BACKGROUND: The CloudSat Education Network (CEN) is a network of about 100 schools and communities around the world that have signed up to help collect ground data for the CloudSat mission. The purpose is twofold: to develop an interest in earth science among students of all ages, while at the same time collecting ground-based data around the world to test the accuracy of the radar instrument. Currently, schools in Africa, Europe, Southeast Asia, Oceania and the United States are participating.
WHAT IS CLOUDSAT: CloudSat is a NASA Earth System Science Pathfinder mission that uses Cloud Profiling Radar to study the insides to clouds, one of the least understood elements of the water cycle, in hopes of improving weather forecasting and climate models. Until now, there has been no practical way to measure the vertical structure of clouds over large areas. CloudSat scientists will compare student-generated ground-based data to the satellite's radar data to test the accuracy of the radar instrument.
ABOUT THE WATER CYCLE: The water cycle describes how water circulates from the land to the sky and back. The sun's heat causes water to evaporate into the air, and the vapor eventually condenses to form tiny droplets in clouds. When those clouds meet cool air over land, rain, sleep or snow results, returning the water to the land (or sea). The clouds that produce heavy thunderstorms in the winter are a form of cumulus clouds called cumulonimbus clouds. They form as moisture evaporates from the earth into the atmosphere, where the droplets congregate and jostle against each other. The air cools off rapidly with altitude. Sometimes a cold front – the boundary between where the cold air from one thunderstorm meets the air outside the storm for example – will force the moist air upward into the colder air. This moist air cools off and the water vapor "condenses" into liquid drops, forming clouds. The process continues: more and more water vapor turns into liquid, and the moist air warms up even more and rises higher and higher. A thunderstorm results.
TYPES OF CLOUDS: Most clouds are a combination or variation of three basic types. Stratus clouds are horizontal layered clouds that stretch out across the sky like a blanket, They often form at the boundary where a layer of warm moist air passes over a layer of cool air, causing the warm air to cool. If the warm air cools below the dew point, the excess water vapor condenses to form the blanket-like layer of stratus clouds. Cumulus clouds are puffy and look like giant cotton balls. The usually form when warm moist air is forced upward, cooling as it rises. Again, if it cools before the dew point, condensation will occur.
The American Geophysical Union and the American Meteorological Society contributed to the information contained in the TV portion of this report.