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Titel |
Increasing Arabian dust activity and the Indian summer monsoon |
VerfasserIn |
F. Solmon, V. S. Nair, M. Mallet |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 14 ; Nr. 15, no. 14 (2015-07-22), S.8051-8064 |
Datensatznummer |
250119917
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Publikation (Nr.) |
copernicus.org/acp-15-8051-2015.pdf |
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Zusammenfassung |
Over the past decade, aerosol optical depth (AOD) observations based on
satellite and ground measurements have shown a significant increase over
Arabia and the Arabian Sea, attributed to an intensification of regional dust
activity. Recent studies have also suggested that west Asian dust forcing
could induce a positive response of Indian monsoon precipitations on a weekly
timescale. Using observations and a regional climate model including
interactive slab-ocean and dust aerosol schemes, the present study
investigates possible climatic links between the increasing
June–July–August–September (JJAS) Arabian dust activity and precipitation
trends over southern India during the 2000–2009 decade. Meteorological
reanalysis and AOD observations suggest that the observed decadal increase of
dust activity and a simultaneous intensification of summer precipitation
trend over southern India are both linked to a deepening of JJAS surface
pressure conditions over the Arabian Sea. In the first part of the study, we
analyze the mean climate response to dust radiative forcing over the domain,
discussing notably the relative role of Arabian vs. Indo-Pakistani dust
regions. In the second part of the study, we show that the model skills in
reproducing regional dynamical patterns and southern Indian precipitation
trends are significantly improved only when an increasing dust emission trend
is imposed on the basis of observations. We conclude that although
interannual climate variability might primarily determine the observed
regional pattern of increasing dust activity and precipitation during the
2000–2009 decade, the associated dust radiative forcing might in return
induce a critical dynamical feedback contributing to enhancing regional
moisture convergence and JJAS precipitations over southern India. |
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