Multi‐year subsurface mixing properties and air–sea interaction in the Arabian Sea Warm Pool

Abstract

Due to social and economic impacts on India and the surrounding countries, the Indian Summer Monsoon (ISM) has been at the forefront of a rich history of scientific discovery embedded in a broader scientific objective to understand the air–sea coupling, dynamics, and thermodynamics of the Indian Ocean. The Arabian Sea Warm Pool (ASWP), which is located to the west of the Indian subcontinent, is believed to play an important role in the initiation and modulation of the ISM. Past studies have indicated a link between ocean heat content (OHC) and various atmospheric properties related to the ISM (rainfall, onset vortex, etc.). This study uses 20 years of daily reanalysis data sets and observational data sets to analyze the atmosphere and subsurface of the ocean within the ASWP in order to understand better the role of the OHC on characteristics of the ISM. Climatologically, the oceanic and atmospheric reanalyses show many of the salient features that have been seen in past research, indicating high model fidelity overall. The study also uncovers increasing trends in OHC (as seen in previous studies), sea‐surface heights, and the depth of the 20 °C isotherm. This study also shows important pathways for subsurface freshwater flows from the Bay of Bengal to the Arabian Sea (AS), modulating the overall intensity of the ISM.