HR: 09:00h
AN: A11A-03    [Abstracts]
TI: Ozone Surface Flux Measurements Over the Antarctic Snow Pack
AU: * Kalnajs, L
EM: kalnajs@colorado.edu
AF: University of Colorado / Laboratory of Atmospheric and Space Physics, 1234 Innovation Dr, Boulder, CO 80303 United States
AU: Avallone, L
EM: avallone@lasp.colorado.edu
AF: University of Colorado / Laboratory of Atmospheric and Space Physics, 1234 Innovation Dr, Boulder, CO 80303 United States
AU: Davis, S
EM: seand@colorado.edu
AF: University of Colorado / Laboratory of Atmospheric and Space Physics, 1234 Innovation Dr, Boulder, CO 80303 United States
AB: Boundary layer ozone depletion events have previously been observed in the Antarctic Spring, however the exact mechanism for the destruction is not fully understood. The snow surface and blowing snow is thought to play a role in ozone loss but it is unclear if ozone loss is a physical process on the large surface area provided by the snow or through a chemical reaction with species released from the snow. Micrometeorological measurements of surface ozone fluxes were carried out on the Ross Ice Shelf in the austral spring of 2004. These measurements were made using a newly developed fast time-response (> 1 Hz) closed-path optical absorption ozone analyzer. This first deployment of the instrument demonstrated significant improvements in temporal resolution of ozone data as well as high reliability in very harsh conditions. The instrument was configured to measure fluxes using the eddy correlation method in conjunction with a sonic anemometer, and using a gradient flux method with multiple inlets on a flux tower. Simultaneous measurements were also made of meteorological conditions and trace concentrations of nitrogen oxides. The instrumentation ran autonomously and regularly for ten weeks, gathering a comprehensive data set of surface ozone conditions. Observations of ozone concentrations over the depth of the boundary layer were also made using a tethered ozone sonde. Initial results show depletion of ozone in the bottom 1 to 50 meters of the planetary boundary layer, suggesting that the snow surface may play an important role in Antarctic boundary layer ozone depletion events.
DE: 0322 Constituent sources and sinks
DE: 0394 Instruments and techniques
DE: 3307 Boundary layer processes
DE: 9310 Antarctica
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly