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Titel |
Contribution of soil moisture feedback to hydroclimatic variability |
VerfasserIn |
N. Y. Krakauer, B. I. Cook, M. J. Puma |
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 ; 14, no. 3 ; Nr. 14, no. 3 (2010-03-15), S.505-520 |
Datensatznummer |
250012225
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Publikation (Nr.) |
copernicus.org/hess-14-505-2010.pdf |
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Zusammenfassung |
While a variety of model experiments and analyses of observations have
explored the impact of soil moisture variation on climate, it is not yet
clear how large or detectable soil moisture feedback is across spatial and
temporal scales. Here, we study the impact of dynamic versus climatological
soil moisture in the GISS GCM ModelE (with prescribed sea-surface
temperatures) on the variance and on the spatial and temporal correlation
scale of hydrologically relevant climate variables (evaporation,
precipitation, temperature, cloud cover) over the land surface. We also
confirm that synoptic variations in soil moisture have a substantial impact
on the mean climate state, because of the nonlinearity of the dependence of
evapotranspiration on soil moisture.
We find that including dynamic soil moisture increases the interannual
variability of seasonal (summer and fall) and annual temperature,
precipitation, and cloudiness. Dynamic soil moisture tends to decrease the
correlation length scale of seasonal (warm-season) to annual land temperature
fluctuations and increase that of precipitation. Dynamic soil moisture
increases the persistence of temperature anomalies from spring to summer and
from summer to fall, and makes the correlation
between land precipitation and temperature fluctuations substantially more negative.
Global observation sets that allow determination of the spacetime correlation of
variables such as temperature, precipitation, and cloud cover could provide
empirical measures of the strength of soil moisture feedback, given that the feedback strength varies widely among models. |
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