Abstract
The Indian summer monsoon (ISM) transition is characterized by the seasonal reversal of winds from northeasterly in winter to southwesterly in summer over the north Indian Ocean. Physical processes that govern ISM dynamics are complex, with major characteristics being strong monsoon winds that pick up and transport moisture eastward, resulting in rain over the Indian subcontinent. The accumulation of moisture across the northern Indian Ocean depends on processes occurring on a range of scales across the air–sea transition zone, encapsulating the oceanic and atmospheric boundary layers and the air–sea interface. Many small-scale processes across the air–sea transition layer are not resolved by coupled prediction models and are instead represented by parameterizations, introducing uncertainty. The Enhancing Knowledge of the Arabian Sea Marine Environment through Science and Advanced Training (EKAMSAT) program aims to improve the understanding and parameterization of critical, unresolved small-scale processes that will improve monsoon prediction. This is accomplished through a team-based approach led by Indian and U.S. institutions from the research and operational communities that combines in situ process and large-scale remote observations, multiscale modeling, cross-scale synthesis, innovative training, and capacity building. This is being achieved through intensive multiplatform observational programs across the Arabian Sea and Bay of Bengal alongside a hierarchy of numerical simulations spanning process, regional, and global circulation models. With a focus on the northern Indian Ocean, the program aims to identify processes governing momentum, heat, and freshwater exchange across the air–sea interface during the ISM transition.