Indian monsoon and the elevated-heat-pump mechanism in a coupled aerosol-climate model

A coupled aerosol‐atmosphere‐ocean‐sea ice climate model is used to explore the interaction between aerosols and the Indian summer monsoon precipitation on seasonal‐to‐interannual time scales. Results show that when increased aerosol loading is found on the Himalayas slopes in the premonsoon period...

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Bibliographic Details
Published in:Journal of Geophysical Research: Atmospheres
Main Authors: D'Errico, Miriam, Cagnazzo, Chiara, Fogli, Pier Giuseppe, Lau, William K. M., von Hardenberg, Jost, Fierli, Federico, Cherchi, Annalisa
Other Authors: #PLACEHOLDER_PARENT_METADATA_VALUE#, Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Bologna, Bologna, Italia
Format: Article in Journal/Newspaper
Language:English
Published: 2015
Subjects:
Online Access:http://hdl.handle.net/2122/12141
https://doi.org/10.1002/2015JD023346
Description
Summary:A coupled aerosol‐atmosphere‐ocean‐sea ice climate model is used to explore the interaction between aerosols and the Indian summer monsoon precipitation on seasonal‐to‐interannual time scales. Results show that when increased aerosol loading is found on the Himalayas slopes in the premonsoon period (April–May), intensification of early monsoon rainfall over India and increased low‐level westerly flow follow, in agreement with the elevated‐heat‐pump mechanism. The increase in rainfall during the early monsoon season has a cooling effect on the land surface. In the same period, enhanced surface cooling may also be amplified through solar dimming by more cloudiness and aerosol loading, via increased dust transported by low‐level westerly flow. The surface cooling causes subsequent reduction in monsoon rainfall in July–August over India. The time‐lagged nature of the reasonably realistic response of the model to aerosol forcing suggests that absorbing aerosols, besides their potential key roles in impacting monsoon water cycle and climate, may influence the seasonal variability of the Indian summer monsoon. Published 8712-8723 4A. Oceanografia e clima JCR Journal