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| Titel |
The contributions of soil-moisture interactions to climate change in the tropics in CMIP5 projections from the GLACE-CMIP5 experiment |
| VerfasserIn |
Wilhelm May, Markku Rummukainen, Arndt Meier |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102089
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| Publikation (Nr.) |
 EGU/EGU2015-1369.pdf |
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| Zusammenfassung |
| The contributions of the projected changes in soil moisture to the overall climate change in
the tropics at the end of the 21st century are quantified using the simulations from the
GLACE-CMIP5 experiment. This is done by directly comparing the overall projected future
changes in climate, which are partly related to changes in soil moisture, to the changes in
climate that are not affected by any changes in soil moisture. As the five different climate
models contributing to the experiment, i.e., CESM, EC-EARTH, GDFL, IPSL and MPI-ESM
show quite different geographical distributions of the future changes in soil moisture in the
tropics as well as different magnitudes, we do not consider ensemble mean values based on
the corresponding simulations with these models but rather analyse the simulations from
the different models separately. This allows for quantifying the contributions of
the projected changes in soil moisture to climate change in the tropics for each
climate model despite the different characteristics of the soil moisture changes
themselves. We focus on two aspects of the interactions of the soil moisture with
climate, i.e., the soil moisture-temperature coupling and the soil moisture-precipitation
coupling/feedback.
The simulations show marked future changes in soil moisture content in the tropics, with
a general tendency of increases in the central parts of the tropics and decreases in the
subtropics. These changes are associated with corresponding changes in precipitation, with
an overall tendency of a 5change in soil moisture in response to a precipitation change of 1
mm/d. The changes in soil moisture content are found to give major contributions to the
overall climate change in the tropics. This is particularly the case for the latent and sensible
heat fluxes as well as near-surface temperature, where more than 80moisture changes. For
precipitation, on the other hand, 30-40overall future changes are induced by the
changes in soil moisture. The simulations confirm the conceptual models of the soil
moisture-temperature coupling and the soil moisture-precipitation coupling/ feedback
introduced by Seneviratne and colleagues. As for the soil moisture-temperature coupling,
decreases (increases) in soil moisture lead to increasing (decreasing) sensible heat fluxes and
near-surface temperatures. As for the soil moisture-precipitation feedback, increases
(decreases) in precipitation cause increases (decreases) in soil moisture content,
which, in turn, lead to increasing (decreasing) latent heat fluxes and precipitation. |
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