ABSTRACT - DRUM - University of Maryland

is estimated from visible and near-infrared channels of the Visible and Infrared
Scanner (VIRS) onboard the Tropical Rainfall Measuring Mission (TRMM) satellite,
and the height of the cloud is estimated through simple geometry.
762 cases from 4 months are analyzed. The results show a cloud can overshoot
several kilometers above its anvil, which usually forms at or slightly above the level of
neutral buoyancy. I also performed a calculation to estimate the lapse rate in the cloud:
approximately 4 K/km.
This result clearly shows that the measured lapse rate of these clouds is
significantly below the adiabatic lapse rate. Considering an undiluted overshooting
cloud follows the adiabatic process, this result implies a significant amount of diabatic
processes occur. I suggest that mixing between these clouds and the near-tropopause
environment could be an explanation for the diabatic warming in the overshooting
clouds. As a result, these clouds will likely settle at a final altitude above the
convections' initial level of neutral buoyancy. If this mixing occurs, overshooting
clouds can play an important role in the transport of tropospheric air deep into the TTL.
Total heights of overshooting deep convective clouds were also estimated based
on the overshooting height estimated by the shadow method and the anvil height
estimated from the moist adiabat model. In spite of possible errors in this estimation, it
is obvious that there exist overshooting clouds reaching throughout the TTL.
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