Separating Annual, Interannual and Regional Change in Sea Surface Temperature in the Northeastern Atlantic and Nordic Seas

Abstract

 Seasonal fluctuations in Nordic Seas and Northeastern Atlantic sea surface temperatures explains 90 % of the variability. Both summer maxima and winter minima are warming, with summer temperatures warming twice as fast (0.4 and 0.2 °C per decade). Other sources of variability include sea-ice melt and switches in large-scale oceanographic conditions in the Northeastern Atlantic.

Large-scale culturing of the subpolar foraminifera Globigerina bulloides reveals tolerance to a large range of environmental parameters associated to different life-strategies and an extended lifespan

“…G. bulloides was determined to be tolerant of environmental conditions that were well outside its natural optimum range (<10°C, salinity <33, pH <8), with no significant difference in test size on death, between any of the different treatments. This suggests a high degree of adaptability that may serve it well under future ocean warming and acidifying scenarios in the Nordic Seas ( Fransner et al., 2022 ; Saes et al., 2022 ). Its resilience in the low-salinity treatment suggests it will also likely tolerate local freshening events due to changes in ocean circulation and freshwater fluxes ( Glessmer et al., 2014 ; Mork et al., 2019 ).…”

“…The Atlantic Ocean—Nordic Seas—Arctic Ocean interface is currently garnering increased scrutiny in the context of contemporary climate change ( Glessmer et al., 2014 ; Rudels et al., 2015 ; Polyakov et al., 2017 ; Walczowski et al., 2017 ; Asbjørnsen et al., 2020 ; Saes et al., 2022 ). “Atlantification” of the Nordic Seas and Arctic Ocean is causing warming and salinification, due to changes in the transport of Atlantic Water poleward, with consequent impacts on thermohaline circulation, sea ice formation, heat flux, surface water currents, and ecology ( Asbjørnsen et al., 2020 ; Ingvaldsen et al., 2021 ; Gerland et al., 2023 ).…”