Meeting AMOC Observation Needs in a Changing Climate

The Seasonal cycle of the eastern boundary currents of the North Atlantic Subtropical Gyre

18 Jul 2023, 14:36

3m

Poster Lightning poster

Speaker

M. Dolores Pérez Hernández (Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria)

Description

For the first time, four dedicated hydrographic cruises – one in each season – took place in 2015 around the Canary Islands to determine the seasonality of the flows at the eastern boundary of the North Atlantic Subtropical Gyre. The Canary Current (CC) is the eastern boundary current of the North Atlantic Subtropical Gyre and links the Azores Current with the North Equatorial Current. The CC shows a seasonal behavior in its path and strength, flowing on its easternmost position in winter (3.4±0.3 Sv), through the Canary Islands in spring (2.1±0.7 Sv) and summer (2.0±0.6 Sv) and on its westernmost position in fall (3.2±0.4 Sv). At the Lanzarote Passage (LP), the dominant flow is southward except in fall, where a northward transport is observed at the surface (1.1±0.3 Sv) and intermediate (1.3±0.2 Sv) layers. Combining all the available transport estimations a historical composite observational seasonal cycle is constructed and fits the 2015 seasonal cycle. The LP seasonal cycle and seasonal amplitude match the seasonal cycle of the Atlantic Meridional Overturning Circulation (AMOC) measured by the RAPID-MOCHA data array.