Water Vapor in the Boreal Summer TTL: Effects of Microphysics and Convective Injection

Processes in the boreal summer TTL are significantly different from boreal winter; overall upward motion is substantially weaker and the relationship of the temperature field to the distribution of convection is different. There remains substantial controversy on the relative roles of convection and slow ascent in driving the composition of the monsoon anticyclone.

This paper presents water vapor and cloud calculations from a trajectory-based microphysical model with a convective injection scheme based on geostationary satellite data. We calibrate the convective altitudes of the scheme with actual cloud altitudes from lidar/radar satellites, and examine the effects of that convection on the results of the microphysical model. The potential temperatures of convective cloud tops derived using this method are also validated by comparing with aircraft tracer measurements via trajectory methods. Sensitivity tests will examine the impact of extreme events (e.g. tropical cyclones and land-based deep systems), TTL heating rates, and sub grid scale waves on the water vapor distribution.