Jun 8, 2010

Permafrost thermal state in the polar Northern Hemisphere during the international polar year 2007–2009: a synthesis

by
Romanovsky, Vladimir E., Smith, Sharon L., Christiansen, Hanne H.
,
Permafrost and Periglacial Processes
  • States the permafrost monitoring network in the polar regions of the Northern Hemisphere was enhanced during the International Polar Year (IPY), and new information on permafrost thermal state was collected for regions where there was little available
  • States that this augmented monitoring network is an important legacy of the IPY, as is the updated baseline of current permafrost conditions against which future changes may be measured
  • States that within the Northern Hemisphere polar region, ground temperatures are currently being measured in about 575 boreholes in North America, the Nordic region and Russia—these show that in the discontinuous permafrost zone, permafrost temperatures fall within a narrow range, with the mean annual ground temperature (MAGT) at most sites being higher than −2°C
  • Presents a greater range in MAGT within the continuous permafrost zone, from above −1°C at some locations to as low as −15°C
  • Results indicate that the permafrost warming which started two to three decades ago has generally continued into the IPY period
  • Finds that warming rates are much smaller for permafrost already at temperatures close to 0°C compared with colder permafrost, especially for ice-rich permafrost where latent heat effects dominate the ground thermal regime
  • Finds that colder permafrost sites are warming more rapidly
  • States this improved knowledge about the permafrost thermal state and its dynamics is important for multidisciplinary polar research, but also for many of the 4 million people living in the Arctic
  • States that, in particular, this knowledge is required for designing effective adaptation strategies for the local communities under warmer climatic conditions