The Evolution of TTL Cirrus Microphysics and Relative Humidity Downstream of Deep Convection

Ice crystals detrained from deep convection have important impacts on the Earth's climate, both through generation of extensive anvil cirrus and regulation of the water vapor concentration in the upper troposphere. Recent observations of tropical tropopause layer (TTL) anvil cirrus ice crystal habits and size distributions are combined with growth-sedimentation calculations to assess the impacts of vapor deposition growth, sublimation, and sedimentation on anvil ice crystal lifetimes. The idealized simulations are used to evaluate the influences of heating/cooling rates, initial ice size distribution, and ice water content on the evolution of the anvil cirrus and the impacts on the TTL water vapor concentration.