caa a22 4500 605472009 CHVBK 20210128100336.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00382-014-2269-3 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2269-3 Why ensemble mean projection of south Asian monsoon rainfall by CMIP5 models is not reliable? [Elektronische Daten] [C. Sabeerali, Suryachandra Rao, A. Dhakate, K. Salunke, B. Goswami] Future projections of the Indian summer monsoon rainfall (ISMR) and its large-scale thermodynamic driver are studied by using CMIP5 model outputs. While all models project an increasing precipitation in the future warming scenario, most of them project a weakening large-scale thermodynamic driver arising from a weakening of the upper tropospheric temperature (UTT) gradient over south Asian summer monsoon region. The weakening of the UTT gradient under global warming scenarios is related to the increase in sea surface temperature (SST) over the equatorial Indian Ocean (EIO) leading to a stronger increase of UTT over the EIO region relative to the northern Indian region, a hypothesis supported by a series of Atmospheric General Circulation Model (AGCM) experiments forced by projected SSTs. To diagnose the inconsistency between the model projections of precipitation and the large-scale thermodynamic driver, we have examined the rate of total precipitation explained by convective and stratiform precipitations in observations and in CMIP5 models. It is found that most models produce too much (little) convective (stratiform) precipitation compared to observations. In addition, we also find stronger precipitable water—precipitation relationship in most CMIP5 models as compared to observations. Hence, the atmospheric moisture content produced by the model immediately gets converted to precipitation even though the large-scale thermodynamics in models weaken. Therefore, under global warming scenarios, due to increased temperature and resultant increased atmospheric moisture supply, these models tend to produce unrealistic local convective precipitation often not in tune with other large-scale variables. Our results questions the reliability of the ISMR projections in CMIP5 models and highlight the need to improve the convective parameterization schemes in coupled models for the reliable projections of the ISMR. Springer-Verlag Berlin Heidelberg, 2014 Indian summer monsoon rainfall nationallicence CMIP5 nationallicence Global warming nationallicence Climate projections nationallicence Sabeerali C. Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut Rao Suryachandra Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut Dhakate A. Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut Salunke K. Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut Goswami B. Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut Climate Dynamics Springer Berlin Heidelberg 45/1-2(2015-07-01), 161-174 0930-7575 45:1-2<161 2015 45 382 https://doi.org/10.1007/s00382-014-2269-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2269-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sabeerali C. Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut NATIONALLICENCE 700 1- Rao Suryachandra Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut NATIONALLICENCE 700 1- Dhakate A. Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut NATIONALLICENCE 700 1- Salunke K. Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut NATIONALLICENCE 700 1- Goswami B. Indian Institute of Tropical Meteorology, Pune, Maharashtra, India aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 45/1-2(2015-07-01), 161-174 0930-7575 45:1-2<161 2015 45 382