|Wind speed satellite measurements. Animation showing the sea surface becoming rougher during a storm, an ascent through the eye of a hurricane, and the measurement of the surface wind speed by a satellite. Sea surface roughness can be measured from space using microwave scatterometers, and used to gauge the wind speed. But in very intense tropical storms high winds flatten the waves. Microwave emissions from wind-generated foam then dominate the picture. The European Space Agency's SMOS (Soil Moisture and Ocean Salinity) satellite can detect these emissions, allowing hurricane-force wind speeds to be measured from space for the first time. SMOS builds up measurements as it orbits the Earth, but has incomplete coverage. Other satellites are used to fill the gaps, using temporal and spatial interpolation to 'morph' the data to a common time frame. Global wind speed maps for 2015 allow the major storms of that year's typhoon season to be tracked across the Pacific Ocean. For this clip without captions, see K008/6536.
|Science Photo Library