Decadal climate fluctuations are influenced significantly by the variability of the composition and dynamics of the middle atmosphere. At the moment, there is no national or international data base with sufficient spatial and temporal resolution to quantify the underlying physical and chemical processes and to reproduce these adequately in predictive models. The observations of AtmoSat will close this gap and adresses the following main atmospheric and climate research topics:
Variability of atmospheric trace-gases and aerosols: The variability of the near-surface climate is most strongly influenced by the radiative effects of water vapor, ozone, and sulfate aerosols in the upper troposhere and stratosphere. To understand decadal climate variability it is necessary to quantify the temporal and spatial variability of these trace substancies.
Atmospheric processes: The stratospheric Brewer-Dobson circulation and stratosphere-troposphere exchange have a strong impact on the on the variability of water vapour, ozone ans sulfate aerosols in the upper troposphere and stratosphere. An example is the Exchange Between Troposphere and Stratosphere in the Asian Monsoon Region. By unique measurments of transport tracers AtmoSat will contribute to a significantly improved understanding of these processes, their spatial and temporal variability, and their impact on global and regional climate.
Dynamic couplings: The stratosphere influences near-surface regional climate and long-term weather via dynamical coupling with the troposphere. Variations of the strength of the polar jet play a decicive role for this dynamical coupling The 3D temperature data of AtmoSat will allow for a first time a detailed characterisation of the global distribution of mesoskale Gws, their momentum flux and propagation direction.
AtmoSat relies on three main instruments. It combines infrared limb imaging (via Global Limb Radiance Imager for the Atmosphere, GLORIA) with narrow-band observations in other spectral ranges (via Multiple Eye for Remote Investigation of the Atmosphere, MERIA) and GPS radio occultation (via Triple GNSS = GPS/GLONASS/Galileo, TRiG) to provide synergies at the upper and lower measurement boundary. The core instrument is GLORIA will be an adaption of the air-bourne instrumentGLORIA to the requirements in space.