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Increasing Northern Hemisphere water deficit

September 30, 2015

A monthly water-balance model is used with CRUTS3.1 gridded monthly precipitation and potential evapotranspiration (PET) data to examine changes in global water deficit (PET minus actual evapotranspiration) for the Northern Hemisphere (NH) for the years 1905 through 2009. Results show that NH deficit increased dramatically near the year 2000 during both the cool (October through March) and warm (April through September) seasons. The increase in water deficit near 2000 coincides with a substantial increase in NH temperature and PET. The most pronounced increases in deficit occurred for the latitudinal band from 0 to 40°N. These results indicate that global warming has increased the water deficit in the NH and that the increase since 2000 is unprecedented for the 1905 through 2009 period. Additionally, coincident with the increase in deficit near 2000, mean NH runoff also increased due to increases in P. We explain the apparent contradiction of concurrent increases in deficit and increases in runoff.

Publication Year 2015
Title Increasing Northern Hemisphere water deficit
DOI 10.1007/s10584-015-1419-x
Authors Gregory J. McCabe, David M. Wolock
Publication Type Article
Publication Subtype Journal Article
Series Title Climatic Change
Index ID 70189276
Record Source USGS Publications Warehouse
USGS Organization National Research Program - Central Branch