Zur Ozonbilanz in der Troposphaere: Flugzeuggestuetzte Messungen von Ozon, CO und NO_y

Results obtained from 14 flights made within the European research project OCTA (McKenna et al., 1995) on board the British research aircraft Hercules C-130 are presented and discussed. Participants within the project were besides other groups the meteorological research flight (MRF) of the United Kingdom meteorological office (UKMO) and the ICG-2 of Forschungszentrum Juelich (FZJ, former KFA). During 4 intensives during summer 1993 and during winter/spring 1994 a suite of several chemical species, aerosol concentrations, photolysis rates and meteorological parameters were measured in the troposphere over the north Atlantic. Within this work the mixing ratios of CO, NO and NO_y as well as the photolysis frequency of NO_2 were measured. A new instrument for the measurement of atmospheric CO was deployed for the first time. The measurements show that the instrument combines a high time resolution (2 s) with a high accuracy (5 ppb in 30 s, 3 #sigma#), which makes it suitable for airborne measurements. The measurements during August 1993 took place in parallel to the NARE-measurements (North Atlantic regional experiment) near the east coast of the United States. An intercomparison of the measurements of NO and NO_y showed agreement within the experimental errors. The inlet losses for HNO_3 found in several tests during the flights were confirmed by the intercomparison. In general, no region over the north Atlantic can be regarded as truly remote from continental emissions. During the summer intensive several airmasses with enhanced mixing ratios of CO and nitrogen oxides were found, which indicates long range transport of pollutants from Europe or from the US. (orig.)Dissertation submitted by C. Gerbig, 87 refs.Available from TIB Hannover: RA 831(3425) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman