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Global variations of local asymmetry in glacier altitude: separation of north-south and east-west components

Evans, I.S.; Cox, N.J.

Global variations of local asymmetry in glacier altitude: separation of north-south and east-west components Thumbnail


Authors

N.J. Cox



Abstract

North-south and east-west differences in firn-line altitude, equilibrium-line altitude or middle altitudes of glaciers can be separated by regression on the cosine and sine of glacier aspect (accumulation area azimuth). Allowing for regional trends in altitude, the north-south differences expected from radiation and shade effects can be reliably quantified from World Glacier Inventory (WGI) data. The north-south differences are greater in sunnier climates, mid-latitudes and steeper relief. Local altitude differences between north- and south-facing glaciers are commonly 70-320 m. Such asymmetry is near-universal, although weak in the Arctic and tropics. East-west contrasts are less, and found mainly in the tropics and areas most exposed to strong winds. Altitude, latitude, glacier gradient and height range, calculable from most of the WGI data, are potential controls on the degree of north-south contrast, as well as surrogates for climatic controls (temperature, precipitation, radiation and cloudiness). An asymmetric sine-cosine power model is developed to describe the variation of north-south contrast with latitude. Multiple regression over 51 regions shows altitude and latitude to be the strongest controls of this contrast. Aspect-altitude analysis for former glaciers provides new evidence of cloudiness.

Citation

Evans, I., & Cox, N. (2005). Global variations of local asymmetry in glacier altitude: separation of north-south and east-west components. Journal of Glaciology, 51(174), 469-482. https://doi.org/10.3189/172756505781829205

Journal Article Type Article
Publication Date 2005-06
Deposit Date Nov 14, 2006
Publicly Available Date Apr 6, 2010
Journal Journal of Glaciology
Print ISSN 0022-1430
Electronic ISSN 1727-5652
Publisher International Glaciological Society
Peer Reviewed Peer Reviewed
Volume 51
Issue 174
Pages 469-482
DOI https://doi.org/10.3189/172756505781829205
Keywords Equilibrium-line altitudes.
Publisher URL http://www.ingentaconnect.com/content/igsoc/jog/2005/00000051/00000174/art00015

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Copyright Statement
© 2005 International Glaciological Society






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