Title: Evapotranspiration in Northern Eurasia: Impact of forcing uncertainties on terrestrial ecosystem model estimates

Abstract

Abstract The ecosystems in Northern Eurasia (NE) play an important role in the global water cycle and the climate system. While evapotranspiration (ET) is a critical variable to understand this role, ET over this region remains largely unstudied. Using an improved version of the Terrestrial Ecosystem Model with five widely used forcing data sets, we examine the impact that uncertainties in climate forcing data have on the magnitude, variability, and dominant climatic drivers of ET for the period 1979–2008. Estimates of regional average ET vary in the range of 241.4–335.7 mm yr ⁻¹ depending on the choice of forcing data. This range corresponds to as much as 32% of the mean ET. Meanwhile, the spatial patterns of long‐term average ET across NE are generally consistent for all forcing data sets. Our ET estimates in NE are largely affected by uncertainties in precipitation ( P ), air temperature ( T ), incoming shortwave radiation ( R ), and vapor pressure deficit (VPD). During the growing season, the correlations between ET and each forcing variable indicate that T is the dominant factor in the north and P in the south. Unsurprisingly, the uncertainties in climate forcing data propagate as well to estimates of themore » volume of water available for runoff (here defined as P‐ET). While the Climate Research Unit data set is overall the best choice of forcing data in NE according to our assessment, the quality of these forcing data sets remains a major challenge to accurately quantify the regional water balance in NE.« less

Authors:

Liu, Yaling ^[1]; Zhuang, Qianlai ^[2]; Miralles, Diego ^[3]; Pan, Zhihua ^[4]; Kicklighter, David ^[5]; Zhu, Qing ^[6]; He, Yujie ^[1]; Chen, Jiquan ^[7]; Tchebakova, Nadja ^[8]; Sirin, Andrey ^[9]; Niyogi, Dev ^[2]; Melillo, Jerry ^[5]

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+ Show Author Affiliations

1. Department of Earth, Atmospheric, and Planetary Sciences Purdue University West Lafayette Indiana USA
2. Department of Earth, Atmospheric, and Planetary Sciences Purdue University West Lafayette Indiana USA, Department of Agronomy Purdue University West Lafayette Indiana USA
3. Department of Earth Sciences VU University Amsterdam Amsterdam Netherlands, Laboratory of Hydrology and Water Management Ghent University Ghent Belgium
4. College of Resources and Environmental Sciences China Agricultural University Beijing China
5. Ecosystems Center Marine Biological Laboratory Woods Hole Massachusetts USA
6. Climate Sciences Department, Earth Sciences Division Lawrence Berkeley National Laboratory Berkeley California USA
7. CGCEO/Geography Michigan State University East Lansing Michigan USA
8. V N Sukachev Institute of Forest Siberian Branch, Russian Academy of Sciences Krasnoyarsk Russia
9. Laboratory of Peatland Forestry and Amelioration, Institute of Forest Science Russian Academy of Sciences Uspenskoye Russia

Publication Date:

Fri Apr 03 00:00:00 EDT 2015

Sponsoring Org.:

USDOE

OSTI Identifier:

1402264

Grant/Contract Number:  

DE‐FG02‐08ER64599

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

Journal of Geophysical Research: Atmospheres

Additional Journal Information:

Journal Name: Journal of Geophysical Research: Atmospheres Journal Volume: 120 Journal Issue: 7; Journal ID: ISSN 2169-897X

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English