This paper specifically demonstrates an association between seasonal d 18 O variability on Greenland and atmospheric circulation. We determine key patterns of spatial and temporal d 18 O variability occurring over an array of shallow ice cores around the Greenland Summit, and link this spatial and temporal d 18 O variability to changes in atmospheric circulation. Individual ice core time series are available for the period 1959-1987, permitting analysis of 29 winters and 28 summers, excluding summer 1987 when the cores were collected. Figure 2a shows winter spatial loading patterns. Component 1 contains high loadings on five sites across the southern portion of the ice core array, while component 2 has high loadings on four sites including two northern sites 15 and 37.
Some spatial overlap occurs among the first two component patterns.
Component one encompasses four sites along the western side of the ice core array while component three has highest loadings at two adjacent sites on the eastern side. The two highest loadings in component two are on opposite ends of the ice core array. These four core sites tend to exhibit high loadings on component 2. The mean winter pressure differences between terciles with temperature extremes at Angmagssalik peak in approximately the same location as in Figure 3a in the Norwegian Sea. The back-diffused d 18 O values at these three sites have high correlations to Angmagssalik air temperatures.