Changing seasonality reflected in the chloroform breath of the Arctic tundra
Abstract
The Arctic tundra plays an active role in the biogeochemical cycling of ozone-depleting halocarbons. One of these compounds, chloroform (CHCl3), is emitted at high rates from the tundra but only during the thaw season. Thus atmospheric CHCl3 measurements can be used as an indicator of seasonal transitions on the tundra. We tested this idea through an analysis of long-term in situ trace gas measurements conducted by NOAA GMD at the baseline station near Barrow, Alaska. The Barrow Observatory (71.3230° N, 156.6114° W) is surrounded by the Arctic Ocean to the north and west and open tundra to the southeast to southwest. Atmospheric CHCl3 has been measured here hourly since 1998, with only a few breaks in the record. The onset of the thaw season is highlighted by a marked increase in chloroform concentrations in air masses originating from the tundra. The increased variance in concentrations coincides with declining albedo and increasing temperatures. Investigations on the biogeochemistry of chloroform in the Arctic tundra will clarify the mechanistic trigger of this seasonal shift and provide insight on how climate change in the Arctic can cause feedbacks in previously unexplored biogeochemical cycles.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFMGC32A..05R
- Keywords:
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- 0317 ATMOSPHERIC COMPOSITION AND STRUCTURE / Chemical kinetic and photochemical properties;
- 0438 BIOGEOSCIENCES / Diel;
- seasonal;
- and annual cycles;
- 0718 CRYOSPHERE / Tundra;
- 1621 GLOBAL CHANGE / Cryospheric change