Development of sea ice monitoring and forecasting system to support safe operations and navigation in Arctic Seas

The Sentinel-1A and 1B satellites of the Copernicus programme have become the main providers of SAR data both globally and in the Arctic sea ice regions. The SAR data are open and freely available from the ESA data hub as well as the national Sentinel ground segment operated by Norwegian Meteorological Institute. A system for data integration and processing, the Geo-Scientific Platform as a Services (GeoSPaas) is developed at the NERSC with support from several projects including SONARC. The system provides a chain of processing from importing the data, preprocessing, applying the drift algorithms and making the products from the SAR data. The system has been tested and demonstrated both internally and nationally for the Norwegian Meteorological Institute. The SAR data used in the project cover ice areas, mainly in the Fram Strait and the Chucki Sea as part of a demonstration of ice navigation. The main activity in the project has been to develop algorithms for processing and classification of icetypes in SAR data. The most important results has been a method for reduction of noise in the wideswath SAR images, developed by the postdoc scientist. The method is adopted by collaborating partners nationally and internationally because it improves the further analysis of the images, in particular the classification of ice types. Furthermore, algorithms for ice drift iceberg detection have been developed in collaboration with other projects supported by the Research Council of Norway (Ice Motion and CIRFA). The ice classification algorithm can be used to discriminate automatically between ice and open water using dual-polarisation images as well as to classify between thin ice, first-year ice and multiyear ice. This implies that open leads, which are important in ice navigation, can be detected in the SAR images. The algorithm work has been done in close collaboration with scientists and students at the Nansen Center in St. Petersburg. The navigation model developed by Scott Stephenson at University of Connecticut have been implemented at NERSC and can be used to estimate optimal sailing routes through ice for different types of vessels. The model has been adapted to use with SAR-based ice classification maps prepared by the classification algorithm. The model has been tested with ice classification maps from Sentinel1- data in the Kara Sea. A set of AIS data (Automatic Identification System) has been obtained from the Coastal Directorate and has been analysed for ship traffic in the Kara Sea area. The AIS data have been used to relate the speed vessels sailing in ice with ice information obtained from the SAR images. To combine AIS data an SAR data, which both are available in near-real time, will be a useful method for planning navigation routes in ice-covered waters. Use of SAR data with ice classification was demonstrated during a field experiment with the Korean icebreaker ARAON in the Chukci Sea in August 2018. The results of the project have been published in several journals and presented in a number of conferences, workshops, courses including teaching at UNIS. The proejct has been implemented in close collaboration with the partners in Russia and USA. The results have been exploited in other projects, in particular in the H2020 project SPICES, and demonstrated to users such as the Ice Service at Norwegian Meteorological Institute. The project website is http://sonarc.nersc.no.

The most significant outcome of the project is the noise reduction method for wideswath Sentinal-1 SAR images. The method has been adopted by several institutions in Europe working with SAR sea ice data, such as the operational ice charting services at Norwegian Meteorological Institute, Finish Meteorological Institute and Arctic and Antarctic Research Institute in Russia. The European Space Agency is also interested to use this method to improve the SAR products from Sentinel-1. The ice classification algorithm is also expected to be used by the operational ice charting services in Norway, Finland, Russia in order to improve the production of ice charts. The results have also been used to establish new projects at the Nansen Center in St. Petersburg, providing sea ice services to the Russian Oil and Gas industry. The ice navigation model, used in combination with SAR ice classification maps and AIS data, is expected to be a useful method to plan sailing routes in sea ice areas.

The main objective of SONARC is to develop a sea ice monitoring and forecasting system to support safe operations and navigation in Arctic Seas. SONARC will exploit Synthetic Aperture Radar (SAR) data from satellites as a major component of this system. From 2015 Sentinel-1 will the main provider of SAR data, which will be delivered every day in near realtime for monitoring of sea ice and other environmental parameters. The proposal will develop algorithms for (1) sea ice classification of different ice types and open water; (2) ice drift with sufficient resolution to map mesoscale ice motion and deformation fields; and (3) iceberg detection by combined use of SAR and high-resolution optical images. Furthermore, SONARC will integrate SAR data with AIS data (Automatic Identification System) from vessels operating in sea ice areas. With AIS positions combined with SAR images it will be possible for ship captains to find sailing routes through open leads or thin ice and avoid areas ice with ridges and other difficult ice situations. For planning optimal sailing routes in the Arctic, a navigation model will be used in combination with AIS and satellite-based ice data. Finally, the sea ice data and navigation data combined with ice forecasts will be demonstrated to an ice-going vessel during a field trial. The demonstration will also include use of an ice forecasting model developed at NERSC The results of the field trial will be assessed by users and recommendation for future implementation of a monitoring and forecasting system will be made. Key user groups for the system will be shipping companies, oil and gas companies, operational met-ocean services, coastal and ship traffic authorities, risk management, and environmental organizations working in the Arctic.