9.6
Mesoscale circulations driven by subvisible cirrus near the tropical tropopause
Dale Durran, University of Wasington, Seattle, WA; and M. Ammerman
Subvisible cirrus clouds (SVC) occur frequently in the tropical tropopause layer. These clouds are almost completely transparent in the visible and still optically thin in the IR. It has been suggested that SVC may play an important role in the transport of water vapor into the stratosphere, and the radiative and cloud-microphysical properties of these clouds has received a great deal of attention.
Less attention has been paid to the mesoscale dynamics of SVC. In this presentation we will examine the influence of IR radiative heating on SVC with particular attention to whether such heating can allow the cloud to self loft and the influence of this heating on the environment surrounding the cloud. In contrast to the sole previous study of the mesocale dynamics of SVC, we find that the cloud can indeed self loft and thereby provide a potential avenue for the transport of water into the tropical stratosphere.
Session 9, Orographic, Coastal and Other Thermally Driven Mesoscale Circulation Systems
Wednesday, 8 August 2007, 10:30 AM-12:00 PM, Waterville Room
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