Variability and trends in the Hadley and Walker Circulations as expressed in a high elevation ice core from the Gulf of Alaska region

The Hadley and Walker circulations dominate the climate of the tropics and contribute to extra-tropical climate variability through the forcing of wave-like patterns in the atmosphere known as teleconnections. Recent work has indicated that an ice core from a high elevation site on Mount Logan in the Canadian Yukon Territory contains an expression of one such teleconnection, the Pacific North America (PNA) pattern. In this talk, we show that the ice core also contains a signal related to the regional Hadley and Walker circulations in the Pacific. In particular, the recently observed acceleration in the rate of snow accumulation at the ice core site is related to secular changes in the intensities of these circulations.