Microwave sensors can collect data through cloud cover and darkness, revealing details that visual and infrared sensors cannot. Satellite microwave sensors are among the most valuable sources of data for monitoring and tracking typhoons and hurricanes.
The Special Sensor Microwave Imager on DMSP F-8 through F-15 detects sea ice, snow, and surface winds over oceans. It provides ship captains with information needed to plan to the most efficient routes and avoid heavy seas, high winds, and ice—all of which can affect schedules, increase fuel consumption, and damage cargo. Before satellite coverage was available over the oceans, ship captains used less reliable weather data from buoys or other ships.
The Special Sensor Microwave Imager is proving to be a valuable tool in detecting climate change because it provides a long, continuous record from which to construct sea ice climate histories. For example, arctic sea ice retreats to a minimum each year in September, when it covers an area reaching about to the magenta line in the figures below. Data from the Special Sensor Microwave Imager indicate that ice coverage has fallen far short of its median September position in recent years. In fact, in 2002, September ice coverage was at a record low (left image) with extreme ice minimums observed again in 2003 and 2004. Three extreme minimum years in a row is unprecedented in the satellite record.
