Projected Future Changes of Meridional Heat Transport and Heat Balance of the Indian Ocean

Abstract

Abstract An ocean downscaling model product, forced under the Representative Concentration Pathway 8.5 future climate change scenario, has been used to understand the ocean heat balance of the Indian Ocean in a warming climate. Toward the end of the 21th century, the model simulates a significant reduction of Indonesian throughflow (ITF) transport, which reduces the Pacific to Indian Ocean heat transport by 0.20 PW, whereas across 32°S in the Southern Indian Ocean (SIO), the southward heat transport is reduced by 0.28 PW, mainly contributed from the weakening western boundary current, the Agulhas Current (0.21 PW). The projected weakening of the Agulhas Current is to compensate for the reduction of the ITF transport, with additional contribution from the spin‐down of the SIO subtropical gyre. Thus, being amplified by the ocean circulation changes in the SIO, the projected Indian Ocean warming trend will be faster than the direct air‐sea heat flux input.