VSGC Variation of the Sea Ice Concentration in the North Polar Region is coordinated by Professor Jun Yu. This work is an extension of the Arctic sea ice study performed in collaboration with NASA scientists at GODDARD Space Flight Center in Maryland, and supported by the NASA Joint Venture (JOVE) program during the period June 1993 to May 1996. Variations in the Arctic sea ice concentration during 1978-1987 have been studied utilizing the NASA data set obtained from the scanning multichannel microwave radiometer on board the Nimbus 7 satellite. Sea ice in the north and polar regions is one important component of the global climate system. Previous studies have shown that in addition to its various roles of affecting and reflecting conditions in the atmosphere and oceans, global sea ice can be an important indicator of changes occurring in the climate system. Trends and inter-annual variations in the global sea ice variables were studies by Gloersen and Campbell [1988] using a combined data set of Electrically-Scanned Microwave Radiometer on board the NASA Nimbus-5 satellite and SMMR. Parkinson [1992] introduced and analyzed the length of the sea ice season in the north polar region using the SMMR data set. More recently, direct Fourier analysis and multiple-taper filtering techniques [Gloersen, 1995; Gloersen et al., 1995] were applied to the SMMR sea ice concentration data and have revealed many interesting periodicities. Some of these fluctuations have been tentatively identified as tidal components or multi-year components close to those found in the ENSO Index. Spatial coherence of these fluctuations were also shown. A principal component analysis of the Arctic sea ice concentrations were given by Yu and Gloersen [1995], where singular value decomposition was used to obtain both temporal and spatial components of the data set. Multi-year components close to those found in the ENSO Index were also observed in the first five temporal components.
The JOVE project
has been mainly involved with the research reported in Gloersen et al. [1995]
and Yu and Gloersen [1995]. Future extensions of this research will include:
1) Use of the wavelet analysis to provide time-frequency information which may improve the understanding of the propagation of sea ice oscillations;
2) Use of principal component analysis of the residual data set, in which the mean, trend and the seasonal cycle computed by a least squares fit are removed.
These analyses may reveal important new properties of tidal and multi-year components.
[1] Gloersen, P. Nature 373:503-506, 1995.
[2] Gloersen, P. And W.J. Campbell. J Geophys Res 93:10666-10674, 1988.
[3] Gloersen, P., J. Yu, and E. Mollo-Christensen J Geophys Res, accepted for publication, 1995.
[4] Parkinson, C.L. J Geophys Res 97:14377-14388, 1992.
[5] Yu, J. And P. Gloersen. Submitted to J Geophys Res, 1995.