This thesis aims to quantify the direct radiative effects of sea salt aerosol in the atmosphere. The online coupled regional scale model system COSMO-ART is extended for this objective with respect to the sea salt aerosol. Furthermore, a new sea salt optical parameterisation is developed for both the shortwave and longwave spectrum. Based on numerical simulations with the extended model system, the direct radiative effects of sea salt aerosol are investigated.

By using COSMO-ART, highly resolved process study simulations for 2-3 July 2016 are conducted to assess the aerosol effect on the meteorological conditions of southern West Africa. The meteorological phenomenon Evening Monsoon Flow Enhancement (EMFE) is identified as highly susceptible to the aerosol direct effect, leading to a spatial shift of the EMFE front. In a second aerosol feedback chain the aerosol variation leads to a temporal shift of the stratus-to-cumulus transition.

This work addresses the interactions of aerosols, clouds and dynamics in case of a so-called Medicane. This type of cyclone occurs over the Mediterranean Sea, showing similarities to Hurricanes over the Atlantic and Pacific Ocean. Due to the high wind speed of the Medicane, a large amount of sea salt particles is emitted over the sea. This can influence the development of the Medicane, its associated clouds, and precipitation.

Atmospheric processes, such as wind, impact the ground motion of the earth and have the potential to induce strong broad-band noise in seismological records. In order to quantify the influence of wind on ground motion velocity joint seismological and meteorological measurements were conducted at the Dead Sea.Results reveal a pronounced impact of wind on seismological records. A methodology is presented to account for the dependency of PSD of ground motion velocity on the horizontal wind field.