section_path: Physical oceanography/Ross and Weddell gyres
section_name: Ross and Weddell gyres
paragraph_text: Ross and Weddell gyres
  
  The Ross Gyre and Weddell Gyre are two gyres that exist within the Southern Ocean. The gyres are located in the Ross Sea and Weddell Sea respectively, and both rotate clockwise. The gyres are formed by interactions between the Antarctic Circumpolar Current and the Antarctic Continental Shelf.
  
  Sea ice has been noted to persist in the central area of the Ross Gyre. There is some evidence that global warming has resulted in some decrease of the salinity of the waters of the Ross Gyre since the 1950s.
  
  Due to the Coriolis effect acting to the left in the Southern Hemisphere and the resulting Ekman transport away from the centres of the Weddell Gyre, these regions are very productive due to upwelling of cold, nutrient rich water.