FastFind »   Lastname: doi:10.1029/ Year: Advanced Search  

AGU: Journal of Geophysical Research, Earth Surface

 

Keywords

  • Arctic
  • Baffin Island
  • glaciers
  • paleoclimate

Index Terms

  • 0473 - Paleoclimatology and paleoceanography
  • 0720 - Glaciers
  • 0740 - Snowmelt
  • 1621 - Cryospheric change

Paper in Press

JOURNAL OF GEOPHYSICAL RESEARCH, doi:10.1029/2011JF002248

Summer melt rates on Penny Ice Cap, Baffin Island: Past and recent trends, and implications for regional climate

Key Points
  • Summer melt rates on Penny Ice Cap have increased greatly in the past decades
  • The firn temperature of the ice cap is rising
  • The present thermal state of the ice cap resembles that last seen 3000 years ago

Authors:

Christian Zdanowicz

Anna Smetny-Sowa

David Andrew Fisher

Nicole Schaffer

Luke Copland

F Joe Eley

Florent Dupont

At latitude 66{degree sign}N, Penny Ice Cap on Baffin Island is the southernmost large ice cap in the Canadian Arctic, yet its past and recent evolution is poorly documented. Here we present a synthesis of climatological observations, mass balance measurements and proxy climate data from cores drilled on the ice cap over the past five decades (1953 to 2011). We find that since the late 1980s, Penny Ice Cap has entered a phase of enhanced melt rates related to rising summer and winter air temperatures across the eastern Arctic. Presently, 70-100 % (volume) of the annual accumulation at the ice cap summit is in the form of refrozen meltwater. Recent surface melt rates are found to be comparable to those last experienced more than 3000 years ago. Enhanced surface melt, water percolation and refreezing have led to a downward transfer of latent heat that raised the subsurface firn temperature by 10{degree sign}C (at 10 m depth) since the mid-1990s. This process may accelerate further wastage of the ice cap by pre-conditioning the firn for the ensuing melt season. Recent warming in the Baffin region has been larger in winter but more regular in summer, and observations on Penny Ice Cap suggest that it was relatively uniform over an elevation range of ~2 km. Our findings are consistent with trends in glacier mass wastage in the Canadian High Arctic and regional sea-ice cover reduction, reinforcing the view that the Arctic appears to be reverting back to a thermal state not seen in millennia.

Received 17 October 2011; accepted 6 February 2012.

Citation: Zdanowicz, C., A. Smetny-Sowa, D. A. Fisher, N. Schaffer, L. Copland, F. J. Eley, and F. Dupont (2012), Summer melt rates on Penny Ice Cap, Baffin Island: Past and recent trends, and implications for regional climate, J. Geophys. Res., doi:10.1029/2011JF002248, in press.