Astrid Kerkweg

Impact of Different Physical Parameterizations on the Global Modeling of Desert Dust – Importance of the Initialization Fields

In this work we use the atmospheric chemistry general circulation model EMAC (ECHAM5/MESSy2 Atmospheric Chemistry) with new physical parameterizations of desert dust emissions. We assess the impact of the different physical parameterization schemes, highlight the importance of several initialization fields, identify the key-input parameters and explore the benefits and/or disadvantages of using a-priori sources of atmospheric dust particles. This presentation will discuss primarily the processes that lead to dust emissions and explore the difficulties that arise from a global parameterization applied to areas with different and heterogeneous soils (e.g. North African versus Asian deserts). The performed case studies and sensitivity tests include comparisons with in-situ measurements of dust concentrations and satellite retrievals of aerosol optical depth. The conclusions from this work include recommendations on selecting the input fields depending on the application, in order to improve the modelling of dust globally.