Major factors influencing local dust radiative forcing

Kurzfassung

In conclusion, it is shown in this paper that surface albedo variations over desert regions can have a significant influence on the solar and net radiative forcing of desert dust. It is furthermore concluded that desert dust has mostly a cooling effect over oceans, and a warming effect over highly reflecting desert regions. The widespread non-sphericity of the dust particles causes a challenge; it yields an additional contribution to the cooling effect. It is also concluded here that it might be more appropriate not to start with microphysical properties in order to quantify the dust particle radiative effects. Direct measurements of the optical dust particle properties are preferable, otherwise too much uncertainties are coming into play (shape, composition, size). Using the microphysical properties is more suited if the sensitivity of the radiative forcing is investigated.