Photo: Espen Storheim, Nansensenteret
Photo: Espen Storheim, Nansensenteret

Advancing ocean observations below the Arctic sea ice

The challenging conditions in the Arctic require innovative approaches to allow for sustainable long-term observations of the ocean under the Arctic sea ice. Remotely operated vehicles are explored for efficient data retrieval and recharging of batteries in underwater installations. This will contribute to reduce the environmental impact of Arctic research.

Researchers in the EU-project HiAOOS, led by the Nansen Center, are developing technology to advance the ocean observing capabilities for the ice-covered Arctic Ocean. This year, they will deploy an extensive mooring network to provide ice-ocean point measurements and to observe temperatures over large distances using the speed of sound as a thermometer – known as acoustic thermometry. The same network will also support the geo-positioning of autonomously drifting instruments beneath the sea ice. The system will cover a large part of the Nansen and Amundsen Basins north of Svalbard and will be in operation for two years, until it will be recovered again in 2026.

Collecting data on the ocean under the Arctic sea ice comes with unique challenges. Setting out and recovering research infrastructure in an area with drifting ice requires ice breakers with trained personnel and specialized equipment for the operations. Doing this is both time-demanding and expensive, which is why we want to expand the time between deployment and recovery.

HiAOOS is working towards the future generation of underwater observing systems where batteries can be recharged and data can be downloaded with the use of remotely operated vehicles from the instruments underwater, without having to temporarily take the instruments up onboard a ship. This will extend the lifetime of moorings before they are recovered, which will reduce the environmental footprint of our operations, such as by reduced CO2 emissions. Read more on the project website.

Key researchers: Hanne Sagen, Espen Storheim, Torill Hamre, Stein Sandven, Florian Geyer, and Astrid Stallemo

About HiAOOS

  • Project leader: Hanne Sagen
  • Funding source: European Commission
  • Full project name: High Arctic Ocean Observation System
  • Aim: To develop new technologies to better obtain information about the ocean below the ice in the Arctic
  • Project website

What are moorings?

A mooring consists of a line, either wire or Kevlar rope, that is anchored to a heavy weight at the seafloor and has a floating device on top to hold it up straight. Along the line researchers can attach multiple types of instruments that can measure ice-ocean conditions. Mooring networks for acoustic thermometry and geo-positioning of drifting floats are equipped with acoustic sources and receivers.

Are you what will happen in HiAOOS in the future?

Here is an overview of the planned research cruises.