A sustained ocean observing system in the Indian Ocean for climate related scientific knowledge and societal needs

The Indian Ocean is warming faster than any of the global oceans and its climateis uniquely driven by the presence of a landmass at low latitudes, which causesmonsoonal winds and reversing currents. The food, water, and energy security in theIndian Ocean rim countries and islands are intrinsically tied to its climate, with marineenvironmental goods and services, as well as trade within the basin, underpinning theireconomies. Hence, there are a range of societal needs for Indian Ocean observationarising from the influence of regional phenomena and climate change on, for instance,marine ecosystems, monsoon rains, and sea-level. The Indian Ocean Observing System(IndOOS), is a sustained observing system that monitors basin-scale ocean-atmosphereconditions, while providing flexibility in terms of emerging technologies and scientific and societal needs, and a framework for more regional and coastal monitoring. Thispaper reviews the societal and scientific motivations, current status, and future directionsof IndOOS, while also discussing the need for enhanced coastal, shelf, and regionalobservations. The challenges of sustainability and implementation are also addressed,including capacity building, best practices, and integration of resources. The utility ofIndOOS ultimately depends on the identification of, and engagement with, end-usersand decision-makers and on the practical accessibility and transparency of data for arange of products and for decision-making processes. Therefore we highlight currentprogress, issues and challenges related to end user engagement with IndOOS, aswell as the needs of the data assimilation and modeling communities. Knowledge ofthe status of the Indian Ocean climate and ecosystems and predictability of its future,depends on a wide range of socio-economic and environmental data, a significant partof which is provided by IndOOS