On the Seasonal variability eastern boundary of the North Atlantic Subtropical Gyre

2021 ◽  
Author(s):  
Maria Dolores Pérez-Hernández ◽  
Pedro Vélez-Belchí ◽  
Verónica Caínzos ◽  
Daniel Santana-Toscano ◽  
Cristina Arumí-Planas ◽  
...  
Keyword(s):  
North Atlantic ◽  
Seasonal Variability ◽  
Seasonal Cycle ◽  
Subtropical Gyre ◽  
North Equatorial Current ◽  
Eastern Region ◽  
The North ◽  
Equatorial Current ◽  
The North Atlantic ◽  
Ocean Observing

<p>On the eastern region of the North Atlantic Subtropical Gyre, the Canary Current connects the Azores Current with the North Equatorial Current. Several studies link the seasonality of the AMOC (as measured by the RAPID program) to the seasonality of the main flows existing on the Canary basin. Since 2003, the RaProCan project which is the Canary Islands component of the Spanish Institute of Oceanography ocean observing system, monitors the Canary basin. In 2015, the RaProCan project joined efforts with the Seasonal Variability of the AMOC: Canary Current (SeVaCan) project of the Instituto de Oceanografía y Cambio Global (IOCAG) to increase the temporal resolution of the observations. Hence, during 2015 a hydrographic cruise took place in each season (February, April, July, and November) to complete the seasonal cycle of the basin. Here we present results from these cruises to describe the seasonal cycle of the area. A sensitive analysis is carried out to understand the representativeness of the cycle to be able to compare it with the AMOC seasonal cycle.</p>

The Marine Environment

2017 ◽  
Author(s):  
N. Penny Holliday ◽  
Stephanie Henson
Keyword(s):  
Primary Production ◽  
North Atlantic ◽  
Physical Environment ◽  
Seasonal Cycle ◽  
Physical Processes ◽  
The North ◽  
Basin Scale ◽  
The North Atlantic ◽  
Physical Features ◽  
Growth Distribution

The growth, distribution, and variability of phytoplankton populations in the North Atlantic are primarily controlled by the physical environment. This chapter provides an overview of the regional circulation of the North Atlantic, and an introduction to the key physical features and processes that affect ecosystems, and especially plankton, via the availability of light and nutrients. There is a natural seasonal cycle in primary production driven by physical processes that determine the light and nutrient levels, but the pattern has strong regional variations. The variations are determined by persistent features on the basin scale (e.g. the main currents and mixed layer regimes of the subtropical and subpolar gyres), as well as transient mesoscale features such as eddies and meanders of fronts.

Seasonal variability of the bifurcation of the North Equatorial Current

2013 ◽  
Vol 25 (4) ◽  
pp. 550-555 ◽  
Author(s):  
Qiang-chang Ju ◽  
Song Jiang ◽  
Ji-wei Tian ◽  
Ling-hai Kong ◽  
Guo-xi Ni
Keyword(s):  
Seasonal Variability ◽  
North Equatorial Current ◽  
The North ◽  
Equatorial Current

Seasonal Analysis of Air-Sea CO2 Flux Variability in the North Atlantic and the Southern Ocean 

2021 ◽  
Author(s):  
Paridhi Rustogi ◽  
Peter Landschuetzer ◽  
Sebastian Brune ◽  
Johanna Baehr
Keyword(s):  
Southern Ocean ◽  
Observational Data ◽  
North Atlantic ◽  
Seasonal Variability ◽  
Max Planck ◽  
Regional Patterns ◽  
Atlantic Basin ◽  
North Atlantic Basin ◽  
The North ◽  
The North Atlantic

<p>Understanding the variability and drivers of air-sea CO<span><sub>2</sub></span> fluxes on seasonal timescales is critical for resolving the ocean carbon sink's evolution and variability. Here, we investigate whether discrepancies in the representation of air-sea CO<span><sub>2</sub></span> fluxes on a seasonal timescale accumulate to influence the representation of CO<span><sub>2</sub></span> fluxes on an interannual timescale in two important ocean CO<span><sub>2 </sub></span>sink regions – the North Atlantic basin and the Southern Ocean. Using an observation-based product (SOM-FFN) as a reference, we investigate the representation of air-sea CO<span><sub>2</sub></span> fluxes in the Max Planck Institute's Earth System Model Grand Ensemble (MPI-ESM GE). Additionally, we include a simulation based on the same model configuration, where observational data from the atmosphere and ocean components is assimilated (EnKF assimilation) to verify if the inclusion of observational data alters the model state significantly and if the updated modelled CO<span><sub>2 </sub></span>flux values better represent observations.</p><p>We find agreement between all three observation-based and model products on an interannual timescale for the North Atlantic basin. However, the agreement on a seasonal timescale is inconsistent with discrepancies as large as 0.26 PgC/yr in boreal autumn in the North Atlantic. In the Southern Ocean, we find little agreement between the three products on an interannual basis with significant seasonal discrepancies as large as 1.71 PgC/yr in austral winter. However, while we identify regional patterns of dominating seasonal variability in MPI-GE and EnKF, we find that the SOM-FFN cannot demonstrate robust conclusions on the relevance of seasonal variability in the Southern Ocean. In turn, we cannot pin down the problems for this region.</p>

Changes across 66°W, the Caribbean Sea and the Western boundaries of the North Atlantic Subtropical Gyre

2018 ◽  
Vol 168 ◽  
pp. 296-309 ◽  
Author(s):  
M. Casanova-Masjoan ◽  
T.M. Joyce ◽  
M.D. Pérez-Hernández ◽  
P. Vélez-Belchí ◽  
A. Hernández-Guerra
Keyword(s):  
North Atlantic ◽  
Caribbean Sea ◽  
Subtropical Gyre ◽  
The North ◽  
The Caribbean ◽  
The North Atlantic

The spiralling North Atlantic Subtropical Gyre

2020 ◽  
Author(s):  
Kristofer Döös ◽  
Sara Berglund ◽  
Trevor Mcdougall ◽  
Sjoerd Groeskamp
Keyword(s):  
North Atlantic ◽  
Gulf Stream ◽  
Subtropical Gyre ◽  
The South ◽  
Spiral Flow ◽  
The North ◽  
Saline Waters ◽  
Downward Spiral ◽  
Meridional Overturning ◽  
The North Atlantic

<p>The North Atlantic Subtropical Gyre is shown to have a downward spiral flow beneath the mixed layer, where the water slowly gets denser, colder and fresher as it spins around the gyre. This path is traced with Lagrangian trajectories as they enter the Gyre in the Gulf Stream from the south until they exit through the North Atlantic Drift. The preliminary results indicate that these warm, saline waters from the south gradually becomes fresher, colder and denser due to mixing with waters originating from the North Atlantic. There are indications that there is also a diapycnal mixing, in the eastern part of the gyre due to mixing with the saline Mediterranean Waters, which would then be crucial for the Atlantic Meridional Overturning. The mixing in the rest of the gyre is dominated by isopycnic mixing, which transforms gradually the water into colder and fresher water as it spins down the gyre into the abyssal ocean before heading north.</p>

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