Keywords
Arctic, backscatter, ice edge, water, polarization, scatterometer, sea ice
Abstract
Sea-ice edge detection is an essential task at the different national ice services to secure navigation in ice-covered seas. Comparison between the Remund and Long ice mask image from enhanced-resolution QuikScat/SeaWinds (QS) products and the analyzed ice edge from high-resolution RADARSAT synthetic aperture radar has shown that the automatically determined QS ice mask underestimates the Arctic ice extent. QS data was statistically analyzed by colocating the data with ice charts around Greenland and with the National Aeronautics and Space Administration Team's Special Sensor Microwave/Imager (SSM/I) ice concentration algorithm over the whole Arctic region. All variables, i.e., the backscatter in vertical and horizontal polarization, the active polarization ratio (APR) and the daily standard deviation, are sensitive to ice types and are strongly correlated with ice concentration when the relationship is expressed in exponential form. Our study showed that the APR is especially suitable for ice-ocean separation, and a threshold of -0.02 was determined. An ice edge algorithm based on this APR threshold was developed using the other variables with conservative season-dependent thresholds to eliminate additional ocean noise. Also, the history of the ice cover is considered in order to detect single ice fields that are separated from the main Arctic pack ice. Validation with RADARSAT 1 and with the Advanced Very High Resolution Radiometer showed that the new algorithm successfully detects very low ice concentrations of about 10% during the entire year. The validity of the detected ice edge for near-real-time issues is also discussed in relation to the ice motion in the Marginal Ice Zone and the integration time necessary to produce the enhanced-resolution images. The new algorithm improves the automatic global ice edge resolution by a factor of two when compared to SSM/I products and could be used in both model initialization and data assimilation.
Original Publication Citation
Haarpaintner, J., et al. "Automatic Detection and Validity of the Sea-Ice Edge: An Application of Enhanced-Resolution QuikScat/SeaWinds Data." Geoscience and Remote Sensing, IEEE Transactions on 42.7 (24): 1433-43
BYU ScholarsArchive Citation
Long, David G.; Haarpaintner, Jorg; Tonboe, Rasmus T.; and Van Woert, Michael L., "Automatic detection and validity of the sea-ice edge: An application of enhanced-resolution QuikScat/SeaWinds data" (2004). Faculty Publications. 428.
https://scholarsarchive.byu.edu/facpub/428
Document Type
Peer-Reviewed Article
Publication Date
2004-07-01
Permanent URL
http://hdl.lib.byu.edu/1877/1021
Publisher
IEEE
Language
English
College
Ira A. Fulton College of Engineering and Technology
Department
Electrical and Computer Engineering
Copyright Status
© 2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
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