GAS-PHASE FORMALDEHYDE AND PEROXIDE MEASUREMENTS IN THE ARCTIC ATMOSPHERE

Authors
Citation
C. Deserves, GAS-PHASE FORMALDEHYDE AND PEROXIDE MEASUREMENTS IN THE ARCTIC ATMOSPHERE, JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 99(D12), 1994, pp. 25391-25398
Citations number
33
Categorie Soggetti
Metereology & Atmospheric Sciences
Volume
99
Issue
D12
Year of publication
1994
Pages
25391 - 25398
Database
ISI
SICI code
Abstract
Atmospheric peroxides and formaldehyde were measured during the Polar Sunrise Experiment 1992 in Alert, Canada (82.5 degrees N, 62.3 degrees W). Two measurement periods, in the dark winter and in the sunlit spr ing, were chosen to investigate the effects of photochemistry. Continu ous measurements were performed using diffusion scrubbers coupled to a queous phase fluorometry. The concentration of total peroxides varied from below the detection limit (similar to 10 parts per trillion by vo lume (pptv)) to 40 pptv in the dark and 100 to 400 pptv in the sunlit period with large variations in the ratio between H2O2 and organic per oxides. The CH2O concentrations measured in the dark were between 100 and 700 pptv and showed good correlation with a number of atmospheric constituents such as CH4, CO2, and Rn but anticorrelation to O-3. A fr action of the observed CH2O concentrations is believed to be formed by nonphotochemical O-3-alkene chemistry. In the presence of sunlight th e CH2O concentrations ranged between 30 to 600 pptv without correlatio n to CH4, CO2, or Rn. The maximum CH2O concentrations were associated with air, depleted in O-3 coming from the Arctic Ocean. During the O-3 depletions, decreased peroxide concentrations were observed. The orig in of the air mass was a very important factor during both periods in explaining the observed variabilities in CH2O and peroxide concentrati ons.