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Editor's Highlight
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GEOPHYSICAL RESEARCH LETTERS,
VOL. 32,
L21413,
doi:10.1029/2005GL024413,
2005
A decrease in discharge-normalized DOC export by the Yukon River during summer through autumn
Robert G. Striegl
U.S. Geological Survey, Denver, Colorado, USA
George R. Aiken
U.S. Geological Survey, Boulder, Colorado, USA
Mark M. Dornblaser
U.S. Geological Survey, Boulder, Colorado, USA
Peter A. Raymond
School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut, USA
Kimberly P. Wickland
U.S. Geological Survey, Boulder, Colorado, USA
Abstract
Climate warming is having a dramatic effect on the vegetation distribution and carbon cycling of terrestrial subarctic and
arctic ecosystems. Here, we present hydrologic evidence that warming is also affecting the export of dissolved organic carbon
and bicarbonate (DOC and HCO3
−) at the large basin scale. In the 831,400 km2 Yukon River basin, water discharge (Q) corrected DOC export significantly decreased during the growing season from 1978–80
to 2001–03, indicating a major shift in terrestrial to aquatic C transfer. We conclude that decreased DOC export, relative
to total summer through autumn Q, results from increased flow path, residence time, and microbial mineralization of DOC in
the soil active layer and groundwater. Counter to current predictions, we argue that continued warming could result in decreased
DOC export to the Bering Sea and Arctic Ocean by major subarctic and arctic rivers, due to increased respiration of organic
C on land.
Received 22
August
2005;
accepted 5
October
2005;
published 12
November
2005.
Index Terms: 1620 Global Change: Climate dynamics (0429, 3309); 3307 Atmospheric Processes: Boundary layer processes; 3322 Atmospheric Processes: Land/atmosphere interactions (1218, 1631, 1843); 3337 Atmospheric Processes: Global climate models (1626, 4928).
Read Full Article (file size: 4607894 bytes) Cited by
Citation: Striegl, R. G., G. R. Aiken, M. M. Dornblaser, P. A. Raymond, and K. P. Wickland
(2005),
A decrease in discharge-normalized DOC export by the Yukon River during summer through autumn,
Geophys. Res. Lett.,
32,
L21413,
doi:10.1029/2005GL024413.
Copyright 2005 by the American Geophysical Union.
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