C-Streams is a joint UK-US (UKRI-NERC – NSF) Large Grant funded from 2022-2027 that will explore how the Gulf Stream affects the climate system through the transport of nutrients and carbon. 

It will address a key knowledge gap regarding how carbon uptake over the North Atlantic is controlled by ocean circulation: while the importance of the Gulf Stream is well known for its supply of heat supply to northern latitudes, it is less well-understood for its role in setting CO2 uptake from the atmosphere. C-Streams will combine novel observations from a multitude of autonomous platforms with cutting-edge modelling to generate a step-change in our understanding of the contribution of the Gulf Stream to the carbon system. 

section of images for scientific research
Photos: credit Pete Brown (NOC)

Working with US partners, we will measure the strength and variability of Gulf Stream property transports in the Florida Straits, through the deployment of novel deep moorings equipped with physical and biogeochemical sensors and samplers. We will then measure the downstream evolution of Gulf Stream nutrient and carbon concentrations over 2000 miles using targeted observations by autonomous instruments, utilising gliders equipped with microturbulence sensors as well as biogeochemical profiling floats carrying oxygen, carbon, nitrate and chlorophyll sensors. Finally, model simulations will give context to our new observations, and be used to assess how projected changes in circulation characteristics will impact carbon and nutrient pathways and the carbon uptake that results. 

Ultimately, C-Streams will determine how the Gulf Stream provides a far field control of North Atlantic carbon uptake, providing an alternative paradigm to the prevailing view of control by stratification. We will then assess whether climate models provide the right response of the North Atlantic carbon sink to climate change for the right reasons.