Abstract. Since March 1992 the total column abundances of several tropospheric and stratospheric trace gases have been monitored year-round from the Network for Detection of Stratospheric Change station in Ny/•desund, Spitsbergen (78.9øN, 11.9øE). A groundbased Fourier transform infrared (FTIR) spectrometer performed these measurements using the Sun as a light source during the summer, and the Moon during the winter. In situ measurements of C2H2, C2H6, and CC12F2, made from the top of a nearby mountain, were combined with the FTIR column data to infer additional information about the variation of the volume mixing ratio profiles with altitude and season. The short-lived tropospheric trace gases C2H2, C2H6, and CO exhibit large seasonal variations with a summer minimum, caused by reaction with OH. CH20 shows a second maximum during the summer, caused by its formation by methane oxidation. For the long-lived gases HF, N20 , and CH 4 the seasonal cycle is less pronounced and is forced mainly by wintertime stratospheric diabatic descent, which starts in early November and reaches a maximum in March. The total columns of the stratospheric trace gases indicate that the chemical repartitioning of HC1 into C1ONO2 starts in November, before the widespread production of polar stratospheric clouds. The total columns of the sum of HC1 plus C1ONO2 suggests that between December and March they are converted into their active counterparts. Photolysis of HNO 3 gives rise to its summer minimum, and its winter maximum, with no evidence for a strong winter denitrification.

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Articles you may be interested inEventempered atomic orbitals. VII. Theoretical equilibrium geometries and reaction energies for carbon suboxide and other molecules containing carbon, oxygen, and hydrogen 1 This work is summarized in (a) J.

Abstract. Results of the comparison of carbon monoxide ground-based infrared solar spectroscopic measurements with data obtained during 1994 Measurement of AirPollution From Space (MAPS) flights are presented. Spectroscopic measurements were performed correlatively with April and October MAPS flights by nine research groups from Belgium, Canada, Germany, Japan, New Zealand, Russia, and the United States. Characterization of the techniques and error analysis were performed. The role of the CO a priori profile used in the retrieval was estimated. In most cases an agreement between spectroscopic and MAPS data is within estimated MAPS accuracy of _+ 10%. •Department of Physics, University of Toronto, Toronto, Ontario, Canada.•2Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh.• Solar IR Spectroscopic Retrieval TechniqueThe CO total vertical column Q is defined by the equation O = f q(h) dh19,317

Abstract. FTIR-emission measurements of the polar Arctic atmosphere were made in Ny-.•lesund (79øN, 11øE) with commercially available instruments. The infrared emission spectra were analysed with the FASCOD3 algorithm and home made analysis software. In order to get an agreement between experiment and simulation and to retrieve the correct column amounts of trace gases present in the atmosphere, the contribution of aerosols had to be included in subsequent radiative transfer calculations. We varied the aerosol optical depth by the parameter of the visibility in FASCOD3 in selected spectral microwindows, which are not superimposed by molecular emission bands. Furthermore, the optical depth was measured with a sun (under daylight conditions) or a star photometer (during polar night) in the UV/Visible-range. The comparison of the UV/Visible-data with the results from the FTIR-emission measurements shows a strong decay in the optical depth of the tropospheric aerosols over the two spectral regions.