Mesoscale and Submesoscale Variability in the Indian Ocean

Abstract Material transport and air‐sea coupling dynamics associated with monsoon‐related mesoscale and submesoscale processes in the Indian Ocean significantly modulate biogeochemical cycles, the large‐scale energy balance, and both regional and global climate change. A thorough understanding of mesoscale and submesoscale variability in the Indian Ocean is therefore crucial for elucidating the physical mechanisms governing complex interactions among the ocean, ecosystems, and climate. However, substantial challenges remain in accurate observations, diagnoses, and simulations of such variability in the Indian Ocean, which hinders our ability to quantify their impacts on large‐scale processes. This synthetic paper presents an interdisciplinary review on key characteristics of the unique mesoscale and submesoscale processes in the Indian Ocean. We first synthesize current understanding of the generation of bidirectional energy cascades, feedback mechanisms between mesoscale/submesoscale dynamics and the atmosphere, and physical‐biogeochemical interactions mediated by horizontal and vertical transport induced by mesoscale/submesoscale motions. We then highlight outstanding knowledge gaps and uncertainties related to small‐scale physical properties, and provide recommendations for observational, modeling, and theoretical strategies to advance future research on air‐sea interactions and climate change. This review aims to complement existing global ocean process syntheses. Future directions are outlined with an emphasis on short‐term (e.g., dedicated observational campaigns), long‐term (e.g., improved modeling, climate integration) goals, and the emerging applications of machine learning and artificial intelligence in small‐scale parameterization and data assimilation.