Ross Gyre
Climate change predictions anticipate a strengthening of the gyre's circulation which would increase shelf ice melt[12] and slowdown deep water formation.
[2] The eastern boundary is closely linked to where the ACC crosses the Pacific-Antarctic Ridge, at the Udintsev fracture zone, with a southward deflection to conserve vorticity.
[21] The Ross Gyre plays an important role in exchanging polar water masses and heat in Antarctica, connecting the ACC to the Antarctic shelf.
[21] The western limb of the gyre mediates the transfer of cold meltwater and newly formed Antarctic Bottom Water (AABW) originating in the Ross Sea northward.
Recently, Argo floats, autonomous drifting and profiling platforms with various biogeochemical sensors including temperature, salinity, and nutrients, have been used to increase sampling effort.
Its waters contribute to the life cycle of the economically valued Antarctic toothfish (Dissostichus mawsoni),[26] commonly marketed as Chilean seabass, and at least eight species of seabirds[11] have been recorded in the region.
A study in 2019 showed Adélie penguins increased their foraging efforts by traveling beyond the Ross Sea Marine Protected Area during their sub-adult phase and non-breeding season.
[27] Slender-billed prion, mottled petrels, and Adelie penguins all demonstrate a preference towards very cold waters, making the Antarctic current bordering the Ross Gyre a biogeographical boundary in the region.
[11] The Antarctic toothfish (D. mawsoni) plays an essential role in the Ross Gyre's food web, where it is a predator to other invertebrates and also part of the diet of the Weddell seal.
[26] A study by the National Institute of Water and Atmospheric Research in New Zealand found that the ice drift influenced by the Ross Gyre can determine the recruitment success of healthy juveniles.
[26] Historical data from the KRILL-DATABASE[10] project, from 1926 up to 2016, shows the presence of both Antarctic krill (Euphausia superba) and the planktonic tunicate Salpidae along the Polar Front, which accounts for the northern boundary of the Ross Gyre.
Predictions suggest that by the 2050s, the intensification of the Ross Gyre would also enhance the intrusion of warm Circumpolar Deep Water (CDW) towards the Antarctica west shelf, further increasing the loss of the Antarctic ice sheets.
Observational records from 1957 to 2020 have shown a near-linear decrease in salinity of 0.170 PSU in the Ross Sea due to temperature-induced warming in the West Antarctica ice sheet.
[13] Studies has explored the role of the Ross Gyre in carbon uptake by enhancing biological pump though ocean iron fertilization (OIF) experiments.
During the extreme El Niño event in 2015–2016, the SSH was observed to decrease by 6 cm, weakening the Antarctic Slope Current (ASC), which controls Ekman Transport.
Acquiring in-situ ship based measurements on research vessels is costly and challenging due to harsh weather conditions and ice coverage during winter.
[35] Oceanographic research in these remote regions is aided by autonomous monitoring devices, such as Argo Floats, which can constantly measure the ocean's biological, physical, and chemical properties.
This include temperature sensors that detect the presence of ice, allowing the instrument to communicate, avoid its ascend to the surface, store the data, and continue measurements during its descent.
