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| Titel |
Non-linear reduction of Indian summer monsoon rainfall in response to global warming |
| VerfasserIn |
Jacob Schewe, Anders Levermann |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250047044
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| Zusammenfassung |
| In climate model simulations of the coming two centuries, we observe a marked reduction of
the Indian summer monsoon (ISM) circulation along with rising global temperature due to
anthropogenic greenhouse gas emissions. At the same time, the decadal-average seasonal
mean rainfall associated with the ISM first increases by about 10% during the 21st century,
but then experiences a rapid reduction by about 20%, compared to pre-industrial values,
during the 22nd century. The frequency distribution of seasonal mean rainfall changes its
shape during this process, with the skewness of the distribution changing sign, so that weak
monsoon years become much more likely. We explain this non-linear response on the basis of
two distinct monsoon modes. While an increase in specific humidity and in the
land-ocean temperature contrast shifts the baseline towards stronger rainfall, initially
leading to increased mean rainfall, the share of the weak monsoon mode increases at
the cost of the strong mode, causing the subsequent reduction in mean rainfall. |
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