Version 1
: Received: 5 August 2024 / Approved: 6 August 2024 / Online: 6 August 2024 (06:20:52 CEST)
How to cite:
St-Denis, F.; Tremblay, B. L.; Mahoney, A. R.; Takata-Glushkoff, P. A. L. M. Coastal Sea Ice Concentration Derived from Marine Radar Images: A Case Study from Utqiaġvik, Alaska. Preprints2024, 2024080387. https://doi.org/10.20944/preprints202408.0387.v1
St-Denis, F.; Tremblay, B. L.; Mahoney, A. R.; Takata-Glushkoff, P. A. L. M. Coastal Sea Ice Concentration Derived from Marine Radar Images: A Case Study from Utqiaġvik, Alaska. Preprints 2024, 2024080387. https://doi.org/10.20944/preprints202408.0387.v1
St-Denis, F.; Tremblay, B. L.; Mahoney, A. R.; Takata-Glushkoff, P. A. L. M. Coastal Sea Ice Concentration Derived from Marine Radar Images: A Case Study from Utqiaġvik, Alaska. Preprints2024, 2024080387. https://doi.org/10.20944/preprints202408.0387.v1
APA Style
St-Denis, F., Tremblay, B. L., Mahoney, A. R., & Takata-Glushkoff, P. A. L. M. (2024). Coastal Sea Ice Concentration Derived from Marine Radar Images: A Case Study from Utqiaġvik, Alaska. Preprints. https://doi.org/10.20944/preprints202408.0387.v1
Chicago/Turabian Style
St-Denis, F., Andrew R. Mahoney and Pacifica Askitrea Leona Mai Takata-Glushkoff. 2024 "Coastal Sea Ice Concentration Derived from Marine Radar Images: A Case Study from Utqiaġvik, Alaska" Preprints. https://doi.org/10.20944/preprints202408.0387.v1
Abstract
We apply the Canny Edge algorithm to the Utqiaġvik coastal sea ice radar system (CSIRS) to quantify open water and sea ice (landfast or drifting) concentration. The radar-derived sea ice concentration is compared against the 25-km resolution NSIDC Climate Data Record (CDR, one pixel closest to the radar field of view) and the 1-km merged MODIS-AMSR2 sea ice concentrations in the ∼11 km field of view for the year 2022-2023, when improved image contrast was first implemented. The algorithm was first optimized using sea ice concentration from 14 different images and 10 ice analysts (140 analysis in total) covering a wide range of ice condition with landfast ice, drifting ice and open water. The algorithm is also validated quantitatively against high-resolution MODIS-Terra in the visible range. Results show a correlation coefficient and mean bias error between the optimized algorithm, the CDR and MODIS-AMSR2 daily SIC of 0.18 and 0.54, and ∼ -1 and 0.9%, respectively, with an averaged inter-analyst error of ± 3%. In general, the CDR captures the melt period correctly and overestimates the SIC during the winter and freeze-up period, while the merged MODIS-AMSR2 better captures the punctual break-out events in winter including those during the freeze-up events (reduction of in SIC). Remnant issues with the detection algorithm include the false detection of sea ice in the presence, fog or precipitation (up to 20%), quantified from the summer reconstruction with known open water conditions. Coastal marine radars provide prove very useful in bridging the gap between (lower) resolution satellite-derived and in-situ (visual) sea ice conditions, and to quantify land contamination from lower resolution satellite-derived SIC.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
