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Abstracts
SEARCH Open Science Meeting
October 27, 2003
Seattle, Washington, USA
Core Atmospheric Measurements at the Summit, Greenland Environmental Observatory: GEOSummit
John F. Burkhart1, Roger C. Bales2, Joseph R. McConnell3
1Science Coordination Office, Greenland Environmental Observatory, PO 2039, Merced, CA, 95344, USA, Phone 209-724-4347, Fax 520-621-1422, johnny@hwr.arizona.edu
2School of Engineering, University of California - Merced, PO 2039, Merced, CA, 95344, USA, Phone 209-724-4348, Fax 209-724-4356, roger@eng.ucmerced.edu
3Hydrologic Sciences Division, Desert Research Institute, 2215 Raggio Parkway, Reno, NV, 89512, USA, Phone 775-673-7348, Fax 775-673-7363, jmcconn@dri.edu
A program was recently implemented for long-term measurements of the Arctic atmosphere, snow and other Earth system components at the Summit, Greenland Environmental Observatory (GEOSummit), located at an elevation of 3100 m on the Greenland ice sheet. GEOSummit was the site of the Greenland Ice Sheet Project 2 (GISP2) ice core drilling, completed in 1993, and has been a site of atmospheric, snow, and other geophysical measurements since. It is currently the only high-altitude site for continuous atmospheric and related measurements in the Arctic. Many of these measurements, previously made intermittently at GEOSummit, resumed on a continuous basis beginning in summer 2003 and will be publicly available.
There are three main science drivers for the measurement program. First, core atmospheric and snow measurements provide a baseline for the continued operation of GEOSummit as a long-term site for year-round measurements of climate change indices. Second, a number of processes that could amplify atmospheric change need consistent measurements and systematic study. For example, recent evidence indicates that important atmospheric chemical constituents undergo temperature-dependent exchange with ice/snow, and that some species are photochemically transformed and/or produced within the sunlit surface snowpack. The availability of the GEOSummit measurements encourages and facilitates multi-disciplinary research by providing a high-quality core of baseline observations. Third, current investigations to determine the long-term cycling, seasonality, and preservation of key compounds in the surface snow and their relation to paleoclimatic records preserved in ice cores use the year-round records made available through GEOSummit. Because changes in Arctic atmospheric circulation are cyclic over periods of 4-5 years and greater, long-duration measurements are critical to place observed changes in a long-term perspective.
The current program continues and expands the core baseline measurements at GEOSummit for a five-year period, beginning in summer 2003. GEOSummit is currently a partnership between NSF-OPP, NOAA-CMDL, and investigators from Denmark, Germany and Switzerland. Baseline measurements include meteorology, radiation, tropospheric and aerosol chemistry, snow properties and snow chemistry as well as carbon cycle compounds, chlorofluorocarbons, radiation, and ozone. Average water accumulation at GEOSummit is 21 g cm2 y-1, with annual patterns varying significantly from year to year. The mean annual temperature is ~-30 oC, varying between -70 and 0 oC. Near-surface summertime ozone averages 55 ppbv. Aerosol fluxes and atmospheric gas concentrations (e.g., O3, CO, CO2, CH4) exhibit characteristic annual cycling.
Abstract Categories: Changes in the Atmosphere
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