|
|
Abstracts
SEARCH Open Science Meeting
October 27, 2003
Seattle, Washington, USA
Pan-Arctic Observations of Interannual Snowmelt Change and Application to Flood Forecast
Son V. Nghiem1, Gregory Neumann2, Matthew Sturm3, Donald K. Perovich4
1Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 300-235, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA, Phone 818-354-2982, Fax 818-393-3077, Son.V.Nghiem@jpl.nasa.gov
2Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 300-319, 4800 Oak Grove Drive, Pasadena, CA, 91109, USA
3Cold Regions Research and Engineering Laboratory, U.S. Army, P.O. Box 35170, Ft. Wainwright, AK, 99703, USA, Phone 907-353-5183, Fax 907-353-5142, msturm@crrel.usace.army.mil
4Cold Regions Research and Engineering Laboratory, U.S. Army, 72 Lyme Road, Hanover, NH, 03755, USA, Phone 603-646-4255, Fax 603-646-4644, perovich@crrel.usace.army.mil
Global snow influences the global heat budget and has strong feedbacks with the planetary albedo and outgoing longwave radiation. Temperature change in Arctic and sub-Arctic regions is strongly influenced by the albedo-temperature feedback process. Hydrological and general circulation model simulations predict the largest changes in the hydrological cycle for the snow-dominated basins of mid to high latitudes. Water cycle changes are caused in part by the greater amount of warming in these regions, but more importantly, by the role of snow in the water balance [Nijssen et al., 2001]. The timing and magnitude of river discharge in the Arctic drainage system are strongly related to cold season snow mass storage and subsequent snowmelt. Decadal meteorological data sets indicate an increase in the amount of precipitation in winter season, increase in spring air temperature, and adverse shifting of snowmelt onset dates [Ma et al., 2002, Lobanov et al., 2001].
Long-term river-monitoring data reveal an increase in the annual discharge of fresh water from the six largest Eurasian rivers to the Arctic Ocean [Peterson et al., 2002, Yang et al., 2002]. In particular, the Lena River region, a very important region for Russian diamond mining industry, suffered catastrophic floods in recent years (1998, 1999, and 2001), and the 2001 flood was the worst in 100 years [Nghiem and Brakenridge, 2002]. Based on a field experiment [Nghiem et al., 1999] carried out in Ft. Wainwright, Alaska, we determine the relationship between Ku-band backscatter signature with the snowmelt process and snow albedo change.
The experiment results are used to develop an innovative method to determine the timing of snowmelt from onset to ground exposure (complete melt) using QuikSCAT/SeaWinds satellite scatterometer data. The very wide swath of the satellite sensor provides pan-Arctic observations of snowmelt two times per day. Snowmelt onset date, refreezing day, snowmelt duration, and complete melt date are obtained. Results are used to study interannual snowmelt changes in conjunction with flooding over the Lena River region. The analysis shows a distinctive relationship between the number of snowmelt days and flood severity. Furthermore, areal percentage reduction in daily snow coverage during the snowmelt process indicates that such data can be used to predict flooding conditions. This is because changes in snow reduction or snowmelt rate can be observed, thanks to the pan-Arctic coverage with the high temporal resolution of the satellite scatterometer, in advance of subsequent flood events caused by snowmelt. Images and multiple movies/animations showing the above results will be presented.
Abstract Categories: Changes on Land
Back to main abstract page
To view the list of records returned in your search you can use your browser's
back button, or perform the same search again:
|
