HR: 0830h
AN: C41C-1000    [PDF]
TI: Satellite Observation of Spring Ice Breakup on Large Northern Rivers
AU: * Pavelsky, T M
EM: pavelsky@ucla.edu
AF: UCLA Geography Department, Bunche 1255 Box 951524, Los Angeles, CA 90095 United States
AU: Smith, L C
EM: lsmith@geog.ucla.edu
AF: UCLA Geography Department, Bunche 1255 Box 951524, Los Angeles, CA 90095 United States
AB: The annual spring breakup of river ice plays a major role in physical, biological, and human systems on large arctic rivers. In addition, the timing of breakup has been used as a proxy for regional climate variations over the past century or more. However, most observations of ice breakup have been recorded in the form of point data taken from selected ground-based stations. While important, the use of this point-scale data presents difficulties in understanding both the process and the timing of ice breakup. More specifically, it is unknown whether observations of ice breakup taken at one point on a river are representative of breakup patterns along the entire course of that river. Through the use of a daily time series of satellite images, a technique has been developed through which ice breakup may be observed and mapped along the entire length of a river. The technique has been applied to the Lena, Ob, Yenisey, and Mackenzie Rivers for 1992-1993 and 1995-2003, with precision as good as plus or minus one to two days covering at least 75% of observations. While not universal, breakup seems to follow similar patterns on a given river from year to year, with variability of breakup date generally between 10 and 30 days depending on location. Patterns in the timing of breakup seem to be related to a number of factors, with latitude, location of confluences with major tributaries, and degree of braiding playing significant roles.
DE: 1863 Snow and ice (1827)
DE: 9315 Arctic region
SC: Cryosphere [C]
MN: 2003 Fall Meeting