TY - JOUR
T1 - Snowpack processing of acetaldehyde and acetone in the Arctic atmospheric boundary layer
AU - Guimbaud, Christophe
AU - Grannas, Amanda M.
AU - Shepson, Paul B.
AU - Fuentes, José D.
AU - Boudries, Hacene
AU - Bottenheim, Jan W.
AU - Dominé, Florent
AU - Houdier, Stephan
AU - Perrier, Sébastien
AU - Biesenthal, Thomas B.
AU - Splawn, Bryan G.
N1 - Funding Information:
We gratefully acknowledge the NSF Office of Polar Programs and Atmospheric Chemistry program (OPP-9818257) for support of this work, the assistance of the Meteorological Service of Canada, and the logistical support from Alan Gallant and from all the personnel of CFS Alert. AMG acknowledges the Purdue Research Foundation for graduate research support.
PY - 2002
Y1 - 2002
N2 - Acetaldehyde (CH3CHO) and acetone (CH3C(O)CH3) concentrations in ambient air, in snowpack air, and bulk snow were determined at Alert, Nunavut, Canada, as a part of the Polar Sunrise Experiment (PSE): ALERT 2000. During the period of continuous sunlight, vertical profiles of ambient and snowpack air exhibited large concentration gradients through the top ∼10cm of the snowpack, implying a flux of carbonyl compounds from the surface to the atmosphere. From vertical profile and eddy diffusivity measurements made simultaneously on 22 April, acetaldehyde and acetone fluxes of 4.2(±2.1)×108 and 6.2(±4.2)×108moleculescm-2s-1 were derived, respectively. For this day, the sources and sinks of CH3CHO from gas phase chemistry were estimated. The result showed that the snowpack flux of CH3CHO to the atmosphere was as large as the calculated CH3CHO loss rate from known atmospheric gas phase reactions, and at least 40 times larger (in the surface layer) than the volumetric rate of acetaldehyde produced from the assumed main atmospheric gas phase reaction, i.e. reaction of ethane with hydroxyl radicals. In addition, acetaldehyde bulk snow phase measurements showed that acetaldehyde was produced in or on the snow phase, likely from a photochemical origin. The time series for the observed CH3C(O)CH3, ozone (O3), and propane during PSE 1995, PSE 1998, and ALERT 2000 showed a consistent anti-correlation between acetone and O3 and between acetone and propane. However, our data and model simulations showed that the acetone increase during ozone depletion events cannot be explained by gas phase chemistry involving propane oxidation. These results suggest that the snowpack is a significant source of acetaldehyde and acetone to the Arctic boundary layer.
AB - Acetaldehyde (CH3CHO) and acetone (CH3C(O)CH3) concentrations in ambient air, in snowpack air, and bulk snow were determined at Alert, Nunavut, Canada, as a part of the Polar Sunrise Experiment (PSE): ALERT 2000. During the period of continuous sunlight, vertical profiles of ambient and snowpack air exhibited large concentration gradients through the top ∼10cm of the snowpack, implying a flux of carbonyl compounds from the surface to the atmosphere. From vertical profile and eddy diffusivity measurements made simultaneously on 22 April, acetaldehyde and acetone fluxes of 4.2(±2.1)×108 and 6.2(±4.2)×108moleculescm-2s-1 were derived, respectively. For this day, the sources and sinks of CH3CHO from gas phase chemistry were estimated. The result showed that the snowpack flux of CH3CHO to the atmosphere was as large as the calculated CH3CHO loss rate from known atmospheric gas phase reactions, and at least 40 times larger (in the surface layer) than the volumetric rate of acetaldehyde produced from the assumed main atmospheric gas phase reaction, i.e. reaction of ethane with hydroxyl radicals. In addition, acetaldehyde bulk snow phase measurements showed that acetaldehyde was produced in or on the snow phase, likely from a photochemical origin. The time series for the observed CH3C(O)CH3, ozone (O3), and propane during PSE 1995, PSE 1998, and ALERT 2000 showed a consistent anti-correlation between acetone and O3 and between acetone and propane. However, our data and model simulations showed that the acetone increase during ozone depletion events cannot be explained by gas phase chemistry involving propane oxidation. These results suggest that the snowpack is a significant source of acetaldehyde and acetone to the Arctic boundary layer.
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U2 - 10.1016/S1352-2310(02)00107-3
DO - 10.1016/S1352-2310(02)00107-3
M3 - Article
AN - SCOPUS:0036576936
SN - 1352-2310
VL - 36
SP - 2743
EP - 2752
JO - Atmospheric Environment
JF - Atmospheric Environment
IS - 15-16
ER -
