Research and Application News
NASA's GPM satellite examines violent thunderstorms
05 February 2016
Severe weather moved through the southern U.S. on 2 and 3 February, and NASA's Global Precipitation Measurement or GPM core satellite examined the violent thunderstorms.
On 3 February 2016 at 1851 UTC (1:51 p.m. EST) the GPM core observatory satellite flew over a line of storms extending from the Gulf coast of Florida through New York state. Tornadoes were spotted in Georgia and South Carolina within this area of violent weather. GPM's Microwave Imager (GMI) and Dual-frequency Precipitation Radar (DPR) instruments measured the precipitation within the area. As the satellite passed above, GPM's radar (DPR) found that one powerful thunderstorm in North Carolina was dropping rain at the extreme rate of 112.96 mm (4.4 inches) per hour.
At NASA's Goddard Space Flight Center in Greenbelt, Maryland, data collected by GPM's Radar (DPR Ku band) were used to create a 3-D cross-section through the precipitation within the line of violent thunderstorms.
Strong radar reflectivity values greater than 45dBZ (or decibel relative to Z) indicative of moderate to heavy rain, were returned to the GPM satellite from a few intense thundershowers. The dBz is a technical unit used in weather radar. The radar reflectivity (Z) of a cloud is dependent on the number and size of reflectors (like raindrops, snowflakes, hail or graupel). So, the higher the dBZ, the heavier the precipitation. The 45dBZ reading is equivalent to rain falling at 23.7 mm per hour (0.92 inches per hour).
Image credit: NASA/JAXA/SSAI, Hal Pierce - Global Precipitation Measurement (GPM) satellite examines violent thunderstorms