Permafrost Thawing and Hydrologic Response in the Russian Arctic Drainage Basin

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Permafrost Thawing and Hydrologic Response in
the Russian Arctic Drainage Basin
Tingjun Zhang1, Roger G. Barry1, Mark Serreze1,
Daqing Yang2, Andrew Etringer1, David
Gilichinsky3, Oliver Frauenfeld1, Hengchun Ye4,
Christoph Oelke1, Feng Ling1, and Svetlana
Chudinova3 1 University of Colorado at Boulder 2
University of Alaska Fairbanks 3 Russian Academy
of Science, Pushchino 4 California State
University, Los Angeles 2003 SEARCH Open
Science Meeting Oct. 27-31, 2003, Seattle,
Washington
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Problems
Question What causes the increase in discharge
over the Eurasian arctic rivers during the past
decades? Hypothesis We hypothesize that thawing
of permafrost, thickening of the active layer,
and increasing of the length of thaw season are
responsible for the increase in river runoff.
Combined annual discharge from six largest
Eurasian arctic rivers for the period from 1936
to 1999 has increased at a rate of about 2.0
km3/year (Peterson et al., Science, 2002). Yang
et al. (2002) and Serreze et al. (2002) also
reported runoff increase at individual basin.
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Permafrost Distribution
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Soil temperature increase at each river basin
(1969-1990)
Ob 1.2oC Yenisey
0.8oC Lena 1.5oC
Increase in soil temperature basin-wide leads to
thickening the active layer and thawing of
permafrost.
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Based on in-situ measurements, numerical
modeling, and estimate from thawing index, active
layer thickness has increased about 15 to 20 cm
since the 1960s over the Russian Arctic drainage
basin.
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Impacts to Runoff
Lateral thawing of permafrost contributes to
runoff, especially in the discontinuous
permafrost regions, such as Yenisey river basin.
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Summary

• Soil temperature increased about 0.8oC to 1.5oC
  from 1969 to 1990.
• Active layer thickness has increased about 15 to
  20 cm since the 1960s.
• Meltwater of excess ground ice may partly
  contribute to river runoff lateral thawing of
  permafrost, especially in discontinuous
  permafrost regions such as in the Yenesey, may
  potentially also contribute to river runoff.