Monday, 29 April 2002: 2:30 PM
Composite analyses of local influences of tropical convection
We present a composite observational analysis of the velocity and
thermal fields associated with the growth and decay of a typical
maritime deep convective event over the tropical western Pacific.
This composite was constructed using a large database of radiosondes
combined with hourly satellite data. The results show typical heating
and moistening features throughout most of the troposphere, but also
show interesting behavior near and above the tropopause. Features in
the lower stratosphere suggest slowly upward-propogating, free Kelvin
waves. Near the tropopause there appears to be diabatic cooling not
associated with these waves, suggesting either a downward turbulent
heat flux or radiative cloud-top cooling. Changes in the position of
the tropopause also suggest diabatic cooling at tropopause level
caused by convection. These results are discussed in light of
questions concerning the maintenance of the tropical tropopause.
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