Space Observations of Tropospheric CO and CH4

Satellite derived data of atmospheric trace gas constituents essentially contribute to the understanding of physical and chemical processes in the atmosphere from global down to small scale considerations. The experiment MOPITT is a joint US-Canadian effort to determine and interpret the global distribution of carbon monoxide (CO) and methane (CH4 ). CO is produced by a number of natural processes as well as human activities such as biomass burning or fossil fuel consumption. CO concentrations affect the atmospheric OH cycle and further play an important role in tropospheric ozone chemistry. Methane is, beside its meaning in atmospheric chemistry an important greenhouse gas which total amount is increasing by about 1% annually. MOPITT CO and CH 4 data will help to understand the biogeochemical cycles of these chemicals and their effect on climate and will lead to a better prediction of effects of anthropogenic activities. Work in the frame of the proposed project, which will be carried out at the National Atmospheric Research Center (NCAR) in Boulder, Colorado, concerns, on the one hand, to data/algorithm validation, and, on the other hand, to the MOPITT data analysis with regard to regional air pollution studies. The validation activities are essential for determining and ensure the data quality. The proposed work includes the comparison of measured radiances with operational forward model calculations for selected situations where all relevant input parameters to the model are well characterized. As model inputs meteorological data will be combined with CO vertical profiles, e.g. from in-situ aircraft measurements. Further activity in this field of work deals with investigations concerning the estimation of model-measurement errors that arise from temporal and spatial displacements between the MOPITT pixels and the in-situ data or the lack of information of in-situ data in the upper troposphere and stratosphere. In the field of data analysis focus is laid to studies about regional air pollution in Austria by means of MOPITT CO data. Due to its limited lifetime of about two months, CO can be used as a regional tracer of pollution and transport. MOPITT data over central Europe will be used together with weather patterns to look for sources of emission and how pollutants are distributed.