EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Lagrangian Spatiotemporal Fingerprints of Dissolved Inorganic Carbon in Eighteen Degree Water Formation

Daan Reijnders1, Dorothee Bakker2, and Erik van Sebille1
Daan Reijnders et al.
  • 1Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, NL
  • 2Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, UK

Mode waters are defined as thick, weakly stratified layers with homogeneous properties. They have the ability to store these properties, such as heat, carbon and nutrients, and exchange these with the surface or atmosphere during outcropping events or with other layers via mixing processes. Eighteen Degree Water (EDW) is the subtropical mode water of the western North Atlantic. Its yearly outcropping events in late winter makes it an important regulator of ocean heat, nutrients and carbon in the North Atlantic on annual timescales.

Previous studies have given insight into the formation and destruction of Eighteen Degree Water. These have largely focused on physical aspects such as EDW formation rates. Due to the importance of EDW formation in setting the biogeochemical environment in the North Atlantic, it is instructive to investigate how biogeochemical tracers are altered along EDW formation routes. This study investigates in particular how dissolved inorganic carbon (DIC) is altered along ocean water parcel trajectories as EDW is formed. To do so, we compute Lagrangian trajectories of subducted EDW backwards in time using a coupled hydrodynamic and biogeochemical model. By sampling biogeochemical tracer values along Lagrangian pathways, we construct timeseries which we use to map the dominant locations at which DIC concentrations are altered in space and time to identify the Lagrangian fingerprint of DIC in Eighteen Degree Water.

How to cite: Reijnders, D., Bakker, D., and van Sebille, E.: Lagrangian Spatiotemporal Fingerprints of Dissolved Inorganic Carbon in Eighteen Degree Water Formation, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-2725,, 2023.

Supplementary materials

Supplementary material file