On the radiative forcing and precipitation response to dust emission in CMIP6: Potential influence of dust size and concentration

Mineral dust is the most abundant aerosol type by mass in the atmosphere, with substantial impacts on the global energy budget. Dust can directly absorb and scatter solar radiation, warming the atmospheric column and reducing the amount of radiation reaching the Earth’s surface or leaving through the top of the atmosphere. In addition, the amount and distribution of dust particles also have implications for the distribution of clouds and precipitation. Despite its importance, most climate models, including those participating in the Coupled Model Intercomparison Project (CMIP) phase 6, find it difficult to accurately simulate the amount and distribution of dust in the atmosphere. In addition, most of these models also use different particle size representations with substantial impacts on dust interactions with radiation, clouds, and precipitation. Here, we examine the dust radiative forcing, including its precipitation response in CMIP6, leveraging the radiative kernel method. We will show substantial diversity in the estimates of dust radiative forcing and precipitation among the CMIP6 models due in part to the differences in dust size representation and the simulated concentration.