scholarly journals First Detailed Study of Circulation off Angola

Eos ◽  
2017 ◽  
Author(s):  
Sarah Stanley
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
Boundary Current ◽  
Eastern Boundary ◽  
Eastern Boundary Current ◽  
Insight Into

New data give scientists insight into the eastern boundary current off Angola, helping them to evaluate and assess why simulations create sea surface temperature biases in the region.

scholarly journals Observed Transport Variability of the Atlantic Subtropical Cells and Their Connection to Tropical Sea Surface Temperature Variability

2021 ◽  
Author(s):  
Franz Philip Tuchen ◽  
Joke F. Lübbecke ◽  
Peter Brandt ◽  
Yao Fu
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Time Scales ◽  
Wind Stress ◽  
Large Scale ◽  
Sea Surface ◽  
Ekman Transport ◽  
Western Boundary ◽  
Eastern Boundary ◽  
Stress Changes

<p>The shallow meridional overturning cells of the Atlantic Ocean, the subtropical cells (STCs), consist of poleward Ekman transport at the surface, subduction in the subtropics, equatorward flow at thermocline level and upwelling along the equator and at the eastern boundary. In this study, we provide the first observational estimate of transport variability associated with the horizontal branches of the Atlantic STCs in both hemispheres based on Argo float data and supplemented by reanalysis products.</p><p>Thermocline layer transport convergence and surface layer transport divergence between 10°N and 10°S are dominated by seasonal variability. Meridional thermocline layer transport anomalies at the western boundary and in the interior basin are anti-correlated and partially compensate each other at all resolved time scales. It is suggested that the seesaw-like relation is forced by the large-scale off-equatorial wind stress changes through low-baroclinic-mode Rossby wave adjustment. We further show that anomalies of the thermocline layer interior transport convergence modulate sea surface temperature (SST) variability in the upwelling regions along the equator and at the eastern boundary at time scales longer than 5 years. Phases of weaker (stronger) interior transport are associated with phases of higher (lower) equatorial SST. At these time scales, STC transport variability is forced by off-equatorial wind stress changes, especially by those in the southern hemisphere. At shorter time scales, equatorial SST anomalies are, instead, mainly forced by local changes of zonal wind stress.</p>

scholarly journals Malvinas-slope water intrusions on the northern Patagonia continental shelf

Ocean Science ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 345-359 ◽  
Author(s):  
A. R. Piola ◽  
N. Martínez Avellaneda ◽  
R. A. Guerrero ◽  
F. P. Jardón ◽  
E. D. Palma ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Continental Shelf ◽  
Sea Surface Temperature ◽  
Chlorophyll A ◽  
Local Development ◽  
Drake Passage ◽  
Negative Temperature ◽  
Sea Surface ◽  
Western Boundary ◽  
Boundary Current

Abstract. The Patagonia continental shelf located off southeastern South America is bounded offshore by the Malvinas Current, which extends northward from northern Drake Passage (~55° S) to nearly 38° S. The transition between relatively warm-fresh shelf waters and Subantarctic Waters from the western boundary current is characterized by a thermohaline front extending nearly 2500 km. We use satellite derived sea surface temperature, and chlorophyll-a data combined with hydrographic and surface drifter data to document the intrusions of slope waters onto the continental shelf near 41° S. These intrusions create vertically coherent localized negative temperature and positive salinity anomalies extending onshore about 150 km from the shelf break. The region is associated with a center of action of the first mode of non-seasonal sea surface temperature variability and also relatively high chlorophyll-a variability, suggesting that the intrusions are important in promoting the local development of phytoplankton. The generation of slope water penetrations at this location may be triggered by the inshore excursion of the 100 m isobath, which appears to steer the Malvinas Current waters over the outer shelf.

scholarly journals Malvinas-slope water intrusions on the northern Patagonia continental shelf

2009 ◽  
Vol 6 (3) ◽  
pp. 2939-2974 ◽  
Author(s):  
A. R. Piola ◽  
N. M. Avellaneda ◽  
R. A. Guerrero ◽  
F. P. Jardón ◽  
E. D. Palma ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Continental Shelf ◽  
Sea Surface Temperature ◽  
Chlorophyll A ◽  
Local Development ◽  
Drake Passage ◽  
Negative Temperature ◽  
Sea Surface ◽  
Western Boundary ◽  
Boundary Current

Abstract. The Patagonia continental shelf located off southeastern South America is bounded offshore by the Malvinas Current, which extends northward from northern Drake Passage (~55° S) to nearly 38° S. The transition between relatively warm-fresh shelf waters and Subantarctic Waters from the western boundary current is characterized by a thermohaline front extending nearly 2500 km. We use satellite derived sea surface temperature, and chlorophyll-a data combined with hydrographic and surface drifter data to document the intrusions of slope waters onto the continental shelf near 41° S. These intrusions create vertically coherent localized negative temperature and positive salinity anomalies extending onshore about 150 km from the shelf break. The region is associated with a center of action of the first mode of non-seasonal sea surface temperature variability and also relatively high chlorophyll-a variability, suggesting that the intrusions are important in promoting the local development of phytoplankton. The generation of slope water penetrations at this location may be triggered by the inshore excursion of the 100 m isobath, which appears to steer the Malvinas Current waters over the outer shelf.

scholarly journals Sea Surface Temperature intercomparison in the framework of the Copernicus Climate Change Service (C3S)

2021 ◽  
pp. 1-102
Author(s):  
Chunxue Yang ◽  
Francesca Elisa Leonelli ◽  
Salvatore Marullo ◽  
Vincenzo Artale ◽  
Helen Beggs ◽  
...  
Keyword(s):  
Climate Change ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Spatial Patterns ◽  
Early Period ◽  
Warming Trend ◽  
Sea Surface ◽  
Western Boundary ◽  
Scientific Quality ◽  
Boundary Current

AbstractA joint effort between the Copernicus Climate Change Service (C3S) and the Group for High Resolution Sea Surface Temperature (GHRSST) has been dedicated to an intercomparison study of eight global gap-free Sea Surface Temperature (SST) products to assess their accurate representation of the SST relevant to climate analysis. In general, all SST products show consistent spatial patterns and temporal variability during the overlapping time period (2003-2018). The main differences between each product are located in western boundary current and Antarctic Circumpolar Current regions. Linear trends display consistent SST spatial patterns among all products and exhibit a strong warming trend from 2012 to 2018 with the Pacific Ocean basin as the main contributor. SST discrepancy between all SST products is very small compared to the significant warming trend. Spatial power spectral density shows that the interpolation into 1° spatial resolution has negligible impacts on our results. The global mean SST time series reveals larger differences among all SST products during the early period of the satellite era (1982-2002) when there were fewer observations, indicating that the observation frequency is the main constraint of the SST climatology. The maturity matrix scores, which present the maturity of each product in terms of documentation, storage, and dissemination but not the scientific quality, demonstrate that ESA-CCI and OSTIA SST are well documented for users' convenience. Improvements could be made for MGDSST and BoM SST. Finally, we have recommended that these SST products can be used for fundamental climate applications and climate studies (e.g. El Nino).

scholarly journals The diet of greater crested terns off southeast Australia varies with breeding stage and sea surface temperature

2021 ◽  
Vol 168 (9) ◽  
Author(s):  
Katrin Quiring ◽  
G. Carroll ◽  
C. Champion ◽  
E. W. Heymann ◽  
R. Harcourt
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Prey Selection ◽  
Survey Methods ◽  
Sea Surface ◽  
Pelagic Ecosystem ◽  
Breeding Stage ◽  
Southeast Australia ◽  
Selective Foraging ◽  
Insight Into

AbstractMonitoring seabird diet can provide insights into marine ecosystems that are logistically difficult or costly to observe with traditional fisheries survey methods. Using digital photography, we described the diet of greater crested terns (Thalasseus bergii) breeding on Montague Island (36°15′ S, 150°13′ E), a colony located in an oceanographically dynamic region of southeast Australia. We investigated how the type and size of prey brought back to the colony changed in relation to both breeding stage and variation in local environmental conditions. 2469 prey items were identified to species or family level over 35 consecutive days of photo-sampling in 2018. Australian anchovy (Engraulis australis), a surface-schooling clupeid fish, was the most abundant prey returned to the colony during all breeding stages (84.5%). The proportion of anchovy increased from 77.0% when birds were provisioning their adult partners during incubation, to 92.4% when they were provisioning chicks, suggesting selective foraging behaviour on this energy-rich species to facilitate rapid chick growth. Anchovy size was significantly larger during incubation (91.1 ± 14.9 mm), smaller during early chick provisioning (71.8 ± 11.0 mm), and increased slightly during mid provisioning (79.6 ± 11.9 mm), indicating adaptive prey selection that is matched to the physical requirements of different breeding stages. The proportion of anchovy prey was also influenced by sea surface temperature (SST), with anchovy becoming more dominant with increasing local SSTs, up to ~ 17.5 °C. This study gives new insight into the types of prey that are seasonally available to predators in this region. The strong specialisation by greater crested terns for one energy-rich species of schooling fish (anchovy) suggests that variation in the size and composition of their prey may serve as an indicator of change in the pelagic ecosystem off southeast Australia.

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