4 research outputs found
Towards better representation of Indian summer monsoon rainfall in CMIP6 models: Evaluation of MISO and MJO simulation
The seasonal prediction of the Indian summer monsoon (ISM) and Monsoon
Intraseasonal Oscillations (MISO), as well as the Madden Julian Oscillations
(MJO) that strongly modulate MISO, is important to the country for water and
crop management. We have analyzed the precipitation, convection, and total
cloud fraction (TCF) in the sixth Coupled Model Intercomparison Projects
(CMIP6). This study highlights the significant differences in simulating MISO
and MJO between the two groups of selected CMIP6 models and physical reasons
behind them. The mean and intraseasonal features of MISO and MJO varied
significantly in CMIP6 models, which are linked with a better depiction of
convection and total cloud fraction. The probability distributions of rainfall
and OLR in CMIP6 models indicate significant variations in simulating ISM
precipitating clouds. TaiESM1 and IITM-ESM demonstrate improvements in
capturing the MISO features. TaiESM1 depicts better eastward propagation of MJO
during both summer and winter. The biases in OLR and TCF are also less in the
IITM-ESM and TaiESM1 models than in CanESM5 and FGOALS-g3. The results
demonstrate the importance of cloud and convection in CMIP6 models to depict
realistic MISO and MJO and provide a road map for improving ISM climate
prediction and projections.
Keywords: ISM rainfall, CMIP6 models, MISO, MJ
Unraveling the Global Teleconnections of Indian Summer Monsoon Clouds: Expedition from CMIP5 to CMIP6
We have analyzed the teleconnection of total cloud fraction (TCF) with global
sea surface temperature (SST) in multi-model ensembles (MME) of the fifth and
sixth Coupled Model Intercomparison Projects (CMIP5 and CMIP6). CMIP6-MME has a
more robust and realistic teleconnection (TCF and global SST) pattern over the
extra-tropics (R ~0.43) and North Atlantic (R ~0.39) region, which in turn
resulted in improvement of rainfall bias over the Asian summer monsoon (ASM)
region. CMIP6-MME can better reproduce the mean TCF and have reduced dry (wet)
rainfall bias on land (ocean) over the ASM region. CMIP6-MME has improved the
biases of seasonal mean rainfall, TCF, and outgoing longwave radiation (OLR)
over the Indian Summer Monsoon (ISM) region by ~40%, ~45%, and ~31%,
respectively, than CMIP5-MME and demonstrates better spatial correlation with
observation/reanalysis. Results establish the credibility of the CMIP6 models
and provide a scientific basis for improving the seasonal prediction of ISM.Comment: 12 pages, 4 main figures, 2 supplementary figure