98.58.Fd Jets, outflows and bipolar flows in the Milky Way and external galaxies respectively)
	97.30.-b	Variable and peculiar stars (including novae)
	97.30.Dg	Low-amplitude blue variables (alpha Cygni, beta Cephei, delta Scuti, delta Delphini, delta Canis Majoris, SX Phoenicius, etc.)
	97.30.Eh	Emission-line stars (Of, Be, Luminous Blue Variables, Wolf-Rayet, etc.)
	97.30.Fi	Chemically peculiar stars (Ap, Am, etc.)
	97.30.Gj	Cepheids (delta Cephei, W Virginis)
	97.30.Hk	Carbon stars, S stars, and related types (C, S, R, and N)
	97.30.Jm	Long-period variables (Miras) and semiregulars
	97.30.Kn	RR Lyrae stars; RV Tauri and PV Telescopii variables
	97.30.Nr	Flare stars (UV Ceti, RS Canum Venaticorum, FU Orionis, R Coronae Borealis variables, etc.)
	97.30.Qt	Novae, dwarf novae, recurrent novae, and other cataclysmic (eruptive) variables (see also 97.80.Gm, Jp Cataclysmic binaries and X-ray binaries)
	97.30.Sw	Unusual and peculiar variables
	97.60.-s	Late stages of stellar evolution (including black holes) (see also 04.40.Dg Relativistic stars in general relativity and gravitation)
S	97.60.Bw	Supernovae
M	97.60.Bw	Supernovae (see also 26.30.+k Nucleosynthesis in novae, supernovae, and other explosive stars; for nuclear physics aspects of supernovae evolution, see 26.50.+x)
	97.60.Gb	Pulsars
	97.60.Jd	Neutron stars (see also 26.60.+c Nuclear matter aspects of neutron stars in nuclear physics)
	97.60.Lf	Black holes (see also 04.70.-s Physics of black holes in general relativity and gravitation; for galactic black holes, see 98.35.Jk and 98.62.Js)
	97.80.-d	Binary and multiple stars
	97.80.Af	Astrometric and interferometric binaries
	97.80.Di	Visual binaries
	97.80.Fk	Spectroscopic binaries; close binaries
	97.80.Gm	Cataclysmic binaries (novae, dwarf novae, recurrent novae, and nova-like objects); symbiotic stars (see also 97.30.Qt Novae)
	97.80.Hn	Eclipsing binaries
	97.80.Jp	X-ray binaries (see also 98.70.Qy X-ray sources and 97.60.Gb Pulsars)
	97.80.Kq	Multiple stars
	97.82.-j	Extrasolar planetary systems
	97.82.Cp	Photometric and spectroscopic detection; coronographic detection; interferometric detection
	97.82.Fs	Substellar companions; planets
	97.82.Jw	Infrared excess; debris disks; protoplanetary disks; exo-zodiacal dust
	97.90.+j	Other topics on stars (restricted to new topics in section 97)
	98.	Stellar systems; interstellar medium; galactic and extragalactic objects and systems; the Universe
	98.10.+z	Stellar dynamics and kinematics
	98.20.-d	Stellar clusters and associations
	98.20.Af	Associations of stars (OB, T, R) in the Milky Way
	98.20.Bg	Associations of stars (OB, T, R) in external galaxies
	98.20.Di	Open clusters in the Milky Way
	98.20.Fk	Open clusters in external galaxies
	98.20.Gm	Globular clusters in the Milky Way
	98.20.Jp	Globular clusters in external galaxies
	98.35.-a	Characteristics and properties of the Milky Way galaxy
	98.35.Ac	Origin, formation, evolution, age, and star formation
	98.35.Bd	Chemical composition and chemical evolution
	98.35.Ce	Mass and mass distribution
	98.35.Df	Kinematics, dynamics, and rotation
	98.35.Eg	Electric and magnetic fields
	98.35.Gi	Galactic halo
	98.35.Hj	Spiral arms and galactic disk
S	98.35.Jk	Galactic center, bar, circumnuclear matter, and bulge (including black hole and distance measurements)
M	98.35.Jk	Galactic center, bar, circumnuclear matter, and bulge (including black hole and distance measurements)
	98.35.Ln	Stellar content and populations; morphology and overall structure
	98.35.Mp	Infall and accretion
	98.35.Nq	Galactic winds and fountains
	98.35.Pr	Solar neighborhood
	98.38.-j	Interstellar medium (ISM) and nebulae in Milky Way
	98.38.Am	Physical properties (abundances, electron density, magnetic fields, scintillation, scattering, kinematics, dynamics, turbulence, etc.)
	98.38.Bn	Atomic, molecular, and chemical, and grain processes
	98.38.Cp	Interstellar dust grains; diffuse emission; infrared cirrus
	98.38.Dq	Molecular clouds, H2 clouds, dense clouds, and dark clouds
	98.38.Er	Interstellar masers (for circumstellar masers, see 97.10.Fy)
	98.38.Fs	Jets, outflows, and bipolar flows (for pre-main sequence objects, see 97.21.+a)
	98.38.Gt	HI regions and 21-cm lines; diffuse, translucent, and high-velocity clouds
	98.38.Hv	HII regions; emission and reflection nebulae
	98.38.Jw	Infrared emission
	98.38.Kx	Intercloud medium (ICM); hot and highly ionized gas; bubbles
	98.38.Ly	Planetary nebulae (for nuclei of planetary nebulae, see also 97.20.Rp)
	98.38.Mz	Supernova remnants
	98.52.-b	Normal galaxies; extragalactic objects and systems (by type)
	98.52.Cf	Classification and classification systems
	98.52.Eh	Elliptical galaxies
	98.52.Lp	Lenticular (S0) galaxies
	98.52.Nr	Spiral galaxies
	98.52.Sw	Irregular and morphologically peculiar galaxies
	98.52.Wz	Dwarf galaxies (elliptical, irregular, and spheroidal)
	98.54.-h	Quasars; active or peculiar galaxies, objects, and systems
	98.54.Aj	Quasars (for quasar absorption and emission-line systems; Lyman forest, see 98.62.Ra)
	98.54.Cm	Active and peculiar galaxies and related systems (including BL Lacertae objects, blazars, Seyfert galaxies, Markarian galaxies, and active galactic nuclei)
	98.54.Ep	Starburst galaxies and infrared excess galaxies
	98.54.Gr	Radio galaxies
	98.54.Kt	Protogalaxies; primordial galaxies
	98.56.-p	Local group; Magellanic Clouds
	98.56.Ew	Elliptical galaxies
	98.56.Ne	Spiral galaxies (M31 and M33)
	98.56.Si	Magellanic Clouds and other irregular galaxies
	98.56.Tj	Magellanic stream
	98.56.Wm	Dwarf galaxies (elliptical, irregular, and spheroidal)
	98.58.-w	Interstellar medium (ISM) and nebulae in external galaxies