Oceans 2025 Theme 1

Theme 1: Ocean circulation, sea level and climate change

The ocean plays a key role in the global climate system as the Earth’s major reservoir and pathway for heat, freshwater and carbon, and has a direct impact on coastal populations as a result of sea level change. Global climate change is likely to have a particularly strong impact in the North Atlantic, which has undergone a major warming and a possible reduction (by ~30%) in the strength of its meridional overturning circulation (MOC) in recent decades. Furthermore, the high latitude North Atlantic has freshened dramatically since the 1960s and major changes in the Arctic are presently underway (e.g. a historic minimum of summer sea ice extent in 2005). Palæoclimate records and numerical models show that the North Atlantic MOC is particularly vulnerable to perturbations in the freshwater budget, leading to potentially rapid changes in European climate.
 
With colleagues from the National Oceanography Centre (NOC) and the Proudman Oceanographic Laboratory (POL), through fieldwork, analysis and modelling, we will investigate recent, ongoing and future changes in the Atlantic, Arctic and Southern Oceans.

In particular, we address three urgent questions:

1. How is the pole-to-pole Atlantic MOC changing and what impact do the changes have on the ocean and our climate?
2. What are the effects of climate change on the marine Arctic environment?
3. What are the processes controlling past, present and future rates of sea level rise?

SAMS component of Theme 1 is a multi-disciplinary investigation of past and present change in Arctic and Boreal Seas in a rapidly changing climate, and is contained within three work packages:

• WP 1.5a: Mining instrumental records of Atlantic water transport to investigate connectivity and forcing (PIs Toby Sherwin, Finlo Cottier)
  
• WP 1.5b: Palaeoceanographic records of MOC activity (PI John Howe)
• WP 1.6: The effect of climate change on the Arctic marine system (PIs: Ray Leakey and Tracy Shimmield)