Understanding climate
for the benefit of society

The Nordic Seas revisited - 100 years of cooling service for the Global Ocean

In this project we will synthesize existing observations of ocean temperature in the Nordic Seas.


This paper will synthesize existing observations of ocean temperature in the Nordic Seas by integrating it with new CMIP6 and existing NorESM model simulations from 1900 onwards (Muilwijk et al., 2018) and atmospheric re-analysis. This will utilize updated present-day estimates of AW inflow across the Greenland Scotland Ridge (GSR, Østerhus et al. 2019) and incorporate recent findings from the Greenland and Iceland Sea (Våge et al. 2015; Håvik et al. 2017; Brakstad et al. 2019).

The AW inflow anomalies are mostly driven by large-scale atmospheric circulation, and we will use state-of-the art weather feature detection algorithms to detect cyclones (Wernli and Schwierz 2006) and jets (Spensberger et al. 2017). Further will atmospheric heat transport and ocean heat loss be analyzed from re-analysis products (Fasullo and Trenberth 2008; Trenberth and Fasullo 2018).

For the ocean part we will use new in house observations, as well as existing ocean datasets such as EN4, UDASH and the new ECCO ocean state available autumn 2019 (ECCOv4 updated, Fukomori et al., 2017, Forget et al., 2015) to narrow down the essential present-day dynamics. Updated observations of AW heat transport outside Svinøy and BSO sections will be included. The Nordic Seas is an important CO2 sink due to the effective cooling (Jeansson et al., 2010). We will therefore also determine how the heat anomalies affect this absorption of atmospheric CO2.


The main goal is to follow inflowing AW heat anomalies from the GSR and determine their consequences downstream in the Nordic Seas. Do they;

  1. escape to the atmosphere?
  2. are they buffered in the deep and intermediate waters?
  3. are they detectable in the cooled deep water overflow?
  4. do they contribute towards melting of Arctic sea ice and Greenland glaciers?
  5. do they affect the carbon uptake?

Leader: Lars Henrik Smedsrud