Surface Temperature Reconstructions for the Last 2,000 Years (2006) / Chapter Skim
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7 Glacier Length and Mass Balance Records
7 Glacier Length and Mass Balance Records
Pages 71-76
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From page 71... ...
· Glacier length is also influenced by changes in precipitation, but snow fall on mountain glaciers is currently increasing on average, so the retreat pattern is not due to climatic drying. · Glacier lengths provide temperature information that is independent of other temperature reconstruction methods, including the instrumental record.
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From page 72... ...
, providing strong evidence against drying as a cause of retreat for this time period. RECONSTRUCTING TEMPERATURE RECORDS FROM GLACIER RECORDS Records of glacier length changes during the 20th century and earlier have been analyzed to reconstruct past temperature changes (Oerlemans 1994, 2005a; Oerlemans et al.
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From page 73... ...
(B) Best estimate of the global mean temperature, obtained by combining the weighted global mean temperature for 18341990 with the average of temperature records at earlier times.
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From page 74... ...
The dominant climatic influences are temperature and snowfall rate, though other variables such as cloud cover can be important in some situations. A temperature increase in the overlying atmosphere increases the energy input to a melting glacier surface through increased downward longwave radiation and increased sensible heat transfer, increasing the rate of melt.
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From page 75... ...
, so the connection to temperature is different. OTHER INFORMATION AVAILABLE FROM GLACIERS Though not suitable for reconstructing temperature time series, other glacier indicators -- such as melting on ice caps, organic material uncovered when glaciers melt, and disintegration of ice shelves -- provide temperature information.
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From page 76... ...
If its present rate of shrinkage continues, it will disappear entirely within a few decades. Over the last few decades, the floating ice shelves along the Antarctic Peninsula have been disintegrating, following a progressively southward pattern (Vaughan and Doake 1996, Cook et al.
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