Ocean-atmosphere-ice processes in the Ross Sea: A review

The Ross Sea has been the site of extensive investigations since the earliest days of polar exploration. The International Geophysical Year of 1957-58 enhanced research activities with the establishment of scientific stations and the collection of oceanographic observations in the area. While many features of its oceanography, ecology, physics, glaciology, geology, and biogeochemistry are known, recent advances provide new insights into its structure and function, as well as into its relationship to global climate. We present a comprehensive review of the advances of understanding the main processes occurring in the area, such as the formation of dense shelf water and the production of Antarctic Bottom Water (AABW), as well as the main drivers (at both large and local scales) of local dynamics and water mass variability. We also summarize the main modeling applications, which are still limited and need to be improved using high-resolution models and, locally, limited-area models to explain processes driven mainly by thermodynamics and water-mass transformations. The Ross Sea forms the most saline AABW due to the activity of two polynyas in the western sector. A salinity gradient occurs on the shelf, with fresh Low Salinity Shelf Waters concentrated in the eastern Ross Sea, which is influenced by the inflow of fresh water from the Amundsen and Bellingshausen Seas. This freshwater inflow was thought to be the cause of a multi-decadal freshening of the High Salinity Shelf Water, precursor to the AABW, although a rebound in salinity in the Ross Sea has been observed since 2014. The increase in salinity has also affected the production of AABW, with the respective rebound occurring almost simultaneously.