Surface ocean-lower atmospheric processes in the Indian Ocean: Current understanding, knowledge gaps, and future directions

Abstract

Our understanding of surface ocean and lower atmosphere processes in the Indian Ocean (IO) region shows significant knowledge gaps mainly due to the paucity of observational studies. The IO basin is bordered by landmasses and an archipelago on 3 sides with more than one-quarter of the global population dwelling along these coastal regions. Therefore, interactions between dynamical and biogeochemical processes at the ocean-atmosphere interface and human activities are of particular importance here. Quantifying the impacts of changing oceanic and atmospheric processes on the marine biogeochemical cycle, atmospheric chemistry, ecosystems, and extreme events poses a great challenge. A comprehensive understanding of the links between major physical, chemical, and biogeochemical processes in this region is crucial for assessing and predicting local changes and large-scale impacts. The IO is one of the SOLAS (Surface Ocean-Lower Atmosphere Study) cross-cutting themes as summarized in its implementation strategy. This article attempts to compile new scientific results over the past decade focusing on SOLAS relevant processes within the IO. Key findings with respect to monsoon and air-sea interactions, oxygen minimum zones, ocean biogeochemistry, atmospheric composition, upper ocean ecosystem, and interactions between these components are discussed. Relevant knowledge gaps are highlighted, with a goal to assist the development of future IO research programs. Furthermore, we provided several recommendations to conduct interdisciplinary research to advance our understanding on the land-ocean-atmospheric interaction in the IO.