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Natural climate change and variability
Antarctic Oscillation or Southern Annular Mode
The South Pole almost constantly has a low pressure. Sometimes, the pressure is lower than usual around the South Pole, while it is higher than usual in the southern middle latitudes (about 40 to 50 deg S). When this occurs, the Southern Annular Mode (SAM) is said to be in a positive phase.
During this time, there are drier and warmer than usual conditions over southern South America, New Zealand, and Tasmania. It is also warmer than usual over the Antarctic Peninsula which is the northernmost part of Antarctica, the Peninsula extending into the Southern Ocean toward South America. However, the rest of Antarctica is cooler than usual, and parts of Australia are unusually cool, too.
Next page -> Antarctic Oscillation, continued
Links and resources
Antarctic Oscillation or Southern Annular Mode
The South Pole almost constantly has a low pressure. Sometimes, the pressure is lower than usual around the South Pole, while it is higher than usual in the southern middle latitudes (about 40 to 50 deg S). When this occurs, the Southern Annular Mode (SAM) is said to be in a positive phase.
During this time, there are drier and warmer than usual conditions over southern South America, New Zealand, and Tasmania. It is also warmer than usual over the Antarctic Peninsula which is the northernmost part of Antarctica, the Peninsula extending into the Southern Ocean toward South America. However, the rest of Antarctica is cooler than usual, and parts of Australia are unusually cool, too.
Next page -> Antarctic Oscillation, continued
Links and resources
