Extension and combination of existing remote-sensing instruments

Abstract

This dissertation explores possible ways to extend the remote-sensing capabilities of existing instruments.In the theoretical part, the O3(Ozone)-chemistry up to the mesosphere will be reviewed with emphasis on O3 changes due to precipitation of solar particles into the atmosphere. The theoretical background of remote sensing in the microwave and far infrared region will be sketched. Finally the retrieval theory based on Optimal estimation will be reviewed. In the practical part, extensions to existing instruments will be introduced.First a combination of a microwave spectrometer with a Fourier transform spectrometer is theoretically investigated and applied to artificially created O3 and H2O(Water vapour) spectra. O3-profiles can be retrieved from ground level to themesosphere using the combination of the two sensors. In the region from 15 km to 35 km, where both instruments are able to `see' O3 , the results are improved compared to the results obtained by either instrument alone.H2O-spectra are also combined and retrieved. While it is shown to be possible to retrieve combined spectra, there is a pronounced information gap between the tropopause and the middle stratosphere which makes it difficult to retrieve information of the H2O-content in the tropopause region.In a second part, an add-on-spectrometer to the existing microwave radiometers, OZORAM and H2ORAM, in Ny à ?�lesund, Spitsbergen (79N), is devised and explored. The new spectrometer enables a resolution as fine as 100 kHz which makes it possible to retrieve O3, from the 142 GHz-line,and H2O-profiles, from the 22.2 GHz-line, up to 75 km. Investigations have been undertaken in order to define the properties of an instrument which is able to refine the H2O-spectra at 22.2 GHz even further. Due to the weakemission this is more difficult than for the prominent O3-line at 142 GHz.The spectra taken during the October/November 2003 Solar-Proton-Event (SPE) by the OZORAM at Ny à ?�lesund have been reanalysed using an optimised retrieval set-up based on Qpack/arts to investigate the SPE and to compare the measured O3-VMR (volume mixing ratio) to the evolutionof the O3-VMR predicted by a 2-dimensional model.Additionally, a method of comparing profiles obtained from different remote sensors is reviewed and demonstrated. The results are used to back up the results based on the existing spectra for the SPE 2003.