| Summary: | The Tropical Pacific Warm Pool International Cloud Experiment (TWP-ICE)
took place in Darwin, Australia in early 2006. C-band radar data from this experiment
were used to characterize tropical anvil areal coverage, height, and thickness during the
month-long field campaign. The morphology, evolution, and longevity of the anvil were
analyzed as well as the relationship of the anvil to the rest of the precipitating system. In
addition, idealized in-cloud radiative heating profiles were created based on the anvil
observations.
The anvil was separated into mixed (i.e., echo base below 6 km) and ice only
categories. The experiment areal average coverage for both types of anvil was between
4-5% of the radar grid. Ice anvil thickness averaged 2.8 km and mixed anvil thickness
averaged 6.7 km. No consistent diurnal signal was seen in the anvil, implying that the
life cycle of the parent convection was of first order importance in determining the anvil
height, thickness, and area. Areal peaks show that mixed anvil typically formed out of
the stratiform region. Peak production in ice anvil usually followed the mixed anvil peak
by 1-3 hr. Anvil typically lasted 4-10 hr after the initial convective rain area peak. The
TWP-ICE experienced three distinct regimes: the active monsoon, dry monsoon, and break periods. During the entire experiment (except the active monsoon period) there
was a strong negative correlation between ice anvil thickness and ice anvil height, a
strong positive correlation between ice anvil area and thickness, and a greater variance in
ice anvil bottom than ice anvil top. Anvil produced during the active regime had the
most dramatic in-cloud radiative response with a maximum cooling of 0.45ð K day-1 at
12 km, a maximum heating of 3ð K day-1 at 9 km, and a secondary maximum heating of
1.2ð K day-1 at 5 km.
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