EGU21-12120, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Western Boundary of the North Atlantic Subtropical Gyre: Decadal Change

Daniel Santana-Toscano, M. Dolores Pérez-Hernández, Verónica Caínzos, Melania Cubas Armas, Cristina Arumí-Planas, María Casanova-Masjoan, and Alonso Hernández-Guerra
Daniel Santana-Toscano et al.
  • Unidad Océano y Clima, Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, ULPGC, Unidad Asociada ULPGC-CSIC, Canary Islands, Spain

The A20 is a meridional hydrographic section located at 52ºW on the western North Atlantic Subtropical Gyre that encloses the path of the water masses of the Atlantic Meridional Overturning Circulation (AMOC). Using data from three A20 hydrographic cruises carried out in 1997, 2003 and 2012 together with LADCP-SADCP data and the velocities from an inverse box model, the circulation of the western North Atlantic Subtropical Gyre is estimated. The main poleward current of the AMOC is the Gulf Stream (GS) which carries 129.0±10.5 Sv in 2003 and 110.4±12.2 Sv in 2012. Due to the seasonality, the GS position is shifted southward in 2012 - relative to that of 2003 - as both cruises took place in different seasons. In opposite direction, the Deep Western Boundary Current (DWBC) crosses the section twice, first at 39.3-43.2ºN (-34.9±7.5 Sv in 2003 and -25.3±9.4 Sv in 2012) and then at 7.0-11.7ºN (42.0±8.0 Sv in 2003 and 48.0±8.1 Sv in 2012). Additionally, two zonal currents contribute with westward transport below 20ºN: the North Equatorial Current and the North Brazil Current; with a net value of -28.0±4.1 Sv in 2003 and -36.7±3.6 Sv in 2012.

How to cite: Santana-Toscano, D., Pérez-Hernández, M. D., Caínzos, V., Cubas Armas, M., Arumí-Planas, C., Casanova-Masjoan, M., and Hernández-Guerra, A.: Western Boundary of the North Atlantic Subtropical Gyre: Decadal Change, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12120,, 2021.