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Arctic Atmospheric Chemistry: the Polar Sunrise Experiments (PSE). Jan W. Bottenheim 1 , Paul B. Shepson 2 , Jose D. Fuentes 3 , Leonard A. Barrie 4. 1 Meteorological Service of Canada, Toronto, ON, Canada 2 Purdue University, West Lafayette, IN, USA
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Arctic Atmospheric Chemistry: the Polar Sunrise Experiments (PSE) Jan W. Bottenheim1, Paul B. Shepson2, Jose D. Fuentes3, Leonard A. Barrie4 1Meteorological Service of Canada, Toronto, ON, Canada 2Purdue University, West Lafayette, IN, USA 3University of Virginia, Charlottesville, VA, USA 4WMO, Geneva, Switzerland
Chronology of PSEs: 1988: first PSE 1992, 2000: major campaigns Yearly small, dedicated campaigns
Relationship between ozone and bromine From: Barrie et al., 1988
BrO + BrO limiting Br + O3 -> BrO + O2 BrO + BrO -> 2 Br + O2 BrO + HO2 -> HOBr HOBr + Br- -> 2 Br
From: Foster et al., 2001 From: Hoenninger and Platt, 2002
GOME satellite data From: Richter et al., 1998
Frost flowers Frost flower growth is efficient over new sea-ice, at a rate inversely proportional to temperature Most episodes occur where surface temperature is < -20 0C Frequency of depletion episodes is increasing (0.7 % y-1), evidence of climate change?
The HCHO lifetime changes from ~3 months in the dark, to 0.5 days in sunlight From: Sumner and Shepson, 1999
Role of Formaldehyde in Ozone Destruction Radical Source HCHO + h •H HO2• HO2• + BrO• HOBr + O2 HOBr(aq) + Br - + H+ Br2(aq) Br2(g) + h 2 •Br Bromine Radical Sink •Br + O3 BrO• + O2 BrO• + BrO• 2 •Br + O2 •Br + HCHO HBr + HCO•
O3, *20 NOy PAN NOx
Vertical HONO profile at SST, 10:00-14:30, 4/24/00. 110 90 70 Height/Depth, cm 50 30 10 -10 0 10 20 30 40 50 60 70 HONO, ppt Courtesy: X. Zhou, SUNYA
Similarly, ozone depletion in spring is an annually recurring phenomenon (for a graphic representation contact Dr. K.G. Anlauf at the Meteorological Service of Canada, Toronto, Ontario, Canada) Courtesy: Anlauf and Hayden, MSC
TGM at Ice Camp From: Steffen et al., 2002
10 1 0.1 27 Apr: 4 to 12 h 0.01 28 Apr 6 to 16 h 5 May: 0 to 10 h 0 2 4 6 [O ] in ppbv 3 Height (m) Fuentes, unpublished
Some future experiments • Detailed chemistry profiles of the lower atmosphere (< 100 m) • Role of frost flowers on chemical processing • Laboratory experiments devoted to the heterogeneous chemistry • on frozen seawater surfaces • Three-dimensional studies to investigate the climate impact of • ozone depletion • Other? (discuss at meeting on Saturday evening)