News & Events

Atmosphere-snowpack ozone exchanges in the Arctic: Methods, initial results, and meaning

Thursday, March 10, 2011, 4:30PM - 5:30PM

Speaker

Brie Van Dam

INSTAAR

Location:

RL-1 269

The snowpack is an active photochemical environment, driving important chemical interactions at the snow-atmosphere interface. With changes occurring both in the amount of pollutants transported to the Arctic, as well as changing amount and physical properties of the snowpack, significant effects in chemical budgets in the Arctic troposphere are possible. This indicates a need to understand the current dependencies of ozone exchange at the snow surface; yet despite this need, measurements of ozone deposition velocities reported in the literature are highly variable, and the processes impacting ozone behavior within and above the snowpack are not well understood. In order to address these concerns, a study with continuous, year-round measurements of ozone exchanges between the atmosphere and snowpack was implemented at Summit, Greenland between June 2008 and July 2010. Another campaign began at Toolik Field Station in northern Alaska in September 2010 and will continue through this winter and spring season. These measurements consist of a variety of observations used to investigate gas exchanges by implementing multiple techniques such as eddy covariance fluxes and gradient derived methods. Year round measurements at multiple sites in the Arctic and other snow covered regions will greatly improve our description of the processes controlling the exchange of ozone over polar snow, and how this will ultimately have an impact on the tropospheric ozone budget.