HR: 0800h
AN: U21A-0801    [Abstracts]
TI: Towards a satellite-based sea ice climate data record
AU: Meier, W N
EM: walt@nsidc.org
AF: National Snow and Ice Data Center University of Colorado, UCB 449, Boulder, CO 80309 United States
AU: Fetterer, F
EM: fetterer@nsidc.org
AF: National Snow and Ice Data Center University of Colorado, UCB 449, Boulder, CO 80309 United States
AU: Stroeve, J
EM: stroeve@kryos.colorado.edu
AF: National Snow and Ice Data Center University of Colorado, UCB 449, Boulder, CO 80309 United States
AU: Cavalieri, D
EM: Donald.J.Cavalieri@nasa.gov
AF: NASA Goddard Space Flight Center, Code 614.1, Greenbelt, MD 20771 United States
AU: Parkinson, C
EM: Claire.L.Parkinson@nasa.gov
AF: NASA Goddard Space Flight Center, Code 614.1, Greenbelt, MD 20771 United States
AU: Comiso, J
EM: Josefino.C.Comiso@nasa.gov
AF: NASA Goddard Space Flight Center, Code 614.1, Greenbelt, MD 20771 United States
AU: * Weaver, R
EM: weaverr@kryos.colorado.edu
AF: National Snow and Ice Data Center University of Colorado, UCB 449, Boulder, CO 80309 United States
AB: Sea ice plays an important role in the Earth's climate through its influence on the surface albedo, heat and moisture transfer between the ocean and the atmosphere, and the thermohaline circulation. Satellite data reveal that since 1979, summer Arctic sea ice has, overall, been declining at a rate of almost 8%/decade, with recent summers (beginning in 2002) being particularly low. The receding sea ice is having an effect on wildlife and indigenous peoples in the Arctic, and concern exists that these effects may become increasingly severe. Thus, a long-term, ongoing climate data record of sea ice is crucial for tracking the changes in sea ice and for assessing the significance of long-term trends. Since the advent of passive microwave satellite instruments in the early 1970s, sea ice has been one of the most consistently monitored climate parameters. There is now a 27+ year record of sea ice extent and concentration from multi-channel passive microwave radiometers that has undergone inter-sensor calibration and other quality controls to ensure consistency throughout the record. Several algorithms have been developed over the years to retrieve sea ice extent and concentration and two of the most commonly used algorithms, the NASA Team and Bootstrap, have been applied to the entire SMMR-SSM/I record to obtain a consistent time series. These algorithms were developed at NASA Goddard Space Flight Center and are archived at the National Snow and Ice Data Center. However, the complex surface properties of sea ice affect the microwave signature, and algorithms can yield ambiguous results; no single algorithm has been found to work uniformly well under all sea ice conditions. Thus there are ongoing efforts to further refine the algorithms and the time series. One approach is to develop data fusion methods to optimally combine sea ice fields from two or more algorithms. Another approach is to take advantage of the improved capabilities of JAXA's AMSR-E sensor on NASA's Aqua satellite to provide improved parameters and additional insights into deficiencies in the SMMR-SSM/I products. Finally, other fertile sources of sea ice information are operational sea ice charts, such as those produced at the U.S. National Ice Center (NIC). There is a 23-year (1972-1994) record of sea ice available from the NIC ice charts and an update is in progress. These charts have already been used to evaluate passive microwave retrievals and to extend the SMMR-SSM/I time series back to late 1972, when a proof-of-concept single-channel ESMR radiometer began operation.
UR: http://nsidc.org/data/seaice/
DE: 0700 CRYOSPHERE (4540)
DE: 0750 Sea ice (4540)
DE: 0758 Remote sensing
DE: 9310 Antarctica (4207)
DE: 9315 Arctic region (0718, 4207)
SC: Union [U]
MN: Fall Meeting 2005