image: The Tropical Rainfall Measuring Mission Satellite known as TRMM has the ability to measure rainfall from space, and can also provide scientists with cloud heights, eyewall and lightning information. These images and captions of Hurricane Irene were provided by NASA hurricane scientist, Owen Kelley at NASA's Goddard Space Flight Center, Greenbelt, Md. In general, lightning in the inner core suggests the presence of strong updrafts and large ice particles. By implication, lightning suggests that convective cells are pumping a lot of latent heat energy into the tropical cyclone's central vortex, which is favorable for intensification. Hurricane eyewalls often are devoid of lightning, as is the case for Irene on 8/23. But cat-3 Irene (on 8/24) did have lightning flashes in the eyewall, and there were many flashes during Irene's tropical storm phase (on 8/21). Three times this week (week of August 21, 2011) , the radar on the TRMM satellite has observed the three-dimensional structure of the rainfall regions under the cloud-tops of Hurricane Irene. At the same time, TRMM also observed Irene with passive microwave, infrared, and lightning instruments. In this image, the passive microwave estimates of surface rainfall are for all three overflights. view more
Credit: NASA