65th IHC Booklet/Program (pdf - 4.9MB) - Office of the Federal ...

Climatology of Hot Towers in Tropical Cyclone's Inner Cores and Rainbands Based on 12-
year TRMM Data
Cheng Tao and Haiyan Jiang
(ctao003@fiu.edu)
Department of Earth & Environment, Florida International University
Recent studies have shown that hot towers may be an indicator of tropical cyclone (TC)
genesis and intensification. Using a 12-year (December 1997 - December 2009) Tropical
Rainfall Measuring Mission (TRMM) tropical cyclone precipitation feature (TCPF) database, hot
towers in TCs are identified by using the TRMM PR observed maximum 20 dBZ echo height
reaching four different reference heights, i.e., 14 km, NCEP reanalysis derived tropopause
height, Level of Neutral Buoyancy calculated using NCEP sounding and surface equivalent
potential temperatureθ e , Level of Neutral Buoyancy calculated usingθ e at 925 and 1000 mb,
whichever is greater. The common properties of these extreme convective systems are examined
in terms of geographical locations, different TC intensities, and different TC regions, i.e., the
inner core (IC) region, the inner rainband region (IB), and the outer rainband region (OB). It is
found that 13.2% of TC precipitation features reach 14 km, and 2.6% of them may even
penetrate 16 km. Hot towers in TCs are more frequent in the Western North Pacific basin than
any other TC-prone basins. The percentage of precipitation features with one or more hot towers
is greater in the IC region than in the IB and OB regions by a factor of 10-20, depending on
which reference height is used. It is also found that hot towers in the IC region have a higher
mean maximum height of 20 and 40 dBZ echo, stronger ice scattering signature than in
rainbands regions, no matter which reference height is used. The percentage of features with hot
towers increases as TC intensity increases. The mean maximum height of 40 dBZ echo is higher
in hurricanes than in tropical storms and tropical depressions.
Poster Session – Page 26