As Tropical Storm Alex moved through the Gulf of Mexico on June 5, 2022, the Tropical Rainfall Measuring Mission (TRMM) satellite provided forecasters with rainfall data. TRMM was a joint mission between NASA and the Japanese space agency JAXA that operated from 1997 to 2015.
TRMM's Microwave Imager (TMI) and the Precipitation Radar (PR) provided important information about the structure and intensity of Alex's rainfall. The TMI measures microwave radiation emitted by Earth's surface, which can be used to estimate rainfall rates. The PR sends out pulses of microwave energy and measures the amount of time it takes for the pulses to return to the satellite, which can be used to estimate rainfall rates and the size of raindrops.
The TRMM data showed that Alex had areas of heavy rainfall, with rainfall rates exceeding 1 inch per hour (25 millimeters per hour). These areas of heavy rainfall were located near the center of the storm and along the leading edge of the storm's outflow.
The TRMM data also showed that Alex had a well-defined eye, which is a sign of a strengthening storm. The eye of Alex was about 10 miles (16 kilometers) in diameter and was located near the center of the storm.
The TRMM data were used by forecasters to help track Alex and predict its future movement and intensity. The data were also used to issue warnings for heavy rain and flooding.
About TRMM
The Tropical Rainfall Measuring Mission (TRMM) satellite was a joint mission between NASA and the Japanese space agency JAXA. TRMM was launched in 1997 and operated until 2015.
TRMM was equipped with a variety of instruments, including the Microwave Imager (TMI), the Precipitation Radar (PR), and the Lightning Imaging Sensor (LIS). The TMI measured microwave radiation emitted by Earth's surface, which can be used to estimate rainfall rates. The PR sent out pulses of microwave energy and measured the amount of time it took for the pulses to return to the satellite, which can be used to estimate rainfall rates and the size of raindrops. The LIS detected lightning strikes, which can be used to track the location of thunderstorms.
TRMM data were used by scientists to study rainfall in the tropics and subtropics. TRMM data were also used by forecasters to track and predict tropical cyclones and other severe weather events.
