NASA 3-D Map Shows Flooding Rains of Typhoon Ketsana

By Nancy Atkinson - October 1, 2009 at 3:20 PM UTC | Planetary Science
Kensana-rainfall-map.jpg

[/caption] Data from the Tropical Rainfall Measuring Mission or TRMM satellite has been used to create a 3-D map of rainfall over the Phillipines from September 21-28, 2008. Armed with both a passive microwave sensor and a space-borne precipitation radar, TRMM has been measuring the amount of rainfall created by the tropical cyclone, Typhoon Ketsana (known in the Phillippines as "Ondoy"). A record 13.43 inches of rain fell in Manila in six hours between 8 a.m. and 2 p.m. local time, which is equivalent to about a month's worth of rain for the area. In just 24 hours, Ketsana dropped 17.9 inches (455 mm) of rain in Manila in just 24 hours on Saturday, September 26.

The TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA) at the NASA Goddard Space Flight Center, Greenbelt, Md. is used to monitor rainfall over the global Tropics. TMPA rainfall totals for the 7-day period 21 to 28 September 2009 for the northern Philippines and the surrounding region showed that the highest rainfall totals occurred south of the storm's track in an east-west band over central Luzon that includes Manila. Amounts in this region are on the order of 375 mm (~15 inches) to over 475 mm (~19 inches). The highest recorded amount from the TMPA near Manila was 585.5 mm (almost 24 inches).

Ketsana maintained minimal tropical storm intensity as it crossed central Luzon on the afternoon of September 26 (local time). The main deluge in the Manila area, located on the western side of Luzon, began around 8:00 a.m. local time even though the center of Ketsana had yet to make landfall on the eastern side of the island.

Click here

to watch an animation of the TRMM satellite data.

The enhanced rainfall over on the Manila-side of the island as the storm approached was because of an interaction between Ketsana's circulation and the seasonal southwest monsoon.

On-the-ground photos of the devastation Ketsana's rains caused can been seen at the

Boston Globe's Big Picture.

More info about

TRMM.

Source:

NASA

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com