Weather--day-to-day temperature and rainfall--plays an important role in human activities. Weather controls crop growth. It can impact transportation infrastructure and destroy homes and other structures. Accurate weather predictions can help decision makers save lives and property.
NASA develops new technologies that offer unique insight into weather and the processes that generate it. NASA scientists study weather processes to gain a more complete understanding of the Earth system. Advanced technology and greater scientific understanding of weather processes together improve weather forecasts made by operational agencies like the NOAA National Weather Service.
Terra and Weather
Terra data contribute to understanding and predicting weather phenomena. MODIS and MISR provide observations of water vapor, winds and cloud movement that are used to track motion in the atmosphere (atmospheric motion vectors) and improve weather forecasts.
MODIS provides the only high-resolution satellite measurement of water vapor, which can be used with MODIS infrared measurements to observe winds in polar regions. Since Terra is in a polar orbit, MODIS collects observations over the poles every 100 minutes. By tracking how water vapor and clouds move between orbits, scientists can determine wind speed and direction. Such measurements increase the accuracy of numerical weather models used to make 10-day forecasts.
MISR's multi-angle stereo view can be used to track cloud motion and deduce wind speed and direction. In particular, MISR measurements provide insight into how wind speeds vary inside hurricanes of different sizes.