WP1.2 – Circulation and water mass changes in the subpolar North Atlantic

The Atlantic Meridional Overturning Circulation (AMOC) transports warm and salty water from the tropics to the North Atlantic and thereby determines the mild climate in Northern Europe. Climate models show a weakening of this circulation in the future with far-reaching consequences for the climate and sea level. To determine if the circulation has already changed, and to have a basis to detect future changes, the strength of the circulation must be quantified at key points and the natural variability must be determined. We measure the circulation at the junction between the subpolar and the subtropical Atlantic along 47°N. The data acquired in this project forward the understanding of processes contributing to climate variability and constitute an important reference to validate and improve model simulations.


  • Quantification of the strength of the circulation in the subpolar North Atlantic at 47°N
  • Investigation of the processes contributing to the variability of the circulation
  • Comparison of the results with observations conducted south and north (WP2.2 in particular) of our observatory in national and international research efforts to understand changes in the entire circulation system


Simplified circulation scheme of the North Atlantic. Red: warm and salty surface circulation, blue: cold deep circulation. (Image: IUP, Universität Bremen)


Monika Rhein, MARUM-IUP, Uni­ver­si­tät Bre­men

Dagmar Kieke, MARUM-IUP, Uni­ver­si­tät Bre­men

Contributing scientists

Birgit Klein, BSH, Ham­burg

Hol­ger Klein, BSH,Ham­burg

Ma­nue­la Köll­ner, BSH, Hamburg

Martin Moritz, BSH, Hamburg


Chris­ti­an Mer­tens, MARUM-IUP, Uni­ver­si­tät Bre­men

Linn Sanguineti, MARUM-IUP, Universität Bremen