Discovering 'hot towers'

Sep 20, 2012 by Adam Voiland
A satellite-radar view of Hurricane Isaac’s hot towers acquired on August 28, 2012. Data from the TRMM satellite provided by the Precipitation Measurement Missions science team at NASA and by JAXA.

Two hours before Hurricane Isaac made landfall, a satellite orbiting hundreds of miles above the storm used a radar instrument to map the storm's inner structure. The instrument on the Tropical Rainfall Measuring Mission (TRMM) observed two extremely tall complexes of rain clouds called hot towers in the eyewall, a sign that Isaac was trying to strengthen. The towering clouds were so high that they punched through the troposphere (the lowest layer of the atmosphere where most weather occurs) and sent air loaded with ice crystals rushing into the stratosphere, a higher layer that normally contains very little moisture.

Interestingly, the "hot" in the name comes not from the temperature of the air that hot towers loft high into the atmosphere, but because of the latent heat the release. "The latent heat is an important ingredient in fueling the updrafts that allow the towers to rise to such icy heights, so 'in honor' of the role that latent heat plays, the towers are called hot towers," explained Owen Kelley, a research scientist based at NASA's Goddard Space Flight Center.

Early radar instruments first confirmed the existence of hot towers in the 1950s, but such instruments (and those that followed in subsequent decades) did not measure their vertical structure precisely and could not track and catalog the features in a uniform way. That's no longer a problem. Since launched in 1997, the satellite has been monitoring hot towers over land and open ocean throughout the tropics in a consistent fashion. And when the follow-on mission to TRMM (the Global Precipitation Mission) launches in 2014, it will continue to expand TRMM's catalog of radar-observed hot towers further north and south to the edge of Arctic and Antarctic circles. "Before TRMM, we didn't have enough of a sample size to study where, when, and why hot towers form and how hot towers relate to larger systems like ," noted Kelley.

Read this Earth Observatory feature to learn more about how the late Joanne Simpson pioneered the study of hot towers. The video below, produced by NASA Goddard's Scientific Visualization Studio, offers a dramatic view of how hot towers work. There's also a great deal more information about TRMM on NASA's Precipitation Measurement Missions website that's well worth checking out.

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cantdrive85
1 / 5 (1) Sep 20, 2012
These "hot towers" are the signature of the electrical currents flowing through the storms. It is why there is latent heat in the clouds, the convection of the negatively (mostly) charged particles flowing out of the surface of the Earth (from the core) and attracts the warm humid air and pulls it into the atmosphere, eventually to the ionosphere and to the solar circuit. The Heavy rainfall beneath these hot towers is the signature of the electric currents flowing into the Earth, originating at the Sun, as the mostly positive particles flow into the Earth it pulls the electric dipole water molecules from the clouds with it. It is the electric current that is responsible for the evaporation, convection, updrafts, downdrafts, lightning, rain, tornadoes, the shapes of cyclones, low pressure, high pressure, and every other aspect of the weather and climate. It is the electric force that dictates the Universe.