| ABSTRACT | The Mediterranean region is subject to high aerosol loads, from both anthropogenic and natural sources. Because of their optical and microphysical properties, aerosols play an important role in the Mediterranean climate system. Indeed, they interact with radiation and clouds and they provoke a negative radiative forcing at the surface with ensuing cooling and decrease in the activity of the hydrological cycle. The main aerosols in this region are desert dust, sea salt, organic, black carbon, sulphate and ammonium-nitrate particles, whose contribution to aerosol radiative forcing is expected to increase up to the end of the 21st century.
In order to estimate the role of aerosols on the future climate we will use the CNRM-RCSM6 model, which is a coupled regional aerosol-atmosphere-ocean model. Its atmospheric model, namely ALADIN-Climate, incorporates a prognostic aerosol scheme (TACTIC), including already desert dust, sea salt, organic, black carbon and sulphate particles, but not the ammonium and nitrate aerosols. Because of their future contribution to aerosol radiative forcing, we have recently added a new module in TACTIC, adapted from the LMDz-INCA module (Hauglustaine et al., 2014) to represent these types of aerosols.
The aim of this study is to evaluate (Aerosol optical Depth, surface concentration) this new ammonium-nitrate scheme, as well as the aerosol impacts on the radiation and temperature over the Mediterranean. The methodology is based on two parallel simulations of 38 years (1979-2016), driven by the ERA-Interim reanalysis, which have been realized using the atmospheric model of CNRM-RCSM, including or not the ammonium-nitrate aerosol module. |