Changes in glacier extent on north Novaya Zemlya in the twentieth century

Abstract

Glacier retreat on north Novaya Zemlya for the past century was documented by registering glacier terminus positions from expedition and topographic maps and remotely sensed images. Recession of tidewater calving glaciers on north Novaya Zemlya in the first half of the twentieth century was relatively rapid (>300 m yr-1), consistent with post-‘Little Ice Age’ warming documented by a 122-year instrumental record from Malye Karmakuly. The glaciers completed 75 to 100% of the net twentieth-century retreat by 1952. Between 1964 and 1993 half of the studied glaciers were stable; the remainder retreated modest distances of <2.5 km. This stability coincides with decreasing average temperatures, especially during the winter, which is counter to model prediction. There is a statistically significant covariance of unfiltered winter and summer temperatures from Novaya Zemlya and a smoothed 88-year record of SSTs in the southern Barents Sea (r>0.75). Elevated SST in the Barents Sea appear to reflect increased advection of warm North Atlantic water associated with a positive North Atlantic Oscillation index (NAO). Winter temperatures are periodically correlated with the NAO (r = 0.75 to 0.9) reflecting repeated penetration of Atlantic cyclones into the Arctic. During the twentieth century, an overall positive glacier mass balance trend at Novaya Zemlya is associated with a positive phase of the NAO, elevated southern Barents Sea SST, and a concomitant increase of winter precipitation. Strong NAOs enhance winter precipitation and (3–5 yr delayed) summer temperatures on Novaya Zemlya and have a variable effect on Novaya Zemlya glaciers.