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Geodetic and direct mass-balance measurements: comparison and joint analysis

  • J. Graham Cogley (a1)
Abstract

This paper describes a new compilation of both direct and geodetic mass-balance measurements, develops a procedure to reduce diverse balance measurements over different time-spans to common time-spans, and presents updated estimates of global average balance of small glaciers based on the enlarged compilation. Although geodetic measurements are fewer than direct measurements, they cover four times as many balance years. Direct and geodetic measurements are unbiased with respect to one another, but differences are often substantial. The statistical procedure can be understood by imagining that an n-year balance measurement is an average of a series of 1 year measurements. The series is hypothetical but we can calculate the uncertainty of each of its elements if, in addition to its measured average, we can also estimate its standard deviation. For this claim to be valid, the annual series must be stationary and normally distributed with independent (roughly, uncorrelated) elements, for which there is reasonable evidence. The need to know the standard deviation means that annual direct measurements from a nearby glacier, or equally reliable information about variability, are indispensable. Given this information, the new methodology results in moderately more negative balances. This is probably because tidewater glaciers are better represented in the geodetic data. In any case, the most recent published estimate of global average balance, 0.8–1.0mma–1 of sea-level equivalent for 2001–04, is now increased substantially to 1.1–1.4 mma–1 for 2001–05.

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References
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Braithwaite, R. 2008. Temperature and precipitation climate at the equilibrium-line altitude of glaciers expressed by the degree-day factor for melting snow. J. Glaciol., 54(186), 437–444.
Braithwaite, R.J. and Zhang, Y.. 1999. Relationships between interannual variability of glacier mass balance and climate. J. Glaciol., 45(151), 456–462.
Cogley, J.G. 2004. Greenland accumulation: an error model. J. Geophys. Res., 109(D18), D18101. (10.1029/2003JD004449.)
Cogley, J.G. 2005. Mass and energy balances of glaciers and ice sheets. In Anderson, M.G., ed. Encyclopaedia of hydrological sciences. Part 14. Snow and glacier hydrology. New York, Wiley, 2555–2573.
Cogley, J.G. and Adams, W.P.. 1998. Mass balance of glaciers other than the ice sheets. J. Glaciol., 44(147), 315–325.
Cogley, J.G. and M.S., McIntyre. 2003. Hess altitudes and other morphological estimators of glacier equilibrium lines. Arct. Antarct. Alp. Res., 35(4), 482–488.
Dyurgerov, M.B. and Meier, M.F.. 2005. Glaciers and the changing Earth system: a 2004 snapshot. Boulder, CO. Institute of Arctic and Alpine Research. (INSTAAR Occasional Paper, 58.)
Kalnay, E. and 21 others. 1996. The NCEP/NCAR 40-year reanalysis project. Bull. Am. Meteorol. Soc., 77(3), 437–471.
Kaser, G., Cogley, J.G., Dyurgerov, M.B., Meier, M.F. and Ohmura, A.. 2006. Mass balance of glaciers and ice caps: consensus estimates for 1961–2004. Geophys. Res. Lett., 33(19), L19501. (10.1029/2006GL027511.)
Oerlemans, J., Dyurgerov, M. and van de Wal, R.S.W.. 2007. Reconstructing the glacier contribution to sea-level rise back to 1850. Cryosphere, 1(1), 59–65.
Ohmura, A. 2004. Cryosphere during the twentieth century. In Sparling, J.Y. and Hawkesworth, C.J., eds. The state of the planet: frontiers and challenges in geophysics. Washington DC, American Geophysical Union, 239–257.
Ohmura, A., Kasser, P. and Funk, M.. 1992. Climate at the equilibrium line of glaciers. J. Glaciol., 38(130), 397–411.
Østrem, G. 1972. Height of the glaciation level in northern British Columbia and southeastern Alaska. Geogr. Ann., 54A(2), 76–84.
Sapiano, J.J., Harrison, W.D. and Echelmeyer, K.A.. 1998. Elevation, volume and terminus changes of nine glaciers in North America. J. Glaciol., 44(146), 119–135.
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Annals of Glaciology
  • ISSN: 0260-3055
  • EISSN: 1727-5644
  • URL: /core/journals/annals-of-glaciology
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