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| Titel |
Benchmark products for land evapotranspiration: LandFlux-EVAL multi-data set synthesis |
| VerfasserIn |
B. Mueller, M. Hirschi, C. Jimenez, P. Ciais, P. A. Dirmeyer, A. J. Dolman, J. B. Fisher, M. Jung, F. Ludwig, F. Maignan, D. G. Miralles, M. F. McCabe, M. Reichstein, J. Sheffield, K. Wang, E. F. Wood, Y. Zhang, S. I. Seneviratne |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 10 ; Nr. 17, no. 10 (2013-10-01), S.3707-3720 |
| Datensatznummer |
250085941
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| Publikation (Nr.) |
 copernicus.org/hess-17-3707-2013.pdf |
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| Zusammenfassung |
| Land evapotranspiration (ET) estimates are available from several global
data sets. Here, monthly global land ET synthesis products, merged from these
individual data sets over the time periods 1989–1995 (7 yr) and 1989–2005
(17 yr), are presented. The merged synthesis products over the shorter
period are based on a total of 40 distinct data sets while those over the
longer period are based on a total of 14 data sets. In the individual
data sets, ET is derived from satellite and/or in situ observations
(diagnostic data sets) or calculated via land-surface models (LSMs) driven
with observations-based forcing or output from atmospheric reanalyses.
Statistics for four merged synthesis products are provided, one including all
data sets and three including only data sets from one category each
(diagnostic, LSMs, and reanalyses). The multi-annual variations of ET in the
merged synthesis products display realistic responses. They are also
consistent with previous findings of a global increase in ET between 1989 and
1997 (0.13 mm yr−2 in our merged product) followed by a significant
decrease in this trend (−0.18 mm yr−2), although these trends are
relatively small compared to the uncertainty of absolute ET values. The
global mean ET from the merged synthesis products (based on all data sets) is
493 mm yr−1 (1.35 mm d−1) for both the 1989–1995 and 1989–2005 products, which is
relatively low compared to previously published estimates. We estimate global
runoff (precipitation minus ET) to 263 mm yr−1 (34 406 km3 yr−1) for a total
land area of 130 922 000 km2. Precipitation, being an important driving
factor and input to most simulated ET data sets, presents uncertainties
between single data sets as large as those in the ET estimates. In order to
reduce uncertainties in current ET products, improving the accuracy of the
input variables, especially precipitation, as well as the parameterizations
of ET, are crucial. |
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