8.1 The Importance of Aerosol to Deep Convective Cloud Morphology

Wednesday, 9 July 2014: 10:30 AM
Essex Center/South (Westin Copley Place)
Matthew R. Igel, Colorado State University, Fort Collins, CO; and S. C. van den Heever

This study utilizes new additions to a recently developed database of tropical, oceanic deep convection observed from CloudSat. These new additions include information about the local environmental characteristics in which each convective cloud is embedded. They are used to detail the sensitivity of cloud sizes and shapes to the local environment. A measure of aerosol concentration, large-scale vertical velocity, sea surface temperature, vertical shear of horizontal wind, and convective available potential energy are included in the database. First, the dependencies of deep convective morphology to aerosol concentration are examined. Higher aerosol amounts are seen to correlate to clouds that are taller, wider, and higher in both total ice water content and in average ice water path. These results indicate an aerosol invigoration-type response in deep convective clouds in the tropics in which stronger updrafts yield taller clouds and decreased warm rain efficiency results in more anvil ice. The importance of aerosol relative to the other environmental characteristics for convective cloud properties is also assessed. It is shown that aerosol is one of the leading environmental variables to which oceanic deep convection is sensitive. For many morphological aspects of convection, sea surface temperature, and large-scale vertical velocity join aerosol as the three leading predictors, which implies process level dependencies on these quantities. While particular convective properties do appear sensitive to convective available potential energy and vertical wind shear, oceanic deep clouds lack a broad sensitivity to either quantity.
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