- Moorings are autonomous long-term monitoring systems installed at key points in the global ocean circulation system, where they continuously gather data.
- These instruments for marine research make it possible to continuously gather data even in the polar regions and offer valuable insights into how the world’s oceans are changing.
- The Sea Ice Portal now offers information on how moorings work and are deployed, together with an overview of historical and current mooring data.
What are moorings?
Moorings are stationary monitoring systems that continually gather key oceanographic data at a fixed location for years at a time. They can help to identify and understand both natural variations in ocean characteristics and alterations produced by climate change. Each mooring consists of an anchor, a long wire, and several floats, which keep the wire positioned vertically in the water column. Various monitoring devices are mounted along the length of the wire and autonomously measure essential parameters like the water temperature, salinity, flow direction and speed (Figure 1).
Dr Mario Hoppmann, a sea-ice physicist at the AWI, underscores the importance of these tools: “Oceanographic monitoring stations moored to the seafloor are the only way to continuously gather data at a fixed point in the ocean. They are the backbone of our long-term observations in the Arctic Ocean and Southern Ocean, making them an essential basis for investigating how climate change is impacting the polar seas.”
Challenges and innovations
Pursuing research in the polar regions poses unique challenges. Ship-based expeditions are largely limited to the summer months, and the number of available research vessels is limited. Moorings overcome these difficulties, gathering data year-round. Moorings are slowly and gently deployed from ships with the aid of cranes and winches. The monitoring devices are attached to the wire at carefully measured intervals. The length of the wire is also precisely measured, ensuring that the topmost floats remain a safe distance from the water’s surface – and preventing them from being damaged or even torn off by drifting sea ice or icebergs.
Moorings are recovered with the aid of acoustic signals transmitted from the base ship. When it picks up the signal, a “releaser” device opens a catch connecting the wire to the anchor. Now untethered, the wire, along with its floats and monitoring devices, rises to the surface. In ice-covered regions, the recovery process requires a good deal of skill and experience. You can find more details here.
Figure 1: Composition of a simple mooring. The monitoring devices and floats used vary depending on the location and underwater conditions.
What mooring data is available on the Sea Ice Portal’s data portal?
The Sea Ice Portal’s data portal offers an extensive collection of mooring data from the Arctic Ocean and Southern Ocean, divided into two main categories:
1. Collections of raw data from oceanographic moorings
This category includes both historical data from the Arctic Ocean (2018 – 2025) and data from the Southern Ocean (since 2019). In this category, mooring stations in various ocean regions are documented.
2. Currently active moorings
Here you will find information on ongoing mooring projects in the Arctic Ocean and Southern Ocean (since 2022), regularly updated to reflect new moorings, including their locations and monitoring parameters.
All data is updated on a regular basis and can be accessed here to support scientific analyses and/or climate research projects.
Moorings make it possible for researchers to observe and analyse long-term changes in the polar seas. Their data is vital to understanding the impacts of climate change on the delicate ecosystems of the Arctic and Antarctic.
Contact
Leonhard Günther (AWI)
Questions?
Write us an email or use the contact form.
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