02656nas a2200253   4500008004100000022001400041245010800055210006900163260005700232300000900289490000700298520174500305653003402050653002402084653002502108653003002133100001702163700002402180700001502204700001702219700002102236700001702257856012802274       2011                        eng d  a0930-757500aCrucial role of ocean-atmosphere coupling on the Indian monsoon anomalous response during dipole events0 aCrucial role of oceanatmosphere coupling on the Indian monsoon a  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUL  a1-170 v373 a<p>This paper examines an issue concerning the simulation of anomalously wet Indian summer monsoons like 1994 which co-occurred with strong positive Indian Ocean Dipole (IOD) conditions in the tropical Indian Ocean. Contrary to observations it has been noticed that standalone atmospheric general circulation models (AGCM) forced with observed SST boundary condition, consistently depicted a decrease of the summer monsoon rainfall during 1994 over the Indian region. Given the ocean-atmosphere coupling during IOD events, we have examined whether the failure of standalone AGCM simulations in capturing wet Indian monsoons like 1994 can be remedied by including a simple form of coupling that allows the monsoon circulation to dynamically interact with the IOD anomalies. With this view, we have performed a suite of simulations by coupling an AGCM to a slab-ocean model with spatially varying mixed-layer-depth (MLD) specified from observations for the 1994 IOD; as well as four other cases (1983, 1997, 2006, 2007). The specification of spatially varying MLD from observations allows us to constrain the model to observed IOD conditions. It is seen that the inclusion of coupling significantly improves the large-scale circulation response by strengthening the monsoon cross-equatorial flow; leading to precipitation enhancement over the subcontinent and rainfall decrease over south-eastern tropical Indian Ocean-in a manner broadly consistent with observations. A plausible physical mechanism is suggested to explain the monsoonal response in the coupled frame-work. These results warrant the need for improved monsoon simulations with fully coupled models to be able to better capture the observed monsoon interannual variability.</p>10aAnomalous wet Indian monsoons10aIndian ocean dipole10aNumerical simulation10aOcean-atmosphere coupling1 aKrishnan, R.1 aSundaram, Suchithra1 aSwapna, P.1 aKumar, Vinay1 aAyantika, D., C.1 aMujumdar, M.  uhttps://library.ncl.res.in/content/crucial-role-ocean-atmosphere-coupling-indian-monsoon-anomalous-response-during-dipole-0