TY - JOUR

T1 - Effect of Permafrost Thawing on Discharge of the Kolyma River, Northeastern Siberia

AU - Suzuki, Kazuyoshi

AU - Park, Hotaek

AU - Makarieva , Olga

AU - Kanamori, Hironari

AU - Hori, Masahiro

AU - Matsuo, Kotji

AU - Matsumuro, Shinji

AU - Nesterova , Nataliia

AU - Hiyama, Tetsuya

N1 - Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/10/31

Y1 - 2021/10/31

N2 - With permafrost warming, the observed discharge of the Kolyma River in northeastern Siberia decreased between 1930s and 2000; however, the underlying mechanism is not well understood. To understand the hydrological changes in the Kolyma River, it is important to analyze the long-term hydrometeorological features, along with the changes in the active layer thickness. A coupled hydrological and biogeochemical model was used to analyze the hydrological changes due to permafrost warming during 1979–2012, and the simulated results were validated with satellitebased products and in situ observational records. The increase in the active layer thickness by permafrost warming suppressed the summer discharge contrary to the increased summer precipitation. This suggests that the increased terrestrial water storage anomaly (TWSA) contributed to increased evapotranspiration, which likely reduced soil water stress to plants. As soil freeze–thaw processes in permafrost areas serve as factors of climate memory, we identified a two-year lag between precipitation and evapotranspiration via TWSA. The present results will expand our understanding of future Arctic changes and can be applied to Arctic adaptation measures.

AB - With permafrost warming, the observed discharge of the Kolyma River in northeastern Siberia decreased between 1930s and 2000; however, the underlying mechanism is not well understood. To understand the hydrological changes in the Kolyma River, it is important to analyze the long-term hydrometeorological features, along with the changes in the active layer thickness. A coupled hydrological and biogeochemical model was used to analyze the hydrological changes due to permafrost warming during 1979–2012, and the simulated results were validated with satellitebased products and in situ observational records. The increase in the active layer thickness by permafrost warming suppressed the summer discharge contrary to the increased summer precipitation. This suggests that the increased terrestrial water storage anomaly (TWSA) contributed to increased evapotranspiration, which likely reduced soil water stress to plants. As soil freeze–thaw processes in permafrost areas serve as factors of climate memory, we identified a two-year lag between precipitation and evapotranspiration via TWSA. The present results will expand our understanding of future Arctic changes and can be applied to Arctic adaptation measures.

KW - Active layer thickness

KW - Dam regulation

KW - Lag correlation

KW - Permafrost

KW - Terrestrial water storage

KW - The Kolyma River

UR - http://www.scopus.com/inward/record.url?scp=85118511906&partnerID=8YFLogxK

U2 - 10.3390/rs13214389

DO - 10.3390/rs13214389

M3 - Article

VL - 13

JO - Remote Sensing

JF - Remote Sensing

SN - 2072-4292

IS - 21

M1 - 4389

ER -