Distinguishing Developing Versus Non-Developing African Easterly Waves Using Adaptive Observational Strategies

Abstract

The impacts of dust loaded, Saharan Air Layer (SAL) during the life cycle of African Easterly Waves (AEWs) is a many-faceted scientific problem. It entails possible radiative effects of dust aerosols, impacts of dust on cloud physics, and the cloud nuclei of condensation, advective effects, that is, intrusions of dry dusty air versus humid air into the interior of storms. This paper addresses several such AEWs of the eastern Atlantic Ocean, where we have made use of special aircraft reconnaissance data sets that include wind and humidity profiles in the vertical. Using what are called adaptive observational strategies within a mesoscale model, we show the impacts of adding such observations in the analysis and in short-range forecasts of several AEWs. We do not have the direct and indirect effects of aerosols, but we do include the advective component. Our results show that the inclusion of humidity profiling distinguishes between developing versus nondeveloping AEWs from the use of these additional data sets via the adaptive observational strategies.

Keywords:

• African Easterly Waves
• Saharan Air Layer
• adaptive observational strategy

Acknowledgement

This study is being supported by NASA Grant ATM-021289. Thanks to Dr. Robert Ross for his critical review of the manuscript.