Tuesday, 11 February 2003: 3:30 PM
The Influence of the NAO/AO on Temperature Extremes in the Northeastern United States
We analyze the relationships between the North Atlantic Oscillation/Arctic Oscillation (NAO/AO) and local temperature response in the Northeastern United States and neighboring areas of Canada. The study focuses on how contrasts in mean and daily variance, based on AO phase, are associated with contrasts in the frequency and intensity of extreme events in both winter and spring. In this region, notable contrasts in mean temperature in winter and daily variance in spring, which influence the pattern of extremes, are associated with phases of the NAO/AO. Warmer temperatures in New England and cooler temperatures in Quebec results during winter with increases in the index. The mean temperature response is weaker in spring, but the response of daily variance of temperature is stronger; variance increases with the NAO/AO index. Relationships between these effects help explain significant increases in maximum temperature extremes during winter in New England and in minimum temperature extremes during spring in Quebec in high index years. Diurnal temperature range tends to be larger in AO positive winters and springs throughout the region.