The Ross Gyre is one of the two gyres that exist within the Southern Ocean

Southern Ocean

The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...

. The gyre is located in the Ross Sea

Ross Sea

The Ross Sea is a deep bay of the Southern Ocean in Antarctica between Victoria Land and Marie Byrd Land.-Description:The Ross Sea was discovered by James Ross in 1841. In the west of the Ross Sea is Ross Island with the Mt. Erebus volcano, in the east Roosevelt Island. The southern part is covered...

, and rotates clockwise. The gyre is formed by interactions between the Antarctic Circumpolar Current

Antarctic Circumpolar Current

The Antarctic Circumpolar Current is an ocean current that flows from west to east around Antarctica. An alternative name for the ACC is the West Wind Drift. The ACC is the dominant circulation feature of the Southern Ocean and, at approximately 125 Sverdrups, the largest ocean current...

 and the Antarctic Continental Shelf

Antarctic continental shelf

The Antarctic continental shelf is a geological feature that underlies the Southern Ocean, surrounding the continent of Antarctica. The shelf is generally narrow and unusually deep, its edge lying at depths of 400 to 800 meters . It is home to a thriving ecosystem of penguins and cold-water fish....

. Sea ice

Sea ice

Sea ice is largely formed from seawater that freezes. Because the oceans consist of saltwater, this occurs below the freezing point of pure water, at about -1.8 °C ....

 has been noted to persist in the central area of the gyre.

There is some evidence that global warming

Global warming

Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

 has resulted in some decrease of the salinity

Salinity

Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...

of the waters of the Ross Gyre since the 1950s.