Indian Ocean Heat Transport in CMIP5 and CMIP6 models
Saran Rajendran*, S. Sandeep, Vinu Valsala
Centre for Atmospheric Sciences, IIT Delhi New Delhi, New Delhi, India Pincode: 110016 Mobile: 9562443007 E-mail: email@example.com
The oceanic meridional heat transport plays a crucial role in regulating the interannual variability of global climate. The Indian Ocean has a significant cross-equatorial meridional heat transport driven by the summer monsoon circulation. The study aims to understand Indian Ocean meridional ocean heat transport (OHT) in climate models and reanalysis data. The meridional heat transport in the Indian Ocean exhibits a solid annual cycle. The results show that both CMIP5 and CMIP6 climate models report a decline in mean OHT over the Indian Ocean in future projections under RCP8.5 and SSP585 emission scenarios. Specifically, the tropical Indian Ocean OHT shows an apparent decrease in almost all latitudinal sections in the future. These changes in OHT are more evident in CMIP6 compared to CMIP5. The decomposition analysis revealed that the wind-induced velocity-driven overturning component acts as a significant contributing factor for the changes in OHT. The winter heat transport is increasing across all latitudes in the northern Indian Ocean, and summer OHT is showing a decline in CMIP5 and CMIP6 future scenarios. Indonesian Throughflow plays a prominent role in ocean heat transport in the southern Indian Ocean.