Geoscience Reference
In-Depth Information
SEA ICE MOTION AND DEFORMATION
IN THE MARGINAL ICE ZONE THROUGH SAR
∗
JUN YU
†
, ANTONY K. LIU
‡
and YUNHE ZHAO
§
†
Department of Mathematics and Statistics, University of Vermont
16 Colchester Ave, Burlington, VT 05401, USA
‡
ONRIFO Asia, Unit 45002, PO Box 382
APO AP 96337-500
§
Caelum Research Corporation, Rockville, MD 20850, USA
The objective of this study is to explore motion and deformation of sea ice
in the marginal ice zone (MIZ). Sea ice properties in MIZ are highly variable
and complex due to the complexity of the ocean dynamic and thermodynamic
processes, as well as atmosphere-sea and ice-ocean interactions. These pro-
cesses and interactions play important roles in the distribution of heat, mass,
and momentum fluxes in Polar Regions and in the control of the ice edge and
its location. In an earlier study, sea ice features including thickness, type and
motion have been analyzed using the high resolution synthetic aperture radar
(SAR) imagery. A segmentation technique with dynamic local thresholding
(DLT) was used to segment and to perform ice floe tracking. In this paper, we
extend the earlier study to include motion and deformation analyses of the sea
ice, as well as the possible effects of air-ocean-ice interactions associated with
wind and waves. With the sea ice images well classified, it is e
cient to track
ice floes of different sizes and to study ice motions such as translation, rota-
tion, convergence and divergence. Finally, inter-comparisons between remotely
sensed products will be discussed.
1. Introduction
The ice cover in the marginal ice zone (MIZ), where sea ice and ocean
meet, is about 100 km wide from the ice edge. Dynamic and thermody-
namic processes in the MIZ are highly variable and complex due to a
variety of organized nonstationary motions, such as jets, fronts, vortices,
upwelling/downwelling.
1
,
2
The St. Lawrence Island polynya (SLIP) is a
commonly occurring winter phenomenon in the Bering Sea, where open-
ings in the ice cover are recurring.
3
These processes play important roles in
the distribution of heat, mass, and momentum fluxes in Polar Regions and
∗
This work is supported by the Vermont-NASA EPSCoR Program and the University
of Vermont.
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