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Detailed Reference Information |
Kleinböhl, A., Bremer, H., Küllmann, H., Kuttippurath, J., Browell, E.V., Canty, T., Salawitch, R.J., Toon, G.C. and Notholt, J. (2005). Denitrification in the Arctic mid-winter 2004/2005 observed by airborne submillimeter radiometry. Geophysical Research Letters 32: doi: 10.1029/2005GL023408. issn: 0094-8276. |
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We present measurements of unusually low mixing ratios of HNO3 in the exceptionally cold Arctic vortex of late-January and early-February 2005. The measurements were obtained by the airborne submillimeter radiometer ASUR during the polar aura validation experiment (PAVE). The distribution of HNO3 inside the vortex reaches minima below 4 ppbv around 22 km altitude and maxima above 13 ppbv around 16 km altitude, with a considerable spatial variability. We estimate a vortex averaged denitrification of 3.1 ¿ 0.8 ppbv around 20 km altitude, and slight renitrification below ~15.5 km altitude. The observed HNO3 deficit is largest (~6 ppbv) near the center of the vortex, where the air masses had experienced temperatures below the NAT formation threshold for 80--100% of the previous 20 days according to back trajectories. This suggests that the main denitrification mechanism is based on sedimenting nitric acid trihydrate particles. |
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Abstract |
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Keywords
Atmospheric Composition and Structure, Middle atmosphere, composition and chemistry, Atmospheric Composition and Structure, Middle atmosphere, constituent transport and chemistry, Atmospheric Processes, Remote sensing |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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