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Mass Balance of the Largest Ice Cap in the Eurasian Arctic
Reference
Bamber, J., Krabill, W., Raper, V. and Dowdeswell, J.  2004.  Anomalous recent growth of part of a large Arctic ice cap: Austfonna, Svalbard.  Geophysical Research Letters 31: 10.1029/2004GL019667.

What was done
High-accuracy ice-surface elevation measurements of the largest ice cap in the Eurasian Arctic -- Austfonna, which lies on the island of Nordaustlandet in northeastern Svalbard -- were made with the Airborne Topographic Mapper 3 (Krabill et al., 2000) in 1996 and 2002.  Upon finding significant elevation differences between the two measurement times, the authors analyzed meteorological and sea-ice records from adjacent regions in an attempt to find a logical explanation for what their elevation measurements revealed.

What was learned
Bamber et al. determined that the central and highest-altitude area of the ice cap, which comprises 15% of its total area, "increased in elevation by an average of 50 cm per year between 1996 and 2002," while "to the northeast of this region, thickening of about 10 cm per year was also observed."  They further note that the highest of these growth rates represents "as much as a 40% increase in accumulation rate (Pinglot et al., 2001)."

Based on the ancillary sea-ice and meteorological data they analyzed, the authors conclude that the best explanation for the dramatic increase in ice cap growth over the six-year study period was a large increase in precipitation caused by a concomitant reduction in sea-ice cover in this sector of the Arctic.

What it means
One way of characterizing the phenomenon described by Bamber et al. is simply to say that it represents the transference of ice from the top of the sea (in this case, the Barents Sea) to the top of adjacent land (in this case, the Austfonna ice cap).  And as what has been observed to date is but the beginning of the phenomenon, which will become even stronger in the absence of nearby sea-ice, "projected changes in Arctic sea-ice cover," as they say in the concluding sentence of their paper, "will have a significant impact on the mass-balance of land ice around the Arctic Basin over at least the next 50 years," which result may well be far, far different from what the world's climate alarmists are currently anticipating.

References
Krabill, W., Abdalati, W., Frederick, E., Manizade, S., Martin, C., Sonntag, J., Swift, R., Thomas, R., Wright, W. and Yungel, J.  2000.  Greenland ice sheet: High-elevation balance and peripheral thinning.  Science 289: 428-430.

Pinglot, J.F., Hagen, J.O., Melvold, K., Eiken, T. and Vincent, C.  2001.  A mean net accumulation pattern derived from radioactive layers and radar soundings on Austfonna, Nordaustlandet, Svalbard.  Journal of Glaciology 47: 555-566.


Reviewed 28 July 2004