File:Kaemi 2006-07-21 - 2006-07-25 TRMM.jpg

English: Following a path similar to recent Tropical Storm Bilis, which triggered extensive inland flooding and landslides and has been blamed for more than 600 deaths in China, Typhoon Kaemi passed over Taiwan before striking the southeast coast of China. Kaemi means “ant” in Korean. The storm started out as a tropical depression on July 18, 2006, several hundred miles south-southeast of Guam, tracked generally to the northwest, and entered the Philippine Sea as a weak tropical storm on July 19. Over the next two days, Kaemi intensified into a Category 2 typhoon in the central Philippine Sea, with sustained winds estimated at 167 kilometers per hour (104 miles per hour or 90 knots) by the Joint Typhoon Warning Center.

While the typhoon was at Category 2 status on July 21, the Tropical Rainfall Measuring Mission satellite (TRMM) flew over the storm. At the time, Kaemi was over the central Philippine Sea. These images show the horizontal distribution of rain intensity within the storm and provide important clues about Kaemi’s structure. In the top image, taken on July 21, TRMM reveals that Kaemi had a well-defined closed eye (center circular region) indicative of the kind of well-developed circulation that is commonly associated with a mature tropical cyclone. The image also shows that the rain field is very asymmetrical, with the bulk of the rain, including essentially all of the intense rain (shown by the darker reds), occurring in the southern half of storm.

After the top image was taken on July 21, Kaemi continued to track northwest. Although the storm’s center passed well to the north of the main island of Luzon in the northern Philippines, it did bring significant rains to the island. As Kaemi exited the Philippine Sea, it took a direct path over southern Taiwan, crossing over the island on the evening of July 24. By the time it struck, Kaemi had weakened to a Category 1 system.

On July 25, Kaemi passed over the narrow Taiwan Straight between Taiwan and China before making landfall that afternoon (local time) near Jinjiang in Fujian Province on China’s southeast coast. TRMM captured the lower image at 3:40 p.m. local time (7:40 UTC), just as Kaemi was making landfall on the coast of China. In this image, the center is poorly defined, with no closed eye visible. By this time, Kaemi had weakened to a tropical storm, with sustained winds estimated at just 93 km/hr (58 mph or 90 knots). There was, however, a broad area of light (blue) to moderate (green) rain wrapped around the northern and eastern side of the storm over mainland China. This rain eventually triggered flooding and mudslides in the region.

Launched in November of 1997, TRMM was designed to measure rainfall over the global Tropics using a suite of active and passive sensors, including the world’s first space-borne precipitation radar. TRMM has also proven to be extremely valuable for monitoring tropical cyclones, especially over remote parts of the open ocean. In these images, rain rates in the center swath are from the TRMM Precipitation Radar, while those in the outer swath are from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner.

TRMM is a joint mission between NASA and the Japanese space agency, JAXA.