Most of the worlds winds blow over the oceans, unseen and undetected--until now. Last September, the Japanese government launched the Advanced Earth Observing Satellite, which included among its instruments the NASA Scatterometer, or NSCAT.

This ingenious device uses radar to measure the choppiness of the ocean surface, and thereby to infer the speed and direction of the ocean winds (a technique known as scatterometry). The first raw images of NSCAT data, shown here, covering the period from September 20 to 22, 1996, offer an early look at the instrument's capabilities.

This information will improve weather forecasting and storm warnings, and will aid scientists in their studies of longer-term climatic variations. And, as these images show, the fine resolution of the NSCAT data will improve the monitoring of typhoons and other kinds of severe storms. In addition to sending back global maps of atmospheric circulation, including regions of ocean that were not adequately monitored in the past, NSCAT tracked two active typhoons off the coast of Japan.

The NSCAT data can also be superimposed on other earth-sensing images to provide more valuable data for meteorologists.

Credit: All images NASA-JPL