Melting of small Arctic ice caps observed from ERS scatterometer time series

Authors

Laurence C. Smith, University of California, Los Angeles
Yongwei Sheng, University of California, Los Angeles
Richard R. Forster, The University of Utah
Konrad Steffen, University of Colorado Boulder
Karen E. Frey, University of California, Los AngelesFollow
Douglas E. Alsdorf, University of California, Los Angeles

Document Type

Article

Abstract

Time series of active microwave backscatter data from the ERS Wind Scatterometers are used to demonstrate (1) the timing of melt onset can be observed over small ice caps, as well as the major ice sheets and multi-year sea ice; add (2) temporally integrated backscatter reduction (R) is strongly correlated with total annual positive-degree-days (PDD), as measured at four automated weather stations on the surface of the Greenland Ice Sheet. The latter is particularly interesting because unlike melt onset, R is a measure of melt processes integrated over an entire ablation season. Both methods work owing to the well-known sharp decrease in radar backscatter triggered by the appearance of liquid water in a glacier snowpack. Melt onset and R are determined for 14 small Arctic ice caps from 1992-2000. Interannual and regional variability in the timing of melt onset are comparable, averaging 33 ± 9 and 38 ± 13 days, respectively. Regional variability in R exceeds interannual variability, averaging 906 ± 164 and 309 ± 130 dB·d, respectively. The brevity of the derived nine-year records limits their statistical testing for trend. However, their qualitative interpretation suggests that the timing of melt onset is more variable for Arctic ice caps than for sea ice, and the intensity of summer surface melting increased by about 20% in the 1990s. © 2003 by the American Geophysical Union.

Publication Title

Geophysical Research Letters

Publication Date

10-15-2003

Volume

30

Issue

20

ISSN

0094-8276

DOI

10.1029/2003GL017641

Keywords

ice caps, Greenland Ice Sheet, sea ice

Repository Citation

Smith, Laurence C.; Sheng, Yongwei; Forster, Richard R.; Steffen, Konrad; Frey, Karen E.; and Alsdorf, Douglas E., "Melting of small Arctic ice caps observed from ERS scatterometer time series" (2003). Geography. 253.
https://commons.clarku.edu/faculty_geography/253

Copyright

Smith, Laurence C., et al. "Melting of small Arctic ice caps observed from ERS scatterometer time series." Geophysical research letters 30.20 (2003).