Watching the Weather

E-mail Melanie Martella

I don't know about you, but we residents of New Hampshire have had a very stormy spring and summer so far. Between the torrential rains and the frequent violent thunderstorms, it's been anything but dull. Luckily for me and my newfound awareness of extreme weather, there are some very interesting research projects underway to predict droughts, spot floods, and understand the nature of thunderstorms.

Longer-Range Forecasting
The European Space Agency (ESA), for example, has been using its Envisat satellite to track water in the Africa subcontinent and is releasing soil moisture maps based on its satellite data. (Read "ESA space sensor boosts extreme weather forecasting" for more background.) Knowing the soil moisture content of the land not only helps with agricultural planning, but it also helps with weather forecasting-in particular, by providing an early warning that conditions are ripe for flash flooding and the concomitant soil erosion. As Geoff Pegram, a researcher from the University of KwaZulu-Natal, says in the article, "Predicting when and where floods are likely to happen is becoming more and more important. Although we cannot prevent floods, we can anticipate them and hopefully get people out of the way."

The Chinese have also used data from the satellite to help them predict heavy rainfalls (and the resultant flooding).

By using satellite-based sensors rather than relying on scattered ground-based point measurements, the researchers acquire a much richer picture of what's going on, including obtaining data for remote or otherwise inaccessible areas. It's also faster. The combination of a more extensive data set and the ability to acquire data on a daily or weekly basis allows the researchers to track how the water is moving through the soil and aids in their modeling endeavors.

NASA, meanwhile, is preparing to do some thunderstorm research with its Tropical Composition, Cloud and Climate Coupling (TC4) project. Using satellites, heavily instrumented planes, weather radar, and meteorological balloons, researchers will gather data on what happens during thunderstorms ("Flying into a Thunderstorm"). The new twist on this project is the Real Time Mission Monitor (RTMM) that takes all the data from the instruments and satellites and aggregates it into a big picture view of what's happening. Researchers on the plane and on the ground can see this live data rather than having to wait to get back to the ground to analyze their results.

Closer to Home
Here in the wilds of New Hampshire, I have the National Weather Service's excellent Web site to keep me apprised of what's happening, weather-wise, in my own back yard. In particular (should you be worried about flooding), click on the Water tab above the map on the home page. See all those colored squares scattered across the map of the U.S.? Those are the readings from the various water gauges the NOAA maintains across the country, color-coded to denote the presence or absence of flooding. Click on any of the colored squares and you can access the readings from those gauges, seeing how the water level changes over time, where flood stage is, and whether the water's going up or coming down.