Sensors in space to map Earth's water cycle

May 2007

PROBLEM

Soil moisture and freeze/thaw measurements are essential to the accuracy of weather forecasts and predictions of global carbon cycle and climate. Yet scientists have no operational network for gathering this data as they do for rainfall, atmospheric winds, humidity and temperature. As a result, weather forecasts are often inaccurate and climate projections uncertain, particularly in the prediction of precipitation and evaporation. In fact, the degree of uncertainty is so great that global warming projections don’t even agree on the sign of regional water