Short-term modulation of Indian summer monsoon rainfall by West Asian dust

Journal Article · Sun Mar 16 04:00:00 EDT 2014 · Nature Geoscience, 7 :308-313

DOI:https://doi.org/10.1038/NGEO2107· OSTI ID:1124043

Vinoj, V.; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho; Ma, Po-Lun; Landu, Kiranmayi; Singh, Balwinder

The Indian summer monsoon is the result of a complex interplay between radiative heating, dynamics and cloud and aerosol interactions. Despite increased scientific attention, the effect of aerosols on monsoons still remains uncertain. Here we present both observational evidence and numerical modeling results demonstrating a remote aerosol link to Indian summer monsoon rainfall. Rainfall over central India is positively correlated to natural aerosols over the Arabian Sea and West Asia. Simulations using a state-of-the-art global climate model support this remote aerosol link and indicate that dust aerosols induce additional moisture transport and convergence over Central India, producing increased monsoon rainfall. The convergence is driven through solar heating and latent heating within clouds over West Asia that increases surface winds over the Arabian Sea. On the other hand, sea-salt aerosol tends to counteract the effect of dust and reduces rainfall. Our findings highlight the importance of natural aerosols in modulating the strength of the Indian summer monsoon, and motivate additional research in how changes in background aerosols of natural origin may be influencing long-term trends in monsoon precipitation.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1124043
• Report Number(s): PNNL-SA-85785; KP1703020
• Journal Information: Nature Geoscience, 7 :308-313, Journal Name: Nature Geoscience, 7 :308-313
• Country of Publication: United States
• Language: English

Related Subjects

Dusty
Indian
Link
Monsoon
Rainfall
Summer
West Asian