Arctic Oscillation

1
Arctic Oscillation

• Positive Phase
• Prevailing low pressure over North Pole
• Strong Westerlies
• Warmer Winters for Northern Hemisphere

• Negative Phase
• Higher than normal pressure over North
  Pole
• Weak Westerlies
• Colder winters for Northern Hemisphere

2
Responsible for global warming?

• General increase in both trends from 1960-1992
• During 1990s, Arctic Oscillation index levels
  off while global temperature continues to rise
• Arctic Oscillation and broader global warming
  trend not strongly correlated