NASA, NOAA seek the origins of hurricanes

The federal government is sending researchers to Costa Rica on a tropical storm hunting expedition.

During the month-long mission that starts this week, researchers will attempt to determine why some oceanic thunderstorms become tropical cyclones while others do not. They also hope to find the best combinations of satellites and other technologies for predicting tropical storms and hurricanes.

Although scientists have tracked mature hurricanes, they know little about the variables that trigger the storms.

“We want to understand how these conditions should be at a given moment,” said Dr. Ramesh Kakar, Weather Focus Area leader at NASA's Science Mission Directorate. “We want to have all these satellites observing at the same time, so we can figure out what was the temperature, velocity, precipitation…that generated a storm in one case but not in the other case.”

Researchers from NASA, the National Oceanic and Atmospheric Administration and the Costa Rican Centro Nacional de Alta Tecnologia (CENAT) will examine satellite data and information from other airborne remote sensors to determine which meteorological factors, such as temperature, moisture and velocity. This study on the birth of hurricanes could improve forecasts and reduce weather-related fatalities.

Two types of satellites will assist researchers – one in a fixed position based on the Earth’s daily rotation and others that circle the globe in about 90 minutes. Using a handful of satellites, scientists will study many variables, including sea surface temperature, wind velocity and precipitation.

The stationary satellite, NOAA’s GOES-9 – the Geostationary Operational Environmental Satellite — performs constant surveillance over Costa Rica for atmospheric instigators.

The other satellites revolve around the Earth, only periodically focusing on Costa Rica. One of those satellites, NASA’s Tropical Rainfall Measuring Mission, contains a weather radar instrument.

“The radar can see through the clouds and provide a CAT scan of the raining clouds,” Kakar said.

NASA and NOAA researchers will work out of a data center at the Juan Santa Maria Airport in San Jose, Costa Rica, an ideal region for watching tropical weather. The two will work closely because, traditionally, NASA performs the research and development necessary for tools used by the National Weather Service, part of NOAA.