Long-term variability and trends in the Atlantic Water inflow region (A-TWAIN)

Warm water that flows northward from the Atlantic into the Arctic Ocean plays a crucial role for regional environmental conditions. The Fram Centre Flagship project A-TWAIN collects unique new data on the Atlantic Water that enters the Arctic Ocean north of Svalbard.




A-Twain overview map

Map: A. Sundfjord and A. Skoglund / Norwegian Polar Institute

Atlantic Water flows into the Arctic in two branches near Svalbard. One branch follows the outer perimeter of the Yermak Plateau north-west of Svalbard and then turns eastward, flowing as a wide, slow and semi-deep current along the outer, deep part of the continental slope. The other branch is warmer, faster and is found near the surface, following the upper part of the slope north of Svalbard. This large current system carries an enormous amount of heat and salt into the region – of similar magnitude as the Barents Sea Branch but with higher temperature when it enters the Arctic Ocean proper. It also brings a continuous supply of nutrients for primary production (phytoplankton growth) and transports living organisms of lower-latitude Atlantic origin into the area.

Project goals

Photo showing researchers working on the ship

Photo: Amy Cooper / Woods Hole Oceanographic Institute

The primary objective of this project, funded by the Fram Centre “Arctic Ocean” flagship, is to understand how heat from the Atlantic Water influences the Arctic Ocean sea ice cover, but also to provide data for understanding the playing field for some of the key actors in the ecosystem, and components of the carbon system. A-TWAIN (Long-term variability and trends in the Atlantic Water inflow region) was established to gain understanding on how the inflowing current system is distributed at different depths along the continental slope, how it responds to local, short lived atmospheric changes, and how it varies on seasonal and inter-annual timescales.

Project history

Photo showing a researcher working on the ship

Photo: Amy Cooper / Woods Hole Oceanographic Institute

The first moorings were deployed in September 2012, during a cruise where a large survey of hydrography was undertaken. In 2013 the moorings were recovered, and a new spatial mapping of water masses was done. Moorings were deployed again from 2013 to 2015, and redeployed again from 2015 to 2017. More information on the cruises can be found in cruise reports (link to be added). Peer review papers describing some of the first findings from 2012 to 2013 can be found under Publications. Data sets are being published as they are processed and key findings published (see Data sets).


Partner institutes and contact persons

Fram Centre Project partners

  • Norwegian Polar Institute - Arild Sundfjord
  • Institute of Marine Research - Randi Ingvaldsen
  • UiT the Arctic University of Norway - Marit Reigstad
  • UNIS - Frank Nilsen

International collaborators

  • Institute of Oceanology PAS (IOPAS), Poland - Agnieszka Beszczynska-Möller
  • Woods Hole Oceanographic Institution (WHOI), USA - Robert S. Pickart
  • Scottish Association for Marine Science (SAMS), UK - Finlo Cottier


Group photo showing personnel working on the A-Twain project

Photo: Amy Cooper / Woods Hole Oceanographic Institute