Date: 13 April 2021, 9:00 – 10:30 GMT
Hanne Sagen, Senior Researcher, Nansen Environmental and Remote Sensing Center (NERSC), Norway
Agnieszka Beszczynska-Möller, Senior Researcher, Institute of Oceanology of the Polish Academy of Sciences (IOPAN), Poland
Course summary: Fixed ocean moorings are the main platforms to provide long-term observations of marine environment, covering different time scales from shorter than hourly to monthly, seasonal and multi-annual measurements. Moored instruments can measure different ocean variables, including physical, biogeochemical and biological parameters (and also collect samples and visual images) in the entire water column, also under the sea ice. However, mooring operations in the demanding, ice-covered polar areas are linked to unique challenges, related both to the platform design (instrumentation and mooring hardware) and to the manner of deployment and recovery from an icebreaker in conditions of partial or even sea ice cover. During this short course, we introduced the main issues about how to plan, design, equip and operate a mooring for measurements in the polar region and discuss planning the campaign and specific ship operations for deployment and recovery of moorings in ice-covered waters. The details of such work were explored using a case study with the deep ocean acoustic multidisciplinary moorings deployed under the CAATEX project for 2019-2020 in the Arctic Ocean from the Norwegian Coast Guard icebreaker KV Svalbard.
Photo: Lisa Grosfeld / AWI
Part I Mooring operations in polar water – a general introduction (Agnieszka Beszczynska-Möller)
1. Mooring as a platform for long-term measurements.
2. Environmental constraints for mooring measurements in polar waters.
3. Different types of moorings used for applications in the Arctic – open ocean and fjords.
4. Overview of moored instruments used for physical, biogeochemical and biological observations and their applicability to operate in polar waters.
5. Mooring hardware and localization equipment (acoustic pingers, Argos/Iridium beacons, avalanche beacons).
6. Mooring design and requirements for operations in ice-cover waters (MDD Toolbox, distribution of mooring components and buoyancy, ice avoidance, etc.).
7. Deployment procedures (anchor first and anchor last methods, ship equipment).
8. Recovery procedures and possible challenges.
9. Examples of moorings and moored arrays in the Arctic Ocean and a future vision.
Part II Mooring operations in polar water – a case study of the CAATEX experiment in the Arctic Ocean (2019-2020) (Hanne Sagen)
1. The scientific plan and design of the CAATEX experiment.
2. Design of CAATEX moorings for deployment and recovery in ice.
3. Field experiment planning (sea ice information, route planning, logistics) and changes to the plan.
4. Deployment procedure (drift tests, bathymetric survey, deployment procedure).
5. Positioning of moorings and transponder network.
6. Mobilization prior to recovery of under-ice moorings.
7. Recovery under normal conditions in the Nansen Basin (daylight in July)
8. Recovery in cold and dark conditions in the Beaufort Sea (Arctic night in late November)
9. Lessons learned and summary and discussion