Relationships between large-scale climate modes and the South Atlantic Ocean wave climate

Abstract Midtropospheric CO2 data from the Atmospheric Infrared Sounder (AIRS) are used in this study to explore the variability of CO2 over the South Atlantic Ocean. It was found that the area-averaged CO2 over the South Atlantic Ocean is less than that over South America by about 1 ppm during December–March. This CO2 contrast is due to the large-scale vertical circulation over this region. During December–March, there is sinking motion over the South Atlantic Ocean. The sinking motion brings high-altitude air with a slightly lower concentration of CO2 to the midtroposphere. Meanwhile, air rising over South America brings near-surface air with a higher concentration of CO2 to the midtroposphere. As a result, the AIRS midtropospheric CO2 concentration is lower over the South Atlantic Ocean than over South America during December–March. The detrended AIRS midtropospheric CO2 difference correlates well with the inverted and detrended 400-hPa vertical pressure velocity difference between the South Atlantic and South America. Results obtained from this study demonstrate the strong impact of large-scale circulation on the vertical distribution of CO2 in the free troposphere and suggest that midtropospheric CO2 measurements can be used as an innovative observational constraint on the simulation of large-scale circulations in climate models.

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Rockhopper penguins and other marine life threatened by driftnet fisheries at Tristan da Cunha

Oryx ◽

10.1017/s0030605300035109 ◽

1991 ◽

Vol 25 (2) ◽

pp. 76-79 ◽

Cited By ~ 7

Author(s):

Peter G. Ryan ◽

John Cooper

Keyword(s):

Atlantic Ocean ◽

Large Scale ◽

Fishing Effort ◽

South Atlantic ◽

South Atlantic Ocean ◽

Target Species ◽

The South ◽

Tristan Da Cunha ◽

The Pacific ◽

The Impact

The oriental driftnet fleet, which is responsible for the large-scale mortality of non-target species in the Pacific Ocean, has extended its range to include the South Atlantic Ocean. Relatively little is known about the areas of operation and impacts of driftnetting in the South Atlantic as yet, but it is emerging that driftnetting is equally devastating to the fauna of this ocean. This paper reviews the impact of the driftnet fishery on non-target species in the central South Atlantic Ocean. Several lines of evidence suggest that fishing effort is focused on Tristan da Cunha, apparently resulting in considerable mortality of rockhopper penguins Eudyptes chrysocome and other marine organisms. Britain should take steps to curb this destructive fishing technique in Tristan waters.

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Toxigenicity and biogeography of the diatom Pseudo-nitzschia across distinct environmental regimes in the South Atlantic Ocean

Marine Ecology Progress Series ◽

10.3354/meps11027 ◽

2015 ◽

Vol 526 ◽

pp. 67-87 ◽

Cited By ~ 10

Author(s):

ML Guannel ◽

D Haring ◽

MJ Twiner ◽

Z Wang ◽

AE Noble ◽

...

Keyword(s):

Atlantic Ocean ◽

South Atlantic ◽

South Atlantic Ocean ◽

The South ◽

Environmental Regimes

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MODELING THE SOUTH ATLANTIC OCEAN FROM MEDIUM TO HIGH RESOLUTION

Brazilian Journal of Geophysics ◽

10.22564/rbgf.v31i2.27 ◽

2014 ◽

Vol 31 (2) ◽

Author(s):

Mariela Gabioux ◽

Vladimir Santos da Costa ◽

Joao Marcos Azevedo Correia de Souza ◽

Bruna Faria de Oliveira ◽

Afonso De Moraes Paiva

Keyword(s):

High Resolution ◽

Atlantic Ocean ◽

Large Scale ◽

South Atlantic ◽

Surface Relaxation ◽

The South ◽

Small Surface ◽

Basic Model ◽

Basic Set ◽

Set Up

Results of the basic model configuration of the REMO project, a Brazilian approach towards operational oceanography, are discussed. This configuration consists basically of a high-resolution eddy-resolving, 1/12 degree model for the Metarea V, nested in a medium-resolution eddy-permitting, 1/4 degree model of the Atlantic Ocean. These simulations performed with HYCOM model, aim for: a) creating a basic set-up for implementation of assimilation techniques leading to ocean prediction; b) the development of hydrodynamics bases for environmental studies; c) providing boundary conditions for regional domains with increased resolution. The 1/4 degree simulation was able to simulate realistic equatorial and south Atlantic large scale circulation, both the wind-driven and the thermohaline components. The high resolution simulation was able to generate mesoscale and represent well the variability pattern within the Metarea V domain. The BC mean transport values were well represented in the southwestern region (between Vitória-Trinidade sea mount and 29S), in contrast to higher latitudes (higher than 30S) where it was slightly underestimated. Important issues for the simulation of the South Atlantic with high resolution are discussed, like the ideal place for boundaries, improvements in the bathymetric representation and the control of bias SST, by the introducing of a small surface relaxation. In order to make a preliminary assessment of the model behavior when submitted to data assimilation, the Cooper & Haines (1996) method was used to extrapolate SSH anomalies fields to deeper layers every 7 days, with encouraging results.

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