Large‐scale hydro‐climatology of the terrestrial Arctic drainage system

作者：Mark C. Serreze, David H. Bromwich, Martyn Clark, Andrew J. Etringer, Tingjun Zhang, Richard B. Lammers · 发表于：Journal of Geophysical Research Atmospheres · 年份：2002 · DOI：10.1029/2001jd000919 · 被引用次数：270 · 研究领域：Climate change and permafrost、Arctic and Antarctic ice dynamics、Cryospheric studies and observations

The large‐scale hydro‐climatology of the terrestrial Arctic drainage system is examined, focusing on the period 1960 onward. Special attention is paid to the Ob, Yenisey, Lena, and Mackenzie watersheds, which provide the bulk of freshwater discharge to the Arctic Ocean. Station data are used to compile monthly gridded time series of gauge‐corrected precipitation ( P ). Gridded time series of precipitation minus evapotranspiration ( P −ET) are calculated from the moisture flux convergence using NCEP reanalysis data. Estimates of ET are obtained as a residual. Runoff ( R ) is obtained from available discharge records. For long‐term water‐year means, P −ET for the Yenisey, Lena, and Mackenzie watersheds is 16–20% lower than the observed runoff. In the Ob watershed, the two values agree within 9%. Given the uncertainties in P −ET, we consider the atmospheric and surface water budgets to be reasonably closed. Compared to the other three basins, the mean runoff ratio ( R / P ) is lower in the Ob watershed, consistent with the high fraction of annual precipitation lost through ET. All basins exhibit summer maxima in P and minima in P −ET. Summer P −ET in the Ob watershed is negative due to high ET rates. For large domains in northern Eurasia, about 25% of July precipitation is associated with the recycling of water vapor evapotranspirated within each domain. This points to a significant effect of the land surface on the hydrologic regime. Variability in P and P −ET has generally cle...