EGU2020-9130, updated on 05 Feb 2024
https://doi.org/10.5194/egusphere-egu2020-9130
EGU General Assembly 2020
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The penetration of Labrador Slope Water to Cape Hatteras and its role in Gulf Stream Dynamics

Adrian New1, David Smeed2, Adam Blaker3, and Jenny Mecking4
Adrian New et al.
  • 1National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK (a.new@noc.ac.uk)
  • 2National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK (das@noc.ac.uk)
  • 3National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK (atb299@noc.ac.uk)
  • 4National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK (jmecki@noc.ac.uk)

Labrador Slope Water is known to exist in the Slope Sea off the US eastern shelf as a relatively fresh and cool water mass deriving from the Labrador Current further north, and is present between the upper layer US shelf-derived water masses and the deeper Deep Western Boundary current waters, typically near 400-600m. This LSLW  is investigated in the EN4 database and shown to penetrate as far south as Cape Hatteras (74-75°W), having previously only been described as far west as the Gulf of Maine (66°W). We then examine, using both EN4 and Line W observations, the changes of this water mass between 2005-2008, when the strength of Atlantic Meridional Overturning Circulation (AMOC) measured by the RAPID array at 26°N, was high, and 2009-2015, when the AMOC was low. We show that in the AMOC high period, there was a larger volume of the LSSW present on the northern side of the Gulf Stream system which resulted in an increased meridional slope of the isopycnals near these depths, commensurate with increased geostrophic transport, and also in a more southerly position, of the Gulf Stream after separation at Cape Hatteras. The LSLW could therefore play an important role in decadal timescale variations in the North Atlantic climate system through its impact on the Gulf Stream and AMOC.

How to cite: New, A., Smeed, D., Blaker, A., and Mecking, J.: The penetration of Labrador Slope Water to Cape Hatteras and its role in Gulf Stream Dynamics, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9130, https://doi.org/10.5194/egusphere-egu2020-9130, 2020.

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