Enhancing international collaborations for the retrieval of sea ice floe size distribution (FSD) from satellite SAR imagery

Lead Research Organisation: Scottish Association For Marine Science
Department Name: Scottish Association For Marine Science

Abstract

Rapid decline in Arctic sea ice has been observed, and climate models predict even more dramatic changes in the near future. One of the key components that cause such rapid sea ice reduction is sea-ice floe (pieces) breakup in the margin of the ice area during spring and summer. At the edge of sea-ice area, sea-ice floes are exposed to waves and winds and break into smaller pieces. As they become smaller, they become easier to melt from the side and exposing more open water areas. More exposed open water areas then leads to warmer ocean as more sunlight absorb into the ocean, which in turn make sea ice more fragile and breakable. This process can accelerate sea ice retreat in summer and thus impact the minimum ice extent.

To understand the effects of such process on summer sea ice retreat, reliable information on sea-ice floe size distribution (FSD) is necessary. Such observations can be made from satellite Synthetic Aperture Radar (SAR) that can observe sea ice through cloud and darkness. There is an increasing number of satellite SAR images being acquired in the Arctic, and often at spatial resolutions in the images as good as 1-20 m. More importantly satellite SAR images are being acquired over autonomous buoy systems and in conjunction with field campaigns. This provides the ideal framework to measure the full range of ocean, sea-ice and atmosphere parameters to investigate complex floe breakup process.

However the challenge we have is a lack of proven-quality algorithms that can derive FSD from satellite SAR images fast and accurately. Thresholding algorithms previously applied to the problem are not adequate for quantitative analysis and the performance has not been precisely assessed. Recently NERC TPoC funded us to conduct research to develop cutting-edge algorithm for the retrieval of sea-ice FSD from SAR images.

In this IOP proposal we expand our current project internationally in order to add values to the current NERC TPoC project as well as have impacts on wide research communities and commercial companies.

Planned Impact

- Formation of cohesive research and user group. The major impact of this IOP project is to form a focused research group that has common interested in FSD retrieval algorithm (image processing) as well as the use of retrieved data (sea ice observations and modeling, and commercial companies). In this proposal we propose the workshop that involve wide-range of research areas including image processing, sea ice modelling and commercial companies. The workshop provides opportunity to identify and address any sea-ice FSD related issues, and will be the stepping stone to develop a research/user consortium in the future.

- Case study. While the proposed workshop take a holistic approach, the case study will have direct impacts on adding values on current NERC project. We carefully selected four key partners in image processing and remote sensing and one key partner in sea ice FSD modelling. These key partners will be directly involved in the case study that improve image processing algorithm and conduct inter-comparison and validation of the model outputs. This will have significant impacts on improvement of efficiency and accuracy of the sea-ice FSD retrieval algorithm, and also improve sea-ice FSD model parameterisations.
 
Description This grant provided a unique opportunity to establish collaborations with the scientists and engineers in various fields: image processing, machine learning, sea ice and ocean physics, which resulted in co-authored journal publications that highlight the importance of seasonal feedback of sea ice floes. In the Arctic, sea ice undergoes a continuous freeze-up, breakup and melt cycle. For example, in autumn sea ice and open water freeze to form a continuous sheet of winter ice, and the winter ice deforms and breaks apart into small pieces of ice (called floes) in spring and melt away in summer. The collaborative studies, funded by this grant, allowed us to examine this important seasonal cycle through developing computer algorithms to derive sea ice floe size distribution from satellite imagery.
Exploitation Route Our findings have been published in high-impact open-access journals, so that relevant researchers and publics can access the information.
Sectors Environment

 
Description NERC Standard grants
Amount £311,966 (GBP)
Funding ID NE/R000654/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 10/2017 
End 03/2020
 
Description Collaboration with Brown University 
Organisation Brown University
Country United States 
Sector Academic/University 
PI Contribution Our research team contributed Dr Horvat's research by providing observational data set to his modelling studies.
Collaborator Contribution Dr Horvat contributed to journal publication. Dr Horvat is a project partner of our NERC MOSAiC project.
Impact The collaborative workshop (called FSD workshop, held on July 6-7, 2015 at the Scottish Association for Marine Science). The collaboration resulted in a co-authored paper. This collaboration continued to grow, and he is now a formal project partner in the NERC MOSAiC project. This collaboration is not multi-disciplinary, but his expertise lies in numerical modelling but our research in observations, forming a collaborative research.
Start Year 2015
 
Description Collaboration with Dartmouth College 
Organisation Dartmouth College
Country United States 
Sector Academic/University 
PI Contribution The NERC project contributed Drs Song and Polashenski and Ms. Arntsen (PhD student) to join the inter-disciplinary workshop (called FSD workshop, directly funded by NE/M00600X/1).
Collaborator Contribution Dr. Song, Dr. Polashenski and Ms. Arntsen contributed to the collaborative workshop by providing the presentation on their recent works of high-resolution optical data, and participating group discussions regarding future collaborative research involving modelling and observations of sea ice. Prof Perovich and Ms. Arntsen contributed to a co-authored paper published in 2017.
Impact The collaborative workshop (called FSD workshop, held on July 6-7, 2015 at the Scottish Association for Marine Science). The collaboration resulted in a co-authored paper.
Start Year 2015
 
Description Collaboration with ETS 
Organisation Superior Technology School
PI Contribution Through the NERC project (NE/M00600X/1) I was able to visit Dr. Ben Ayed to discuss about future project to apply advanced optimization algorithms to sea ice feature extraction problems.
Collaborator Contribution During the visit Dr. Ben Ayed contributed to the discussion regarding the latest development of optimization algorithms which can be applied to specifically sea ice feature extraction. He contributed to a co-authored paper published in 2017.
Impact As a results of discussion, the collaborative proposal was formulated and successfully submitted to US Office of Naval Research (the funding decision is still pending). The collaboration resulted in a co-authored publication.
Start Year 2014
 
Description Collaboration with Gebze Technical University 
Organisation Gebze Technical University
Department Institute of Information Technologies
PI Contribution My NERC project enabled me to establish the collaboration with Dr. Erhan at Okan University, Turkey. During the visit in Turkey (supported by NE/M00600X/1), I provided significant domain knowledge on sea ice physics and satellite data so that Dr. Erhan can formulate optimized image processing tools to process sea ice remote sensing data. We invited Dr. Erhan to the UK to discuss sea ice image analysis.
Collaborator Contribution Dr. Erhan spent his time to formulate and apply various image processing algorithms (such as region-based classification and deep learning) to derive melt ponds and other sea ice features. He contributed to a co-authored paper published in 2017.
Impact An informal report has been produced between myself and Dr. Erhan. The collaboration resulted in a co-authored publication.
Start Year 2014
 
Description Collaboration with PSC at UW 
Organisation University of Washington
Country United States 
Sector Academic/University 
PI Contribution The NERC funded projects (NE/L012707/1) allowed us to develop state-of-the-art algorithm to derive sea ice floe size distribution (FSD) from high-resolution satellite synthetic aperture radar (SAR) data. Some of the derived FSD data have been contributed to collaborative research with Dr. Zhang at PSC/UW. We provided sea ice FSD (ranging between 200 m to 2 km) that significantly contributed to calibration of the recently developed numerical sea ice FSD model. Dr Zhang is now a project partner in the NERC MOSAiC project (NE/S0025454/1).
Collaborator Contribution Dr. Zhang contributed my NERC projects by providing detailed comparison between satellite-derived sea ice FSD and model-simulated FSD. This type of studies have not been attempted before. Some results of this collaborative partnership contributed to one co-authored manuscript submitted to Elementa. Dr Zhang has contributed to the NERC MOSAiC project (NE/S0025454/1 ) by proving his expertise on numerical modelling.
Impact The collaboration resulted in a co-authored paper published in 2016 and another paper in review, as well as a NERC proposal in 2018.
Start Year 2014
 
Description Collaboration with U of Strathclyde 
Organisation University of Strathclyde
Country United Kingdom 
Sector Academic/University 
PI Contribution The NERC project contributed Drs Ren, Marshall and Murray to join the inter-disciplinary workshop (called FSD workshop, directly funded by NE/M00600X/1).
Collaborator Contribution Dr. Ren (Co-I of the NERC project) contributed to the coordination of the workshop. Dr Ren contributed to two co-authored papers published in 2017. Drs Marshall and Murray contributed to the collaborative workshop by providing the presentation on their image processing works and participating group discussions regarding future collaborative research involving image processing and observations of sea ice.
Impact The collaborative workshop (called FSD workshop, held on July 6-7, 2015 at the Scottish Association for Marine Science). The collaboration resulted in two co-authored papers in 2017, and one NERC proposal (Dr Ren as CoI) in 2018.
Start Year 2015
 
Description Guest speaker at SOLAS Workshop on Remote Sensing for Studying the Ocean-Atmosphere Interface 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact I was invited as a guest speaker at the SOLAS (Surface Ocean Lower Atmosphere Study) Workshop on Remote Sensing for Studying the Ocean-Atmosphere Interface, USA. In this talk, I introduced my research on Marginal Ice Zone (MIZ) from the algorithm development to process studies. This talk raised the importance of MIZ process related research and discussions and led to future related activity within SOLAS community: forming a discussion session on MIZ process at the SOLAS Open Science Conference to be held in Japan in April 2019.
Year(s) Of Engagement Activity 2012,2018
URL https://www.confmanager.com/main.cfm?cid=2778&nid=16562
 
Description Invited talk at the Beijing University of Aeronautics and Astronautics, Beijing, China 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Postgraduate students
Results and Impact Invited talk at the Beijing University of Aeronautics and Astronautics. We shared our findings with Chinese professors and postgradudate students, and discussed about future collobrations.
Year(s) Of Engagement Activity 2017
 
Description Talk at the Isaac Newton Institute for Mathematical Sciences, University of Cambridge, UK 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The workshop was organised by international leading scientists in sea ice modelling and observation. More than 50 scientists were attended at the workshop. This provided an opportunity to introduce our findings and enhance further collaborations.
Year(s) Of Engagement Activity 2017
URL https://www.newton.ac.uk/event/sipw01