The TRMM satellite can also use its microwave sensors to measure ocean surface temperatures beneath a hurricane. Higher sea surface temperatures mean more evaporation of ocean water into the air. As that moisture condenses into clouds, it releases heat to the air that causes the air to rise. The rising air creates a low pressure area beneath it that pulls the surrounding air spiralling inward, perpetuating the hurricane. We tend to think of hurricanes as big heat engines.
Blues represent cooler water, greens and yellows are warmer water.
TMI is the first satellite microwave sensor capable of accurately measuring sea surface temperature through clouds. While the kind of rainfall and sea surface temperature data produced by TRMM holds great potential for improving hurricane forecasting, TRMM is not primarily a hurricane-monitoring satellite. Send us an e-mail and we'll publish your most interesting views on our comments page. Those published will be entered into a draw to win a book.