HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

On the relationship between Arctic ice clouds and polluted air masses over the North Slope of Alaska in April 2008

Caroline Jouan 1, 2 Jacques Pelon 1 Eric Girard 2 Gérard Ancellet 1 Jean-Pierre Blanchet 2 Julien Delanoë 3
LATMOS - Laboratoire Atmosphères, Milieux, Observations Spatiales
LATMOS - Laboratoire Atmosphères, Milieux, Observations Spatiales
Abstract : Recently, two Types of Ice Clouds (TICs) properties have been characterized using ISDAC airborne measurements (Alaska, April 2008). TIC-2B were characterized by fewer (<10 L−1) and larger (>110 μm) ice crystals, a larger ice supersaturation (>15%) and a fewer ice nuclei (IN) concentration (<2 order of magnitude) when compared to TIC-1/2A. It has been hypothesized that emissions of SO2 may reduce the ice nucleating properties of IN through acidification, resulting to a smaller concentration of larger ice crystals and leading to precipitation (e.g. cloud regime TIC-2B) because of the reduced competition for the same available moisture. Here, the origin of air masses forming the ISDAC TIC-1/2A (1 April 2008) and TIC-2B (15 April 2008) is investigated using trajectory tools and satellite data. Results show that the synoptic conditions favor air masses transport from the three potentials SO2 emission areas to Alaska: eastern China and Siberia where anthropogenic and biomass burning emission respectively are produced and the volcanic region from the Kamchatka/Aleutians. Weather conditions allow the accumulation of pollutants from eastern China/Siberia over Alaska, most probably with the contribution of acid volcanic aerosol during the TIC-2B period. OMI observations reveal that SO2 concentrations in air masses forming the TIC-2B were larger than in air masses forming the TIC-1/2A. Airborne measurements show high acidity near the TIC-2B flight where humidity was low. These results strongly support the hypothesis that acidic coating on IN are at the origin of the formation of TIC-2B.
Complete list of metadata

Cited literature [60 references]  Display  Hide  Download

Contributor : Catherine Cardon Connect in order to contact the contributor
Submitted on : Friday, December 18, 2015 - 10:11:25 AM
Last modification on : Tuesday, November 16, 2021 - 4:47:03 AM
Long-term archiving on: : Saturday, April 29, 2017 - 8:58:11 PM


Publication funded by an institution



Caroline Jouan, Jacques Pelon, Eric Girard, Gérard Ancellet, Jean-Pierre Blanchet, et al.. On the relationship between Arctic ice clouds and polluted air masses over the North Slope of Alaska in April 2008. Atmospheric Chemistry and Physics, European Geosciences Union, 2014, 14 (3), pp.1205-1224. ⟨10.5194/acp-14-1205-2014⟩. ⟨hal-00789168⟩



Record views


Files downloads