Linking the South Atlantic Meridional Overturning Circulation and the Global Monsoons

Science.gov (United States)

Lopez, H.; Dong, S.; Goni, G. J.; Lee, S. K.

2016-02-01

This study tested the hypothesis whether low frequency decadal variability of the South Atlantic meridional heat transport (SAMHT) influences decadal variability of the global monsoons. A multi-century run from a state-of-the-art coupled general circulation model is used as basis for the analysis. Our findings indicate that multi-decadal variability of the South Atlantic Ocean plays a key role in modulating atmospheric circulation via interhemispheric changes in Atlantic Ocean heat content. Weaker SAMHT produces anomalous ocean heat divergence over the South Atlantic resulting in negative ocean heat content anomaly about 15 years later. This, in turn, forces a thermally direct anomalous interhemispheric Hadley circulation in the atmosphere, transporting heat from the northern hemisphere (NH) to the southern hemisphere (SH) and moisture from the SH to the NH, thereby intensify (weaken) summer (winter) monsoon in the NH and winter (summer) monsoon in the SH. Results also show that anomalous atmospheric eddies, both transient and stationary, transport heat northward in both hemispheres producing eddy heat flux convergence (divergence) in the NH (SH) around 15-30°, reinforcing the anomalous Hadley circulation. Overall, SAMHT decadal variability leads its atmospheric response by about 15 years, suggesting that the South Atlantic is a potential predictor of global climate variability.

Seasonal influence of ENSO on the Atlantic ITCZ and equatorial South America

Science.gov (United States)

Münnich, M.; Neelin, J. D.

2005-11-01

In late boreal spring, especially May, a strong relationship exists in observations among precipitation anomalies over equatorial South America and the Atlantic intertropical convergence zone (ITCZ), and eastern equatorial Pacific and central equatorial Atlantic sea surface temperature anomalies (SSTA). A chain of correlations of equatorial Pacific SSTA, western equatorial Atlantic wind stress (WEA), equatorial Atlantic SSTA, sea surface height, and precipitation supports a causal chain in which El Niño/Southern Oscillation (ENSO) induces WEA stress anomalies, which in turn affect Atlantic equatorial ocean dynamics. These correlations show strong seasonality, apparently arising within the atmospheric links of the chain. This pathway and the influence of equatorial Atlantic SSTA on South American rainfall in May appear independent of that of the northern tropical Atlantic. Brazil's Nordeste is affected by the northern tropical Atlantic. The equatorial influence lies further to the north over the eastern Amazon and the Guiana Highlands.

The South Atlantic Anomaly: the key for a possible geomagnetic reversal

Directory of Open Access Journals (Sweden)

F. Javier ePavón-Carrasco

2016-04-01

Full Text Available The South Atlantic Anomaly is nowadays one of the most important features of the Earth’s magnetic field. Its extent area at the Earth’s surface is continuously growing since the intensity instrumental measurements are available covering part of the Southern Hemisphere and centred in South America. Several studies associate this anomaly as an indicator of an upcoming geomagnetic transition, such an excursion or reversal. In this paper we carry out a detailed study about this issue using the most recent models that also include data from the last ESA mission Swarm. Our results reveal that one of the reversed polarity patch located under the South Atlantic Ocean is growing with a pronounced rate of -2.54•105 nT per century and with western drift. In addition, we demonstrate that the quadrupole field mainly controls this reversal patch at the CMB along with the rapid decay of the dipolar field. The presence of the reversal patches at the CMB seems to be characteristic during the preparation phase of a geomagnetic transition. However, the present value of the dipolar moment (7.7 1022A•m2 is not so low when compared with recent paleomagnetic data for the Holocene (last 12ka and for the entire Brunhes geomagnetic normal polarity (last 0.8 Ma, although the rate of decay is similar of the previous documented geomagnetic reversals or excursions.

Multibeam Mapping of the South Atlantic Bight: South Carolina 2005, a Proposed MPA on the Continental Shelf

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Fisheries laboratory in Panama City, Florida coordinated an acoustic survey at the new proposed Marine Protected Areas in the South Atlantic Bight area June...

The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient

International Nuclear Information System (INIS)

Espinoza, Jhan Carlo; Marengo, José Antonio; Ronchail, Josyane; Carpio, Jorge Molina; Flores, Luís Noriega; Guyot, Jean Loup

2014-01-01

Unprecedented wet conditions are reported in the 2014 summer (December–March) in South-western Amazon, with rainfall about 100% above normal. Discharge in the Madeira River (the main southern Amazon tributary) has been 74% higher than normal (58 000 m 3 s −1 ) at Porto Velho and 380% (25 000 m 3 s −1 ) at Rurrenabaque, at the exit of the Andes in summer, while levels of the Rio Negro at Manaus were 29.47 m in June 2014, corresponding to the fifth highest record during the 113 years record of the Rio Negro. While previous floods in Amazonia have been related to La Niña and/or warmer than normal tropical South Atlantic, the 2014 rainfall and flood anomalies are associated with warm condition in the western Pacific-Indian Ocean and with an exceptionally warm Subtropical South Atlantic. Our results suggest that the tropical and subtropical South Atlantic SST gradient is a main driver for moisture transport from the Atlantic toward south-western Amazon, and this became exceptionally intense during summer of 2014. (letter)

The Future of the South Atlantic Anomaly and Implications for Radiation Damage in Space

Science.gov (United States)

Heirtzler, J. R.; Smith, David E. (Technical Monitor)

2000-01-01

South Atlantic Anomaly of the geomagnetic field plays a dominant role in where radiation damage occurs in near Earth orbits. The historic and recent variations of the geomagnetic field in the South Atlantic are used to estimate the extent of the South Atlantic Anomaly until the year 2000. This projection indicates that radiation damage to spacecraft and humans in space will greatly increase and cover a much larger geographic area than present.

76 FR 30921 - South Atlantic Fishery Management Council; Public Meetings

Science.gov (United States)

2011-05-27

.... SUMMARY: The South Atlantic Fishery Management Council will hold a joint meeting of its Executive/Finance... Atlantic Fishery Management Council; Public Meetings AGENCY: National Marine Fisheries Service (NMFS..., Assessment and Review (SEDAR) Committee; Law Enforcement [[Page 30922

South Atlantic pale oceanography and evolution during the Albian; Paleoceanografia e a evolucao do Atlantico Sul no Albiano

Energy Technology Data Exchange (ETDEWEB)

Azevedo, Ricardo Latge Milward de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Diretoria de Exploracao e Producao]. E-mail: ricardolatge@petrobras.com.

2004-11-01

A vast array of geochemical, geophysical, sedimentological and paleontological data, together with modern environmental analogues in the Red Sea, support the view that the South Atlantic maintained its bi partitioned condition from latest Aptian to the middle Albian. The lineament comprising the Florianopolis High and Sao Paulo Dorsal formed an effective barrier to sea-water circulation between the Southern South Atlantic (SSA) and Central South Atlantic (CSA) until late Albian times. During that time, the latter communicated mainly with the North Atlantic, which in turn was connected to the Tethys Sea. The CSA was then entirely located within an arid climatic belt, and subject to a negative hydric balance, whereas an estuarine circulation pattern prevailed in the SSA. The comparison of carbon and oxygen stable isotope results from limestones in various parts of the world demonstrates that the CSA waters were warmer than those of the Malvinas in the South, and the Tethyan Sea to the North. The CSA sedimentary evolution was coeval with profound paleoceanographic changes. These were mainly induced by global tectonic phenomena related to the dynamics of oceanic crustal accretion, culminating with the definitive interconnection of the Tethyan and Indian oceanic waters by the end-Albian. Halokynetic movements and orbital variations brought about oscillations in accommodation space, which permitted the stacking of tens of shallowing-upward cycles with varied magnitudes. (author)

78 FR 62587 - Fisheries of the South Atlantic; South Atlantic Fishery Management Council; Public Meeting

Science.gov (United States)

2013-10-22

... Essential Fish Habitat Policy Statements and receive training on the use of the Regional Habitat and... meeting of the South Atlantic Fishery Management Council's Habitat and Environmental Protection (Habitat... of its Habitat AP in St. Petersburg, FL. The meeting is open to the public. DATES: The meeting will...

Brazilian Policy and the Creation of a Regional Security Complex in the South Atlantic: Pax Brasiliana?

Directory of Open Access Journals (Sweden)

Beatriz Rodrigues Bessa Mattos

Full Text Available Abstract Over the past five years, the South Atlantic region has become a central element of Brazilian security policy, with Brazil actively supporting the notion of a trans-oceanic security consciousness involving African littoral states. It has invested in diplomatic initiatives such as the Zone of Peace and Cooperation of the South Atlantic (ZPCSA, or ZOPACAS, and extensive military co-operation with West African states such as São Tomé e Príncipe, Namibia and Cape Verde. Its internal security and defence policy documents have repeatedly been updated to reflect this dimension, and now provide the foundation for advancing these initiatives. This policy thrust is directed at securing Brazil’s offshore oil assets, and limiting the influence of what it has termed ‘extra-regional powers’ such as the P-5. This article highlights these initiatives and reviews the prospects for this policy by examining the plausibility of the South Atlantic region as a regional security complex in the sense coined by Buzan and Wæver. The analysis is based on the role of geographical and linguistic proximity in international relations, and the impact of multilateral bodies on building support for a regional approach to security governance.

75 FR 42378 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); South Atlantic...

Science.gov (United States)

2010-07-21

... public. Those interested in participating should contact Kari Fenske at SEDAR. See FOR FURTHER... CONTACT: Kari Fenske, SEDAR Coordinator, 4055 Faber Place Drive, Suite 201, North Charleston, SC 29405; (843) 571- 4366; kari.fenske@safmc.net . SUPPLEMENTARY INFORMATION: The Gulf of Mexico, South Atlantic...

Estuarine demersal fish assemblage from a transition region between the tropics and the subtropics of the South Atlantic

Directory of Open Access Journals (Sweden)

Mauricio Hostim-Silva

2013-06-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2013v26n3p153 Estuarine demersal fish assemblage from a transition region between the tropics and the subtropics of the South Atlantic. The coastal state of Espírito Santo is in the central region of Brazil, where biological productivity is considered low. The objective of this work is to present a current list of demersal, estuarine fish from northern Espírito Santo. This work is based on the compilation of data collected monthly using trawl nets. The ichthyofauna comprises 57 species, within 10 orders and 32 families. The family Sciaenidae has the largest number of species (8, followed by Carangidae (4 and Gerreidae (4. This coincides with what has been found for the Brazilian coast and for the coast of the South Atlantic. It is important to note that the total species richness in the estuaries of northern Espírito Santo is lower than other estuaries of the South West Atlantic coast. Most of the species are widely distributed in the Western Atlantic. Only a small part (14% of the fauna of northern Espírito Santo was evaluated in regards to risk of extinction, but conservation should be prioritized in the area due to overexploitation of species.

Evolution of South Atlantic density and chemical stratification across the last deglaciation.

Science.gov (United States)

Roberts, Jenny; Gottschalk, Julia; Skinner, Luke C; Peck, Victoria L; Kender, Sev; Elderfield, Henry; Waelbroeck, Claire; Vázquez Riveiros, Natalia; Hodell, David A

2016-01-19

Explanations of the glacial-interglacial variations in atmospheric pCO2 invoke a significant role for the deep ocean in the storage of CO2. Deep-ocean density stratification has been proposed as a mechanism to promote the storage of CO2 in the deep ocean during glacial times. A wealth of proxy data supports the presence of a "chemical divide" between intermediate and deep water in the glacial Atlantic Ocean, which indirectly points to an increase in deep-ocean density stratification. However, direct observational evidence of changes in the primary controls of ocean density stratification, i.e., temperature and salinity, remain scarce. Here, we use Mg/Ca-derived seawater temperature and salinity estimates determined from temperature-corrected δ(18)O measurements on the benthic foraminifer Uvigerina spp. from deep and intermediate water-depth marine sediment cores to reconstruct the changes in density of sub-Antarctic South Atlantic water masses over the last deglaciation (i.e., 22-2 ka before present). We find that a major breakdown in the physical density stratification significantly lags the breakdown of the deep-intermediate chemical divide, as indicated by the chemical tracers of benthic foraminifer δ(13)C and foraminifer/coral (14)C. Our results indicate that chemical destratification likely resulted in the first rise in atmospheric pCO2, whereas the density destratification of the deep South Atlantic lags the second rise in atmospheric pCO2 during the late deglacial period. Our findings emphasize that the physical and chemical destratification of the ocean are not as tightly coupled as generally assumed.

Geomagnetic observations on Tristan da Cunha, South Atlantic Ocean

DEFF Research Database (Denmark)

Matzka, J.; Olsen, Nils; Maule, C. F.

2009-01-01

Few geomagnetic ground observations exist of the Earth's strongest core field anomaly, the South Atlantic Anomaly (SAA). The geomagnetic repeat station on the island Tristan da Cunha, located half-way between South Africa and South America at 37 degrees 05' S, 12 degrees 18' W, is therefore of cr...

The potential of the coral species Porites astreoides as a paleoclimate archive for the Tropical South Atlantic Ocean

DEFF Research Database (Denmark)

Pereira, Natan S.; Sial, Alcides N.; Frei, Robert

2017-01-01

, Red Sea and Caribbean, but lack for the Equatorial South Atlantic. Here we present coral-based records of Sr/Ca, δ18O and δ13C and the first δ18O–SST calibration for the scleractinian coral species Porites astreoides from the Rocas Atoll, Equatorial South Atlantic. The investigated geochemical proxies...

76 FR 57958 - Fisheries of the South Atlantic and Gulf of Mexico; South Atlantic Fishery Management Council...

Science.gov (United States)

2011-09-19

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN: 0648-XA708 Fisheries...), Commerce. ACTION: Notice of public meetings. SUMMARY: The South Atlantic Fishery Management Council (SAFMC...-pane reviews social and economic information and reports its findings to the SSC. The SEP will discuss...

The relative importance of ENSO and tropical Atlantic sea surface temperature anomalies for seasonal precipitation over South America: a numerical study

Science.gov (United States)

Pezzi, L. P.; Cavalcanti, I. F. A.

The role of tropical Atlantic sea surface temperature (SST) anomalies during ENSO episodes over northeast Brazil (Nordeste) is investigated using the CPTEC/COLA Atmospheric General Circulation Model (AGCM). Four sets of integrations are performed using SST in El Niño and La Niña (ENSO) episodes, changing the SST of the Atlantic Ocean. A positive dipole (SST higher than normal in the tropical North Atlantic and below normal in the tropical South Atlantic) and a negative dipole (opposite conditions), are set as the boundary conditions of SST in the Atlantic Ocean. The four experiments are performed using El Niño or La Niña SST in all oceans, except in the tropical Atlantic where the two phases of the SST dipole are applied. Five initial conditions were integrated in each case in order to obtain four ensemble results. The positive SST dipole over the tropical Atlantic Ocean and El Niño conditions over the Pacific Ocean resulted in dry conditions over the Nordeste. When the negative dipole and El Niño conditions over the Pacific Ocean were applied, the results showed precipitation above normal over the north of Nordeste. When La Niña conditions over Pacific Ocean were tested together with a negative dipole, positive precipitation anomalies occurred over the whole Nordeste. Using the positive dipole over the tropical Atlantic, the precipitation over Nordeste was below average. During La Niña episodes, the Atlantic Ocean conditions have a larger effect on the precipitation of Nordeste than the Pacific Ocean. In El Niño conditions, only the north region of Nordeste is affected by the Atlantic SST. Other tropical areas of South America show a change only in the intensity of anomalies. Central and southeast regions of South America are affected by the Atlantic conditions only during La Niña conditions, whereas during El Niño these regions are influenced only by conditions in the Pacific Ocean.

76 FR 69230 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2011-11-08

...: PART 622--FISHERIES OF THE CARIBBEAN, GULF, AND SOUTH ATLANTIC 1. The authority citation for part 622... and styles used in the South Atlantic snapper- grouper fishery. (b) Extended reach handle. The... appropriate to secure the range of hook sizes and styles used in the South Atlantic snapper-grouper fishery...

77 FR 4493 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2012-01-30

... CARIBBEAN, GULF, AND SOUTH ATLANTIC 0 1. The authority citation for part 622 continues to read as follows... and styles used in the South Atlantic snapper- grouper fishery. (b) Extended reach handle. The... appropriate to secure the range of hook sizes and styles used in the South Atlantic snapper-grouper fishery...

76 FR 61285 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; South Atlantic Snapper-Grouper...

Science.gov (United States)

2011-10-04

... recreational ACL overage. This action is necessary to reduce overfishing of the South Atlantic black sea bass... (AMs) be implemented to end overfishing and prevent overfishing from occurring. AMs are management... overfishing, including black sea bass, and AMs if these ACLs are reached or exceeded. The recreational ACL for...

75 FR 12507 - Fisheries of the South Atlantic and Gulf of Mexico; South Atlantic Fishery Management Council...

Science.gov (United States)

2010-03-16

... analysis. Members will develop fishing level recommendations for black and red grouper, and ABC and OFL... recommendations for black and red grouper, discuss Acceptable Biological Catch (ABC) Control Rules, and recommend ABC values for South Atlantic managed species. The meeting will be held in North Charleston, SC. DATES...

77 FR 75613 - Fisheries of the South Atlantic; Southeast Data, Assessment and Review (SEDAR); Data Webinar for...

Science.gov (United States)

2012-12-21

... discuss data needs and treatments. Special Accommodations These meetings are physically accessible to... the South Atlantic; Southeast Data, Assessment and Review (SEDAR); Data Webinar for South Atlantic...: Notice of SEDAR 32 data webinar for South Atlantic gray triggerfish and blueline tilefish. SUMMARY: The...

KAPEX RAFOS float data report 1997 - 1999. Pt. A. The Agulhas- and South Atlantic current components

Energy Technology Data Exchange (ETDEWEB)

Boebel, O.; Anderson-Fontana, S.; Lazarevich, P.; Prater, M.; Rossby, T. [Rhode Island Univ., Narragansett, RI (United States). Graduate School of Oceanography; Schmid, C.; Zenk, W. [Institut fuer Meereskunde an der Univ. Kiel (Germany); Ansorge, I.; Lutjeharms, J. [Cape Town Univ. (South Africa). Dept. of Oceanography

2000-10-01

This data report presents trajectories and corresponding in-situ data for all acoustically tracked RAFOS floats that were deployed within the Agulhas and the South Atlantic Current components of KAPEX. KAPEX stands for Cape of Good Hope Experiment, Kaap die Goeie Hoop Eksperimente or Kap der Guten Hoffnung Experiment in the three languages of the participating authors. The objective of the program was to study the interocean exchange of subsurface waters south of Africa between the Atlantic and the Indian Oceans. A total of 92 floats were deployed during four cruises at depths between 100 - 1200 m during March 1997 and June 1998. It is the first time that eddy-resolving floats are used to measure ocean flow patterns at intermediate and thermocline levels off southern Africa. (orig.)

South Atlantic Ocean circulation: Simulation experiments with a quasi-geostrophic model and assimilation of TOPEX/POSEIDON and ERS 1 altimeter data

Science.gov (United States)

Florenchie, P.; Verron, J.

1998-10-01

Simulation experiments of South Atlantic Ocean circulations are conducted with a 1/6°, four-layered, quasi-geostrophic model. By means of a simple nudging data assimilation procedure along satellite tracks, TOPEX/POSEIDON and ERS 1 altimeter measurements are introduced into the model to control the simulation of the basin-scale circulation for the period from October 1992 to September 1994. The model circulation appears to be strongly influenced by the introduction of altimeter data, offering a consistent picture of South Atlantic Ocean circulations. Comparisons with observations show that the assimilating model successfully simulates the kinematic behavior of a large number of surface circulation components. The assimilation procedure enables us to produce schematic diagrams of South Atlantic circulation in which patterns ranging from basin-scale currents to mesoscale eddies are portrayed in a realistic way, with respect to their complexity. The major features of the South Atlantic circulation are described and analyzed, with special emphasis on the Brazil-Malvinas Confluence region, the Subtropical Gyre with the formation of frontal structures, and the Agulhas Retroflection. The Agulhas eddy-shedding process has been studied extensively. Fourteen eddies appear to be shed during the 2-year experiment. Because of their strong surface topographic signature, Agulhas eddies have been tracked continuously during the assimilation experiment as they cross the South Atlantic basin westward. Other effects of the assimilation procedure are shown, such as the intensification of the Subtropical Gyre, the appearance of a strong seasonal cycle in the Brazil Current transport, and the increase of the mean Brazil Current transport. This last result, combined with the westward oriention of the Agulhas eddies' trajectories, leads to a southward transport of mean eddy kinetic energy across 30°S.

ATLANTIC BATS: a data set of bat communities from the Atlantic Forests of South America.

Science.gov (United States)

Muylaert, Renata D L; Stevens, Richard D; Esbérard, Carlos E L; Mello, Marco A R; Garbino, Guilherme S T; Varzinczak, Luiz H; Faria, Deborah; Weber, Marcelo D M; Kerches Rogeri, Patricia; Regolin, André L; Oliveira, Hernani F M D; Costa, Luciana D M; Barros, Marília A S; Sabino-Santos, Gilberto; Crepaldi de Morais, Mara Ariane; Kavagutti, Vinicius S; Passos, Fernando C; Marjakangas, Emma-Liina; Maia, Felipe G M; Ribeiro, Milton C; Galetti, Mauro

2017-12-01

Bats are the second most diverse mammal order and they provide vital ecosystem functions (e.g., pollination, seed dispersal, and nutrient flux in caves) and services (e.g., crop pest suppression). Bats are also important vectors of infectious diseases, harboring more than 100 different virus types. In the present study, we compiled information on bat communities from the Atlantic Forests of South America, a species-rich biome that is highly threatened by habitat loss and fragmentation. The ATLANTIC BATS data set comprises 135 quantitative studies carried out in 205 sites, which cover most vegetation types of the tropical and subtropical Atlantic Forest: dense ombrophilous forest, mixed ombrophilous forest, semideciduous forest, deciduous forest, savanna, steppe, and open ombrophilous forest. The data set includes information on more than 90,000 captures of 98 bat species of eight families. Species richness averaged 12.1 per site, with a median value of 10 species (ranging from 1 to 53 species). Six species occurred in more than 50% of the communities: Artibeus lituratus, Carollia perspicillata, Sturnira lilium, Artibeus fimbriatus, Glossophaga soricina, and Platyrrhinus lineatus. The number of captures divided by sampling effort, a proxy for abundance, varied from 0.000001 to 0.77 individuals·h -1 ·m -2 (0.04 ± 0.007 individuals·h -1 ·m -2 ). Our data set reveals a hyper-dominance of eight species that together that comprise 80% of all captures: Platyrrhinus lineatus (2.3%), Molossus molossus (2.8%), Artibeus obscurus (3.4%), Artibeus planirostris (5.2%), Artibeus fimbriatus (7%), Sturnira lilium (14.5%), Carollia perspicillata (15.6%), and Artibeus lituratus (29.2%). © 2017 by the Ecological Society of America.

Tropical South-East Atlantic response to ENSO as an ecosystem ...

African Journals Online (AJOL)

Cases were selected based on indices of Pacific sea surface temperature and South-East African rainfall. ... an El Niño event, and higher sardine Sardinops sagax catches tend to follow a La Niña event, through the northward and southward shift respectively of the South Atlantic anticyclone and attendant coastal upwelling.

Patagonian and southern South Atlantic view of Holocene climate

Science.gov (United States)

Kaplan, M. R.; Schaefer, J. M.; Strelin, J. A.; Denton, G. H.; Anderson, R. F.; Vandergoes, M. J.; Finkel, R. C.; Schwartz, R.; Travis, S. G.; Garcia, J. L.; Martini, M. A.; Nielsen, S. H. H.

2016-06-01

We present a comprehensive 10Be chronology for Holocene moraines in the Lago Argentino basin, on the east side of the South Patagonian Icefield. We focus on three different areas, where prior studies show ample glacier moraine records exist because they were formed by outlet glaciers sensitive to climate change. The 10Be dated records are from the Lago Pearson, Herminita Península-Brazo Upsala, and Lago Frías areas, which span a distance of almost 100 km adjacent to the modern Icefield. New 10Be ages show that expanded glaciers and moraine building events occurred at least at 6120 ± 390 (n = 13), 4450 ± 220 (n = 7), 1450 or 1410 ± 110 (n = 18), 360 ± 30 (n = 5), and 240 ± 20 (n = 8) years ago. Furthermore, other less well-dated glacier expansions of the Upsala Glacier occurred between 1400 and ∼1000 and ∼2300 and ∼2000 years ago. The most extensive glaciers occurred over the interval from ∼6100 to ∼4500 years ago, and their margins over the last ∼600 years were well within and lower than those in the middle Holocene. The 10Be ages agree with 14C-limiting data for the glacier histories in this area. We then link southern South American, adjacent South Atlantic, and other Southern Hemisphere records to elucidate broader regional patterns of climate and their possible causes. In the early Holocene, a far southward position of the westerly winds fostered warmth, small Patagonian glaciers, and reduced sea ice coverage over the South Atlantic. Although we infer a pronounced southward displacement of the westerlies during the early Holocene, these conditions did not occur throughout the southern mid-high latitudes, an important exception being over the southwest Pacific sector. Subsequently, a northward locus and/or expansion of the winds over the Patagonia-South Atlantic sector promoted the largest glaciers between ∼6100 and ∼4500 years ago and greatest sea ice coverage. Over the last few millennia, the South Patagonian Icefield has experienced

South Atlantic Seasonal and/or Area Closures GIS data

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data represent the geographic area described in Title 50 CFR Part 622 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic, Subpart A - General...

Decadal-scale teleconnection between South Atlantic SST and southeast Australia surface air temperature in austral summer

Science.gov (United States)

Xue, Jiaqing; Li, Jianping; Sun, Cheng; Zhao, Sen; Mao, Jiangyu; Dong, Di; Li, Yanjie; Feng, Juan

2018-04-01

Austral summer (December-February) surface air temperature over southeast Australia (SEA) is found to be remotely influenced by sea surface temperature (SST) in the South Atlantic at decadal time scales. In austral summer, warm SST anomalies in the southwest South Atlantic induce concurrent above-normal surface air temperature over SEA. This decadal-scale teleconnection occurs through the eastward propagating South Atlantic-Australia (SAA) wave train triggered by SST anomalies in the southwest South Atlantic. The excitation of the SAA wave train is verified by forcing experiments based on both linear barotropic and baroclinic models, propagation pathway and spatial scale of the observed SAA wave train are further explained by the Rossby wave ray tracing analysis in non-uniform basic flow. The SAA wave train forced by southwest South Atlantic warming is characterized by an anomalous anticyclone off the eastern coast of the Australia. Temperature diagnostic analyses based on the thermodynamic equation suggest anomalous northerly flows on western flank of this anticyclone can induce low-level warm advection anomaly over SEA, which thus lead to the warming of surface air temperature there. Finally, SST-forced atmospheric general circulation model ensemble experiments also demonstrate that SST forcing in the South Atlantic is associated with the SAA teleconnection wave train in austral summer, this wave train then modulate surface air temperature over SEA on decadal timescales. Hence, observations combined with numerical simulations consistently demonstrate the decadal-scale teleconnection between South Atlantic SST and summertime surface air temperature over SEA.

Groundwater availability in the Atlantic Coastal Plain of North and South Carolina

Science.gov (United States)

Campbell, Bruce G.; Coes, Alissa L.

2010-01-01

The Atlantic Coastal Plain aquifers and confining units of North and South Carolina are composed of crystalline carbonate rocks, sand, clay, silt, and gravel and contain large volumes of high-quality groundwater. The aquifers have a long history of use dating back to the earliest days of European settlement in the late 1600s. Although extensive areas of some of the aquifers have or currently (2009) are areas of groundwater level declines from large-scale, concentrated pumping centers, large areas of the Atlantic Coastal Plain contain substantial quantities of high-quality groundwater that currently (2009) are unused. Groundwater use from the Atlantic Coastal Plain aquifers in North Carolina and South Carolina has increased during the past 60 years as the population has increased along with demands for municipal, industrial, and agricultural water needs. While North Carolina and South Carolina work to increase development of water supplies in response to the rapid growth in these coastal populations, both States recognize that they are facing a number of unanswered questions regarding availability of groundwater supplies and the best methods to manage these important supplies. An in-depth assessment of groundwater availability of the Atlantic Coastal Plain aquifers of North and South Carolina has been completed by the U.S. Geological Survey Groundwater Resources Program. This assessment includes (1) a determination of the present status of the Atlantic Coastal Plain groundwater resources; (2) an explanation for how these resources have changed over time; and (3) development of tools to assess the system's response to stresses from potential future climate variability. Results from numerous previous investigations of the Atlantic Coastal Plain by Federal and State agencies have been incorporated into this effort. The primary products of this effort are (1) comprehensive hydrologic datasets such as groundwater levels, groundwater use, and aquifer properties; (2) a

77 FR 51771 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR...

Science.gov (United States)

2012-08-27

... Process Webinar for Gulf of Mexico and South Atlantic Spanish Mackerel and Cobia AGENCY: National Marine... of SEDAR 28 Gulf of Mexico and South Atlantic Spanish mackerel and cobia assessment webinar. SUMMARY: The SEDAR 28 assessment of the Gulf of Mexico and South Atlantic Spanish mackerel and cobia fisheries...

Estuarine demersal fish assemblage from a transition region between the tropics and the subtropics of the South Atlantic

Directory of Open Access Journals (Sweden)

Mauricio Hostim-Silva

2013-09-01

Full Text Available The coastal state of Espírito Santo is in the central region of Brazil, where biological productivity is considered low. The objective of this work is to present a current list of demersal, estuarine fish from northern Espírito Santo. This work is based on the compilation of data collected monthly using trawl nets. The ichthyofauna comprises 57 species, within 10 orders and 32 families. The family Sciaenidae has the largest number of species (8, followed by Carangidae (4 and Gerreidae (4. This coincides with what has been found for the Brazilian coast and for the coast of the South Atlantic. It is important to note that the total species richness in the estuaries of northern Espírito Santo is lower than other estuaries of the South West Atlantic coast. Most of the species are widely distributed in the Western Atlantic. Only a small part (14% of the fauna of northern Espírito Santo was evaluated in regards to risk of extinction, but conservation should be prioritized in the area due to overexploitation of species.

33 CFR 162.65 - All waterways tributary to the Atlantic Ocean south of Chesapeake Bay and all waterways tributary...

Science.gov (United States)

2010-07-01

... Atlantic Ocean south of Chesapeake Bay and all waterways tributary to the Gulf of Mexico east and south of... All waterways tributary to the Atlantic Ocean south of Chesapeake Bay and all waterways tributary to..., which are tributary to or connected by other waterways with the Atlantic Ocean south of Chesapeake Bay...

75 FR 39638 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2010-07-12

...; Comprehensive Ecosystem-Based Amendment 1 for the South Atlantic Region; Correction AGENCY: National Marine... Comprehensive Ecosystem-Based Amendment 1 for the South Atlantic region that published in the Federal Register...

Current and other data from fixed platforms from the South Atlantic Ocean as part of the International Decade of Ocean Exploration / International Ocean Studies / First Dynamic Response and Kinematics Experiment in the Drake Passage (IDOE/ISOS/FDRAKE) from 1975-02-22 to 1980-02-24 (NODC Accession 9500011)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Current and other data were collected from fixed platforms in the South Atlantic Ocean from 22 February 1975 to 24 February 1980. Data were collected by the Texas...

Multibeam Mapping of the South Atlantic Bight: Georgia 2005, a Proposed MPA on the Continental Shelf

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Fisheries laboratory in Panama City, Florida coordinated an acoustic survey at the new proposed Marine Protected Areas in the South Atlantic Bight area June...

Influence of Tropical South Atlantic Sea Surface Temperatures on the Indian Summer monsoon in CMIP5 models

Science.gov (United States)

Kucharski, Fred; Joshi, Manish K.

2017-04-01

In this study the teleconnection from the tropical south Atlantic to the Indian monsoon has been assessed in observations and in 32 models from the World Climate Research Program (WCRP) Coupled Model Intercomparison Project Phase 5 (CMIP5). All models show that the regression pattern of tropics-wide Atlantic sea surface temperature (SST) anomalies onto the tropical south Atlantic index correlates well with that in observations, even though with varying spatial standard deviations. However, only about half of the 32 models considered show the correct sign of rainfall response over India to a warm anomaly in the south tropical Atlantic, which is a reduction of rainfall. On the other hand, models generally do show large-scale responses broadly consistent with the observations, and the signal over India depends on relatively subtle changes in the response. This response to a tropical south Atlantic warm (cold) anomaly is a low-level quadrupole in streamfunction with an anticyclonic (cyclonic) anomaly over the Arabian Sea and India. This anticyclonic (cyclonic) anomaly leads to a weakening (strengthening) of the Somali jet and low-level divergence (convergence) over India, both inducing a reduction (increase) of Indian rainfall. The models which do not show the correct rainfall response over India also show a response similar to the one indicated above, but with maximum of the anticyclonic (cyclonic) response shifted to the western Pacific. The large-scale Walker circulation adjustment to the tropical south Atlantic SST anomalies is identified as one of the factors which account for the differences in the low-level streamfunction response. Models (and the observations) with the correct sign of the rainfall signal over India show the dominant upper-level convergence (divergence) as response to a warm (cold) tropical south Atlantic in the western Pacific region, whereas models with the wrong sign of the rainfall signal show it predominantly in the central-eastern Pacific

The meteorological environment of the tropospheric ozone maximum over the tropical South Atlantic

Energy Technology Data Exchange (ETDEWEB)

Krishnamurti, T N; Fuelberg, H E; Bensman, E L; Sinha, M C; Oosterhof, D; Kumar, V B [Florida State University, Tallahassee, FL (United States). Department of Meteorology

1993-01-01

This paper examines atmospheric flow patterns over the Southern Atlantic Ocean, where a maximum of tropospheric ozone is observed just west of Southern Africa. The climatology of the South Atlantic basin is shown to favour flow off from South America and Africa converging into the area of high tropospheric ozone. This ozone is initially attributable to byproducts of biomass burning over both these continents. A case study, carried out over 6 days during October 1989, was used to determine the effect of a purely advective scheme (no photochemistry) on the distribution of ozone over the basin. The results showed a pattern in which ozone accumulated off the west coast of South Africa within 72 hours after beginning with an homogenous, zonally-symmetric distribution of ozone. 11 refs.

76 FR 82183 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2011-12-30

... THE CARIBBEAN, GULF, AND SOUTH ATLANTIC 0 1. The authority citation for part 622 continues to read as... appropriate to secure the range of hook sizes and styles used in the South Atlantic snapper- grouper fishery.... The device must be of a size appropriate to secure the range of hook sizes and styles used in the...

South Atlantic meridional transports from NEMO-based simulations and reanalyses

Science.gov (United States)

Mignac, Davi; Ferreira, David; Haines, Keith

2018-02-01

The meridional heat transport (MHT) of the South Atlantic plays a key role in the global heat budget: it is the only equatorward basin-scale ocean heat transport and it sets the northward direction of the global cross-equatorial transport. Its strength and variability, however, are not well known. The South Atlantic transports are evaluated for four state-of-the-art global ocean reanalyses (ORAs) and two free-running models (FRMs) in the period 1997-2010. All products employ the Nucleus for European Modelling of the Oceans (NEMO) model, and the ORAs share very similar configurations. Very few previous works have looked at ocean circulation patterns in reanalysis products, but here we show that the ORA basin interior transports are consistently improved by the assimilated in situ and satellite observations relative to the FRMs, especially in the Argo period. The ORAs also exhibit systematically higher meridional transports than the FRMs, which is in closer agreement with observational estimates at 35 and 11° S. However, the data assimilation impact on the meridional transports still greatly varies among the ORAs, leading to differences up to ˜ 8 Sv and 0.4 PW in the South Atlantic Meridional Overturning Circulation and the MHTs, respectively. We narrow this down to large inter-product discrepancies in the western boundary currents (WBCs) at both upper and deep levels explaining up to ˜ 85 % of the inter-product differences in MHT. We show that meridional velocity differences, rather than temperature differences, in the WBCs drive ˜ 83 % of this MHT spread. These findings show that the present ocean observation network and data assimilation schemes can be used to consistently constrain the South Atlantic interior circulation but not the overturning component, which is dominated by the narrow western boundary currents. This will likely limit the effectiveness of ORA products for climate or decadal prediction studies.

76 FR 34061 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

Science.gov (United States)

2011-06-10

...: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction with... Workshops are appointed by the Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils and...; constituency representatives including fishermen, environmentalists, and NGO's; International experts; and...

Biological processes in the water column of the South Atlantic bight

Energy Technology Data Exchange (ETDEWEB)

Paffenhoefer, G.A.; Yoder, J.A.

1980-01-31

Progress is reported on research conducted during 1979 on the biological oceanography of the South Atlantic Bight. The presentation consists of a number of published articles and abstracts of oral presentations. (ACR)

77 FR 1908 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery Off the...

Science.gov (United States)

2012-01-12

.... SUMMARY: NMFS announces that the South Atlantic Fishery Management Council (Council) has submitted Amendment 20A to the Fishery Management Plan (FMP) for the Snapper-Grouper Fishery of the South Atlantic... for the wreckfish individual transferable quota (ITQ) program, including actions to define and revert...

Distribution of oxygen isotopes in the water masses of Drake Passage and the South Atlantic

Science.gov (United States)

Meredith, Michael P.; Grose, Katie E.; McDonagh, Elaine L.; Heywood, Karen J.; Frew, Russell D.; Dennis, Paul F.

1999-09-01

Measurements of the ratio of stable isotopes of oxygen (18O and 16O) from samples collected on World Ocean Circulation Experiment sections SR1b (eastern Drake Passage) and A11 (Punta Arenas to Cape Town) are used, together with hydrographic data, to deduce information about the formation and variability of South Atlantic and Southern Ocean water masses. The Drake Passage surface waters south of the Polar Front (PF) are isotopically light (δ18O around -0.4‰) owing to the influence of meteoric waters. The salinity and δ18O of the A11 surface waters yield an apparent freshwater end-member which is much isotopically lighter than the local precipitation, thus advection of these waters from farther south dominates over local effects in determining the surface water properties. The Drake Passage section shows unusual proximity of the two main fronts of the Antarctic Circumpolar Current (the PF and Subantarctic Front (SAF)), and we observe cold, fresh, and isotopically light water derived from the temperature-minimum Winter Water at the SAF. This water is of the correct density to freshen the intermediate water north of the SAF and thus play a role in the formation of the comparatively fresh Antarctic Intermediate Water (AAIW) of the South Atlantic. This confirms the role of Antarctic water in forming the South Atlantic variety of AAIW. Across the A11 section the oxygen isotope and salinity data at the AAIW core show very similar traces, with waters in the Malvinas Current loop showing lowest values of both. At the eastern boundary of the South Atlantic, the input of Red Sea Water from east of South Africa is observed via the presence of anomalously isotopically heavy AAIW. We deduce potentially significant temporal variability in the isotopic composition of Weddell Sea Deep Water (WSDW) by comparing the Drake Passage data to earlier data covering the outflow of the Weddell Sea. The A11 data show WSDW consistent with such variability, indicating that its effects could

76 FR 16730 - South Atlantic Fishery Management Council; Public Meetings

Science.gov (United States)

2011-03-25

... migratory groups of king mackerel, Spanish mackerel and cobia. The amendment addresses establishment of... separate migratory groups of cobia (between the Gulf and South Atlantic), sector allocations, and possible...

Linking the basement geology along the Africa-South America coasts in the South Atlantic

Czech Academy of Sciences Publication Activity Database

Konopásek, J.; Sláma, Jiří; Košler, J.

2016-01-01

Roč. 280, July (2016), s. 221-230 ISSN 0301-9268 Institutional support: RVO:67985831 Keywords : Gondwana reconstruction * South Atlantic Ocean * Plate tectonics * Kaoko Belt * Dom Feliciano Belt Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.843, year: 2016

Trade in the Atlantic Basin, 2000-2012: a panoramic view

Directory of Open Access Journals (Sweden)

Lorena Ruano

2013-09-01

Full Text Available This article offers a descriptive analysis of the goods trade in the Atlantic, and provides the following data: the largest trade volume can be found in the North Atlantic and the Americas, albeit with slower growth; Africa and South America trade mainly with the North, but with a tendency towards diversification; Europe depends less on Atlantic trade than other regions, South America being the most dependent of these; Africa mainly trades with extra-regional partners; the Atlantic’s role in world trade is diminishing owing to the rise of Asia (China; exports can be divided into those from the North (products with greater added value and the South (raw materials; imports are dominated by automobiles and oil; the main challenge is the economic crisis in Europe; with the Doha round havingstalled, the Atlantic free trade agreements under negotiation (Canada-EU; TTIP are gaining importance, with the aim of boosting the flow of goods, which represents one of the largest in the world.

Paleomagnetic evidence for the persistence or recurrence of the South Atlantic geomagnetic Anomaly

Science.gov (United States)

Shah, Jay; Koppers, Anthony A. P.; Leitner, Marko; Leonhardt, Roman; Muxworthy, Adrian R.; Heunemann, Christoph; Bachtadse, Valerian; Ashley, Jack A. D.; Matzka, Jürgen

2017-04-01

The South Atlantic geomagnetic Anomaly (SAA) is known as a region of the geomagnetic field that is approximately 25 μT in intensity, compared to an expected value of ˜43 μT. Geomagnetic field models do not find evidence for the SAA being a persistent feature of the geomagnetic field, however these models are constructed from paleomagnetic data that is sparse in the southern hemisphere. We present a full-vector paleomagnetic study of 40Ar/39Ar dated Late Pleistocene lavas from Tristan da Cunha in the South Atlantic Ocean (Shah et al., 2016; EPSL). Paleointensity estimations using the Thellier method of eight lava flows yield an average paleointensity of the Tristan da Cunha lavas as 18 ± 6 μT and an average virtual axial dipole moment (VADM) of 3.1 ± 1.2 × 1022 Am2. Comparing the VADM of the lava flows against the PADM2M, PINT and SINT-800 databases indicates that the lava flows represent four distinct periods of anomalously weak intensity in the South Atlantic between 43 and 90 ka ago, constrained by newly obtained 40Ar/39Ar ages. This anomalously weak intensity in the Late Pleistocene is similar to the present-day SAA and SAA-like anomalous behavior found in the recent archeomagnetic study by Tarduno et al. (2015; Nat. Commun.). Our dataset provides evidence for the persistence or recurrence of geomagnetic main field anomalies in the South Atlantic, and potentially indicates such anomalies are the geomagnetic field manifestation of the long-existing core-mantle boundary heterogeneity seismically identified as the African Large Low Velocity Shear Province (LLSVP).

Influence of Surface Processes over Africa on the Atlantic Marine ITCZ and South American Precipitation.

Science.gov (United States)

Hagos, Samson M.; Cook, Kerry H.

2005-12-01

Previous studies show that the climatological precipitation over South America, particularly the Nordeste region, is influenced by the presence of the African continent. Here the influence of African topography and surface wetness on the Atlantic marine ITCZ (AMI) and South American precipitation are investigated.Cross-equatorial flow over the Atlantic Ocean introduced by north south asymmetry in surface conditions over Africa shifts the AMI in the direction of the flow. African topography, for example, introduces an anomalous high over the southern Atlantic Ocean and a low to the north. This results in a northward migration of the AMI and dry conditions over the Nordeste region.The implications of this process on variability are then studied by analyzing the response of the AMI to soil moisture anomalies over tropical Africa. Northerly flow induced by equatorially asymmetric perturbations in soil moisture over northern tropical Africa shifts the AMI southward, increasing the climatological precipitation over northeastern South America. Flow associated with an equatorially symmetric perturbation in soil moisture, however, has a very weak cross-equatorial component and very weak influence on the AMI and South American precipitation. The sensitivity of the AMI to soil moisture perturbations over certain regions of Africa can possibly improve the skill of prediction.

75 FR 27658 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery of the...

Science.gov (United States)

2010-05-18

... reduce overfishing of red snapper in the South Atlantic implemented by a temporary rule published by NMFS... reduce overfishing of red snapper in the South Atlantic. DATES: The effective date for the interim rule... extension of the rule is to reduce the overfishing of red snapper while long-term management measures are...

76 FR 30110 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the...

Science.gov (United States)

2011-05-24

... the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the Southern Atlantic..., Coral Reefs, and Live/Hardbottom Habitat of the South Atlantic Region. The applicant has requested.... HHSN261200900012C) between the National Cancer Institute ( http://www.cancer.gov/ ) and the Coral Reef Research...

76 FR 59102 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

Science.gov (United States)

2011-09-23

... Atlantic; Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 10 AGENCY: National... Fishery Management Plan for the Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic (FMP), as... implemented, this rule would revise the lobster species contained within the fishery management unit...

76 FR 75488 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

Science.gov (United States)

2011-12-02

... Atlantic; Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 10 AGENCY: National... Plan for the Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic (FMP), as prepared and... the lobster species contained within the fishery management unit; establishes an annual catch limit...

Deep circulation changes in the South Atlantic since the Last Glacial Maximum from Nd isotope and multi-proxy records

Science.gov (United States)

Wei, R.; Abouchami, W.; Zahn, R.; Masque, P.

2016-01-01

We report down-core sedimentary Nd isotope (εNd) records from two South Atlantic sediment cores, MD02-2594 and GeoB3603-2, located on the western South African continental margin. The core sites are positioned downstream of the present-day flow path of North Atlantic Deep Water (NADW) and close to the Southern Ocean, which makes them suitable for reconstructing past variability in NADW circulation over the last glacial cycle. The Fe-Mn leachates εNd records show a coherent decreasing trend from glacial radiogenic values towards less radiogenic values during the Holocene. This trend is confirmed by εNd in fish debris and mixed planktonic foraminifera, albeit with an offset during the Holocene to lower values relative to the leachates, matching the present-day composition of NADW in the Cape Basin. We interpret the εNd changes as reflecting the glacial shoaling of Southern Ocean waters to shallower depths combined with the admixing of southward flowing Northern Component Water (NCW). A compilation of Atlantic εNd records reveals increasing radiogenic isotope signatures towards the south and with increasing depth. This signal is most prominent during the Last Glacial Maximum (LGM) and of similar amplitude across the Atlantic basin, suggesting continuous deep water production in the North Atlantic and export to the South Atlantic and the Southern Ocean. The amplitude of the εNd change from the LGM to Holocene is largest in the southernmost cores, implying a greater sensitivity to the deglacial strengthening of NADW at these sites. This signal impacted most prominently the South Atlantic deep and bottom water layers that were particularly deprived of NCW during the LGM. The εNd variations correlate with changes in 231Pa/230Th ratios and benthic δ13C across the deglacial transition. Together with the contrasting 231Pa/230Th: εNd pattern of the North and South Atlantic, this indicates a progressive reorganization of the AMOC to full strength during the Holocene.

The American South in the Atlantic World

DEFF Research Database (Denmark)

decisively shaped the history and culture of the American South from colonial times to the modern era. The essays in this interdisciplinary volume examine a wide range of topics, including race, migration, religion, law, slavery, emancipation, literature, memoir, popular culture, and ethnography. At a time...... when there is growing emphasis on globalizing southern studies the collection both demonstrates and critiques the value of Atlantic World perspectives on the region. Equally important, the mix of case studies and state-of-the field essays combines the latest historical thinking on the South’s myriad...

Evidence for cosmic ray modulation in temperature records from the South Atlantic Magnetic Anomaly region

Energy Technology Data Exchange (ETDEWEB)

Frigo, E. [Sao Paulo Univ. (Brazil). Dept. de Geofisica; Federal do Pampa Univ., Cacapava do Sul (Brazil); Pacca, I.G. [Sao Paulo Univ. (Brazil). Dept. de Geofisica; Pereira-Filho, A.J. [Sao Paulo Univ. (Brazil). Dept. de Ciencias Atmosfericas; Rampelloto, P.H. [Federal do Pampa Univ., Sao Gabriel (Brazil); Rigozo, N.R. [Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos (Brazil). Div. de Geofisica Espacial

2013-11-01

Possible direct or indirect climatic effects related to solar variability and El Nino-Southern Oscillation (ENSO) were investigated in the southern Brazil region by means of the annual mean temperatures from four weather stations 2 degrees of latitude apart over the South Atlantic Magnetic Anomaly (SAMA) region. Four maximum temperature peaks are evident at all stations in 1940, 1958, 1977 and 2002. A spectral analysis indicates the occurrence of periodicities between 2 and 7 yr, most likely associated with ENSO, and periodicities of approximately 11 and 22 yr, normally associated with solar variability. Cross-wavelet analysis indicated that the signal associated with the 22 yr solar magnetic cycle was more persistent in the last decades, while the 11 yr sunspot cycle and ENSO periodicities were intermittent. Phase-angle analysis revealed that temperature variations and the 22 yr solar cycle were in anti-phase near the SAMA center. Results show an indirect indication of possible relationships between the variability of galactic cosmic rays and climate change on a regional scale.

Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the THALASSA in the North Atlantic Ocean and South Atlantic Ocean from 1999-07-12 to 1999-09-22 (NODC Accession 0113601)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113601 includes chemical, discrete sample, physical and profile data collected from THALASSA in the North Atlantic Ocean and South Atlantic Ocean...

Ascension and Port Stanley geomagnetic observatories and monitoring the South Atlantic Anomaly

International Nuclear Information System (INIS)

Macmillan, S.; Turbitt, C.; Thomson, A.

2009-01-01

Our 15-year experience of operating two remote observatories, Ascension and Port Stanley, in the south Atlantic is described. These observatories help monitor the South Atlantic Anomaly (SAA), a region of weak magnetic field which causes considerable problems for spacecraft operators. One-minute and one-second values from these observatories, and other observatories both inside and outside the SAA, are analysed. We investigate whether the SAA, and its growth over time, are having any tangible effect on the observed external field variations. Whilst only able to illustrate the long-term characteristics of the irregular external field related to the solar cycle and not due to any long-term changes in the internal field, we do isolate micro pulsation signals at sites inside the SAA which contain more power than at sites outside.

78 FR 46923 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery off the...

Science.gov (United States)

2013-08-02

... the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery off the South Atlantic... following an ACL overage, could have adverse economic and social impacts on fishery participants... implementing the procedural provisions of the National Environmental Policy Act (NEPA; 40 CFR parts 1500-1508...

Immunohistochemical localization of CYP1A, vitellogenin and Zona radiata proteins in the liver of swordfish (Xiphias gladius L.) taken from the Mediterranean Sea, South Atlantic, South Western Indian and Central North Pacific Oceans

International Nuclear Information System (INIS)

Desantis, S.; Corriero, A.; Cirillo, F.; Deflorio, M.; Brill, R.; Griffiths, M.; Lopata, A.L.; Serna, J.M. de la; Bridges, C.R.; Kime, D.E.; De Metrio, G.

2005-01-01

Cytochrome P4501A (CYP1A) monoxygenase, vitellogenin (Vtg) and Zona radiata proteins (Zrp) are frequently used as biomarkers of fish exposure to organic contaminants. In this work, swordfish liver sections obtained from the Mediterranean Sea, the South African coasts (South Atlantic and South Western Indian Oceans) and the Central North Pacific Ocean were immunostained with antisera against CYP1A, Zrp, and Vtg. CYP1A induction was found in hepatocytes, epithelium of the biliary ductus and the endothelium of large blood vessels of fish from the Mediterranean Sea and South African waters, but not from the Pacific Ocean. Zrp and Vtg were immunolocalized in hepatocytes of male swordfish from the Mediterranean Sea and from South African waters. Plasma Dot-Blot analysis, performed in Mediterranean and Pacific specimens, revealed the presence of Zrp and Vtg in males from Mediterranean but not from Pacific. These results confirm previous findings about the potential exposure of Mediterranean swordfish to endocrine, disrupting chemicals and raise questions concerning the possible presence of xenobiotic contaminants off the Southern coasts of South Africa in both the South Atlantic and South Western Indian Oceans

Wetland forest statistics for the South Atlantic States

Science.gov (United States)

Mark J. Brown; Greg M. Smith; Joseph McCollum

2001-01-01

Twenty-one percent, or 17.6 million acres, of the timberland in the South Atlantic States was classified as wetland timberland. Sixty percent of the region’s wetland timberland was under nonindustrial private forest ownership. Forty-eight percent of the region’s wetland timberland was classified as sawtimber-sized stands. Lowland hardwood types made up 62 percent of...

78 FR 62586 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR...

Science.gov (United States)

2013-10-22

.... Participants will present summary data and will discuss data needs and treatments. Although non-emergency... the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meeting...), Commerce. ACTION: Notice of SEDAR 38 data webinar for Gulf of Mexico and South Atlantic King Mackerel...

Profile and bottle data collected on the RV Melville (cruise Vancouver 06) from the Agulhas-South Atlantic Thermohaline Transport Experiment (ASTTEX) in the Atlantic Ocean from 20030102 to 20030115 (NODC Accession 0074001)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Introduction: The Agulhas-South Atlantic Thermohaline Experiment (ASTTEX) examined the fluxes of heat, salt and mass entering the South Atlantic ocean via the...

75 FR 44223 - Fisheries of the Northeast Region; South Atlantic Region

Science.gov (United States)

2010-07-28

... overfishing or an overfished condition. SUMMARY: This action serves as a notice that NMFS, on behalf of the... condition. In the South Atlantic Region, red grouper is subject to overfishing and is in an overfished...; overfishing is occurring, a stock is in an overfished condition, or a stock is approaching an overfished...

77 FR 30506 - Fisheries of the Caribbean, Gulf of Mexico, South Atlantic; Comprehensive Amendment

Science.gov (United States)

2012-05-23

... Golden Crab Fishery of the Atlantic (Golden Crab FMP); the Shrimp Fishery of the South Atlantic Region... ``search.'' Comments received through means not specified in this rule will not be considered. FOR FURTHER..., dolphin and wahoo, golden crab, shrimp and spiny lobster fisheries in the exclusive economic zone are...

77 FR 25407 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the...

Science.gov (United States)

2012-04-30

... the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the Southern Atlantic... South Carolina Aquarium to collect, with certain conditions, various species of reef fish, crabs, and..., marine sanctuaries, special management zones, or artificial reefs without additional authorization...

pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the HESPERIDES in the North Atlantic Ocean, South Atlantic Ocean and Strait of Gibraltar from 2013-03-20 to 2013-05-22 (NODC Accession 0114434)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0114434 includes chemical, discrete sample, physical and profile data collected from HESPERIDES in the North Atlantic Ocean, South Atlantic Ocean and...

Examining South Atlantic Subtropical Cyclone Anita using the Satellite-Enhanced Regional Downscaling for Applied Studies Hourly Outputs

Science.gov (United States)

Vaicberg, H.; Palmeira, A. C. P. A.; Nunes, A.

2017-12-01

Studies on South Atlantic cyclones are mainly compromised by scarcity of observations. Therefore, remote sensing and global (re) analysis products are usually employed in investigations of their evolution. However, the frequent use of global reanalysis might difficult the assessment of the characteristics of the cyclones found in South Atlantic. In that regard, studies on "subtropical" cyclones have been performed using the 25-km resolution, Satellite-enhanced Regional Downscaling for Applied Studies (SRDAS), a product developed at the Federal University of Rio de Janeiro in Brazil. In SRDAS, the Regional Spectral Model assimilates precipitation estimates from environmental satellites, while dynamically downscaling a global reanalysis using the spectral nudging technique to maintain the large-scale features in agreement with the regional model solution. The use of regional models in the downscaling of general circulation models provides more detailed information on weather and climate. As a way of illustrating the usefulness of SRDAS in the study of the subtropical South Atlantic cyclones, the subtropical cyclone Anita was selected because of its intensity. Anita developed near Brazilian south/southeast coast, with damages to local communities. Comparisons with available observations demonstrated the skill of SRDAS in simulating such an extreme event.

77 FR 32572 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the...

Science.gov (United States)

2012-06-01

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA935 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs Off the Southern Atlantic... conditions, various species of reef fish, crabs, and lobsters in Federal waters off South Carolina and North...

Fires, East Falkland Island, South Atlantic

Science.gov (United States)

2007-01-01

This near-nadir image (looking almost straight down) of the Falkland Islands in the South Atlantic was acquired at the southernmost extent of the International Space Station's latitudinal orbit range of approximately 52 degrees north to 52 degrees south relative to the surface of the Earth. The windy and relatively dry climate, which includes roughly 600 millimeters (24 inches) of precipitation annually, has given rise to natural vegetation comprised of treeless grassland with scattered bogs. The grasslands are ideal for sheep rearing--the dominant occupation until recent decades, when fishing (mainly squid for Spain) and tourism became the mainstays of the economy. These expanses of grassland provide ready fuel for fires, as indicated by the several long smoke plumes visible in this astronaut photograph. Astronaut photograph ISS015-E-30526 was acquired on September 25, 2007, with a Kodak 760C digital camera fitted with a 58 mm lens. The image was taken by the Expedition 15 crew, and is provided by the ISS Crew Earth Observations experiment and Image Science and Analysis Laboratory, Johnson Space Center. The image in this article has been cropped and enhanced to improve contrast. Lens artifacts have been removed.

A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient

Directory of Open Access Journals (Sweden)

L. E. Lisiecki

2010-05-01

Full Text Available The fact that the deep-ocean benthic δ13C minimum shifted from the North Pacific to the South Atlantic during the Last Glacial Maximum is often interpretted as evidence of a change in deep water circulation, such as the development of deep water ventilation in the North Pacific or a decrease in Southern Ocean overturning. This study re-evaluates the implications of changes in benthic δ13C gradients by comparing Pacific Deep Water (PDW δ13C measurements with the values expected for the null hypothesis that PDW ventilation sources remained unchanged throughout the Late Pleistocene. The δ13C compositions of PDW, Northern Component Water (NCW and Southern Component Water (SCW are estimated from regional benthic δ13C stacks of 3–6 sites. Changes in PDW δ13C and PDW-SCW δ13C gradients over the past 800 kyr are found to be well described by a constant mixture of 60% NCW and 40% SCW plus a constant Pacific remineralization offset of −0.5‰. Thus, a change in PDW ventilation cannot be inferred solely on the basis of changes in the Pacific-South Atlantic benthic δ13C gradient.

75 FR 51242 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

Science.gov (United States)

2010-08-19

... Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction with NOAA Fisheries and... Caribbean Fishery Management Councils; the Atlantic and Gulf States Marine Fisheries Commissions; and NOAA... representatives including fishermen, environmentalists, and NGO's; International experts; and staff of Councils...

Improving geomagnetic observatory data in the South Atlantic Anomaly

Science.gov (United States)

Matzka, Jürgen; Morschhauser, Achim; Brando Soares, Gabriel; Pinheiro, Katia

2016-04-01

The Swarm mission clearly proofs the benefit of coordinated geomagnetic measurements from a well-tailored constellation in order to recover as good as possible the contributions of the various geomagnetic field sources. A similar truth applies to geomagnetic observatories. Their scientific value can be maximised by properly arranging the position of individual observatories with respect to the geometry of the external current systems in the ionosphere and magnetosphere, with respect to regions of particular interest for secular variation, and with respect to regions of anomalous electric conductivity in the ground. Here, we report on our plans and recent efforts to upgrade geomagnetic observatories and to recover unpublished data from geomagnetic observatories at low latitudes in the South Atlantic Anomaly. In particular, we target the magnetic equator with the equatorial electrojet and low latitudes to characterise the Sq- and ring current. The observatory network that we present allows also to study the longitudinal structure of these external current systems. The South Atlantic Anomaly region is very interesting due to its secular variation. We will show newly recovered data and comparisons with existing data sets. On the technical side, we introduce low-power data loggers. In addition, we use mobile phone data transfer, which is rapidly evolving in the region and allows timely data access and quality control at remote sites that previously were not connected to the internet.

76 FR 82403 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and...

Science.gov (United States)

2011-12-30

... Atmospheric Administration 50 CFR Part 622 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and Reef Fish Fishery Management Plans of Puerto Rico and the U.S. Virgin... South Atlantic; Amendments to the Queen Conch and Reef Fish Fishery Management Plans of Puerto Rico and...

76 FR 59371 - Fisheries of the Caribbean, Gulf of Mexico and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2011-09-26

...-BB26 Fisheries of the Caribbean, Gulf of Mexico and South Atlantic; Comprehensive Ecosystem-Based... Atlantic Fishery Management Council (Council) has submitted the Comprehensive Ecosystem-Based Amendment (CE... were established under the Comprehensive Ecosystem-Based Amendment 1 and include Cape Lookout Coral...

Transport of North Pacific 137Cs labeled waters to the south-eastern Atlantic Ocean

Science.gov (United States)

Sanchez-Cabeza, J. A.; Levy, I.; Gastaud, J.; Eriksson, M.; Osvath, I.; Aoyama, M.; Povinec, P. P.; Komura, K.

2011-04-01

During the reoccupation of the WOCE transect A10 at 30°S by the BEAGLE2003 cruise, the SHOTS project partners collected a large number of samples for the analysis of isotopic tracers. 137Cs was mostly deposited on the oceans surface during the late 1950s and early 1960s, after the atmospheric detonation of large nuclear devices, which mostly occurred in the Northern Hemisphere. The development of advanced radioanalytical and counting techniques allowed to obtain, for the first time in this region, a zonal section of 137Cs water concentrations, where little information existed before, thus constituting an important benchmark for further studies. 137Cs concentrations in the upper waters (0-1000 m) of the south-eastern Atlantic Ocean are similar to those observed in the south-western Indian Ocean, suggesting transport of 137Cs labeled waters by the Agulhas current to the Benguela Current region. In contrast, bomb radiocarbon data do not show this feature, indicating the usefulness of 137Cs as a radiotracer of water mass transport from the Indian to the South Atlantic Ocean.

76 FR 23940 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery; Framework Adjustment 22

Science.gov (United States)

2011-04-29

... the LA fleet, Amendment 15 proposes a management uncertainty buffer based on the F associated with a... to implement Framework Adjustment 22 (Framework 22) to the Atlantic Sea Scallop Fishery Management Plan (FMP), which was developed and adopted by the New England Fishery Management Council (Council) and...

Topographic asymmetry of the South Atlantic from global models of mantle flow and lithospheric stretching

Science.gov (United States)

Flament, Nicolas; Gurnis, Michael; Williams, Simon; Seton, Maria; Skogseid, Jakob; Heine, Christian; Müller, Dietmar

2014-05-01

The relief of the South Atlantic is characterized by elevated passive continental margins along southern Africa and eastern Brazil, and by the bathymetric asymmetry of the southern oceanic basin where the western flank is much deeper than the eastern flank. We investigate the origin of these topographic features in the present and over time since the Jurassic with a model of global mantle flow and lithospheric deformation. The model progressively assimilates plate kinematics, plate boundaries and lithospheric age derived from global tectonic reconstructions with deforming plates, and predicts the evolution of mantle temperature, continental crustal thickness, long-wavelength dynamic topography, and isostatic topography. Mantle viscosity and the kinematics of the opening of the South Atlantic are adjustable parameters in multiple model cases. Model predictions are compared to observables both for the present-day and in the past. Present-day predictions are compared to topography, mantle tomography, and an estimate of residual topography. Predictions for the past are compared to tectonic subsidence from backstripped borehole data along the South American passive margin, and to dynamic uplift as constrained by thermochronology in southern Africa. Comparison between model predictions and observations suggests that the first-order features of the topography of the South Atlantic are due to long-wavelength dynamic topography, rather than to asthenospheric processes. We find the uplift of southern Africa to be best reproduced with a lower mantle that is at least 40 times more viscous than the upper mantle.

Changes in ocean circulation in the South-east Atlantic Ocean during the Pliocene

Science.gov (United States)

Petrick, B. F.; McClymont, E.; Felder, S.; Leng, M. J.

2013-12-01

The Southeast Atlantic Ocean is an important ocean gateway because major oceanic systems interact with each other in a relatively small geographic area. These include the Benguela Current, Antarctic Circumpolar Current, and the input of warm and saline waters from the Indian Ocean via the Agulhas leakage. However, there remain questions about circulation change in this region during the Pliocene, including whether there was more or less Agulhas Leakage, which may have implications for the strength of the global thermohaline circulation. ODP Site 1087 (31°28'S, 15°19'E, 1374m water depth) is located outside the Benguela upwelling region and is affected by Agulhas leakage in the modern ocean. Sea-surface temperatures (SSTs) are thus sensitive to the influence of Agulhas Leakage at this site. Our approach is to apply several organic geochemistry proxies and foraminiferal analyses to reconstruct the Pliocene history of ODP 1087, including the UK37' index (SSTs), pigments (primary productivity) and planktonic foraminifera (water mass changes). SSTs during the Pliocene range from 17 to 22.5 °C (mean SSTs at 21 °C), and show variability on orbital and suborbital time scales. Our results indicate that the Benguela upwelling system had intensified and/or shifted south during the Pliocene. We find no evidence of Agulhas leakage, meaning that either Agulhas Leakage was severely reduced or displaced during the mid-Pliocene. Potential causes of the observed signals include changes to the local wind field and/or changes in the temperature of intermediate waters which upwell in the Benguela system. Pronounced cooling is observed during cold stages in the Pliocene, aligned with the M2 and KM2 events. These results may indicate that changes to the extent of the Antarctic ice sheet had impact on circulation in the south east Atlantic during the Pliocene via displacement of the Antarctic Circumpolar Currents.

Convective Lofting Links Indian Ocean Air Pollution to Recurrent South Atlantic Ozone Maxima

Science.gov (United States)

Chatfield, R. B.; Guan, H.; Thompson, A. M.; Witte, J.

2003-12-01

We extend on our analysis of equatorial tropospheric ozone to illustrate the contributions of South Asian pollution export in forming episodes of high O3 over the Atlantic Ocean. We amplify on an earlier description of a broad resolution of the "Atlantic Paradox," for the Jan-Feb-March period, which included initial indications of a very long-distance contribution from South Asia. The approach has been to describe typical periods of significant maximum and minimum tropospheric ozone for early 1999, exploiting TOMS tropospheric ozone estimates jointly with characteristic features of the SHADOZ (Southern Hemisphere Additional Ozonesondes) ozone soundings. Further investigation of the Total Tropospheric Ozone (TTO) record for all of 1999 suggests that there are repeated periods of very long-distance Asian influence crossing Africa, with an apparent effect on those portions of the Atlantic Equatorial troposphere which are downwind. Trajectory analyses suggest that the pattern over the Indian Ocean is complex: a sequence invoving multiple or mixed combustion sources, low level transport, cumulonimbus venting, and high-level transport to the west seem to be indicated by the TTO record. Biomass burning, fossil and biofuel combustion, and lighting seem to all contribute. For the Atlantic, burning and lighting on adjacent continents as well as episodes of this cross-Africa long-distance transport are all linked in a coordinated seasonal march: all are related by movement of the sun. However, interseasonal tropical variability related to the Madden-Julian oscillation allows intermittent ozone buildups that depart from the seasonal norm.

Climate Change in U.S. South Atlantic, Gulf of Mexico and Caribbean Fisheries Regions

Science.gov (United States)

Roffer, M. A.; Hernandez, D. L.; Lamkin, J. T.; Pugliese, R.; Reichert, M.; Hall, C.

2016-02-01

A review of the recent evidence that climate change is affecting marine ecosystems in the U.S. fishery management zones of the South Atlantic, Gulf of Mexico and Caribbean regions will be presented. This will include affects on the living marine resources (including fish, invertebrates, marine mammals and turtles), fisheries, habitat and people. Emphasis will be given on the effects that impact managed species and the likely new challenges that they present to fishery managers. The evidence is being derived from the results of the "Climate Variability and Fisheries Workshop: Setting Research Priorities for the Gulf of Mexico, South Atlantic, and Caribbean Regions," October 26-28, 2015 in St. Petersburg Beach, Florida. Commonalities and regional differences will be presented in terms of how climate variability is likely to impact distribution, catch, catchability, socioeconomics, and management.

TEMPO: an ESA-funded project for uncovering significant features of the South Atlantic Anomaly

Science.gov (United States)

Pavón-Carrasco, F. Javier; De Santis, Angelo

2016-04-01

In this work we provide the last results of the ESA (European Space Agency) funded project TEMPO ("Is The Earth's Magnetic field POtentially reversing? New insights from Swarm mission"). The mail goal of this project is to analyse the time and spatial evolution of one of the most important features of the present geomagnetic field, i.e. the South Atlantic Anomaly (SAA). The region covered by this anomaly is characterized by values of geomagnetic field intensity around 30% lower than expected for those latitudes and extends over a large area in the South Atlantic Ocean, South America, South Africa and the Eastern Pacific Ocean. This large depression of the geomagnetic field strength has its origin in a prominent patch of reversed polarity flux in the Earth's outer core. The study of the SAA is an important challenge nowadays not only for the geomagnetic and paleomagnetic community, but also for other areas focused on the Earth Observation due to the protective role of this potential field against the charged particles forming the solar wind. A further increase of the SAA surface extent could have dramatic consequences for human health and technologies because a larger number of solar charged particles could reach the Earth's surface.

Palaeomagnetic evidence for the persistence or recurrence of geomagnetic main field anomalies in the South Atlantic

Science.gov (United States)

Shah, Jay; Koppers, Anthony A. P.; Leitner, Marko; Leonhardt, Roman; Muxworthy, Adrian R.; Heunemann, Christoph; Bachtadse, Valerian; Ashley, Jack A. D.; Matzka, Jürgen

2016-05-01

We present a dataset of a full-vector palaeomagnetic study of Late Pleistocene lavas from the island Tristan da Cunha in the South Atlantic Ocean. The current day geomagnetic field intensity in this region is approximately 25 μT, compared to an expected value of ∼43 μT; this phenomenon is known as the South Atlantic geomagnetic Anomaly (SAA). Geomagnetic field models extending back to the last 10 ka find no evidence for this being a persistent feature of the geomagnetic field, albeit, all models are constructed from data which is particularly sparse in the southern hemisphere. New 40Ar/39Ar incremental heating dating indicates the studied lavas from Tristan da Cunha extruded between 90 and 46 ka. Palaeointensity estimations of eight lava flows made using the Thellier method yield an average palaeointensity of 18 ± 6 μT and virtual axial dipole moment (VADM) of 3.1 ± 1.2 ×1022 Am2. The lava flows demonstrate four time intervals comparable to the present day SAA, where the average VADM of the Tristan da Cunha lavas is weaker than the global VADM average. This suggests a persistent or recurring low intensity anomaly to the main geomagnetic field similar to the SAA existed in the South Atlantic between 46 and 90 ka.

75 FR 20985 - Fisheries of the South Atlantic and Gulf of Mexico; Southeastern Data, Assessment, and Review...

Science.gov (United States)

2010-04-22

....net SUPPLEMENTARY INFORMATION: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management... Atlantic, and Caribbean Fishery Management Councils and NOAA Fisheries Southeast Regional Office and..., environmentalists, and NGO's; International experts; and staff of Councils, Commissions, and state and federal...

Revisiting the South Atlantic Anomaly after 3 years of Swarm satellite mission

Science.gov (United States)

Pavón-Carrasco, F. Javier; Campuzano, Saioa A.; De Santis, Angelo

2017-04-01

Covering part of Southern America and the South Atlantic Ocean, the South Atlantic Anomaly (SAA) is nowadays one of the most important and largest features of the geomagnetic field at the Earth's surface. It is characterized by lower intensity values than expected for those geomagnetic latitudes. Thanks to the global geomagnetic models, the spatial and temporal geometry of the Earth's magnetic field can be defined at the core-mantle boundary, showing the origin of the SAA as a reversal polarity patch that is growing with a pronounced rate of -2.54ṡ105 nT per century and with western drift. Since the Swarm satellite mission of the European Space Agency was launched at the end of 2013, the three twin satellites are picking up the most accurate values of the geomagnetic field up to now. In this work, we use the satellite magnetic data from Swarm mission along with the observatory ground data of surrounding areas to evaluate the spatial and temporal evolution of the SAA during the Swarm-life.

Variations of Sea Surface Temperature, Wind Stress, and Rainfall over the Tropical Atlantic and South America.

Science.gov (United States)

Nobre, Paulo; Srukla, J.

1996-10-01

Empirical orthogonal functions (E0Fs) and composite analyses are used to investigate the development of sea surface temperature (SST) anomaly patterns over the tropical Atlantic. The evolution of large-scale rainfall anomaly patterns over the equatorial Atlantic and South America are also investigated. 71e EOF analyses revealed that a pattern of anomalous SST and wind stress asymmetric relative to the equator is the dominant mode of interannual and longer variability over the tropical Atlantic. The most important findings of this study are as follows.Atmospheric circulation anomalies precede the development of basinwide anomalous SST patterns over the tropical Atlantic. Anomalous SST originate off the African coast simultaneously with atmospheric circulation anomalies and expand westward afterward. The time lag between wind stress relaxation (strengthening) and maximum SST warming (cooling) is about two months.Anomalous atmospheric circulation patterns over northern tropical Atlantic are phase locked to the seasonal cycle. Composite fields of SLP and wind stress over northern tropical Atlantic can be distinguished from random only within a few months preceding the March-May (MAM) season. Observational evidence is presented to show that the El Niño-Southern Oscillation phenomenon in the Pacific influences atmospheric circulation and SST anomalies over northern tropical Atlantic through atmospheric teleconnection patterns into higher latitudes of the Northern Hemisphere.The well-known droughts over northeastern Brazil (Nordeste) are a local manifestation of a much larger-scale rainfall anomaly pattern encompassing the whole equatorial Atlantic and Amazon region. Negative rainfall anomalies to the south of the equator during MAM, which is the rainy season for the Nordeste region, are related to an early withdrawal of the intertropical convergence zone toward the warm SST anomalies over the northern tropical Atlantic. Also, it is shown that precipitation anomalies

76 FR 41764 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs off the...

Science.gov (United States)

2011-07-15

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration [RIN 0648-XA491] Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs off the Southern Atlantic... sanctuaries, special management zones, or artificial reefs without additional authorization. A report on the...

The Impact of the AMOC Resumption in the Western South Atlantic Thermocline at the Onset of the Last Interglacial

Science.gov (United States)

Santos, Thiago P.; Lessa, Douglas O.; Venancio, Igor M.; Chiessi, Cristiano M.; Mulitza, Stefan; Kuhnert, Henning; Albuquerque, Ana Luiza S.

2017-11-01

After glacial terminations, large amounts of heat and salt were transferred from low to high latitudes, which is a crucial phenomenon for the reestablishment of the Atlantic Meridional Overturning Circulation (AMOC). However, how different glacial terminations evolved in the (sub)tropics is still poorly documented. Here we use foraminifera oxygen (δ18O) and carbon (δ13C) stable isotopes to show that the North Atlantic heat piracy, following the AMOC resumption at the early Last Interglacial, affected the thermocline δ18O levels of the subtropical western South Atlantic. Because of the cooling imposed by this process, glacial δ18O persisted in the thermocline for 7 kyr after the onset of the Last Interglacial, dampening the effect of sea level rise usually imprinted on foraminifera δ18O during terminations. Faunal composition and δ13C also suggest the existence of a colder and thicker South Atlantic Central Water coeval with the AMOC recovery. This process apparently did not occur during the last deglaciation.

The Security of the South Atlantic: Is It a Case for ’SATO’--South Atlantic Treaty Organization

Science.gov (United States)

1982-05-10

p. 704. 21Ibid. 2 2 Ibid. 2 3A.R.A. Nicolas Piccaluga, Control Del Trafico Maritimo en el Atlantic Sud. Politics para la Defensa v Seguridad de las...1981. Piccaluga, A. R. A, Nicolis. Control Del Trafico Maritimo En El Atlantico Sud. Politicar, Para La Defensa Y Seguridad De Las Rutas Maritimas En

South Atlantic Anomaly evolution by means of Swarm data

Science.gov (United States)

Pavon-Carrasco, F. Javier; Qamili, Enkelejda; De Santis, Angelo

2015-04-01

The study of the South Atlantic Anomaly (SAA) is an important challenge nowadays not only for the geomagnetic and paleomagnetic community, but also for other areas focused on the Earth Observation. This large magnetic anomaly is characterized by values of geomagnetic field intensity around 30% lower than expected for those latitudes and covers a large area in the South Atlantic Ocean between Southwest Brazil and South Africa. This great depression of the geomagnetic field strength at the Earth's surface has an internal deep origin: it is caused by a prominent patch of reversed polarity flux in the outer core. Since the Earth's magnetic field has an important protective role for the all geosphere because it deflects a large part of the solar radiation that would otherwise reach the Earth's surface, a large increase of the SAA could have dramatic consequences for human health and technologies. In the last three decades, an almost constant monitoring of the SAA has been carried out using satellite data showing a clear picture of the behaviour and evolution of the SAA, which area is growing alarmingly during the most recent years at the Earth's surface and at the core mantle boundary. In this context, the ESA Swarm mission (constituted by a constellation of three satellites in near-polar low orbits at two different altitudes) is providing detailed measurements of the intensity and directional elements of the geomagnetic field with high-precision and resolution never reached in the former space missions. This work aims to analyse in detail in space and time the SAA from the Earth's surface up to the satellite altitude. In order to carry out this study, comprehensive geomagnetic models at regional and global scale will be performed using the dataset provided by the Swarm satellites and all the available ground data. This kind of study is crucial to understand the evolution of the Earth's magnetic field in this area, and to possibly predict its future behaviour.

75 FR 23676 - Fisheries of the Gulf of Mexico and South Atlantic; Southeast Data, Assessment, and Review (SEDAR...

Science.gov (United States)

2010-05-04

... Caribbean Fishery Management Councils, in conjunction with NOAA Fisheries and the Atlantic and Gulf States... of Mexico, South Atlantic, and Caribbean Fishery Management Councils and NOAA Fisheries Southeast... fishermen, environmentalists, and NGO's; International experts; and staff of Councils, Commissions, and...

A new daily observational record from Grytviken, South Georgia: exploring 20th century extremes in the South Atlantic

Science.gov (United States)

Thomas, Z.; Turney, C. S.; Allan, R.; Colwell, S.; Kelly, G.; Lister, D.; Jones, P. D.; Beswick, M.; Alexander, L. V.; Lippmann, T.; Herold, N.; Jones, R. T.

2017-12-01

Although recent work has highlighted a host of significant late 20th century environmental changes across the mid to high latitudes of the Southern Hemisphere, the sparse nature of observational records limits our ability to place these changes in the context of long-term (multi-decadal and centennial) variability. As a result, investigating the impact of anthropogenic forcing on climate modes of variability and ecosystems is particularly challenging. Sub-Antarctic islands are particularly important in this regard, straddling major ocean and atmospheric boundaries and offering the potential to develop highly resolved records of change. In 1905, a whaling and meteorological station was established at Grytviken on Sub-Antarctic South Georgia in the South Atlantic (54°S) providing near-continuous observations through to present day. Although South Georgia lies in a strategic location for understanding Southern Ocean atmosphere-ocean dynamics, only a monthly resolved dataset has until now been available. Here we report a near continuous daily observational record from Grytviken for temperature and precipitation, which we compare to different datasets (including Twentieth Century Reanalysis; 20CR version 2c). A warming trend over the 20th century is observed in mean daily temperature at Grytviken with an average rate of temperature rise of 0.14°C per decade over the period 1907-2016 (p<0.0001). We find a significant trend towards increasingly warmer daytime extremes commencing from the mid-20th century accompanied by warmer night-time temperatures. Analysis of these data, and reanalysis products, suggest a realignment of synoptic conditions across the mid to high-latitudes, with a link between increasing temperature trends and atmospheric circulation dominated by stronger westerly airflow, resulting in significant foehn-related warming.

76 FR 99 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendment 24 to the Fishery...

Science.gov (United States)

2011-01-03

...NMFS, Southeast Region, in collaboration with the South Atlantic Fishery Management Council (Council), intends to prepare an EIS to describe and analyze a range of alternatives for management actions to be included in an amendment to the Fishery Management Plan for the Snapper-Grouper Fishery of the South Atlantic Region (FMP). These alternatives will consider measures to establish a rebuilding plan for the red grouper stock, while setting annual catch limits (ACLs), accountability measures (AMs), allocations, maximum sustainable yield (MSY), and optimum yield (OY) for red grouper. The purpose of this NOI is to solicit public comments on the scope of issues to be addressed in the EIS.

77 FR 32914 - Snapper-Grouper Fishery of the South Atlantic; 2012 Recreational Accountability Measure and...

Science.gov (United States)

2012-06-04

... Accountability Measure and Closure for South Atlantic Golden Tilefish AGENCY: National Marine Fisheries Service...; closure. SUMMARY: NMFS implements accountability measures (AMs) for the recreational sector of golden...

78 FR 30779 - Snapper-Grouper Fishery of the South Atlantic; 2013 Recreational Accountability Measure and...

Science.gov (United States)

2013-05-23

... Accountability Measure and Closure for South Atlantic Snowy Grouper AGENCY: National Marine Fisheries Service...; closure. SUMMARY: NMFS implements accountability measures (AMs) for the recreational sector of snowy...

78 FR 32995 - Snapper-Grouper Fishery of the South Atlantic; 2013 Recreational Accountability Measure and...

Science.gov (United States)

2013-06-03

... Accountability Measure and Closure for South Atlantic Golden Tilefish AGENCY: National Marine Fisheries Service...; closure. SUMMARY: NMFS implements accountability measures (AMs) for the recreational sector of golden...

75 FR 39917 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs off the...

Science.gov (United States)

2010-07-13

... the Caribbean, Gulf of Mexico, and South Atlantic; Coral and Coral Reefs off the Southern Atlantic... regulations implementing the Fishery Management Plan for Coral, Coral Reefs, and Live/Hardbottom Habitat of... Cancer Institute (http:// [[Page 39918

Tectono-Magmatic Evolution of the South Atlantic Continental Margins with Respect to Opening of the Ocean

Science.gov (United States)

Melankholina, E. N.; Sushchevskaya, N. M.

2018-03-01

The history of the opening of the South Atlantic in Early Cretaceous time is considered. It is shown that the determining role for continental breakup preparation has been played by tectono-magmatic events within the limits of the distal margins that developed above the plume head. The formation of the Rio Grande Rise-Walvis Ridge volcanic system along the trace of the hot spot is considered. The magmatism in the South Atlantic margins, its sources, and changes in composition during the evolution are described. On the basis of petrogeochemical data, the peculiarities of rocks with a continental signature are shown. Based on Pb-Sr-Nd isotopic studies, it is found that the manifestations of magmatism in the proximal margins had features of enriched components related to the EM I and EM II sources, sometimes with certain participation of the HIMU source. Within the limits of the Walvis Ridge, as magmatism expanded to the newly formed oceanic crust, the participation of depleted asthenospheric mantle became larger in the composition of magmas. The role played by the Tristan plume in magma generation is discussed: it is the most considered as the heat source that determined the melting of the ancient enriched lithosphere. The specifics of the tectono-magmatic evolution of the South Atlantic is pointed out: the origination during spreading of a number of hot spots above the periphery of the African superplume. The diachronous character of the opening of the ocean is considered in the context of northward progradation of the breakup line and its connection with the northern branch of the Atlantic Ocean in the Mid-Cretaceous.

A new gonad-infecting species of Philometra (Nematoda: Philometridae) from the Atlantic Spanish mackerel Scomberomorus maculatus (Scombridae) off the Atlantic Coast of Florida and South Carolina.

Science.gov (United States)

Moravec, František; Bakenhaster, Micah; de Buron, Isaure

2013-04-01

A new nematode species, Philometra atlantica n. sp. (Philometridae), is described from male and female specimens found in the ovary of the Atlantic Spanish mackerel, Scomberomorus maculatus (Mitchill) (Scombridae, Perciformes), off the Atlantic coast of Florida and South Carolina. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in the length of spicules (111-126 μm), number and arrangement of genital papillae, and a U-shaped, dorsally interrupted caudal mound in the male. A unique feature among all gonad-infecting philometrids is the presence of 2 reflexed dorsal barbs on the distal end of the gubernaculum. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by some morphological and biometrical features found in gravid females (body length, length of first-stage larvae or esophagus, structure of caudal end) and by the host type (fish family) and geographical distribution. Philometra atlantica is the fourth valid gonad-infecting species of Philometra reported from fishes of the family Scombridae.

76 FR 35409 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fisheries of the Gulf of...

Science.gov (United States)

2011-06-17

... Atlantic States AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric..., red drum, coastal migratory pelagics, stone crab, and lobsters in the Gulf, and snapper-grouper, coastal migratory pelagics, dolphin and wahoo, and lobsters in the South Atlantic. The EFP exempts...

75 FR 24883 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meeting

Science.gov (United States)

2010-05-06

... Assessment Process is a stock assessment report which describes the fisheries, evaluates the status of the stock, estimates biological benchmarks, projects future population conditions, and recommends research... South Atlantic stock of red snapper will consist of a series of workshops and webinars: a Data Workshop...

77 FR 29555 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2012-05-18

...; Comprehensive Ecosystem-Based Amendment 2 for the South Atlantic Region; Correction AGENCY: National Marine...: Correcting amendment. SUMMARY: This action corrects the final rule implementing the Comprehensive Ecosystem...

77 FR 74119 - Snapper-Grouper Fishery of the South Atlantic; 2012 Commercial Accountability Measure and Closure...

Science.gov (United States)

2012-12-13

... Accountability Measure and Closure for South Atlantic Snowy Grouper AGENCY: National Marine Fisheries Service...; closure. SUMMARY: NMFS implements accountability measures (AMs) for the commercial sector for snowy...

Otolith chemical composition as a useful tool for sciaenid stock discrimination in the south-western Atlantic

Directory of Open Access Journals (Sweden)

Alejandra V. Volpedo

2006-06-01

Full Text Available Striped weakfish (Cynoscion guatucupa and whitemouth croaker (Micropogonias furnieri are important commercial and recreational species found in abundance along the South American Atlantic coast. In recent years otolith chemical composition has been used as a tool for identifying fish stocks for several species. The chemical composition of C. guatucupa and M. furnieri otoliths was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES in samples from coastal sites (Partido de La Costa, Mar del Plata and San Blás Bay. Significant differences in the ratios of Mg/Ca, Mn/Ca and Sr/Ca for C. guatucupa otoliths and Cd/Ca, Cu/Ca, Mg/Ca, Sr/Ca and Zn/Ca for M. furnieri otoliths suggest the existence of two different fish stocks, one originating in the north (including Samborombón Bay and Partido de La Costa fisheries and another originating in the south (including “El Rincón” and San Blás fisheries. These results agree with previous studies on the same species using different methodologies. These stocks may be separated by an oceanographic barrier, the “Frente El Rincón”. Otolith chemical composition has not been previously used in South America for identifying fish stocks and may be a simple, quick and useful tool for the sustainable exploitation and management of commercial species.

Decadal change of the south Atlantic ocean Angola-Benguela frontal zone since 1980

Science.gov (United States)

Vizy, Edward K.; Cook, Kerry H.; Sun, Xiaoming

2018-01-01

High-resolution simulations with a regional atmospheric model coupled to an intermediate-level mixed layer ocean model along with multiple atmospheric and oceanic reanalyses are analyzed to understand how and why the Angola-Benguela frontal Zone (ABFZ) has changed since 1980. A southward shift of 0.05°-0.55° latitude decade-1 in the annual mean ABFZ position accompanied by an intensification of + 0.05 to + 0.13 K/100-km decade-1 has occurred as ocean mixed layer temperatures have warmed (cooled) equatorward (poleward) of the front over the 1980-2014 period. These changes are captured in a 35-year model integration. The oceanic warming north of the ABFZ is associated with a weakening of vertical entrainment, reduced cooling associated with vertical diffusion, and a deepening of the mixed layer along the Angola coast. These changes coincide with a steady weakening of the onshore atmospheric flow as the zonal pressure gradient between the eastern equatorial Atlantic and the Congo Basin weakens. Oceanic cooling poleward of the ABFZ is primarily due to enhanced advection of cooler water from the south and east, increased cooling by vertical diffusion, and shoaling of the mixed layer depth. In the atmosphere, these changes are related to an intensification and poleward shift of the South Atlantic sub-tropical anticyclone as surface winds, hence the westward mixed layer ocean currents, intensify in the Benguela upwelling region along the Namibian coast. With a few caveats, these findings demonstrate that air/sea interactions play a prominent role in influencing the observed decadal variability of the ABFZ over the southeastern Atlantic since 1980.

High energy electron and proton observations in the South Atlantic geomagnetic anomaly

International Nuclear Information System (INIS)

Nakamura, Y.; Takahashi, H.; Nagata, K.; Kohno, T.; Murakami, H.

1988-01-01

The method developed by researchers of cooperation agreement between Japan and Brazil, to observe high energy particles in the South Atlantic Geomagnetic Anomaly, is described. The energy spectra and pitch angle distributions of electrons and protons, using silicon detectors of good energy resolution and two spectrometers with different geometrical factors, on board of the OHZORA satellite, were determined. (M.C.K.) [pt

78 FR 16657 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Public Meetings

Science.gov (United States)

2013-03-18

... the status of the stock, estimates biological benchmarks, projects future population conditions, and... and gray triggerfish. SUMMARY: The SEDAR 32 assessments of the South Atlantic stocks of blueline... Review (SEDAR) process, a multi-step method for determining the status of fish stocks in the Southeast...

Bacterial diversity and biogeography in deep-sea sediments of the South Atlantic Ocean

DEFF Research Database (Denmark)

Schauer, Regina; Bienhold, Christina; Ramette, Alban

2010-01-01

in 1051 sequences. Phylotypes affiliated with Gammaproteobacteria, Deltaproteobacteria and Acidobacteria were present in all three basins. The distribution of these shared phylotypes seemed to be influenced neither by the Walvis Ridge nor by different deep water masses, suggesting a high dispersal......Microbial biogeographic patterns in the deep sea depend on the ability of microorganisms to disperse. One possible limitation to microbial dispersal may be the Walvis Ridge that separates the Antarctic Lower Circumpolar Deep Water from the North Atlantic Deep Water. We examined bacterial...... communities in three basins of the eastern South Atlantic Ocean to determine diversity and biogeography of bacterial communities in deep-sea surface sediments. The analysis of 16S ribosomal RNA (rRNA) gene clone libraries in each basin revealed a high diversity, representing 521 phylotypes with 98% identity...

Trophic ecology of yellownose skate Zearaja chilensis, a top predator in the south-western Atlantic Ocean.

Science.gov (United States)

Belleggia, M; Andrada, N; Paglieri, S; Cortés, F; Massa, A M; Figueroa, D E; Bremec, C

2016-03-01

The diet and trophic level (TL ) of the yellownose skate Zearaja chilensis in the south-western Atlantic Ocean (35°-54° S), and how these varied in relation to body size, sex, maturity stage, depth and region were determined by analysis of stomach contents. From 776 specimens analysed, 671 (86·5%) ranging from 180 to 1190 mm total length (LT ) had prey in their stomachs. The diet was dominated by fishes, mainly the notothenioid Patagonotothen ramsayi and the Argentine hake Merluccius hubbsi. The consumption of fishes and crabs increased with increasing predator size, and these preys were more important in the north than in the south. Isopods and other crustaceans were consumed more in the south and their consumption decreased as the size of Z. chilensis increased. The TL of Z. chilensis increased with LT from 4·29 to 4·59 (mean 4·53), confirming their ecological role as a top predator. The small and large size classes exhibited a low diet overlap and the highest spatial segregation, whereas medium and large specimens had higher co-occurrence and dietary overlap indices. A clear distinction in tooth shape was noted between sexes in adult specimens, with males having longer cusps. This sexual heterodonty may be related to reproductive behaviour, increasing the grasping ability of males during courtship, because there were no differences in diet between the sexes. © 2016 The Fisheries Society of the British Isles.

Southern limit of the Western South Atlantic mangroves: Assessment of the potential effects of global warming from a biogeographical perspective

Science.gov (United States)

Soares, Mário Luiz Gomes; Estrada, Gustavo Calderucio Duque; Fernandez, Viviane; Tognella, Mônica Maria Pereira

2012-04-01

The objective of the present study was to determine the exact location of the latitudinal limit of western South Atlantic mangroves, and to describe how these forests develop at this limit; as well as to analyze the potential responses of these communities to global warming. The study was carried out along the coast of Santa Catarina, Brazil. Specific studies on mangrove structure were carried out in the Santo Antônio Lagoon (28°28'34″S; 48°51'40″W). The coastline of Santa Catarina was surveyed for the occurrence of mangrove species. In the mangrove located at the southernmost distributional limit, the forest structure was characterized. Mean height and diameter, trunks density and basal area were calculated. Climatic and oceanographic factors controlling the occurrence and development of the mangrove forests at their latitudinal limit were analyzed, as well as the possible changes of this limit based on global warming scenarios. The results confirmed that the Santo Antônio Lagoon is the southern limit of the western South Atlantic mangroves. At this limit, the mangrove forests show a low degree of development, defined by low mean diameter and height, and high trunks density and trunks/tree ratio. The observed structural pattern and the local alternation of these forests with salt marsh species are typical of mangrove forests at their latitudinal limits. The absence of mangroves south of Laguna and forest structure at the latitudinal limit are controlled by rigorous climate and oceanographic characteristics. In response to the planetary warming process, we expect that mangroves will expand southward, as a consequence of an increase in air and ocean surface temperatures, a reduction in the incidence of frosts, an increased influence of the Brazil Current and a decreased influence of the Falkland Current, and the availability of sheltered estuarine systems for the establishment of new mangroves.

Effects of Atlantic warm pool variability over climate of South America tropical transition zone

Science.gov (United States)

Ricaurte Villota, Constanza; Romero-Rodríguez, Deisy; Andrés Ordoñez-Zuñiga, Silvio; Murcia-Riaño, Magnolia; Coca-Domínguez, Oswaldo

2016-04-01

Colombia is located in the northwestern corner of South America in a climatically complex region due to the influence processes modulators of climate both the Pacific and Atlantic region, becoming in a transition zone between phenomena of northern and southern hemisphere. Variations in the climatic conditions of this region, especially rainfall, have been attributed to the influence of the El Nino Southern Oscillation (ENSO), but little is known about the interaction within Atlantic Ocean and specifically Caribbean Sea with the environmental conditions of this region. In this work We studied the influence of the Atlantic Warm Pool (AWP) on the Colombian Caribbean (CC) climate using data of Sea Surface Temperature (SST) between 1900 - 2014 from ERSST V4, compared with in situ data SIMAC (National System for Coral Reef Monitoring in Colombia - INVEMAR), rainfall between 1953-2013 of meteorological stations located at main airports in the Colombian Caribbean zone, administered by IDEAM, and winds data between 2003 - 2014 from WindSat sensor. The parameters analyzed showed spatial differences throughout the study area. SST anomalies, representing the variability of the AWP, showed to be associated with Multidecadal Atlantic Oscillation (AMO) and with the index of sea surface temperature of the North-tropical Atlantic (NTA), the variations was on 3 to 5 years on the ENSO scale and of approximately 11 years possibly related to solar cycles. Rainfall anomalies in the central and northern CC respond to changes in SST, while in the south zone these are not fully engage and show a high relationship with the ENSO. Finally, the winds also respond to changes in SST and showed a signal approximately 90 days possibly related to the Madden-Julian Oscillation, whose intensity depends on the CC region being analyzed. The results confirm that region is a transition zone in which operate several forcing, the variability of climate conditions is difficult to attribute only one, as ENSO

Seaweed beds support more juvenile reef fish than seagrass beds in a south-western Atlantic tropical seascape

Science.gov (United States)

Eggertsen, L.; Ferreira, C. E. L.; Fontoura, L.; Kautsky, N.; Gullström, M.; Berkström, C.

2017-09-01

Seascape connectivity is regarded essential for healthy reef fish communities in tropical shallow systems. A number of reef fish species use separate adult and nursery habitats, and hence contribute to nutrient and energy transfer between habitats. Seagrass beds and mangroves often constitute important nursery habitats, with high structural complexity and protection from predation. Here, we investigated if reef fish assemblages in the tropical south-western Atlantic demonstrate ontogenetic habitat connectivity and identify possible nurseries on three reef systems along the eastern Brazilian coast. Fish were surveyed in fore reef, back reef, Halodule wrightii seagrass beds and seaweed beds. Seagrass beds contained lower abundances and species richness of fish than expected, while Sargassum-dominated seaweed beds contained significantly more juveniles than all other habitats (average juvenile fish densities: 32.6 per 40 m2 in Sargassum beds, 11.2 per 40 m2 in back reef, 10.1 per 40 m2 in fore reef, and 5.04 per 40 m2 in seagrass beds), including several species that are found in the reef habitats as adults. Species that in other regions worldwide (e.g. the Caribbean) utilise seagrass beds as nursery habitats were here instead observed in Sargassum beds or back reef habitats. Coral cover was not correlated to adult fish distribution patterns; instead, type of turf was an important variable. Connectivity, and thus pathways of nutrient transfer, seems to function differently in east Brazil compared to many tropical regions. Sargassum-dominated beds might be more important as nurseries for a larger number of fish species than seagrass beds. Due to the low abundance of structurally complex seagrass beds we suggest that seaweed beds might influence adult reef fish abundances, being essential for several keystone species of reef fish in the tropical south-western Atlantic.

Foraminifera Population from South Africa Coast Line (Indian and Atlantic Oceans

Directory of Open Access Journals (Sweden)

Engin Meriç

2014-11-01

Full Text Available Cape Town is the second-largest city of the Republic of South Africa. Research is conducted in 3 different stations: Maori Bay, which lies in the southwest of Cape Town, and Pyramid Rock and Partridge Points which lies in the False Bay, southeast part of Cape Town. Samples are taken from young sediments at 10.00 and 20.00 m depths, and collected by scuba-diving method. The aim of the study is to investigate the living benthic foraminifera assemblages in the Atlantic Ocean, and to compare these assemblages with the southeastern part of the Atlantic Ocean, the Arabian Sea, Indian Ocean and Western Pacific assemblages. Moreover, the aim of the study is to determine whether there are any benthic foraminifera forms reaching to the Mediterranean from Pacific Ocean, Indian Ocean or Red Sea via Suez Channel.

Vulnerability of teleosts caught by the pelagic tuna longline fleets in South Atlantic and Western Indian Oceans

Science.gov (United States)

Lucena-Frédou, Flávia; Kell, Laurie; Frédou, Thierry; Gaertner, Daniel; Potier, Michel; Bach, Pascal; Travassos, Paulo; Hazin, Fábio; Ménard, Frédéric

2017-06-01

Productivity and Susceptibility Analysis (PSA) is a methodology for evaluating the vulnerability of a stock based on its biological productivity and susceptibility to fishing. In this study, we evaluated the vulnerability of 60 stocks of tuna, billfishes and other teleosts caught by the tuna longline fleets operating in the South Atlantic and Indian Ocean using a semi-quantitative PSA. We (a) evaluated the vulnerability of the species in the study areas; (b) compared the vulnerability of target and non-target species and oceans; (c) analyzed the sensitivity of data entry; and (d) compared the results of the PSA to other fully quantitative assessment methods. Istiophoridae exhibited the highest scores for vulnerability. The top 10 species at risk were: Atlantic Istiophorus albicans; Indian Ocean Istiompax indica; Atlantic Makaira nigricans and Thunnus alalunga; Indian Ocean Xiphias gladius; Atlantic T. albacares, Gempylus serpens, Ranzania laevis and X. gladius; and Indian Ocean T. alalunga. All species considered at high risk were targeted or were commercialized bycatch, except for the Atlantic G. serpens and R. laevis which were discarded, and may be considered as a false positive. Those species and others at high risk should be prioritized for further assessment and/or data collection. Most species at moderate risk were bycatch species kept for sale. Conversely, species classified at low risk were mostly discarded. Overall, species at high risk were overfished and/or subjected to overfishing. Moreover, all species considered to be within extinction risk (Critically Endangered, Endangered and Vulnerable) were in the high-risk category. The good concordance between approaches corroborates the results of our analysis. PSA is not a replacement for traditional stock assessments, where a stock is assessed at regular intervals to provide management advice. It is of importance, however, where there is uncertainty about catches and life history parameters, since it can

78 FR 27957 - Fisheries of the South Atlantic, Southeast Data, Assessment, and Review (SEDAR); Public Meetings

Science.gov (United States)

2013-05-13

..., describes the fisheries, evaluates the status of the stock, estimates biological benchmarks, projects future... to evaluate stock status, estimate population benchmarks and management criteria, and project future... South Atlantic stock of snowy [[Page 27958

Measurements of additional X-ray flux in South Atlantic magnetic anomaly region

International Nuclear Information System (INIS)

Martin, I.M.

1968-01-01

The purpose of this study is the calculation of the additional X-ray flux (20 - 150 KeV), produced by electron precipitation in the South Atlantic anomaly region. The kind of detector and the technique employed in the observations of this flux, utilizing stratospheric balloons as a means of transport of the payload across the anomaly region, are described. The results of two balloon launchins in Sao Jose dos Campos in July 1968, with the expected flux, are compared. (author) [pt

76 FR 18532 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); Assessment...

Science.gov (United States)

2011-04-04

... interested in participating should contact Kari Fenske at SEDAR (See FOR FURTHER INFORMATION CONTACT to request an invitation providing webinar access information.) FOR FURTHER INFORMATION CONTACT: Kari Fenske...-mail: kari.fenske@safmc.net . SUPPLEMENTARY INFORMATION: The Gulf of Mexico, South Atlantic, and...

76 FR 17625 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review; Public Meeting

Science.gov (United States)

2011-03-30

...: Participants will present summary data, and discuss data needs and treatments. Special Accommodations The... the South Atlantic; Southeast Data, Assessment, and Review; Public Meeting AGENCY: National Marine... of Southeast Data and Review (SEDAR) 26 data webinar for Caribbean Silk snapper, Queen snapper, and...

A neural network-based estimate of the seasonal to inter-annual variability of the Atlantic Ocean carbon sink

DEFF Research Database (Denmark)

Landschützer, P.; Gruber, N.; Bakker, D.C.E.

2013-01-01

The Atlantic Ocean is one of the most important sinks for atmospheric carbon dioxide (CO2), but this sink is known to vary substantially in time. Here we use surface ocean CO2 observations to estimate this sink and the temporal variability from 1998 to 2007 in the Atlantic Ocean. We benefit from ......, leading to a substantial trend toward a stronger CO2 sink for the entire South Atlantic (–0.14 Pg C yr–1 decade–1). The Atlantic carbon sink varies relatively little on inter-annual time-scales (±0.04 Pg C yr–1; 1σ)......The Atlantic Ocean is one of the most important sinks for atmospheric carbon dioxide (CO2), but this sink is known to vary substantially in time. Here we use surface ocean CO2 observations to estimate this sink and the temporal variability from 1998 to 2007 in the Atlantic Ocean. We benefit from (i...... poleward of 40° N, but many other parts of the North Atlantic increased more slowly, resulting in a barely changing Atlantic carbon sink north of the equator (–0.007 Pg C yr–1 decade–1). Surface ocean pCO2 was also increasing less than that of the atmosphere over most of the Atlantic south of the equator...

Dominance of Epsilonproteobacteria associated with a whale fall at a 4204 m depth - South Atlantic Ocean

Science.gov (United States)

Cavalett, Angélica; Silva, Marcus Adonai Castro da; Toyofuku, Takashi; Mendes, Rodrigo; Taketani, Rodrigo Gouvêa; Pedrini, Jéssica; Freitas, Robert Cardoso de; Sumida, Paulo Yukio Gomes; Yamanaka, Toshiro; Nagano, Yuriko; Pellizari, Vivian Helena; Perez, José Angel Alvarez; Kitazato, Hiroshi; Lima, André Oliveira de Souza

2017-12-01

The deep ocean is the largest marine environment on Earth and is home to a large reservoir of biodiversity. Within the deep ocean, large organic falls attract a suite of metazoans and microorganisms, which form an important community that, in part, relies on reduced chemical compounds. Here, we describe a deep-sea (4204 m) microbial community associated with sediments collected underneath a whale fall skeleton in the South Atlantic Ocean. Metagenomic analysis of 1 Gb of Illumina HiSeq. 2000 reads, including taxonomic and functional genes, was performed by using the MG-RAST pipeline, SEED, COG and the KEGG database. The results showed that Proteobacteria (79%) was the main phylum represented. The most dominant bacterial class in this phylum was Epsilonproteobacteria (69%), and Sulfurovum sp. NBC37-1 (97%) was the dominant species. Different species of Epsilonproteobacteria have been described in marine and terrestrial environments as important organisms for nutrient cycling. Functional analysis revealed key genes for nitrogen and sulfur cycles, including protein sequences for Sox system (sulfur oxidation) enzymes. These enzymes were mainly those of the Epsilonproteobacteria, indicating their importance for nitrogen and sulfur cycles and the balance of nutrients in this environment.

Biological response to millennial variability of dust and nutrient supply in the Subantarctic South Atlantic Ocean.

Science.gov (United States)

Anderson, Robert F; Barker, Stephen; Fleisher, Martin; Gersonde, Rainer; Goldstein, Steven L; Kuhn, Gerhard; Mortyn, P Graham; Pahnke, Katharina; Sachs, Julian P

2014-07-13

Fluxes of lithogenic material and fluxes of three palaeo-productivity proxies (organic carbon, biogenic opal and alkenones) over the past 100,000 years were determined using the (230)Th-normalization method in three sediment cores from the Subantarctic South Atlantic Ocean. Features in the lithogenic flux record of each core correspond to similar features in the record of dust deposition in the EPICA Dome C ice core. Biogenic fluxes correlate with lithogenic fluxes in each sediment core. Our preferred interpretation is that South American dust, most probably from Patagonia, constitutes a major source of lithogenic material in Subantarctic South Atlantic sediments, and that past biological productivity in this region responded to variability in the supply of dust, probably due to biologically available iron carried by the dust. Greater nutrient supply as well as greater nutrient utilization (stimulated by dust) contributed to Subantarctic productivity during cold periods, in contrast to the region south of the Antarctic Polar Front (APF), where reduced nutrient supply during cold periods was the principal factor limiting productivity. The anti-phased patterns of productivity on opposite sides of the APF point to shifts in the physical supply of nutrients and to dust as cofactors regulating productivity in the Southern Ocean. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Measurements of VLF-particle interactions at the South Atlantic Magnetic Anomaly on board a Brazilian geophysical satellite

International Nuclear Information System (INIS)

Gonzalez, W.D.; Pinto Junior, O.; Dutra, S.L.G.; Takahashi, H.

1988-01-01

A summary of the proposal for measurements of VLF wave-particle interactions, expected to occur at the South Atlantic magnetic anomaly, to be carried out on board a Brazilian geophysical satellite, will be presented. The expected domain of such interactions refers to electromagnetic VLF waves and to energetic-relativistic inner belt electrons, pitch angle diffusing into the atmosphere via cyclotron resonances. The detectors involve a tri-axial search coil magnetometer and a surface barrier silicon telescope. A modified and preliminary version of this proposed experiment will be carried out on board long duration balloon flights, well before the beginning of the intended satellite measurements. For the ballon flights the particle detector will be replaced by an x-ray detector, which can also monitor parameters related to the electron precipitation. (author) [pt

Imaging the lithosphere and underlying mantle of the South Atlantic, South America and Africa using waveform tomography with massive datasets

Science.gov (United States)

Celli, N. L.; Lebedev, S.; Schaeffer, A. J.; Ravenna, M.; Gaina, C.

2017-12-01

Recent growth in global seismic station coverage has created dense data sampling of the previously poorly constrained lithosphere and underlying mantle beneath the South Atlantic, South America and Africa. The new data enable us to image the vast region at a new level of detail and address important open questions regarding its lithospheric architecture and mantle dynamics. In order to fully exploit the data sampling, we use an efficient, multimode waveform tomography scheme that enables the extraction of structural information from millions of seismograms and use the inherent data redundancy to minimize effects of errors in the data. Our tomographic model is constrained by waveform fits of over 1.2 million vertical-component seismograms, computed using the Automated Multimode Inversion of surface, S- and multiple S-waves. Each successful seismogram fit provides a set of linear equations describing 1D average velocity perturbations within approximate sensitivity volumes, with respect to a 3D reference model. We then combine all equations into a large linear system and invert jointly for a model of S- and P-wave speeds and azimuthal anisotropy within the lithosphere and underlying mantle. We are now able to image the detailed structure of various African shields. For example, in West Africa, two clearly separate high-velocity units underlay the Reguibat and Man-Léo Shields; in the Congo area, a single high-velocity body, formed by three main units correspond to the Gabon-Cameroon, Bomu-Kibali and Kasai Shields. Strong low-velocity anomalies underlay the Afar Hotspot and the East African Rift; pronounced low velocities are also seen beneath parts of the Sahara Desert. We discuss the shape of the deep Afar anomaly and its possible relationships with the Saharan volcanism and the neighboring Tanzania Craton. In the South Atlantic, we retrieve fine-scale velocity structure along the Mid-Atlantic Ridge (MAR), indicative of hotspot-ridge interactions. Major hotspots show

Taxonomic review of the species of Mugil (Teleostei: Perciformes: Mugilidae) from the Atlantic South Caribbean and South America, with integration of morphological, cytogenetic and molecular data.

Science.gov (United States)

Menezes, Naércio A; Nirchio, Mauro; De Oliveira, Cláudio; Siccharamirez, Raquel

2015-01-10

Analysis of morphological, molecular and cytological data helped to define and more precisely characterize the species of Mugil from the Atlantic coasts of South Caribbean and South America, allowing a correction of prior misidentifications and distributional ranges. A new species from Venezuela is described and all the species from the area are redescribed. It is demonstrated that the apparent similarity in morphological traits, which contradicted the results from recent molecular studies, is the result of the misuse of traditional morphological characters, and thus both the molecular and cytological data instead are congruent with the morphological differences that are found among mullet species. The presence of Mugil hospes Jordan & Culver in the western south Atlantic is refuted based on the comparison of type material of this species with specimens from this area that also indicated a very significant morphological difference, what on the other hand justifies the recognition of these specimens as Mugil brevirostris (Ribeiro). The distribution of Mugil incilis Hancock is restricted and the similarities among the species formerly depicted in a prior dendrogram is modified following the inclusion of recently obtained molecular data for Mugil curvidens Valenciennes.

Particle precipitation and atmospheric X-and gamma-rays in the South Atlantic magnetic anomaly by balloon experiments

International Nuclear Information System (INIS)

Costa, J.M. da.

1981-06-01

Studies concerning particle precipitation and atmospheric X-and low energy gamma-rays in the South Atlantic magnetic anomaly by balloons experiments that have been made at INPE since 1968 are reported. (Author) [pt

Carbonate dissolution in the South Atlantic Ocean: evidence from ultrastructure breakdown in Globigerina bulloides

Science.gov (United States)

Dittert, Nicolas; Henrich, Rüdiger

2000-04-01

Ultrastructure dissolution susceptibility of the planktic foraminifer Globigerina bulloides, carbonate ion content of the water column, calcium carbonate content of the sediment surface, and carbonate/carbon weight percentage ratio derived from sediment surface samples were investigated in order to reconstruct the position of the calcite saturation horizon, the sedimentary calcite lysocline, and the calcium carbonate compensation depth (CCD) in the modern South Atlantic Ocean. Carbonate ion data from the water column refer to the GEOSECS locations 48, 103, and 109 and calcium carbonate data come from 19 GeoB sediment surface samples of 4 transects into the Brazil, the Guinea, and the Cape Basins. We present a new (paleo-) oceanographic tool, namely the Globigerina bulloides dissolution index (BDX). Further, we give evidence (a) for progressive G. bulloides ultrastructural breakdown with increasing carbonate dissolution even above the lysocline; (b) for a sharp BDX increase at the sedimentary lysocline; and (c) for the total absence of this species at the CCD. BDX puts us in the position to distinguish the upper open ocean and the upwelling influenced continental margin above from the deep ocean below the sedimentary lysocline. Carbonate ion data from water column samples, calcite weight percentage data from surface sediment samples, and carbonate/carbon weight percentage ratio appear to be good proxies to confirm BDX. As shown by BDX both the calcite saturation horizon (in the water column) and the sedimentary lysocline (at the sediment-water interface) mark the boundary between the carbonate ion undersaturated and highly corrosive Antarctic Bottom Water and the carbonate ion saturated North Atlantic Deep Water (NADW) of the modern South Atlantic.

Reproductive and population parameters of spiny dogfish Squalus acanthias in the south-western Atlantic Ocean.

Science.gov (United States)

Colonello, J H; Cortés, F; Belleggia, M; Massa, A M

2016-05-01

The objective of this study was to estimate reproductive and population parameters of the spiny dogfish Squalus acanthias for the south-western Atlantic Ocean. In total, 2714 specimens (1616 males and 1098 females) were collected from surveys carried out using research vessels. Males ranged from 225 to 861 mm total length (LT ) and females from 235 to 925 mm LT . The size at maturity of females (651 mm) was significantly greater than that of males (565 mm). The maximum proportion of mature individuals (Pmax ) of the gestation ogive was 156 mm). The temporal and spatial co-occurrence of non-gravid adult females at different stages of ovarian development, as well as gravid females at all embryonic development stages would indicate that the female reproductive cycle in the south-western Atlantic Ocean is asynchronous. The results indicate that S. acanthias is susceptible to fishing pressure on account of its length at maturity, extended reproductive cycles and low fecundity. © 2016 The Fisheries Society of the British Isles.

Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO2

Directory of Open Access Journals (Sweden)

M. A. Maslin

2008-12-01

Full Text Available A detailed record of benthic foraminifera carbon isotopes from the intermediate-depth South East Atlantic margin shows little glacial-interglacial variability between MIS-12 to MIS-10, suggesting that Northern Atlantic deepwaters consistently penetrated to at least 30° S. Millennial-scale increases in either the mass or flux of northern-sourced deepwaters over the core site occurred alongside reductions in Lower North Atlantic Deep Water recorded in North Atlantic sediment cores and show that the lower and intermediate limb of the Atlantic deepwater convective cell oscillated in anti-phase during previous glacial periods. In addition, a 500 yr resolution record of the Cape Basin intermediate-deep δ13C gradient shows that a reduction in deep Southern Ocean ventilation at the end of MIS-11 was consistent with a modelled CO2 drawdown of ~21–30 ppm. Further increases in the Southern Ocean chemical divide during the transition into MIS-10 were completed before minimum CO2 levels were reached, suggesting that other mechanisms such as alkalinity changes were responsible for the remaining ~45 ppm drawdown.

Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from POLARSTERN in the South Atlantic Ocean and Southern Oceans from 2005-01-22 to 2005-04-06 (NODC Accession 0108100)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108100 includes discrete sample and profile data collected from POLARSTERN in the South Atlantic Ocean and Southern Oceans (> 60 degrees South)...

Relationship between radionuclides and sedimentological variables in the South Atlantic Continental Margin

International Nuclear Information System (INIS)

Ferreira, Paulo A.L.; Figueira, Rubens C.L.

2015-01-01

There is a lack of information regarding marine radioactivity in sediments of the Continental Margin of the South Atlantic. "1"3"7Cs and "4"0K radioactivity and sedimentological variables were determined in superficial sediment samples. It was demonstrated that "4"0K is a good indicator for sediment granulometry, whilst "1"3"7Cs presents a good correlation with its chemical composition. Moreover, it was identified through the radiometric data the occurrence of input of allochtonous matter to the Brazilian southernmost compartment from the Rio de La Plata estuary, as previously reported in the literature. (author)

Clean Coal Technology: Region 4 Market Description, South Atlantic

International Nuclear Information System (INIS)

1993-09-01

The Region 4 Market Description Summary provides information that can be used in developing an understanding of the potential markets for clean coal technologies (CCTs) in the South Atlantic Region. This region (which geographically is Federal Region 4) consists of the following eight states: Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee. In order to understand the potential market. A description is provided of the region's energy use, power generation capacity, and potential growth. Highlights of state government activities that could have a bearing on commercial deployment of CCTs are also presented. The potential markets characterized in this summary center on electric power generation by investor-owned, cooperative, and municipal electric utilities and involve planned new capacity additions and actions taken by utilities to comply with Phases I and II of the Clean Air Act Amendments (CAAA) of 1990. Regulations, policies, utility business strategies, and organizational changes that could impact the role of CCTs as a utility option are identified and discussed. The information used to develop the Region 4 Market Description is based mainly on an extensive review of plans and annual reports of 29 investor-owned, cooperative, and municipal coal-using electric utilities and public information on strategies and actions for complying with the CAAA of 1990

78 FR 34041 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Fishery Management...

Science.gov (United States)

2013-06-06

... environmental impact statement (DEIS); scoping meetings; request for comments. SUMMARY: NMFS, Southeast Region... in developing the final environmental impact statement (FEIS), and before voting to submit the FMP to... the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Fishery Management Plan for the...

78 FR 34042 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Fishery Management...

Science.gov (United States)

2013-06-06

... environmental impact statement (DEIS); scoping meetings; request for comments. SUMMARY: NMFS, Southeast Region... in developing the final environmental impact statement (FEIS), and before voting to submit the FMP to... the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Fishery Management Plan for the...

75 FR 79309 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery Off the...

Science.gov (United States)

2010-12-20

...-Grouper Fishery Off the South Atlantic States; Emergency Rule To Delay Effectiveness of the Snapper... Atmospheric Administration (NOAA), Commerce. ACTION: Temporary rule; correction. SUMMARY: This document contains a correction to the temporary rule that delays the effective date of the area closure for snapper...

75 FR 12506 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

Science.gov (United States)

2010-03-16

... stock, estimates biological benchmarks, projects future population conditions, and recommends research...: The SEDAR assessments of the South Atlantic and Gulf of Mexico stocks of goliath grouper will consist... Review (SEDAR) process, a multi-step method for determining the status of fish stocks in the Southeast...

76 FR 81479 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

Science.gov (United States)

2011-12-28

... stock, estimates biological benchmarks, projects future population conditions, and recommends research... mackerel and cobia. SUMMARY: The SEDAR assessments of the South Atlantic and Gulf of Mexico stocks of... Review (SEDAR) process, a multi-step method for determining the status of fish stocks in the Southeast...

Freshening of Antarctic Intermediate Water in the South Atlantic Ocean in 2005–2014

OpenAIRE

W. Yao; J. Shi; X. Zhao

2017-01-01

Basin-scale freshening of Antarctic Intermediate Water (AAIW) is reported to have occurred in the South Atlantic Ocean during the period from 2005 to 2014, as shown by the gridded monthly means of the Array for Real-time Geostrophic Oceanography (Argo) data. This phenomenon was also revealed by two repeated transects along a section at 30° S, performed during the World Ocean Circulation Experiment Hydrographic Program. Freshening of the AAIW was compensated for by a salinity...

Assessing the role of North Atlantic freshwater forcing in millennial scale climate variability: a tropical Atlantic perspective

Energy Technology Data Exchange (ETDEWEB)

Dahl, Kristina A [Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program, Woods Hole, MA (United States); Broccoli, Anthony J [Rutgers University, Department of Environmental Sciences, New Brunswick, NJ (United States); Stouffer, Ronald J [Geophysical Fluid Dynamics Laboratory, Princeton, NJ (United States)

2005-03-01

This study analyzes a three-member ensemble of experiments, in which 0.1 Sv of freshwater was applied to the North Atlantic for 100 years in order to address the potential for large freshwater inputs in the North Atlantic to drive abrupt climate change. The model used is the GFDL R30 coupled ocean-atmosphere general circulation model. We focus in particular on the effects of this forcing on the tropical Atlantic region, which has been studied extensively by paleoclimatologists. In response to the freshwater forcing, North Atlantic meridional overturning circulation is reduced to roughly 40% by the end of the 100 year freshwater pulse. Consequently, the North Atlantic region cools by up to 8 C. The extreme cooling of the North Atlantic increases the pole-to-equator temperature gradient and requires more heat be provided to the high latitude Atlantic from the tropical Atlantic. To accommodate the increased heat requirement, the ITCZ shifts southward to allow for greater heat transport across the equator. Accompanying this southward ITCZ shift, the Northeast trade winds strengthen and precipitation patterns throughout the tropical Atlantic are altered. Specifically, precipitation in Northeast Brazil increases, and precipitation in Africa decreases slightly. In addition, we find that surface air temperatures warm over the tropical Atlantic and over Africa, but cool over northern South America. Sea-surface temperatures in the tropical Atlantic warm slightly with larger warm anomalies developing in the thermocline. These responses are robust for each member of the ensemble, and have now been identified by a number of freshwater forcing studies using coupled OAGCMs. The model responses to freshwater forcing are generally smaller in magnitude, but have the same direction, as paleoclimate data from the Younger Dryas suggest. In certain cases, however, the model responses and the paleoclimate data directly contradict one another. Discrepancies between the model simulations

75 FR 9864 - Fisheries of the Caribbean, Gulf of Mexico and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2010-03-04

...-AY32 Fisheries of the Caribbean, Gulf of Mexico and South Atlantic; Comprehensive Ecosystem-Based... thought to be the largest distribution (>23,000 square miles) of pristine deepwater coral ecosystems in... golden crab and deepwater shrimp fisheries while extending protection for deepwater coral ecosystems. CE...

75 FR 14548 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2010-03-26

...; Comprehensive Ecosystem-Based Amendment for the South Atlantic Region AGENCY: National Marine Fisheries Service... for comments. SUMMARY: NMFS issues this proposed rule to implement the Comprehensive Ecosystem-Based... ecosystems in the world while minimizing the effects on traditional fishing in the Deepwater Coral HAPCs...

76 FR 61284 - Accountability Measures and Reduced Season for the South Atlantic Recreational Sector of Golden...

Science.gov (United States)

2011-10-04

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 622 [Docket No. 0907271173-0629-03] RIN 0648-XA701 Accountability Measures and Reduced Season for the South Atlantic.... SUMMARY: NMFS implements accountability measures (AMs) for the recreational sector of golden tilefish in...

Mammal occurrence and roadkill in two adjacent ecoregions (Atlantic Forest and Cerrado in south-western Brazil

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Nilton C. Cáceres

2010-10-01

Full Text Available This paper examines the frequencies of mammal roadkill in two adjacent biogeographic ecoregions (Atlantic Forest and Cerrado of Brazil. Mammals were recorded during a seven-year period and over 3,900 km of roads, in order to obtain data for frequencies of species in habitats (sites and frequencies of species killed by cars on roads. Sites (n = 80 within ecoregions (Cerrado, n = 57; Atlantic Forest, n = 23 were searched for records of mammals. Species surveyed in the entire region totaled 33, belonging to nine orders and 16 families. In the Cerrado, 31 species were recorded in habitats; of these, 25 were found dead on roads. In the Atlantic Forest ecoregions, however, we found 21 species in habitats, 16 of which were also found dead on roads. There was no overall significant difference between ecoregions for frequencies of occurrence in habitats or for roadkills, but there were differences between individual species. Hence, anteaters were mostly recorded in the Cerrado ecoregion, whereas caviomorph rodents tended to be more frequent in the Atlantic Forest ecoregion (seen mainly by roadkills. The greater number of species (overall and threatened and the greater abundance of species records in the Cerrado suggest that this ecoregion has a greater biodiversity and is better conserved than the Atlantic Forest ecoregion, in the state of Mato Grosso do Sul, south-western Brazil.

78 FR 58248 - Coastal Migratory Pelagic Resources of the Gulf of Mexico and South Atlantic; 2013-2014...

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2013-09-23

... between the eastern and western zones at 87[deg]31.1' W. long., which is a line directly south from the... Atlantic; 2013-2014 Accountability Measure and Closure for Gulf King Mackerel in Western Zone AGENCY... king mackerel in the western zone of the Gulf of Mexico (Gulf) exclusive economic zone (EEZ) through...

Corallimorpharia collected during the CANCAP expeditions (1976-1986) in the south-eastern part of the North Atlantic*

NARCIS (Netherlands)

Hartog, den J.C.; Ocaña, O.; Brito, A.

1993-01-01

Species of Corallimorpharia collected during the CANCAP expeditions in the south-eastern part of the North Atlantic are described and discussed, altogether five species belonging to three genera of Corallimorphidae: the shallow water forms Corynactis viridis Allman, 1846, Pseudocorynactis

Key sources and distribution patterns of particulate material in the South Atlantic: data from the UK GEOTRACES A10 cruise

Science.gov (United States)

Milne, A.; Palmer, M.; Lohan, M. C.

2016-02-01

Particles play a fundamental role in the biogeochemical cycling of both major- and micro-nutrients in marine systems, including trace elements and isotopes. However, knowledge of particulate distributions, and their potential to regulate dissolved elemental concentrations, remains limited and poorly understood. The paradox is, that the oceanic inventory of trace metals is dominated by particulate inputs (e.g. aerosol deposition, shelf sediment resuspension). Moreover the labile fraction of particulate trace elements could be an important regulator of dissolved concentrations. Here we present particulate data from the UK GEOTRACES South Atlantic transect (GA10) from South Africa to Uruguay. Data from a range of elements (e.g. Fe, Al, Mn) revealed a greater input of particulate metals from the Argentine shelf (up to 290 nM of pFe) in comparison to the South African shelf (basin and penetrated deeper up the water column (up to 1300 m), a result of intense benthic storms. The imprint of leakage from the Agulhas Current, identified through temperature and salinity, was observed in the upper water column profile of numerous particulate data (e.g. Pb, Ni, Cd). Measured elemental gradients, combined with measurements from a vertical mixing-profiler, will allow estimates of particulate fluxes to be calculated.

Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the METEOR in the North Atlantic Ocean and South Atlantic Ocean from 1981-03-28 to 1981-04-23 (NODC Accession 0116646)

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National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116646 includes chemical, discrete sample, physical and profile data collected from METEOR in the North Atlantic Ocean and South Atlantic Ocean from...

Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the SONNE in the North Atlantic Ocean and South Atlantic Ocean from 2000-11-28 to 2000-12-27 (NODC Accession 0115599)

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National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115599 includes chemical, discrete sample, physical and profile data collected from SONNE in the North Atlantic Ocean and South Atlantic Ocean from...

Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the METEOR in the North Atlantic Ocean and South Atlantic Ocean from 1990-10-04 to 1990-10-27 (NODC Accession 0116643)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116643 includes chemical, discrete sample, physical and profile data collected from METEOR in the North Atlantic Ocean and South Atlantic Ocean from...

Variability of the Tropical Ocean Surface Temperatures at Decadal-Multidecadal Timescales. Part I: The Atlantic Ocean.

Science.gov (United States)

Mehta, Vikram M.

1998-09-01

Gridded time series from the Global Ocean Surface Temperature Atlas were analyzed with a variety of techniques to identify spatial structures and oscillation periods of the tropical Atlantic sea surface temperature (SST) variations at decadal timescales, and to develop physical interpretations of statistical patterns of decadal SST variations. Each time series was 110 yr (1882-1991) long. The tropical Atlantic SST variations were compared with decadal variations in a 74-yr-long (1912-85) north Nordeste Brazil rainfall time series and a 106-yr-long (1886-1991) tropical Atlantic cyclone activity index time series. The tropical Atlantic SST variations were also compared with decadal variations in the extratropical Atlantic SST.Multiyear to multidecadal variations in the cross-equatorial dipole pattern identified as a dominant empirical pattern of the tropical Atlantic SST variations in earlier and present studies are shown to be variations in the approximately north-south gradient of SST anomalies. It is also shown that there was no dynamical-thermodynamical, dipole mode of SST variations during the analysis period. There was a distinct decadal timescale (12-13 yr) of SST variations in the tropical South Atlantic, whereas no distinct decadal timescale was found in the tropical North Atlantic SST variations. Approximately 80% of the coherent decadal variance in the cross-equatorial SST gradient was `explained' by coherent decadal oscillations in the tropical South Atlantic SSTs. There were three, possibly physical, modes of decadal variations in the tropical Atlantic SSTs during the analysis period. In the more energetic mode of the North Atlantic decadal SST variations, anomalies traveled into the tropical North Atlantic from the extratropical North Atlantic along the eastern boundary of the basin. The anomalies strengthened and resided in the tropical North Atlantic for several years, then frequently traveled northward into the mid-high-latitude North Atlantic along

75 FR 39918 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

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2010-07-13

...-4366. SUPPLEMENTARY INFORMATION: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management... Management Councils and NOAA Fisheries Southeast Regional Office and Southeast Fisheries Science Center... researchers; constituency representatives including fishermen, environmentalists, and NGO's; International...

PARTICULATE ORGANIC CARBON, cloud amount/frequency and other data from COLUMBUS ISELIN in the North American Coastline-South and South Atlantic Ocean from 1990-05-23 to 1990-06-13 (NODC Accession 9100150)

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National Oceanic and Atmospheric Administration, Department of Commerce — Data was collected from R/V COLUMBUS ISELIN in South Atlantic Ocean and North American Coast line-South during the Amazon Shelf Sediment Study (AMASSEDS) between May...

75 FR 35330 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Comprehensive Ecosystem-Based...

Science.gov (United States)

2010-06-22

...; Comprehensive Ecosystem-Based Amendment for the South Atlantic Region AGENCY: National Marine Fisheries Service...: NMFS issues this final rule to implement the Comprehensive Ecosystem-Based Amendment 1 (CE-BA1) to the... pristine deepwater coral ecosystems in the world while minimizing the effects on traditional fishing in the...

Level of polychlorinated biphenyls in the lower troposphere of the North-and South-Atlantic Ocean. Studies of global baseline pollution. Pt. 17

International Nuclear Information System (INIS)

Schreitmueller, J.; Ballschmiter, K.

1994-01-01

Fourteen polychlorinated biphenyl (PCB) congeners were quantified in air samples of the tropospheric boundary layer of the Atlantic Ocean. The samples were taken on the German research vessel 'Polarstern' during north-south cruises across the Atlantic Ocean (1990, 1991), and on the Capo Verde islands in the North Atlantic Ocean (1992). Values for the sum of PCB were between 48 pg/m 3 (values for the seven indicator congeners were [ in pg/m 3 ]: PCB 28: 1.3; PCB 52: 5.0; PCB 101: 3.0; PCB 118: ≤0.5; PCB 138: 1; PCB 153: 1; PCB 180: 3 (values for the seven indicator congeners were [in pg/m 3 ]: PCB 28: 2.3; PCB 52: 3.4; PCB 101: ≤0.5; PCB 118: 3 (values for the seven indicator congeners were [in pg/m 3 ]: PCB 28: 2.6; PCB 52: 11.7; PCB 101: 28.4; PCB 118: 9; PCB 138: 21; PCB 153: 18; PCB 180: 5.5) were measured of the coast of South Patagonia. A difference depending on latitude and on terrestrial influenced air masses between the lower and the higher chlorinated congeners was observed. The levels of three- and tetrachlorinated congeners were highest in the Trade Wind regions. The contents of the higher chlorinated congeners had maxima in samples influenced by continental air masses. A correlation of the levels of the lower chlorinated congeners in air over the South Atlantic with the surface water temperature and thus with the temperature dependent gas/water partition coefficient K gw was observed. (orig.)

Were sea level changes during the Pleistocene in the South Atlantic Coastal Plain a driver of speciation in Petunia (Solanaceae)?

Science.gov (United States)

Ramos-Fregonezi, Aline M C; Fregonezi, Jeferson N; Cybis, Gabriela B; Fagundes, Nelson J R; Bonatto, Sandro L; Freitas, Loreta B

2015-05-20

Quaternary climatic changes led to variations in sea level and these variations played a significant role in the generation of marine terrace deposits in the South Atlantic Coastal Plain. The main consequence of the increase in sea level was local extinction or population displacement, such that coastal species would be found around the new coastline. Our main goal was to investigate the effects of sea level changes on the geographical structure and variability of genetic lineages from a Petunia species endemic to the South Atlantic Coastal Plain. We employed a phylogeographic approach based on plastid sequences obtained from individuals collected from the complete geographic distribution of Petunia integrifolia ssp. depauperata and its sister group. We used population genetics tests to evaluate the degree of genetic variation and structure among and within populations, and we used haplotype network analysis and Bayesian phylogenetic methods to estimate divergence times and population growth. We observed three major genetic lineages whose geographical distribution may be related to different transgression/regression events that occurred in this region during the Pleistocene. The divergence time between the monophyletic group P. integrifolia ssp. depauperata and its sister group (P. integrifolia ssp. integrifolia) was compatible with geological estimates of the availability of the coastal plain. Similarly, the origin of each genetic lineage is congruent with geological estimates of habitat availability. Diversification of P. integrifolia ssp. depauperata possibly occurred as a consequence of the marine transgression/regression cycles during the Pleistocene. In periods of high sea level, plants were most likely restricted to a refuge area corresponding to fossil dunes and granitic hills, from which they colonized the coast once the sea level came down. The modern pattern of lineage geographical distribution and population variation was established by a range

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2006-12-22 to 2007-12-30 (NCEI Accession 0157245)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157245 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2011-01-22 to 2011-12-11 (NCEI Accession 0157336)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157336 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

75 FR 51983 - Fisheries of the South Atlantic and Gulf of Mexico; Southeast Data, Assessment, and Review (SEDAR...

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2010-08-24

... INFORMATION: The Gulf of Mexico, South Atlantic, and Caribbean Fishery Management Councils, in conjunction... Caribbean Fishery Management Councils and NOAA Fisheries Southeast Regional Office and Southeast Fisheries..., biologists, and researchers; constituency representatives including fishermen, environmentalists, and NGO's...

Hydrology and water budget for a forested atlantic coastal plain watershed, South Carolina

Science.gov (United States)

Scott V. Harder; Devendra M Amatya; Callahan Timothy J.; Carl C. Trettin; Hakkila Jon

2007-01-01

Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

Hyrdology and water budget for a forested atlantic coastal plain watershed, South Carolina

Science.gov (United States)

Scott V. Harder; Devendra M. Amatya; Timothy J. Callahan; Carl C. Trettin; Jon Hakkila

2007-01-01

Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

The influence of Atmospheric Rivers over the South Atlantic on rainfall in South Africa

Science.gov (United States)

Ramos, A. M.; Trigo, R. M.; Blamey, R. C.; Tome, R.; Reason, C. J. C.

2017-12-01

An automated atmospheric river (AR) detection algorithm is used for the South Atlantic Ocean basin, allowing the identification of the major ARs impinging on the west coast of South Africa during the austral winter months (April-September) for the period 1979-2014, using two reanalysis products (NCEP-NCAR and ERA-Interim). The two products show relatively good agreement, with 10-15 persistent ARs (lasting 18h or longer) occurring on average per winter and nearly two thirds of these systems occurring poleward of 35°S. The relationship between persistent AR activity and winter rainfall is demonstrated using South African Weather Service rainfall data. Most stations positioned in areas of high topography contained the highest percentage of rainfall contributed by persistent ARs, whereas stations downwind, to the east of the major topographic barriers, had the lowest contributions. Extreme rainfall days in the region are also ranked by their magnitude and spatial extent. It is found that around 70% of the top 50 daily winter rainfall extremes in South Africa were in some way linked to ARs (both persistent and non-persistent). Results suggest that although persistent ARs are important contributors to heavy rainfall events, they are not necessarily a prerequisite. Overall, the findings of this study support akin assessments in the last decade on ARs in the northern hemisphere bound for the western coasts of USA and Europe. AcknowledgementsThe financial support for attending this workshop was possible through FCT project UID/GEO/50019/2013 - Instituto Dom Luiz. The author wishes also to acknowledge the contribution of project IMDROFLOOD - Improving Drought and Flood Early Warning, Forecasting and Mitigation using real-time hydroclimatic indicators (WaterJPI/0004/2014, Funded by Fundação para a Ciência e a Tecnologia, Portugal (FCT)), with the data provided to achieve this work. A. M. Ramos was also supported by a FCT postdoctoral grant (FCT/DFRH/ SFRH/BPD/84328/2012).

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2007-01-02 to 2007-12-22 (NCEI Accession 0144528)

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National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144528 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

NOAA TIFF Image - 30m Backscatter, South Atlantic Bight - Deep Coral Priority Areas - Navy Pathfinder - (2003), UTM 17N NAD83

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National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 30x30 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

NOAA TIFF Image - 30m Rugosity, South Atlantic Bight - Deep Coral Priority Areas - Navy Pathfinder - (2003), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 30x30 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the L'ATALANTE in the North Atlantic Ocean and South Atlantic Ocean from 2008-02-23 to 2008-03-15 (NODC Accession 0117496)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0117496 includes chemical, discrete sample, physical and profile data collected from L'ATALANTE in the North Atlantic Ocean and South Atlantic Ocean...

Evolution of Interhemispheric Sea-Surface Temperature Contrast in the Tropical Atlantic During Termination I

Science.gov (United States)

Kim, J.

2001-12-01

Meteorological and oceanographic studies show that interannual and decadal variability in tropical Atlantic sea-surface temperature (SST) strongly influences the climates over northeast Brazil, sub-Saharan Africa, as well as the Central American and Caribbean regions. In this context, it is worthwhile to reconstruct spatial temperature patterns for the longer-term tropical Atlantic SST history. In this study, a high-resolution alkenone-derived SST record from the subtropical eastern South Atlantic (core GeoB 1023-5) is compared with one from the tropical western North Atlantic (core M35003-4). This comparison reveals synchronous SST variations between both near equatorial Atlantic regions during the Heinrich Event 1 (H1) (18-15.5 cal kyr B.P.), but dipole-like SST variations during the Younger Dryas (YD) (13-11.5 cal kyr B.P.). To assess the relationship of SST variations between both regions, we calculated SST differences between cores GeoB 1023-5 and M35003-4, and compared it with the coccolithophorid Florisphaera profunda abundance record from the equatorial eastern Atlantic (core RC24-08) as an indicator of variations in intensity of south-easterly trade winds [McIntyre and Molfino, 1996]. This comparison suggests that synchronous warming in both regions during the H1 can be attributed to a reduced northward heat transport from the warm equatorial Atlantic to the cold high-latitude North Atlantic linked to the slowdown of thermohaline circulation overturning during cold events under full glacial conditions. However, dipole-like SST variations during the YD is probably more associated with strengthened south-easterly trade winds, which led to a strong upwelling-related cooling in the eastern South Atlantic region and concurrently enhanced advection of warm subtropical South Atlantic waters to the tropical western Atlantic during that time. Accordingly, a coupled oceanic-atmospheric process created a warm pool in the tropical western Atlantic and thus a dipole

Temporal Variations of Strength and Location of the South Atlantic Anomaly as Measured by RXTE

Science.gov (United States)

Wilms, Jorn; Felix, Furst; Rothschild, Richard E.; Pottschmidt, Katja; Smith, David M.; Lingenfelter, Richard

2009-01-01

The evolution of the particle background at an altitude of approx.540km during the time interval between 1996 and 2007 is studied using the particle monitor of the High Energy X-ray Timing Experiment on board NASA's Rossi X-ray Timing Explorer. A special emphasis of this study is the location and strength of the South Atlantic Anomaly (SAA). The size and strength of the SAA are anti-correlated with the the 10.7 cm radio flux of the Sun, which leads the SAA strength by approx.1 year reflecting variations in solar heating of the upper atmosphere. The location of the SAA is also found to drift westwards with an average drift rate of about 0.3deg/yr following the drift of the geomagnetic field configuration. Superimposed to this drift rate are irregularities, where the SAA suddenly moves eastwards and where furthermore the speed of the drift changes. The most prominent of these irregularities is found in the second quarter of 2003 and another event took place in 1999. We suggest that these events are previously unrecognized manifestations of the geomagnetic jerks of the Earth's magnetic field. Key words: space radiation environment, South Atlantic Anomaly, radiation monitors, Rossi X-ray Timing Explorer

Mitogenomic phylogeny, diversification, and biogeography of South American spiny rats

DEFF Research Database (Denmark)

Fabre, Pierre-Henri; Upham, Nathan S.; Emmons, Louise H.

2017-01-01

Echimyidae is one of the most speciose and ecologically diverse rodent families in the world, occupying a wide range of habitats in the Neotropics. However, a resolved phylogeny at the genus-level is still lacking for these 22 genera of South American spiny rats, including the coypu (Myocastorina...... Atlantic and Amazonian Forests and (2) the Northern uplift of the Andes....

A new Eastern Central Atlantic skate Raja parva sp. nov. (Rajoidei: Rajidae) belonging to the Raja miraletus species complex.

Science.gov (United States)

Last, Peter R; Séret, Bernard

2016-08-05

An investigation of combined CO1 and NADH2 data for rajid skates referable to Raja miraletus provided evidence that populations ranging from southern Africa to the North-East Atlantic and Mediterranean Sea, once considered to represent a cline, belong to a species complex consisting of at least four valid species. Raja miraletus appears to be confined to the Mediterranean Sea, and the North-East Atlantic from the Bay of Biscay south to Morocco and Madeira. The southernmost species, referable to the resurrected Raja ocellifera, occurs off southern Africa, off Namibia and from False Bay to Durban (South Africa). Two species occur off tropical West Africa, including Raja parva sp. nov. (Senegal, Liberia and Angola but is probably more widespread within the region), and another unidentified species needing further investigation. Raja cf. miraletus, confirmed from Mauritania and Senegal, appears to be a larger skate with a broader disc, more broadly pointed snout, larger spiracles, and a slightly longer and broader tail. Raja parva sp. nov. differs from nominal members of the complex in having an unusually long procaudal tail (exceeding 22% TL), as well as a combination of other external characters. Past investigators observed morphological and anatomical differences between these forms but these were thought to be due to intraspecific variability. They postulated that an upwelling at Cape Blanco (21°N) may have isolated the Mediterranean form (R. miraletus) from Mauritania-Senegal form (now known to be two species). Similarly, the Benguela Current and upwelling off Cape Frio (18°S) were thought to be responsible for separating the Angolan form (R. parva) and South African form (R. ocellifera).

ATLANTIC MAMMAL TRAITS: a data set of morphological traits of mammals in the Atlantic Forest of South America.

Science.gov (United States)

Gonçalves, Fernando; Bovendorp, Ricardo S; Beca, Gabrielle; Bello, Carolina; Costa-Pereira, Raul; Muylaert, Renata L; Rodarte, Raisa R; Villar, Nacho; Souza, Rafael; Graipel, Maurício E; Cherem, Jorge J; Faria, Deborah; Baumgarten, Julio; Alvarez, Martín R; Vieira, Emerson M; Cáceres, Nilton; Pardini, Renata; Leite, Yuri L R; Costa, Leonora P; Mello, Marco A R; Fischer, Erich; Passos, Fernando C; Varzinczak, Luiz H; Prevedello, Jayme A; Cruz-Neto, Ariovaldo P; Carvalho, Fernando; Percequillo, Alexandre R; Paviolo, Agustin; Nava, Alessandra; Duarte, José M B; de la Sancha, Noé U; Bernard, Enrico; Morato, Ronaldo G; Ribeiro, Juliana F; Becker, Rafael G; Paise, Gabriela; Tomasi, Paulo S; Vélez-Garcia, Felipe; Melo, Geruza L; Sponchiado, Jonas; Cerezer, Felipe; Barros, Marília A S; de Souza, Albérico Q S; Dos Santos, Cinthya C; Giné, Gastón A F; Kerches-Rogeri, Patricia; Weber, Marcelo M; Ambar, Guilherme; Cabrera-Martinez, Lucía V; Eriksson, Alan; Silveira, Maurício; Santos, Carolina F; Alves, Lucas; Barbier, Eder; Rezende, Gabriela C; Garbino, Guilherme S T; Rios, Élson O; Silva, Adna; Nascimento, Alexandre Túlio A; de Carvalho, Rodrigo S; Feijó, Anderson; Arrabal, Juan; Agostini, Ilaria; Lamattina, Daniela; Costa, Sebastian; Vanderhoeven, Ezequiel; de Melo, Fabiano R; de Oliveira Laroque, Plautino; Jerusalinsky, Leandro; Valença-Montenegro, Mônica M; Martins, Amely B; Ludwig, Gabriela; de Azevedo, Renata B; Anzóategui, Agustin; da Silva, Marina X; Figuerêdo Duarte Moraes, Marcela; Vogliotti, Alexandre; Gatti, Andressa; Püttker, Thomas; Barros, Camila S; Martins, Thais K; Keuroghlian, Alexine; Eaton, Donald P; Neves, Carolina L; Nardi, Marcelo S; Braga, Caryne; Gonçalves, Pablo R; Srbek-Araujo, Ana Carolina; Mendes, Poliana; de Oliveira, João A; Soares, Fábio A M; Rocha, Patrício A; Crawshaw, Peter; Ribeiro, Milton C; Galetti, Mauro

2018-02-01

Measures of traits are the basis of functional biological diversity. Numerous works consider mean species-level measures of traits while ignoring individual variance within species. However, there is a large amount of variation within species and it is increasingly apparent that it is important to consider trait variation not only between species, but also within species. Mammals are an interesting group for investigating trait-based approaches because they play diverse and important ecological functions (e.g., pollination, seed dispersal, predation, grazing) that are correlated with functional traits. Here we compile a data set comprising morphological and life history information of 279 mammal species from 39,850 individuals of 388 populations ranging from -5.83 to -29.75 decimal degrees of latitude and -34.82 to -56.73 decimal degrees of longitude in the Atlantic forest of South America. We present trait information from 16,840 individuals of 181 species of non-volant mammals (Rodentia, Didelphimorphia, Carnivora, Primates, Cingulata, Artiodactyla, Pilosa, Lagomorpha, Perissodactyla) and from 23,010 individuals of 98 species of volant mammals (Chiroptera). The traits reported include body mass, age, sex, reproductive stage, as well as the geographic coordinates of sampling for all taxa. Moreover, we gathered information on forearm length for bats and body length and tail length for rodents and marsupials. No copyright restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data. © 2018 by the Ecological Society of America.

Propagation of Atlantic Ocean swells in the north Indian Ocean: A case study

Digital Repository Service at National Institute of Oceanography (India)

Samiksha, S.V.; Vethamony, P.; Aboobacker, V.M.; Rashmi, R.

An analysis of altimeter significant wave height data of May 2007 revealed the occurrence of an extreme weather event off southern tip of South Africa in the Atlantic Ocean, and generation of a series of very high swells at 40 degrees S...

Phanerozoic burial, uplift and denudation of the Equatorial Atlantic margin of South America

Science.gov (United States)

Japsen, Peter; Bonow, Johan M.; Green, Paul F.; dall'Asta, Massimo; Roig, Jean-Yves; Theveniaut, Hervé

2017-04-01

We have initiated a study aimed at understanding the history of burial, uplift and denudation of the South American Equatorial Atlantic Margin (SAEAM Uplift) including the Guiana Shield to provide a framework for investigating the hydrocarbon prospectivity of the offshore region. We report first results including observations from fieldwork at the northern and southern flank of the Guiana Shield. The study combines apatite fission-track analysis (AFTA) and vitrinite reflectance data from samples of outcrops and drillcores, sonic velocity data from drill holes and stratigraphic landscape analysis (mapping of peneplains) - all constrained by geological evidence, following the methods of Green et al. (2013). The study will thus combine the thermal history from AFTA data with the denudation history from stratigraphic landscape analysis to provide magnitudes and timing of vertical movements (Japsen et al. 2012, 2016). Along the Atlantic margin of Suriname and French Guiana, tilted and truncated Lower Cretaceous strata rest on Precambrian basement (Sapin et al. 2016). Our AFTA data show that the basement underwent Mesozoic exhumation prior to deposition of the Lower Cretaceous cover. Sub-horizontal peneplains define the landscape of the Guiana Shield at elevations up to 500 m a.s.l. As these sub-horizontal peneplains truncate the tilted, sub-Cretaceous surface along the Atlantic margin, these peneplains were therefore formed and uplifted in post-Cretaceous time. This interpretation is in good agreement with our AFTA data that define Paleogene exhumation along the margin and with the results of Theveniaut and Freyssinet (2002) who used palaeomagnetic data to conclude that bauxitic surfaces across basement at up to 400 m a.s.l. on the Guiana Shield formed during the Palaeogene. Integration of the results from AFTA with stratigraphic landscape analysis (currently in progress) and geological evidence will provide a robust reconstruction of the tectonic development of the

Paleohydrology of tropical South America and paleoceanography of the tropical Atlantic as deduced from two new sediment cores on the Brazilian continental slope

Science.gov (United States)

Nace, T.; Baker, P. A.; Dwyer, G. S.; Silva, C. G.; Hollander, D. J.; Rigsby, C. A.; Giosan, L.; Burns, S. J.

2011-12-01

Paleoclimate/paleoceanographic reconstructions of the Amazon Basin, Brazilian Nordeste, and western equatorial Atlantic have been undertaken on two new sediment cores located on the Brazilian continental slope (Core CDH-5 at 1708 mbsl, 4N, 48W, 32m long, ~30 ka record; Core CDH-86 at 3708 mbsl, 0N/S, 44W, 30m long, ~100ka record). High-resolution XRF analyses of Fe, Ti, and Ca are used to define the paleohydrologic history of the adjacent continent at both sites. Large and abrupt excursions of Ti/Ca ratios are observed in both cores, but are significantly better defined in the southern core, representative of Nordeste conditions. In this core there are a total of 9 Ti/Ca excursions, the oldest recovered dating to ~98ka. These excursions correlate well with Heinrich events from the North Atlantic. High-resolution stable oxygen isotopic analysis and Mg/Ca paleothermometry undertaken on the near-surface-dwelling planktic foraminiferal species Globierinoides ruber provide a picture of paleoceanographic forcings in the western equatorial Atlantic. The northern and southern cores respectively exhibit rapid warming of ~3C and ~3.5C between the last glacial maximum and the early Holocene. Furthermore, in almost all cases, during the last glacial stage, there was a 0.5C to 2C warming of the western equatorial Atlantic during the periods of high Ti/Ca ratios that correlate with Heinrich events. Thus, as observed in some previous studies, the western equatorial Atlantic was warm and the adjacent southern tropical continent was wet at the same time that the high-latitude North Atlantic was cold. The largely accepted paradigm is that Northern hemisphere cold events result in a southward migration of the Intertropical Convergence Zone (ITCZ), contributing to drier conditions at the northern extent of the ITCZ annual range (Cariaco Basin) and increased precipitation in the southern tropics of South America. The ITCZ appears to have been influenced by millennial variability of

77 FR 50672 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery Off the...

Science.gov (United States)

2012-08-22

... National Environmental Policy Act, including biological, economic, social, administrative, and cumulative... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 622 RIN 0648-BC30 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery Off the...

Partial pressure (or fugacity) of carbon dioxide and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from POLARSTERN in the North Atlantic Ocean, South Atlantic Ocean and others from 2016-02-20 to 2016-05-08 (NCEI Accession 0160572)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0160572 includes Surface underway, chemical and meteorological data collected from POLARSTERN in the North Atlantic Ocean, South Atlantic Ocean, South...

pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the HESPERIDES in the North Atlantic Ocean and South Atlantic Ocean from 2001-03-05 to 2001-04-17 (NODC Accession 0108096)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108096 includes chemical, discrete sample, physical and profile data collected from HESPERIDES in the North Atlantic Ocean and South Atlantic Ocean...

pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the HESPERIDES in the North Atlantic Ocean and South Atlantic Ocean from 2002-03-04 to 2002-04-09 (NODC Accession 0108097)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108097 includes chemical, discrete sample, physical and profile data collected from HESPERIDES in the North Atlantic Ocean and South Atlantic Ocean...

Freshening of Antarctic Intermediate Water in the South Atlantic Ocean in 2005–2014

OpenAIRE

Yao, Wenjun; Shi, Jiuxin

2016-01-01

Basin-scaled freshening of Antarctic Intermediate Water (AAIW) is reported to have dominated South Atlantic Ocean during period from 2005 to 2014, as shown by the gridded monthly means Argo (Array for Real-time Geostrophic Oceanography) data. The relevant investigation was also revealed by two transatlantic occupations of repeated section along 30° S, from World Ocean Circulation Experiment Hydrographic Program. Freshening of the AAIW was compensated by the opposing salinity increase o...

NOAA TIFF Image - 30m Multibeam Bathymetry, South Atlantic Bight - Deep Coral Priority Areas - Navy Pathfinder - (2003), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 30x30 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

77 FR 66744 - Temporary Rule to Increase the Commercial Annual Catch Limit for South Atlantic Yellowtail Snapper

Science.gov (United States)

2012-11-07

... South Atlantic Comprehensive ACL Amendment and the Generic ACL Amendment to the Red Drum, Reef Fish Resources, Shrimp, and Coral and Coral Reefs FMPs for the Gulf of Mexico (Generic ACL Amendment) (76 FR... (518,270 kg), round weight. The AM implemented through that rule states that the commercial sector will...

77 FR 50642 - Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 11; Correction

Science.gov (United States)

2012-08-22

.... 110908576-2240-02] RIN 0648-BB44 Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment... the final rule to implement Amendment 11 to the Fishery Management Plan for the Spiny Lobster Fishery..., 2012), incorrect latitudinal coordinates for Lobster Trap Gear Closed Areas 16 and 17, and longitudinal...

Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the OCEANUS in the North Atlantic Ocean and South Atlantic Ocean from 1988-07-23 to 1988-09-01 (NODC Accession 0117675)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0117675 includes chemical, discrete sample, physical and profile data collected from OCEANUS in the North Atlantic Ocean and South Atlantic Ocean from...

Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the METEOR in the North Atlantic Ocean and South Atlantic Ocean from 2002-10-13 to 2002-11-16 (NODC Accession 0113890)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113890 includes chemical, discrete sample, physical and profile data collected from METEOR in the North Atlantic Ocean and South Atlantic Ocean from...

Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from METEOR in the North Atlantic Ocean and South Atlantic Ocean from 2006-06-06 to 2006-07-09 (NODC Accession 0108078)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108078 includes chemical, discrete sample, physical and profile data collected from METEOR in the North Atlantic Ocean and South Atlantic Ocean from...

Genetic connectivity between north and south Mid-Atlantic Ridge chemosynthetic bivalves and their symbionts.

Directory of Open Access Journals (Sweden)

Karina van der Heijden

Full Text Available Transform faults are geological structures that interrupt the continuity of mid-ocean ridges and can act as dispersal barriers for hydrothermal vent organisms. In the equatorial Atlantic Ocean, it has been hypothesized that long transform faults impede gene flow between the northern and the southern Mid-Atlantic Ridge (MAR and disconnect a northern from a southern biogeographic province. To test if there is a barrier effect in the equatorial Atlantic, we examined phylogenetic relationships of chemosynthetic bivalves and their bacterial symbionts from the recently discovered southern MAR hydrothermal vents at 5°S and 9°S. We examined Bathymodiolus spp. mussels and Abyssogena southwardae clams using the mitochondrial cytochrome c oxidase subunit I (COI gene as a phylogenetic marker for the hosts and the bacterial 16S rRNA gene as a marker for the symbionts. Bathymodiolus spp. from the two southern sites were genetically divergent from the northern MAR species B. azoricus and B. puteoserpentis but all four host lineages form a monophyletic group indicating that they radiated after divergence from their northern Atlantic sister group, the B. boomerang species complex. This suggests dispersal of Bathymodiolus species from north to south across the equatorial belt. 16S rRNA genealogies of chemoautotrophic and methanotrophic symbionts of Bathymodiolus spp. were inconsistent and did not match the host COI genealogy indicating disconnected biogeography patterns. The vesicomyid clam Abyssogena southwardae from 5°S shared an identical COI haplotype with A. southwardae from the Logatchev vent field on the northern MAR and their symbionts shared identical 16S phylotypes, suggesting gene flow across the Equator. Our results indicate genetic connectivity between the northern and southern MAR and suggest that a strict dispersal barrier does not exist.

THE ATMOSPHERIC CYCLING AND AIR-SEA EXCHANGE OF MERCURY SPECIES IN THE SOUTH AND EQUATORIAL ATLANTIC OCEAN. (R829796)

Science.gov (United States)

Measurements of gas-, particle- and precipitation-phases of atmospheric mercury(Hg) were made in the South and equatorial Atlantic Ocean as part of the 1996IOC Trace Metal Baseline Study (Montevideo, Uruguay to Barbados). Total gaseousmercury (TGM) ranged from ...

Seabirds indicate changes in the composition of plastic litter in the Atlantic and south-western Indian Oceans.

Science.gov (United States)

Ryan, Peter G

2008-08-01

I compare plastic ingested by five species of seabirds sampled in the 1980s and again in 1999-2006. The numbers of ingested plastic particles have not changed significantly, but the proportion of virgin pellets has decreased 44-79% in all five species: great shearwater Puffinus gravis, white-chinned petrel Procellaria aequinoctialis, broad-billed prion Pachyptila vittata, white-faced storm petrel Pelagodroma marina and white-bellied storm petrel Fregetta grallaria. The populations sampled range widely in the South Atlantic and western Indian Oceans. The most marked reduction occurred in great shearwaters, where the average number of pellets per bird decreased from 10.5 to 1.6. This species migrates between the South and North Atlantic each year. Similar decreases in virgin pellets have been recorded in short-tailed shearwaters Puffinus tenuirostris in the Pacific Ocean and northern fulmars Fulmarus glacialis in the North Sea. More data are needed on the relationship between plastic loads in seabirds and the density of plastic at sea in their foraging areas, but the consistent decrease in pellets in birds suggests there has been a global change in the composition of small plastic debris at sea over the last two decades.

Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from METEOR in the North Atlantic Ocean and South Atlantic Ocean from 2009-10-26 to 2009-11-23 (NODC Accession 0109918)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0109918 includes discrete sample and profile data collected from METEOR in the North Atlantic Ocean and South Atlantic Ocean from 2009-10-26 to...

78 FR 27956 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendment 39 to the Fishery...

Science.gov (United States)

2013-05-13

... environmental impact statement (DEIS); notice of public hearings; request for comments. SUMMARY: NMFS, Southeast... comments received on the DEIS in developing the final environmental impact statement (FEIS) and before... the Caribbean, Gulf of Mexico, and South Atlantic; Amendment 39 to the Fishery Management Plan for the...

78 FR 66900 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendment 28 to the Fishery...

Science.gov (United States)

2013-11-07

... environmental impact statement (DEIS); scoping; request for comments. SUMMARY: NMFS, Southeast Region, in... received on the DEIS in developing the final environmental impact statement (FEIS), and before voting to... the Caribbean, Gulf of Mexico, and South Atlantic; Amendment 28 to the Fishery Management Plan for the...

From deregulation to decentering in the South Atlantic and the construction of «Lusofonia»

Directory of Open Access Journals (Sweden)

Armando Marques Guedes

2012-01-01

Full Text Available The papel shall rest on the geopolitics of the evolving security situation in the southern reaches of the Atlantic, and what this means for Portuguese and Lusophone interests. It will focus, mainly, on the growing threats the region faces and the risks of a rapid degradation which could result from the simultaneous ever louder affirmation of both regional and extra-regional players (State and non-State ones and the glaring absence of an overarching security architecture there. Brazil, Argentina, Venezuela, South Africa, Angola and Nigeria (to take a few obvious examples have to contend with a growing US, Russian, and Chinese presence in the area, a presence with an ever-increasing clout economic, political, and military. Geostrategically, the region is subdivided into four sub-regions, as concerns these enhanced tensions, each raising thorny issues of its own. Special attention is given to Brazilian, Cape Verdian and Angolan interests and responses to this, and on the role Portuguese foreign policy has been playing in the developing and emergent regional tensions, potential and actual. The role of multilateral organization and coalitions, and the various degrees of formality of objectives they display, is also touched upon, albeit only lightly. More than simply on hard economic, political, and military data, the analysis endeavours to take stock of the discursive dimension of threats and tensions in the four sub-regions identified in the South Atlantic.

An Atlantic influence on Amazon rainfall

Energy Technology Data Exchange (ETDEWEB)

Yoon, Jin-Ho [University of Maryland, Department of Atmospheric and Oceanic Science, College Park, MD (United States); Zeng, Ning [University of Maryland, Earth System Science Interdisciplinary Center, College Park, MD (United States); University of Maryland, Department of Atmospheric and Oceanic Science, College Park, MD (United States)

2010-02-15

Rainfall variability over the Amazon basin has often been linked to variations in Pacific sea surface temperature (SST), and in particular, to the El Nino/Southern Oscillation (ENSO). However, only a fraction of Amazon rainfall variability can be explained by ENSO. Building upon the recent work of Zeng (Environ Res Lett 3:014002, 2008), here we provide further evidence for an influence on Amazon rainfall from the tropical Atlantic Ocean. The strength of the North Atlantic influence is found to be comparable to the better-known Pacific ENSO connection. The tropical South Atlantic Ocean also shows some influence during the wet-to-dry season transition period. The Atlantic influence is through changes in the north-south divergent circulation and the movement of the ITCZ following warm SST. Therefore, it is strongest in the southern part of the Amazon basin during the Amazon's dry season (July-October). In contrast, the ENSO related teleconnection is through anomalous east-west Walker circulation with largely concentrated in the eastern (lower) Amazon. This ENSO connection is seasonally locked to boreal winter. A complication due to the influence of ENSO on Atlantic SST causes an apparent North Atlantic SST lag of Amazon rainfall. Removing ENSO from North Atlantic SST via linear regression resolves this causality problem in that the residual Atlantic variability correlates well and is in phase with the Amazon rainfall. A strong Atlantic influence during boreal summer and autumn is particularly significant in terms of the impact on the hydro-ecosystem which is most vulnerable during the dry season, as highlighted by the severe 2005 Amazon drought. Such findings have implications for both seasonal-interannual climate prediction and understanding the longer-term changes of the Amazon rainforest. (orig.)

Discovery of a chemosynthesis-based community in the western South Atlantic Ocean

Science.gov (United States)

Giongo, Adriana; Haag, Taiana; Simão, Taiz L. Lopes; Medina-Silva, Renata; Utz, Laura R. P.; Bogo, Maurício R.; Bonatto, Sandro L.; Zamberlan, Priscilla M.; Augustin, Adolpho H.; Lourega, Rogério V.; Rodrigues, Luiz F.; Sbrissa, Gesiane F.; Kowsmann, Renato O.; Freire, Antonio F. M.; Miller, Dennis J.; Viana, Adriano R.; Ketzer, João M. M.; Eizirik, Eduardo

2016-06-01

Chemosynthetic communities have been described from a variety of deep-sea environments across the world's oceans. They constitute very interesting biological systems in terms of their ecology, evolution and biogeography, and also given their potential as indicators of the presence and abundance of consistent hydrocarbon-based nutritional sources. Up to now such peculiar biotic assemblages have not been reported for the western South Atlantic Ocean, leaving this large region undocumented with respect to the presence, composition and history of such communities. Here we report on the presence of a chemosynthetic community off the coast of southern Brazil, in an area where high-levels of methane and the presence of gas hydrates have been detected. We performed metagenomic analyses of the microbial community present at this site, and also employed molecular approaches to identify components of its benthic fauna. We conducted phylogenetic analyses comparing the components of this assemblage to those found elsewhere in the world, which allowed a historical assessment of the structure and dynamics of these systems. Our results revealed that the microbial community at this site is quite diverse, and contains many components that are very closely related to lineages previously sampled in ecologically similar environments across the globe. Anaerobic methanotrophic (ANME) archaeal groups were found to be very abundant at this site, suggesting that methane is indeed an important source of nutrition for this community. In addition, we document the presence at this site of a vestimentiferan siboglinid polychaete and the bivalve Acharax sp., both of which are typical components of deep-sea chemosynthetic communities. The remarkable similarity in biotic composition between this area and other deep-sea communities across the world supports the interpretation that these assemblages are historically connected across the global oceans, undergoing colonization from distant sites and

77 FR 76458 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of Puerto...

Science.gov (United States)

2012-12-28

... the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of Puerto Rico and the U.S. Virgin Islands; Exempted Fishing Permit AGENCY: National Marine Fisheries Service (NMFS), National... in the U.S. Virgin Islands. Currently, data on U.S. Caribbean spiny lobster life history are limited...

75 FR 62488 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Snapper-Grouper Fishery off the...

Science.gov (United States)

2010-10-12

... U.S.C. 1801 et seq. 2. In Sec. 622.2, the definitions of ``Deep-water grouper (DWG)'' and ``Shallow... neither overfished nor undergoing overfishing. Red snapper overfishing is being addressed separately in... and possession of all South Atlantic shallow-water groupers (gag, black grouper, red grouper, scamp...

Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the POLARSTERN in the South Atlantic Ocean from 1992-12-03 to 1993-01-22 (NODC Accession 0116565)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116565 includes chemical, discrete sample, physical and profile data collected from POLARSTERN in the South Atlantic Ocean from 1992-12-03 to...

NOAA TIFF Image - 10m Bathymetry Mosaic, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ron Brown - (2010), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the bathymetry (depth) of several deep coral priority areas off the South Atlantic...

Correlation of Ice-Rafted Detritus in South Atlantic Sediments with Climate Proxies in Polar Ice over the Last Glacial Period

Directory of Open Access Journals (Sweden)

Sharon L. Kanfoush

2013-03-01

Full Text Available Previous study identified 6–7 millennial-scale episodes of South Atlantic ice-rafted sediment deposition (SA events during the glaciation. Questions remain, however, regarding their origin, significance for sea-ice and/or Antarctic ice-sheet dynamics, and relationship to climate. Here I correlate sediment core (TTN057–21 SA events to Greenland and Antarctic ice using two independent methods, stable isotopes and geomagnetic paleointensity, placing SA events in the context of polar climate change in both hemispheres. Marine isotopic stage (MIS 3 SA events generally coincided with Greenland interstadials and with cooling following Antarctic warm events (A1-A4. This anti-phase behavior is best illustrated when SA0 coincided with both the Antarctic Cold Reversal and Bolling-Allerod warming in Greenland. Moreover, SA events coincide with sea-level rises during the deglaciation (mwp1A and MIS 3 (30.4, 38.3, 43.7, 51.5 ka, implying unpinning of grounded Weddell Sea region ice masses discharged debris-laden bergs that had a chilling effect on South Atlantic surface temperatures.

Correlations between hemoglobin type and temperature preference of juvenile Atlantic cod Gadus morhua

DEFF Research Database (Denmark)

Behrens, Jane W.; Gräns, Albin; Therkildsen, Nina Overgaard

2012-01-01

Atlantic cod (Gadus morhua L.) exhibits polymorphic hemoglobin variants with the HbI locus showing a strong North-South geographic cline in frequency distribution of three main types (1/1, 1/2 and 2/2). This may indicate selective advantages of the different HbI types under various temperature re...... inconsistent thermoregulatory behavior. To obtain a more definitive picture of the extent to which thermal niches are realized under natural conditions field observations in areas where the 3 HbI types co-exist should be performed...

Antarctic Bottom Water temperature changes in the western South Atlantic from 1989 to 2014

Science.gov (United States)

Johnson, Gregory C.; McTaggart, Kristene E.; Wanninkhof, Rik

2014-12-01

Warming of abyssal waters in recent decades contributes to global heat uptake and sea level rise. Repeat oceanographic section data in the western South Atlantic taken mostly in 1989 (1995 across the Scotia Sea), 2005, and 2014 are used to quantify warming in abyssal waters that spread northward through the region from their Antarctic origins in the Weddell Sea. While much of the Scotia Sea warmed between 1995 and 2005, only the southernmost portion, on the north side of the Weddell Gyre, continued to warm between 2005 and 2014. The abyssal Argentine Basin also warmed between 1989 and 2005, but again only the southernmost portion continued to warm between 2005 and 2014, suggesting a slowdown in the inflow of the coldest, densest Antarctic Bottom Waters into the western South Atlantic between 1989 and 2014. In contrast, the abyssal waters of the Brazil Basin warmed both between 1989 and 2005 and between 2005 and 2014, at a rate of about 2 m°C yr-1. This warming is also assessed in terms of the rates of change of heights above the bottom for deep isotherms in each deep basin studied. These results, together with findings from previous studies, suggest the deep warming signal observed in the Weddell Sea after the mid-1970s Weddell Polynya was followed by abyssal warming in the Argentine Basin from the late 1970s through about 2005, then warming in the deep Vema Channel from about 1992 through at least 2010, and warming in the Brazil Basin from 1989 to 2014.

Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the THOMAS WASHINGTON in the South Atlantic Ocean from 1984-10-01 to 1984-10-22 (NODC Accession 0117693)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0117693 includes chemical, discrete sample, physical and profile data collected from THOMAS WASHINGTON in the South Atlantic Ocean from 1984-10-01 to...

Temperature profile data collected using BT and XBT casts in the North/South Atlantic Ocean and North/South Pacific Ocean from NOAA Ship RESEARCHER and other platforms from 1987-05-20 to 1992-04-19 (NODC Accession 9200105)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship RESEARCHER and other platforms in the North/South Atlantic Ocean and North/South...

76 FR 30554 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto...

Science.gov (United States)

2011-05-26

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 622 [Docket No. 0907151138-1235-03] RIN 0648-AY03 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto Rico and the U.S. Virgin Islands; Queen Conch Management Measures Correction In rule...

Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from HESPERIDES in the North Atlantic Ocean and South Atlantic Ocean from 2010-04-05 to 2010-05-16 (NODC Accession 0109927)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0109927 includes discrete sample and profile data collected from HESPERIDES in the North Atlantic Ocean and South Atlantic Ocean from 2010-04-05 to...

Micro-phytoplankton photosynthesis, primary production and potential export production in the Atlantic Ocean

Science.gov (United States)

Tilstone, Gavin H.; Lange, Priscila K.; Misra, Ankita; Brewin, Robert J. W.; Cain, Terry

2017-11-01

Micro-phytoplankton is the >20 μm component of the phytoplankton community and plays a major role in the global ocean carbon pump, through the sequestering of anthropogenic CO2 and export of organic carbon to the deep ocean. To evaluate the global impact of the marine carbon cycle, quantification of micro-phytoplankton primary production is paramount. In this paper we use both in situ data and a satellite model to estimate the contribution of micro-phytoplankton to total primary production (PP) in the Atlantic Ocean. From 1995 to 2013, 940 measurements of primary production were made at 258 sites on 23 Atlantic Meridional Transect Cruises from the United Kingdom to the South African or Patagonian Shelf. Micro-phytoplankton primary production was highest in the South Subtropical Convergence (SSTC ∼ 409 ± 720 mg C m-2 d-1), where it contributed between 38 % of the total PP, and was lowest in the North Atlantic Gyre province (NATL ∼ 37 ± 27 mg C m-2 d-1), where it represented 18 % of the total PP. Size-fractionated photosynthesis-irradiance (PE) parameters measured on AMT22 and 23 showed that micro-phytoplankton had the highest maximum photosynthetic rate (PmB) (∼5 mg C (mg Chl a)-1 h-1) followed by nano- (∼4 mg C (mg Chl a)-1 h-1) and pico- (∼2 mg C (mg Chl a)-1 h-1). The highest PmB was recorded in the NATL and lowest in the North Atlantic Drift Region (NADR) and South Atlantic Gyre (SATL). The PE parameters were used to parameterise a remote sensing model of size-fractionated PP, which explained 84 % of the micro-phytoplankton in situ PP variability with a regression slope close to 1. The model was applied to the SeaWiFS time series from 1998-2010, which illustrated that micro-phytoplankton PP remained constant in the NADR, NATL, Canary Current Coastal upwelling (CNRY), Eastern Tropical Atlantic (ETRA), Western Tropical Atlantic (WTRA) and SATL, but showed a gradual increase in the Benguela Upwelling zone (BENG) and South Subtropical Convergence (SSTC

Atlantic multidecadal oceanic variability and its influence on the atmosphere in a climate model

Energy Technology Data Exchange (ETDEWEB)

Msadek, Rym; Frankignoul, Claude [Universite Pierre et Marie Curie, Paris 6, LOCEAN/IPSL, Paris (France)

2009-07-15

The mechanisms controlling the decadal to multidecadal variability of the Atlantic Meridional Overturning Circulation (MOC) and its influence on the atmosphere are investigated using a control simulation with the IPSL-CM4 climate model. The multidecadal fluctuations of the MOC are mostly driven by deep convection in the subpolar gyre, which occurs south of Iceland in the model. The latter is primarily influenced by the anomalous advection of salinity due to changes in the East Atlantic Pattern (EAP), which is the second mode of atmospheric variability in the North Atlantic region. The North Atlantic Oscillation is the dominant mode, but it plays a secondary role in the MOC fluctuations. During summer, the MOC variability is shown to have a significant impact on the atmosphere in the North Atlantic-European sector. The MOC influence is due to an interhemispheric sea surface temperature (SST) anomaly with opposite signs in the two hemispheres but largest amplitude in the northern one. The SST pattern driven by the MOC mostly resembles the model Atlantic Multidecadal Oscillation (AMO) and bears some similarity with the observed one. It is shown that the AMO reflects both the MOC influence and the local atmospheric forcing. Hence, the MOC influence on climate is best detected using lagged relations between climatic fields. The atmospheric response resembles the EAP, in a phase that might induce a weak positive feedback on the MOC. (orig.)

76 FR 3596 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto...

Science.gov (United States)

2011-01-20

.... 0907151138-1011-02] RIN 0648-AY03 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto Rico and the U.S. Virgin Islands; Queen Conch Management Measures AGENCY: National... includes Lang Bank east of St. Croix, U.S. Virgin Islands (USVI), when harvest and possession of queen...

78 FR 34310 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto...

Science.gov (United States)

2013-06-07

.... 130402313-3499-01] RIN 0648-BD15 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto Rico and the U.S. Virgin Islands; Regulatory Amendment 2 AGENCY: National Marine... the Fishery Management Plan (FMP) for the Queen Conch Resources of Puerto Rico and the U.S. Virgin...

78 FR 56171 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto...

Science.gov (United States)

2013-09-12

.... 130402313-3748-02] RIN 0648-BD15 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Queen Conch Fishery of Puerto Rico and the U.S. Virgin Islands; Regulatory Amendment 2 AGENCY: National Marine... Management Plan (FMP) for the Queen Conch Resources of Puerto Rico and the U.S. Virgin Islands (USVI...

Nematocarcinus Milne Edwards, 1881 (Crustacea, Decapoda) from Southwestern Atlantic, including the Southern Mid-Atlantic Ridge area.

Science.gov (United States)

Cardoso, Irene A; Burukovsky, Rudolf N

2014-11-26

The deep sea shrimp genus Nematocarcinus Milne Edwards, 1881 includes 47 species, ten of them have been recorded from the Atlantic Ocean. Herein, material sampled during three scientific projects (REVIZEE Central Fishery project; Campos Basin Deep Sea Environmental Project; Evaluation of Environmental Heterogeneity in the Campos Basin) made in the Southwestern Atlantic, off Brazil, is examined. In addition, material sampled from the South Mid Atlantic Ridge (MAR-ECO Project) was also examined. Four species are recorded for the first time to the southwestern Atlantic Ocean including Mid Atlantic Ridge area: Nematocarcinus faxoni Burukovsky, 2001; N. gracilipes Filhol, 1884; N. rotundus Crosnier & Forest, 1973 and N. tenuipes Spence-Bate, 1888.

A new species of Hyalella (Crustacea, Amphipoda, Dogielinotidae) from the Atlantic Forest of Misiones, Argentina

Science.gov (United States)

Colla, María Florencia; César, Inés Irma

2015-01-01

Abstract The freshwater genus Hyalella Smith, 1874 has a distribution restricted to the Western Hemisphere with most species being found in South America. In this report we describe a new species of Hyalella from the Atlantic Forest of the Misiones province, Argentina. PMID:25685030

Temperature profile data collected using BT and XBT casts from NOAA Ship MALCOLM BALDRIGE and another platforms in the North/South Atlantic Ocean and North/South Pacific Ocean from 1988-10-31 to 1989-07-26 (NODC Accession 8900197)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from NOAA Ship MALCOLM BALDRIGE and other platforms in the North/South Atlantic Ocean and North/South...

NOAA TIFF Image - 10m Bathymetric Rugosity, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2007), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the rugosity of several deep coral priority areas off the South Atlantic Bight,...

NOAA TIFF Image - 10m Multibeam Bathymetry, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2010), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

NOAA TIFF Image - 10m Multibeam Bathymetry, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2007), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

NOAA TIFF Image - 5m Backscatter Mosaic, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2007), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 5x5 meter cell size representing the backscatter (intensity) of several deep coral priority areas off the South Atlantic...

NOAA TIFF Image - 10m Multibeam Bathymetry, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2009), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the bathymetry of several deep coral priority areas off the South Atlantic Bight,...

78 FR 37208 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of Puerto Rico...

Science.gov (United States)

2013-06-20

... the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of Puerto Rico and the U.S. Virgin Islands; Exempted Fishing Permit AGENCY: National Marine Fisheries Service (NMFS), National... implementing the Fishery Management Plan for the Reef Fish Fishery of Puerto Rico and the U.S. Virgin Islands...

NOAA TIFF Image - 3m Multibeam Bathymetry, Miami, South Atlantic Bight - Deep Coral Priority Areas - Lost Coast Explorer - (2010), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 3x3 meter cell size representing the bathymetry of the continental shelf off of Jacksonville, FL in the South Atlantic...

NOAA TIFF Image - 10m Bathymetric Slope, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2009), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the slope (in degrees) of several deep coral priority areas off the South Atlantic...

NOAA TIFF Image - 10m Bathymetric Slope, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Ron Brown - (2010), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the slope (in degrees) of several deep coral priority areas off the South Atlantic...

NOAA TIFF Image - 10m Bathymetric Slope, South Atlantic Bight - Deep Coral Priority Areas - NOAA Ship Nancy Foster - (2007), UTM 17N NAD83

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains a unified GeoTiff with 10x10 meter cell size representing the slope (in degrees) of several deep coral priority areas off the South Atlantic...

Rare earth element geochemistry of South Atlantic deep sea sediments: Ce anomaly change at approx. 54 My

International Nuclear Information System (INIS)

Wang, Y.L.; Liu, Y.-G.; Schmitt, R.A.; Oregon State Univ., Corvallis; Oregon State Univ., Corvallis; Oregon State Univ., Corvallis

1986-01-01

The geochemistry of the REE (rare earth elements) in oceanic sediments is discussed, based mainly on samples from DSDP Holes 530A and 530B, Leg 75, and Hole 525A, Leg 74. The proposed mechanisms for incorporation of the REE into the marine carbonate phases are adsorption, chiefly onto the carbonate minerals and on Sc, Hf, and Ta-rich FE-Mn hydroxide flocs as carbonate coatings. The Ce anomaly of marine carbonate was used as an indicator of paleo-ocean water redox conditions: the bottom water of the Angola Basin was in a reducing condition in the Cretaceous. At ca. 54 My, the South Atlantic water condition became oxidizing, similar to the present seawater redox condition. This change was related to the improvement of circulation due to the widening of South Atlantic and the subsidence of water circulation barriers such as the Walvis Ridge and perhaps the Romanche Fracture Zone. The REE abundances and patterns of younger sediments in the Angola Basin (YSAB) are very similar to those observed in NASC, PAAS, and ES sediments. The YSAB REE abundances and patterns may represent the average REE distribution of the exposed African continental crust. The strong resemblance of REE distributions of YSAB, NASC, PAAS and ES suggests thorough REE mixing from different sources and the uniformity of the average crustal compositions of different continents: Africa, North America, Australia, and Europe. (author)

Understanding the Transport of Patagonian Dust and Its Influence on Marine Biological Activity in the South Atlantic Ocean

Science.gov (United States)

Johnson, Matthew; Meskhidze, Nicholas; Kiliyanpilakkil, Praju; Gasso, Santiago

2010-01-01

Modeling and remote sensing techniques were applied to examine the horizontal and vertical transport pathways of Patagonian dust and quantify the effect of soluble-iron- laden mineral dust deposition on marine primary productivity in the South Atlantic Ocean (SAO) surface waters. The global chemistry transport model GEOS-Chem, implemented with an iron dissolution scheme, was applied to evaluate the atmospheric transport and deposition of mineral dust and bioavailable iron during two dust outbreaks originating in the source regions of Patagonia. In addition to this "rapidly released" iron, offline calculations were also carried out to estimate the amount of bioavailable iron leached during the residence time of dust in the ocean mixed layer. Model simulations showed that the horizontal and vertical transport pathways of Patagonian dust plumes were largely influenced by the synoptic meteorological patterns of high and low pressure systems. Model-predicted horizontal and vertical transport pathways of Patagonian dust over the SAO were in reasonable agreement with remotely-sensed data. Comparison between remotely-sensed and offline calculated ocean surface chlorophyll-a concentrations indicated that, for the two dust outbreaks examined in this study, the deposition of bioavailable iron in the SAO through atmospheric pathways was insignificant. As the two dust transport episodes examined here represent typical outflows of mineral dust from South American sources, our study suggests that the atmospheric deposition of mineral dust is unlikely to induce large scale marine primary productivity and carbon sequestration in the South Atlantic sector of the Southern Ocean.

Basin-scale changes of total organic carbon profiles in the eastern South Atlantic

Directory of Open Access Journals (Sweden)

X. A. Alvarez-Salgado

2001-03-01

Full Text Available Total organic carbon (TOC samples were collected at 6 stations spaced ~800 km apart in the eastern South Atlantic, from the Equator to 45°S along 9°W. Analyses were performed by high temperature catalytic oxidation (HTCO in the base laboratory. Despite the complex advection and mixing patterns of North Atlantic and Antarctic waters with extremely different degrees of ventilation, TOC levels below 500 m are quasi-constant at 55±3 µmol C l-1, pointing to the refractory nature of deep-water TOC. On the other hand, a TOC excess from 25 to 38 g C m-2 is observed in the upper 100 m of the permanently stratified nutrient-depleted Equatorial, Subequatorial and Subtropical upper ocean, where vertical turbulent diffusion is largely prevented. Conversely, TOC levels in the nutrient-rich upper layer of the Subantarctic Front only exceeds 9 g C m-2 the deep-water baseline. As much as 70% of the TOC variability in the upper 500 m is due to simple mixing of reactive TOC formed in the surface layer and refractory TOC in deep ocean waters, with a minor contribution (13% to oxygen consumption in the prominent subsurface AOU maximum at 200-400 m depth.

Fast northward energy transfer in the Atlantic due to Agulhas Rings

NARCIS (Netherlands)

van Sebille, Erik; van Leeuwen, P.J.

2007-01-01

The adiabatic transit time of wave energy radiated by an Agulhas ring released in the South Atlantic Ocean to the North Atlantic Ocean is investigated in a two-layer ocean model. Of particular interest is the arrival time of baroclinic energy in the northern part of the Atlantic, because it is

78 FR 17358 - Mid-Atlantic Fishery Management Council (MAFMC); Public Meetings

Science.gov (United States)

2013-03-21

... Organizational Reports, the New England and South Atlantic Liaison Reports, the Executive Director's Report, the... December 2012 and February 2013 minutes, receive Organizational Reports, the New England and South Atlantic... recommendation on the workshop results to include control dates, roll-over provisions, GRAs, port meetings, etc...

The Imaging and Evolution of Seismic Layer 2A Thickness from a 0-70 Ma Oceanic Crustal Transect in the South Atlantic

Science.gov (United States)

Estep, J. D.; Reece, R.; Kardell, D. A.; Christeson, G. L.; Carlson, R. L.

2017-12-01

Seismic layer 2A, the uppermost igneous portion of oceanic crust, is commonly used to refer to the seismic velocities of upper crust that are bounded below by a steep vertical velocity gradient. Layer 2A velocities are known to increase with crustal age, from 2.5 km/s in crust 15 Ma. Thickness of layer 2A has been shown to increase by a factor of 2 within 1 Ma at fast spreading ridges and then remain relatively constant, while layer 2A maintains a fairly consistent thickness, irrespective of age, at slow-intermediate spreading ridges. Layer 2A thickness and velocity evolution studies to date have been largely focused on young oceanic crust very proximal to a spreading center with little investigation of changes (or lack thereof) that occur at crustal ages >10 Ma. We utilize a multichannel seismic dataset collected at 30° S in the western South Atlantic that continuously images 0 - 70 Ma oceanic crust along a single flowline generated at the slow-intermediate spreading Mid-Atlantic Ridge. We follow the methods of previous studies by processing the data to image the layer 2A event, which is then used for calculating thickness. 1D travel time forward modeling at regularly spaced age intervals across the transect provides for the conversion of time to depth thickness, and for determining the evolution of velocities with age. Our results show layer 2A in 20 Ma crust is roughly double the thickness of that in crust 0-5 Ma (830 vs. 440 m), but thickness does not appear to change beyond 20 Ma. The layer 2A event is readily observable in crust 0-50 Ma, is nearly completely absent in crust 50-65 Ma, and then reappears with anomalously high amplitude and lateral continuity in crust 65-70 Ma. Our results suggest that layer 2A thickens with age at the slow-intermediate spreading southern Mid-Atlantic Ridge, and that layer 2A either continues to evolve at the older crustal ages, well beyond the expected 10-15 Ma "mature age", or that external factors have altered the crust at

76 FR 54727 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

Science.gov (United States)

2011-09-02

... RIN 0648-AY72 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of...) have submitted Amendment 10 to the Fishery Management Plan for the Spiny Lobster Fishery of the Gulf of... actions to revise the lobster species contained within the fishery management unit; revise definitions of...

78 FR 45894 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of Puerto Rico...

Science.gov (United States)

2013-07-30

.... 120510052-3615-02] RIN 0648-BC20 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of Puerto Rico and the U.S. Virgin Islands; Parrotfish Management Measures in St. Croix AGENCY.... Virgin Islands (FMP), as prepared by the Caribbean Fishery Management Council (Council). This rule...

Fish Species in a Changing World: The Route and Timing of Species Migration between Tropical and Temperate Ecosystems in Eastern Atlantic.

Directory of Open Access Journals (Sweden)

Awaluddin Halirin Kaimuddin

2016-09-01

Full Text Available The presence of tropical species has been reported in Atlantic-European waters with increasing frequency in recent years. Unfortunately, the history of their migrations is not well understood. In this study, we examined the routes and timing of fish migrations in several ecosystems of the East Atlantic Ocean, combining several publicly available and unpublicized datasets on species occurrences. The species studied were those noted as exotic or rare outside their previous known area of distribution. We used sea surface temperature (SST data obtained from 30 years of satellite observation to define three distinct time periods. Within these periods, temperature trends were studied in six ecosystems: the North Sea, the Celtic Sea, the South European Atlantic Waters, the Mediterranean Sea, the Canary Current and the Guinea Current. We also incorporated bathymetry data to describe the distribution of species. Measurement across a relatively large spatial extent was made possible by incorporating the capabilities of GIS.While SST increased consistently over time in all of the ecosystems observed, the change in number of species differed among ecosystems. The number of species in the middle regions, such as the South European Atlantic Shelf and the Western Mediterranean Sea, tended to increase over time. These regions received numbers of species from the lower or the upper latitudes according to season. Of all of the species observed in the recent period, 7 species from the Canary Current tended to be found in the Western Mediterranean Sea, and 6 species from these two regions extended their distributions to the South European Atlantic Shelf. Twelve species from the Canary Current moved seasonally to the Guinea Current. In the northern regions, 13 species moved seasonally in the North Sea and the Celtic Seas, and 12 of these species reached the South European Atlantic Shelf.This study presents a picture of routes and timing of species migration at the

Tree species composition in areas of Atlantic Forest in southeastern Brazil is consistent with a new system for classifying the vegetation of South America

Directory of Open Access Journals (Sweden)

Pedro Vasconcellos Eisenlohr

2014-06-01

Full Text Available Rigorous and well-defined criteria for the classification of vegetation constitute a prerequisite for effective biodiversity conservation strategies. In 2009, a new classification system was proposed for vegetation types in extra-Andean tropical and subtropical South America. The new system expanded upon the criteria established in the existing Brazilian Institute of Geography and Statistics classification system. Here, we attempted to determine whether the tree species composition of the formations within the Atlantic Forest Biome of Brazil is consistent with this new classification system. We compiled floristic surveys of 394 sites in southeastern Brazil (between 15º and 25ºS; and between the Atlantic coast and 55ºW. To assess the floristic consistency of the vegetation types, we performed non-metric multidimensional scaling (NMDS ordination analysis, followed by multifactorial ANOVA. The vegetation types, especially in terms of their thermal regimes, elevational belts and top-tier vegetation categories, were consistently discriminated in the first NMDS axis, and all assessed attributes showed at least one significant difference in the second axis. As was expected on the basis of the theoretical background, we found that tree species composition, in the areas of Atlantic Forest studied, was highly consistent with the new system of classification. Our findings not only help solidify the position of this new classification system but also contribute to expanding the knowledge of the patterns and underlying driving forces of the distribution of vegetation in the region.

The oceanic tides in the South Atlantic Ocean

Directory of Open Access Journals (Sweden)

M. L. Genco

Full Text Available The finite element ocean tide model of Le Provost and Vincent (1986 has been applied to the simulation of the M₂ and K₁ components over the South Atlantic Ocean. The discretisation of the domain, of the order of 200 km over the deep ocean, is refined down to 15 km along the coasts, such refinement enables wave propagation and damping over the continental shelves to be correctly solved. The marine boundary conditions, from Dakar to Natal, through the Drake passage and from South Africa to Antarctica, are deduced from in situ data and from Schwiderski's solution and then optimised following a procedure previously developed by the authors. The solutions presented are in very good agreement with in situ data: the root mean square deviations from a standard subset of 13 pelagic stations are 1.4 cm for M₂ and 0.45 cm for K₁, which is significantly better overall than solutions published to date in the literature. Zooms of the M₂ solution are presented for the Falkland Archipelago, the Weddell Sea and the Patagonian Shelf. The first zoom allows detailing of the tidal structure around the Falklands and its interpretation in terms of a stationary trapped Kelvin wave system. The second zoom, over the Weddell Sea, reveals for the first time what must be the tidal signal under the permanent ice shelf and gives a solution over that sea which is generally in agreement with observations. The third zoom is over the complex Patagonian Shelf. This zoom illustrates the ability of the model to simulate the tides, even over this area, with a surprising level of realism, following purely hydrodynamic modelling procedures, within a global ocean tide model. Maps of maximum associated tidal currents are also given, as a first illustration of a by-product of these simulations.

A synthesis of the environmental response of the North and South Atlantic Sub-Tropical Gyres during two decades of AMT

Science.gov (United States)

Aiken, Jim; Brewin, Robert J. W.; Dufois, Francois; Polimene, Luca; Hardman-Mountford, Nick J.; Jackson, Thomas; Loveday, Ben; Hoya, Silvana Mallor; Dall'Olmo, Giorgio; Stephens, John; Hirata, Takafumi

2017-11-01

Anthropogenically-induced global warming is expected to decrease primary productivity in the subtropical oceans by strengthening stratification of the water column and reducing the flux of nutrients from deep-waters to the sunlit surface layers. Identification of such changes is hindered by a paucity of long-term, spatially-resolved, biological time-series data at the basin scale. This paper exploits Atlantic Meridional Transect (AMT) data on physical and biogeochemical properties (1995-2014) in synergy with a wide range of remote-sensing (RS) observations from ocean colour, Sea Surface Temperature (SST), Sea Surface Salinity (SSS) and altimetry (surface currents), combined with different modelling approaches (both empirical and a coupled 1-D Ecosystem model), to produce a synthesis of the seasonal functioning of the North and South Atlantic Sub-Tropical Gyres (STGs), and assess their response to longer-term changes in climate. We explore definitive characteristics of the STGs using data of physical (SST, SSS and peripheral current systems) and biogeochemical variables (chlorophyll and nitrate), with inherent criteria (permanent thermal stratification and oligotrophy), and define the gyre boundary from a sharp gradient in these physical and biogeochemical properties. From RS data, the seasonal cycles for the period 1998-2012 show significant relationships between physical properties (SST and PAR) and gyre area. In contrast to expectations, the surface layer chlorophyll concentration from RS data (CHL) shows an upward trend for the mean values in both subtropical gyres. Furthermore, trends in physical properties (SST, PAR, gyre area) differ between the North and South STGs, suggesting the processes responsible for an upward trend in CHL may vary between gyres. There are significant anomalies in CHL and SST that are associated with El Niño events. These conclusions are drawn cautiously considering the short length of the time-series (1998-2012), emphasising the need

Molecular phylogeny of the genus Lolliguncula steenstrup, 1881 based on nuclear and mitochondrial DNA sequences indicates genetic isolation of populations from north and South atlantic, and the possible presence of further cryptic species.

Directory of Open Access Journals (Sweden)

João Bráullio L Sales

Full Text Available Squid of the genus Lolliguncula Steenstrup, 1881 are small bodied, coastal species capable of tolerating low salinity. Lolliguncula sp. are found exclusively in the New World, although only one of the four recognized species (Lolliguncula brevis occurs in the Atlantic Ocean. Preliminary morphological analyses suggest that Lolliguncula brevis populations in the North and South Atlantic may represent distinct species. The principal objective of the present study was to verify the phylogenetic relationships within the genus and test for the presence of possible cryptic species. Both gene and species tree topologies indicated that Lolliguncula brevis specimens from the North and South Atlantic represent distinct phylogenetic clades. In contrast with previous studies, L. panamensis was identified as the basal species of the genus. Our results provide important insights into the phylogenetic relationships among the Lolliguncula specimens analyzed, and confirm the genetic separation of Lolliguncula brevis populations of the North and South Atlantic at the level of sister species.

South African Journal of Higher Education - Vol 22, No 1 (2008)

African Journals Online (AJOL)

A model for the branding of higher education in South Africa · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. HR Hay, GA van Gensen, 78-99. http://dx.doi.org/10.4314/sajhe.v22i1.25775 ...

77 FR 25116 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

Science.gov (United States)

2012-04-27

...-BB44 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf... (Councils) have submitted Amendment 11 to the Fishery Management Plan for the Spiny Lobster Fishery of the... proposes to limit spiny lobster fishing using trap gear in certain areas in the exclusive economic zone off...

78 FR 15338 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of Puerto Rico...

Science.gov (United States)

2013-03-11

.... 120510052-3174-01] RIN 0648-BC20 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of Puerto Rico and the U.S. Virgin Islands; Parrotfish Management Measures in St. Croix AGENCY... Puerto Rico and the U.S. Virgin Islands (FMP), as prepared by the Caribbean Fishery Management Council...

Observation of high energy electrons and protons in the South Atlantic geomagnetic anomaly by Ohzora Satellite

International Nuclear Information System (INIS)

Nagata, K.; Murakami, H.; Nakamoto, A.; Hasebe, N.; Kikuche, J.; Doke, T.

1988-01-01

Observed results of the high energy electrons (0.19 - 3.2 MeV) and protons (0.58 - 35 MeV) of the South Atlantic Geomagnetic Anomaly are presented. Two silicon Δ E-E telescopes on the ohzora satellite (EXOS-C, 1984-15A) were used to observe the high energy particle and the maximum intensity of electrons and protons. The powers of energy spectra above 1 MeV have different values from energy region below 1 MeV. The electron and proton intensities are greatest at pitch angle maximized at 90 0 . (author) [pt

Evidences linking ENSO and coral growth in the Southwestern-South Atlantic

Energy Technology Data Exchange (ETDEWEB)

Evangelista, H. [LARAMG, Laboratorio de Radioecologia e Mudancas Globais/DBB/UERJ. Pav. HLC, Subsolo, Maracana, RJ (Brazil); Godiva, D. [LARAMG, Laboratorio de Radioecologia e Mudancas Globais/DBB/UERJ. Pav. HLC, Subsolo, Maracana, RJ (Brazil); Universidade Federal Fluminense, Outeiro Sao Joao Batista, s/n, Centro, Departamento de Geoquimica Ambiental, Niteroi, RJ (Brazil); Sifeddine, A. [IRD, Institut de Recherche Pour le Developpement, UR055 Paleotropique, Bondy (France); Universidade Federal Fluminense, Outeiro Sao Joao Batista, s/n, Centro, Departamento de Geoquimica Ambiental, Niteroi, RJ (Brazil); Leao, Z.M.A.N.; Kikuchi, R.K.P. [UFBA/Instituto de Geociencias. Rua Barao de Geremoabo, s/n, Federacao, Salvador, BA (Brazil); Rigozo, N.R. [LARAMG, Laboratorio de Radioecologia e Mudancas Globais/DBB/UERJ. Pav. HLC, Subsolo, Maracana, RJ (Brazil); FAETEC, Faculdade de Educacao e Tecnologia Thereza Porto Marques, Jacarei, SP (Brazil); Segal, B. [UFRJ/Museu Nacional/Setor de Celenterologia/Departamento de Invertebrados, Quinta da Boa Vista s/n, Sao Cristovao, RJ (Brazil); Ambrizzi, T. [USP/Department of Atmospheric Sciences, Sao Paulo, SP (Brazil); Kampel, M. [INPE/Divisao de Sensoriamento Remoto, Sao Paulo, SP (Brazil); Cornec, F. le [Universidade Federal Fluminense, Outeiro Sao Joao Batista, s/n, Centro, Departamento de Geoquimica Ambiental, Niteroi, RJ (Brazil)

2007-12-15

Physical and biological changes in the marine environment, induced by oceanic-atmospheric processes, can be imprinted in massive coral skeletons. Herein, we present an evidence of potential El Nino impacts at the Southwestern South Atlantic Ocean (SWSA) inferred from the sclerochronology of the reef coral Favia leptophylla. The application of spectral analysis (wavelet decomposition and the iterative regression) to coral growth length and to meteorological-oceanographic parameters (air temperature, sea surface temperature and precipitation) as well as to Southern Oscillation Index (SOI) and solar irradiation indicated a major significant inverse relationship between SOI and coral growth length at the 4-8 years frequency band. We propose here that coral growth length from the SWSA could be affected by El Nino Southern Oscillation (ENSO) events through an ''atmospheric bridge'', in contrast to its direct effect at the Pacific Ocean, related to the increase in sea surface temperature. (orig.)

Mechanisms of the atmospheric response to North Atlantic multidecadal variability: a model study

Energy Technology Data Exchange (ETDEWEB)

Msadek, Rym [Universite Pierre et Marie Curie-Paris 6, LOCEAN/IPSL, Paris Cedex 05 (France); Princeton University, GFDL/NOAA, AOS Program, Princeton, NJ (United States); Frankignoul, Claude [Universite Pierre et Marie Curie-Paris 6, LOCEAN/IPSL, Paris Cedex 05 (France); Li, Laurent Z.X. [Universite Pierre et Marie Curie-Paris 6, LMD/IPSL, Paris Cedex 05 (France)

2011-04-15

The atmospheric circulation response to decadal fluctuations of the Atlantic meridional overturning circulation (MOC) in the IPSL climate model is investigated using the associated sea surface temperature signature. A SST anomaly is prescribed in sensitivity experiments with the atmospheric component of the IPSL model coupled to a slab ocean. The prescribed SST anomaly in the North Atlantic is the surface signature of the MOC influence on the atmosphere detected in the coupled simulation. It follows a maximum of the MOC by a few years and resembles the model Atlantic multidecadal oscillation. It is mainly characterized by a warming of the North Atlantic south of Iceland, and a cooling of the Nordic Seas. There are substantial seasonal variations in the geopotential height response to the prescribed SST anomaly, with an East Atlantic Pattern-like response in summer and a North Atlantic oscillation-like signal in winter. In summer, the response of the atmosphere is global in scale, resembling the climatic impact detected in the coupled simulation, albeit with a weaker amplitude. The zonally asymmetric or eddy part of the response is characterized by a trough over warm SST associated with changes in the stationary waves. A diagnostic analysis with daily data emphasizes the role of transient-eddy forcing in shaping and maintaining the equilibrium response. We show that in response to an intensified MOC, the North Atlantic storm tracks are enhanced and shifted northward during summer, consistent with a strengthening of the westerlies. However the anomalous response is weak, which suggests a statistically significant but rather modest influence of the extratropical SST on the atmosphere. The winter response to the MOC-induced North Atlantic warming is an intensification of the subtropical jet and a southward shift of the Atlantic storm track activity, resulting in an equatorward shift of the polar jet. Although the SST anomaly is only prescribed in the Atlantic ocean

Comparison of the rift and post-rift architecture of conjugated salt and salt-free basins offshore Brazil and Angola/Namibia, South Atlantic

Science.gov (United States)

Strozyk, Frank; Back, Stefan; Kukla, Peter A.

2017-10-01

This study presents a regional comparison between selected 2D seismic transects from large, conjugated salt and salt-free basins offshore southern Brazil (Campos Basin, Santos Basin, Pelotas Basin) and southwest Africa (Kwanza Basin, northern and southern Namibe Basin, Walvis Basin). Tectonic-stratigraphic interpretation of the main rift and post-rift units, free-air gravity data and flexural isostatic backstripping were used for a comprehensive basin-to-basin documentation of key mechanisms controlling the present-day differences in conjugated and neighbouring South Atlantic basins. A significant variation in the tectonic-sedimentary architecture along-strike at each margin and between the conjugated basins across the South Atlantic reflects major differences in (1) the structural configuration of each margin segment at transitional phase between rifting and breakup, as emphasized in the highly asymmetric settings of the large Santos salt basin and the conjugated, salt-free southern Namibe Basin, (2) the post-breakup subsidence and uplift history of the respective margin segment, which caused major differences for example between the Campos and Espirito Santo basins and the conjugated northern Namibe and Kwanza basins, (3) variations in the quantity and distribution of post-breakup margin sediments, which led to major differences in the subsidence history and the related present-day basin architecture, for example in the initially rather symmetric, siliciclastic Pelotas and Walvis basins, and (4) the deposition of Aptian evaporites in the large rift and sag basin provinces north of the Rio Grande Rise and Walvis Ridge, highly contrasting the siliciclastic basins along the margin segments south of the ridges. The resulting present-day architecture of the basins can be generally classified as (i) moderately symmetric, salt-free, and magma-rich in the northern part of the southern segment, (i) highly asymmetric, salt-bearing and magma-poor vs. salt-free and magma

76 FR 66675 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and...

Science.gov (United States)

2011-10-27

.... 100120037-1626-01] RIN 0648-AY55 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendments to the Queen Conch and Reef Fish Fishery Management Plans of Puerto Rico and the U.S. Virgin Islands... the Fishery Management Plan for Queen Conch Resources of Puerto Rico and the U.S. Virgin Islands and...

76 FR 47563 - Fisheries of the South Atlantic; Southeast Data, Assessment, and Review (SEDAR); South Atlantic...

Science.gov (United States)

2011-08-05

... Management Councils, in conjunction with NOAA Fisheries and the Atlantic and Gulf States Marine Fisheries... Management Councils and NOAA Fisheries Southeast Regional Office and Southeast Fisheries Science Center..., biologists, and researchers; constituency representatives including fishermen, environmentalists, and NGO's...

The establishment of Atlantic Water transport as a topographically trapped slope current off Scotland

Directory of Open Access Journals (Sweden)

Qin Zhou

2013-05-01

Full Text Available Atlantic Water, with its origin in the western Atlantic, enters the Nordic Seas partly as a barotropic current following the continental slope. This water mass is carried across the Atlantic by the baroclinic North Atlantic Current (NAC. When the NAC meets the continental slope at the east side of the Atlantic, some of the transport is converted to barotropic transport over the slope before continuing northward. Here, we show that this baroclinic to barotropic conversion is in agreement with geostrophic theory. Historical observations show that the transport of the slope current increases significantly from the Rockall Channel (RC to the Faroe–Shetland Channel (FSC. Geostrophy predicts that with a northward decreasing buoyancy, baroclinic currents from the west will be transferred into northward topographically steered barotropic flow. We use hydrographic data from two sections crossing the continental slope, one located in the RC and another in the FSC, to estimate baroclinic and barotropic transport changes over the slope, within the framework of geostrophic dynamics. Our results indicate that ~1 Sv of the cross-slope baroclinic flow is mainly converted to northward barotropic transport above the 200–500m isobaths, which is consistent with observed transport changes between the RC and the FSC. Similar processes are also likely to occur further south, along the eastern Atlantic margin. This shows that AW within the slope current in the FSC is derived from both the eastern and the western Atlantic, in agreement with earlier studies of AW inflow to the Nordic Seas.

Copepod distribution and production in a Mid-Atlantic Ridge archipelago

Directory of Open Access Journals (Sweden)

PEDRO A.M.C. MELO

2014-12-01

Full Text Available The Saint Peter and Saint Paul Archipelago (SPSPA are located close to the Equator in the Atlantic Ocean. The aim of this study was to assess the spatial variations in the copepod community abundance, and the biomass and production patterns of the three most abundant calanoid species in the SPSPA. Plankton samples were collected with a 300 µm mesh size net along four transects (north, east, south and west of the SPSPA, with four stations plotted in each transect. All transects exhibited a tendency toward a decrease in copepod density with increasing distance from the SPSPA, statistically proved in the North. Density varied from 3.33 to 182.18 ind.m−3, and differences were also found between the first perimeter (first circular distance band and the others. The total biomass varied from 15.25 to 524.50 10−3 mg C m−3 and production from 1.19 to 22.04 10−3 mg C m−3d−1. The biomass and production of Undinula vulgaris (Dana, 1849, Acrocalanus longicornis Giesbrecht, 1888 and Calocalanus pavo (Dana, 1849 showed differences between some transects. A trend of declining biodiversity and production with increasing distance from archipelago was observed, suggesting that even small features like the SPSPA can affect the copepod community in tropical oligotrophic oceanic areas.

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the MELVILLE in the North Atlantic Ocean and South Atlantic Ocean from 1989-01-23 to 1989-04-12 (NODC Accession 0115014)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115014 includes chemical, discrete sample, physical and profile data collected from MELVILLE in the North Atlantic Ocean and South Atlantic Ocean...

Temperature profile, pressure, and nutrients data from bottle in South Atlantic Ocean from 24 November 1987 to 12 March 1989 (NODC Accession 0000196)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile, pressure, and nutrients data were collected using bottle in the South Atlantic Ocean from 24 November 1987 to 12 March 1989. Data were collected...

77 FR 2960 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2012-01-20

... the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of Mexico; Exempted... and retention. This study, to be conducted in the exclusive economic zone (EEZ) of the Gulf of Mexico (Gulf) off Louisiana, is intended to better document the age structure and life history of fish...

77 FR 30507 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2012-05-23

... the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of Mexico; Exempted... and retention. This study, to be conducted in the exclusive economic zone (EEZ) of the Gulf of Mexico (Gulf), is intended to better document the age structure and life history of fish associated with...

77 FR 28305 - Temporary Rule To Delay Start Date of 2012-2013 South Atlantic Black Sea Bass Commercial Fishing...

Science.gov (United States)

2012-05-14

.... 120501426-2426-01] RIN 0648-BB98 Temporary Rule To Delay Start Date of 2012-2013 South Atlantic Black Sea... this temporary rule to delay the start date of the 2012-2013 fishing season for the commercial black... temporary rule delays the start date of the 2012-2013 commercial fishing season for black sea bass from June...

Multilocus Bayesian Estimates of Intra-Oceanic Genetic Differentiation, Connectivity, and Admixture in Atlantic Swordfish (Xiphias gladius L..

Directory of Open Access Journals (Sweden)

Brad L Smith

Full Text Available Previous genetic studies of Atlantic swordfish (Xiphias gladius L. revealed significant differentiation among Mediterranean, North Atlantic and South Atlantic populations using both mitochondrial and nuclear DNA data. However, limitations in geographic sampling coverage, and the use of single loci, precluded an accurate placement of boundaries and of estimates of admixture. In this study, we present multilocus analyses of 26 single nucleotide polymorphisms (SNPs within 10 nuclear genes to estimate population differentiation and admixture based on the characterization of 774 individuals representing North Atlantic, South Atlantic, and Mediterranean swordfish populations. Pairwise FST values, AMOVA, PCoA, and Bayesian individual assignments support the differentiation of swordfish inhabiting these three basins, but not the current placement of the boundaries that separate them. Specifically, the range of the South Atlantic population extends beyond 5°N management boundary to 20°N-25°N from 45°W. Likewise the Mediterranean population extends beyond the current management boundary at the Strait of Gibraltar to approximately 10°W. Further, admixture zones, characterized by asymmetric contributions of adjacent populations within samples, are confined to the Northeast Atlantic. While South Atlantic and Mediterranean migrants were identified within these Northeast Atlantic admixture zones no North Atlantic migrants were identified respectively in these two neighboring basins. Owing to both, the characterization of larger number of loci and a more ample spatial sampling coverage, it was possible to provide a finer resolution of the boundaries separating Atlantic swordfish populations than previous studies. Finally, the patterns of population structure and admixture are discussed in the light of the reproductive biology, the known patterns of dispersal, and oceanographic features that may act as barriers to gene flow to Atlantic swordfish.

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from KNORR and MELVILLE in the North Atlantic Ocean and South Atlantic Ocean from 1987-11-23 to 1989-04-19 (NCEI Accession 0157692)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157692 includes chemical, discrete sample, physical and profile data collected from KNORR and MELVILLE in the North Atlantic Ocean and South Atlantic...

Teleconnections of the tropical Atlantic to the tropical Indian and Pacific Oceans. A review of recent findings

Energy Technology Data Exchange (ETDEWEB)

Wang Chunzai [NOAA Atlantic Oceanographic and Meteorological Lab., Miami, FL (United States); Kucharski, Fred; Barimalala, Rondrotiana [The Abdus Salam International Centre for Theoretical Physics, Earth System Physics, Section Trieste (Italy); Bracco, Annalisa [School of Earth and Atmospheric Sciences Georgia, Inst. of Tech., Atlanta, GA (United States)

2009-08-15

Recent studies found that tropical Atlantic variability may affect the climate in both the tropical Pacific and Indian Ocean basins, possibly modulating the Indian summer monsoon and Pacific ENSO events. A warm tropical Atlantic Ocean forces a Gill-Matsuno-type quadrupole response with a low-level anticyclone located over India that weakens the Indian monsoon circulation, and vice versa for a cold tropical Atlantic Ocean. The tropical Atlantic Ocean can also induce changes in the Indian Ocean sea surface temperatures (SSTs). especially along the coast of Africa and in the western side of the Indian basin. Additionally, it can influence the tropical Pacific Ocean via an atmospheric teleconnection that is associated with the Atlantic Walker circulation. Although the Pacific El Nino does not contemporaneously correlate with the Atlantic Nino, anomalous warming or cooling of the two equatorial oceans can form an inter-basin SST gradient that induces surface zonal wind anomalies over equatorial South America and other regions in both ocean basins. The zonal wind anomalies act as a bridge linking the two ocean basins, and in turn reinforce the inter-basin SST gradient through the atmospheric Walker circulation and oceanic processes. Thus, a positive feedback seems to exist for climate variability of the tropical Pacific-Atlantic Oceans and atmospheric system, in which the inter-basin SST gradient is coupled to the overlying atmospheric wind. (orig.)

Solar wind: A possible factor driving the interannual sea surface temperature tripolar mode over North Atlantic

Science.gov (United States)

Xiao, Ziniu; Li, Delin

2016-06-01

The effect of solar wind (SW) on the North Atlantic sea surface temperature (SST) in boreal winter is examined through an analysis of observational data during 1964-2013. The North Atlantic SSTs show a pronounced meridional tripolar pattern in response to solar wind speed (SWS) variations. This pattern is broadly similar to the leading empirical orthogonal function (EOF) mode of interannual variations in the wintertime SSTs over North Atlantic. The time series of this leading EOF mode of SST shows a significant interannual period, which is the same as that of wintertime SWS. This response also appears as a compact north-south seesaw of sea level pressure and a vertical tripolar structure of zonal wind, which simultaneously resembles the North Atlantic Oscillation (NAO) in the overlying atmosphere. As compared with the typical low SWS winters, during the typical high SWS winters, the stratospheric polar night jet (PNJ) is evidently enhanced and extends from the stratosphere to the troposphere, even down to the North Atlantic Ocean surface. Notably, the North Atlantic Ocean is an exclusive region in which the SW signal spreads downward from the stratosphere to the troposphere. Thus, it seems that the SW is a possible factor for this North Atlantic SST tripolar mode. The dynamical process of stratosphere-troposphere coupling, together with the global atmospheric electric circuit-cloud microphysical process, probably accounts for the particular downward propagation of the SW signal.

The Western South Atlantic Ocean in a High-CO2 World: Current Measurement Capabilities and Perspectives

Science.gov (United States)

Kerr, Rodrigo; da Cunha, Letícia C.; Kikuchi, Ruy K. P.; Horta, Paulo A.; Ito, Rosane G.; Müller, Marius N.; Orselli, Iole B. M.; Lencina-Avila, Jannine M.; de Orte, Manoela R.; Sordo, Laura; Pinheiro, Bárbara R.; Bonou, Frédéric K.; Schubert, Nadine; Bergstrom, Ellie; Copertino, Margareth S.

2016-03-01

An international multi-disciplinary group of 24 researchers met to discuss ocean acidification (OA) during the Brazilian OA Network/Surface Ocean-Lower Atmosphere Study (BrOA/SOLAS) Workshop. Fifteen members of the BrOA Network (www.broa.furg.br) authored this review. The group concluded that identifying and evaluating the regional effects of OA is impossible without understanding the natural variability of seawater carbonate systems in marine ecosystems through a series of long-term observations. Here, we show that the western South Atlantic Ocean (WSAO) lacks appropriate observations for determining regional OA effects, including the effects of OA on key sensitive Brazilian ecosystems in this area. The impacts of OA likely affect marine life in coastal and oceanic ecosystems, with further social and economic consequences for Brazil and neighboring countries. Thus, we present (i) the diversity of coastal and open ocean ecosystems in the WSAO and emphasize their roles in the marine carbon cycle and biodiversity and their vulnerabilities to OA effects; (ii) ongoing observational, experimental, and modeling efforts that investigate OA in the WSAO; and (iii) highlights of the knowledge gaps, infrastructure deficiencies, and OA-related issues in the WSAO. Finally, this review outlines long-term actions that should be taken to manage marine ecosystems in this vast and unexplored ocean region.

Atlantic Marine Mammal Assessment Vessel Surveys

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These data sets are a compilation of large vessel surveys for marine mammal stock assessments in South Atlantic (Florida to Maryland) waters from 1994 to the...

The South African traditional health practitioner as a beneficiary of and provider to medical funds and schemes through the traditional health practitioners Act (Act No 22, 2007: A present-day perspective

Directory of Open Access Journals (Sweden)

Gabriel Louw

2017-01-01

Full Text Available Background Payments to traditional health practitioners for services rendered from medical funds and schemes, as envisaged by the Traditional Health Practitioners Act (Act No 22, 2007, is controversial and a point of contention. Such policy was followed before in South Africa in the 1990s when some funds and schemes offered limited alternative healthcare benefits for members consulting traditional healers. Aims The study aimed to offer a contemporary view of the South African traditional health practitioner as a provider to and beneficiary of the medical funds and schemes through the Traditional Health Practitioners Act (No 22, 2007. Methods This is an exploratory and descriptive study that makes use of an historical approach by means of investigation and a literature review. The emphasis is on using current documentation like articles, books and newspapers as primary sources to reflect on the South African traditional health practitioner as a provider to and beneficiary of the medical schemes and funds through the Traditional Health Practitioners Act (No 22, 2007. The findings are offered in narrative form. Results It seems as if the South African authorities completely misunderstand the future implications of the Traditional Health Practitioners Act (No 22, 2007 on healthcare. This is specifically true when it comes to the right to claim from medical funds and schemes for services rendered by traditional health practitioners and the possible extra costs for these medical schemes and funds. Conclusion The implications of Section 42(2 of the Traditional Health Practitioners Act (No 22, 2007 which aims to set up a claiming process for traditional health practitioners, seems to be very problematic. The fact that Act No 22 (2007 has not been enacted properly nine years after its promulgation has put a halt on the professionalization of traditional healers until 2015. This also affected their status as a beneficiary of and service provider to the

Projected changes to South Atlantic boundary currents and confluence region in the CMIP5 models: the role of wind and deep ocean changes

Science.gov (United States)

Pontes, G. M.; Gupta, A. Sen; Taschetto, A. S.

2016-09-01

The South Atlantic (SA) circulation plays an important role in the oceanic teleconnections from the Indian, Pacific and Southern oceans to the North Atlantic, with inter-hemispheric exchanges of heat and salt. Here, we show that the large-scale features of the SA circulation are projected to change significantly under ‘business as usual’ greenhouse gas increases. Based on 19 models from the Coupled Model Intercomparison Project phase 5 there is a projected weakening in the upper ocean interior transport (stress curl over this region. The reduction in ocean interior circulation is largely compensated by a decrease in the net deep southward ocean transport (>1000 m), mainly related to a decrease in the North Atlantic deep water transport. Between 30° and 40°S, there is a consistent projected intensification in the Brazil current strength of about 40% (30%-58% interquartile range) primarily compensated by an intensification of the upper interior circulation across the Indo-Atlantic basin. The Brazil-Malvinas confluence is projected to shift southwards, driven by a weakening of the Malvinas current. Such a change could have important implications for the distribution of marine species in the southwestern SA in the future.

Bird Habitat Conservation at Various Scales in the Atlantic Coast Joint Venture

Science.gov (United States)

Andrew Milliken; Craig Watson; Chuck Hayes

2005-01-01

The Atlantic Coast Joint Venture is a partnership focused on the conservation of habitats for migratory birds within the Atlantic Flyway/Atlantic Coast Region from Maine south to Puerto Rico. In order to be effective in planning and implementing conservation in this large and diverse area, the joint venture must work at multiple spatial scales, from the largest ?...

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the EDWIN LINK in the North Atlantic Ocean and South Atlantic Ocean from 1996-04-15 to 1996-05-16 (NODC Accession 0113539)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113539 includes chemical, discrete sample, physical and profile data collected from EDWIN LINK in the North Atlantic Ocean and South Atlantic Ocean...

The Japanese alga Polysiphonia morrowii (Rhodomelaceae, Rhodophyta) on the South Atlantic Ocean: first report of an invasive macroalga inhabiting oyster reefs

Science.gov (United States)

Croce, M. Emilia; Parodi, Elisa R.

2014-06-01

Conspicuous tufts of the filamentous algae Polysiphonia Greville inhabit the reefs of Crassostrea gigas on the Atlantic Patagonian coast. The population was recorded for the first time in 1994 and identified as P. argentinica. This study exhaustively investigated the morphology and reproduction of specimens and the seasonality of the population. The results revealed the identity of the specimens as the invasive Japanese macroalga Polysiphonia morrowii Harvey, on the basis of several striking features: the setaceous and tufted thalli, the corymbose growing apices, the endogenous axillary branches, the urceolate cystocarps and the sharply pointed branches. Sexual reproduction was evidenced; however, fertile male gametophytes were absent in the samples. The population was found almost all year round, but its abundance became higher in autumn and winter. The present study constitutes the first record of this invasive macroalga on the South Atlantic Ocean; the fourth record of an exotic macroalgal species on the Atlantic Patagonian coast; and the first record of an invasive species related to the establishment of C. gigas in Atlantic Patagonia.

22nd Annual congress of the South African Society of Pathologists

International Nuclear Information System (INIS)

1982-01-01

This publication only contains the abstracts of papers delivered on the 22nd annual congress of the South African Society of Pathologists on 5-7 July 1987. The topics covered, include anatomical pathology, haematology, biochemistry microbiology, and immunology

Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from POLARSTERN in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2010-11-28 to 2011-02-05 (NODC Accession 0108155)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108155 includes discrete sample and profile data collected from POLARSTERN in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (>...

Aqua-planet simulations of the formation of the South Atlantic convergence zone

Science.gov (United States)

Nieto Ferreira, Rosana; Chao, Winston C.

2013-01-01

The impact of Amazon Basin convection and cold fronts on the formation and maintenance of the South Atlantic convergence zone (SACZ) is studied using aqua-planet simulations with a general circulation model. In the model, a circular patch of warm sea-surface temperature (SST) is used to mimic the effect of the Amazon Basin on South American monsoon convection. The aqua-planet simulations were designed to study the effect of the strength and latitude of Amazon Basin convection on the formation of the SACZ. The simulations indicate that the strength of the SACZ increases as the Amazon convection intensifies and is moved away from the equator. Of the two controls studied here, the latitude of the Amazon convection exerts the strongest effect on the strength of the SACZ. An analysis of the synoptic-scale variability in the simulations shows the importance of frontal systems in the formation of the aqua-planet SACZ. Composite time series of frontal systems that occurred in the simulations show that a robust SACZ occurs when fronts penetrate into the subtropics and become stationary there as they cross eastward of the longitude of the Amazon Basin. Moisture convergence associated with these frontal systems produces rainfall not along the model SACZ region and along a large portion of the northern model Amazon Basin. Simulations in which the warm SST patch was too weak or too close to the equator did not produce frontal systems that extended into the tropics and became stationary, and did not form a SACZ. In the model, the SACZ forms as Amazon Basin convection strengthens and migrates far enough southward to allow frontal systems to penetrate into the tropics and stall over South America. This result is in agreement with observations that the SACZ tends to form after the onset of the monsoon season in the Amazon Basin.

Seamount physiography and biology in the north-east Atlantic and Mediterranean Sea

Directory of Open Access Journals (Sweden)

T. Morato

2013-05-01

Full Text Available This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (north-east Atlantic Ocean and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (north-east Atlantic and in the Mediterranean Sea is large with around 557 and 101 seamount-like features, respectively. Similarly, seamounts occupy large areas of about 616 000 km2 in the OSPAR region and of about 89 500 km2 in the Mediterranean Sea. The presence of seamounts in the north-east Atlantic has been known since the late 19th century, but overall knowledge regarding seamount ecology and geology is still relatively poor. Only 37 seamounts in the OSPAR area (3.5% of all seamounts in the region, 22 in the Mediterranean Sea (9.2% of all seamounts in the region and 25 in the north-east Atlantic south of the OSPAR area have in situ information. Seamounts mapped in both areas are in general very heterogeneous, showing diverse geophysical characteristics. These differences will likely affect the biological diversity and production of resident and associated organisms.

Similarity and Difference between the South Atlantic Convergence Zone and the Baiu Frontal Zone Simulated by an AGCM

OpenAIRE

Kozo, NINOMIYA; Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology

2007-01-01

Features of the South Atlantic convergence zone (SACZ) and the Baiu frontal zone (BFZ) simulated by an AGCM (T106L56: a primitive equation spectral model which has 56 σ-levels and triangular spectral truncation at wave-number 106) are studied. The 24-year integration, from 1979 to 2002, by the model constrained by observed sea-surface temperature and sea-ice distribution, is used for this study. The detailed analysis is made for the typical case of SACZ and BFZ selected from data in 1985-1996...

Genomic signatures of local directional selection in a high gene flow marine organism, the Atlantic cod (Gadus morhua)

DEFF Research Database (Denmark)

Eg Nielsen, Einar; Hansen, Jakob Hemmer; Poulsen, Nina Aagaard

2009-01-01

-associated single nucleotide polymorphisms (SNPs) for evidence of selection in local populations of Atlantic cod (Gadus morhua L.) across the species distribution. Results: Our global genome scan analysis identified eight outlier gene loci with very high statistical support, likely to be subject to directional...... selection in local demes, or closely linked to loci under selection. Likewise, on a regional south/north transect of central and eastern Atlantic populations, seven loci displayed strongly elevated levels of genetic differentiation. Selection patterns among populations appeared to be relatively widespread...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from ANTARES in the North Atlantic Ocean and South Atlantic Ocean from 2009-03-20 to 2010-08-06 (NODC Accession 0114477)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0114477 includes Surface underway, chemical, meteorological and physical data collected from ANTARES in the North Atlantic Ocean and South Atlantic...

PH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from JAMES CLARK ROSS in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2015-12-17 to 2016-01-13 (NCEI Accession 0157011)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157011 includes chemical, discrete sample, physical and profile data collected from JAMES CLARK ROSS in the South Atlantic Ocean, South Pacific Ocean...

Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from JAMES CLARK ROSS in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 1992-11-01 to 1992-12-08 (NODC Accession 0115024)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0115024 includes chemical, discrete sample, physical and profile data collected from JAMES CLARK ROSS in the South Atlantic Ocean, South Pacific Ocean...

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from L'ATALANTE in the North Atlantic Ocean and South Atlantic Ocean from 1993-01-02 to 1993-02-10 (NODC Accession 0115753)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0115753 includes discrete sample and profile data collected from L'ATALANTE in the North Atlantic Ocean and South Atlantic Ocean from 1993-01-02 to...

Lead-strontium isotopic variations along the East Pacific Rise and the Mid-Atlantic Ridge: A comparative study

International Nuclear Information System (INIS)

Hamelin, B.; Dupre, B.; Allegre, C.J.

1984-01-01

We have determined the Pb and Sr isotopic compositions in a number of fresh young oceanic basalts from the East Pacific Rise (between 20 0 N and 21 0 S latitudes), and from the Mid-Atlantic Ridge (between 65 0 N and 10 0 N). A comparison between the Atlantic and Pacific results reveals that there is a wider range of values for the Atlantic than for the Pacific. After filtering the short wavelengths, a good correlation is obtained between long-wavelength bathymetric and isotopic variations for the Atlantic. The preferred model proposed to explain these differences involves the constant presence of hot spots under ridges. On slow-spreading ridges like the Atlantic, the host spots signature is clearly visible in both bathymetry and isotopic ratios. On fast-spreading centres, the hot spot signature in both the bathymetry and isotopic signature may be diluted by the rapid supply of material coming from the asthenosphere. However, an alternative explanation for which no hot spot influence is found on the East Pacific Rise cannot be definitely ruled out. In two occurrences, south of the Hayes fracture zone (Atlantic), large isotopic heterogeneities are observed within a single dredge. This does not contradict the concept of regional isotopic regularities, but suggests that blob injection and source mixing may be observed at very different scales under the ridges. (orig./WB)

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from KNORR in the North Atlantic Ocean, South Atlantic Ocean and Southern Oceans from 1983-10-07 to 1984-02-19 (NODC Accession 0117503)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0117503 includes chemical, discrete sample, physical and profile data collected from KNORR in the North Atlantic Ocean, South Atlantic Ocean and...

Monitoring the South Atlantic Anomaly Using ATSR

Science.gov (United States)

Casadio, Stefano; Arino, Olivier; Serpe, Danilo

2010-12-01

Space mission planning needs to quantify the risks arising from exposure to high doses of radiation, as to both the effects on human health and the impact on instrumental efficiency. Constant monitoring of the South Atlantic Anomaly (SAA) is therefore required as it is a major cause of radiation flux increase. In order to address this need, the time evolution of the particle induced noise of the SWIR channels of the Along Track Scanning Radiometer (ATSR) instrument series is analysed in the 1991-2009 time window. The data considered in this work are the night-time SWIR hot spots generated by energetic particles hitting the ATSR detectors when satellites pass through the SAA region. To avoid misinterpretation of results, hot spots due to wildfires (individuated from the ATSR World Fire Atlas products) have been removed. The location and area of the SAA are inferred by fitting a two-dimensional, elliptical Gaussian equation to the SWIR (1.6 μm) night- time hot spots detected over the SAA region. The location of the SAA is found to drift westwards with an average drift rate of about 0.35 deg/yr and northward with an average drift rate of about 0.12 deg/yr. These results are in very good agreement with latest works. Irregularities are found where the speed of the drift changes and the SAA moves eastward and southward, especially in the late 1991 and 2002-2003 time windows. These drift anomalies are attributed to geomagnetic jerks. Results indicate that, as expected, the strength and the area of the SAA are anti-correlated with the sun-spot numbers (SSN) and the 11.7 cm Solar Flux (SF).

Geometry and structure of the pull-apart basins developed along the western South American-Scotia plate boundary (SW Atlantic Ocean)

Science.gov (United States)

Esteban, F. D.; Tassone, A.; Isola, J. I.; Lodolo, E.; Menichetti, M.

2018-04-01

The South American-Scotia plate boundary is a left-lateral fault system which runs roughly E-W for more than 3000 km across the SW Atlantic Ocean and the Tierra del Fuego Island, reaching to the west the southern Chile Trench. Analyses of a large dataset of single- and multi-channel seismic reflection profiles acquired offshore has allowed to map the trace of the plate boundary from Tierra del Fuego to the Malvinas Trough, a tectonic depression located in the eastern part of the fault system, and to reconstruct the shape and geometry of the basins formed along the principal displacement zone of the fault system. Three main Neogene pull-apart basins that range from 70 to 100 km in length, and from 12 to 22 km in width, have been identified along this segment of the plate boundary. These basins have elongated shapes with their major axes parallel to the ENE-WSW direction of the fault zone. The sedimentary architecture and the infill geometry of the basins suggest that they represent mostly strike-slip dominated transtension basins which propagated from E to W. The basins imaged by seismic data show in some cases geometrical and structural features linked to the possible reactivation of previous wedge-top basins and inherited structures pertaining to the external front of the Magallanes fold-and-thrust compression belt, along which the South American-Scotia fault system has been superimposed. It is suggested that the sequence of the elongated basins occur symmetrically to a thorough going strike-slip fault, in a left-stepping geometrical arrangement, in a manner similar to those basins seen in other transcurrent environments.

A mid-Pleistocene rainforest corridor enabled synchronous invasions of the Atlantic Forest by Amazonian anole lizards.

Science.gov (United States)

Prates, Ivan; Rivera, Danielle; Rodrigues, Miguel T; Carnaval, Ana C

2016-10-01

Shifts in the geographic distribution of habitats over time can promote dispersal and vicariance, thereby influencing large-scale biogeographic patterns and ecological processes. An example is that of transient corridors of suitable habitat across disjunct but ecologically similar regions, which have been associated with climate change over time. Such connections likely played a role in the assembly of tropical communities, especially within the highly diverse Amazonian and Atlantic rainforests of South America. Although these forests are presently separated by open and dry ecosystems, paleoclimatic and phylogenetic evidence suggest that they have been transiently connected in the past. However, little is known about the timing, magnitude and the distribution of former forest connections. We employ sequence data at multiple loci from three codistributed arboreal lizards (Anolis punctatus, Anolis ortonii and Polychrus marmoratus) to infer the phylogenetic relationships among Amazonian and Atlantic Forest populations and to test alternative historical demographic scenarios of colonization and vicariance using coalescent simulations and approximate Bayesian computation (ABC). Data from the better-sampled Anolis species support colonization of the Atlantic Forest from eastern Amazonia. Hierarchical ABC indicates that the three species colonized the Atlantic Forest synchronously during the mid-Pleistocene. We find support of population bottlenecks associated with founder events in the two Anolis, but not in P. marmoratus, consistently with their distinct ecological tolerances. Our findings support that climatic fluctuations provided key opportunities for dispersal and forest colonization in eastern South America through the cessation of environmental barriers. Evidence of species-specific histories strengthens assertions that biological attributes play a role in responses to shared environmental change. © 2016 John Wiley & Sons Ltd.

The ecology of intertidal oyster reefs of the South Atlantic Coast: A community profile

Science.gov (United States)

Bahr, Leonard M.; Lanier, William P.

1981-01-01

The functional role of the intertidal oyster reef community in the southeastern Atlantic coastal zone is described. This description is based on a compilation of published data, as well as some unpublished information presented as hypotheses. The profile is organized in a hierarchical manner, such that relevant details of reef oyster biology (autecology) are presented, followed by a description of the reef community level of organization. Then the reef community is described as a subsystem of the coastal marsh-ecosystem (synecoloqy). This information is also synthesized in a series of nested conceptual models of oyster reefs at the regional level, the drainage basin level, and the individual reef level. The final chapter includes a summary overview and a section on management implications and guidelines. Intertidal oyster reefs are relatively persistent features of the salt marsh estuarine ecosystem in the southeastern Atlantic coastal zone. The average areal extent of the oyster reef subsystem in this larger ecosystem is relatively small (about 0.05%). This proportion does not reflect, however, the functional importance of the reef subsystem in stablizing the marsh, providing food for estuarine consumers, mineralizing organic matter, and providing firm substrates in this otherwise soft environment.

Invasion of the Indo-Pacific blenny Omobranchus punctatus (Perciformes: Blenniidae on the Atlantic Coast of Central and South America

Directory of Open Access Journals (Sweden)

Oscar Lasso-Alcalá

Full Text Available We examined 308 specimens of the Indo-Pacific blenniid Omobranchus punctatus deposited in four museum collections, and analyzed data on their collection locations to assess its invasion on the Atlantic coast of Central and South America. This species occurs in shoreline estuarine and marine habitats in the Indo-West Pacific. Previous sampling and recent records in the Tropical West Atlantic from 1930 to 2004 produced 20 records for: Panamá, Colombia, Venezuela, Trinidad and Brazil. In this work, we provide data on 17 new records for the Gulfs of Venezuela and Paria in Venezuela, as well as four records for Maranhão and Pará states in NE Brazil. The temporal pattern of collections (1930 - 2009 and the proximity of most localities to ports and zones of ship traffic indicate that O. punctatus was initially introduced to the Atlantic by ships travelling from India to Trinidad. Within Brazil the introduction is linked to shipping connected to petroleum platforms. In Maranhão and Pará the introduction may have occurred as a result of fish sheltering in fouling on hulls of ships moving between ports around the mouth of the Amazon River. Alternatively, the spread of this species along of the American coast may reflect the expansion of the range of O. puntactus through larval dispersal in northward flowing currents. We recommend monitoring of this introduced species, and studies of its ecology in West Atlantic areas.

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the North Pacific Ocean, South Atlantic Ocean and others from 2008-12-31 to 2009-12-22 (NCEI Accession 0144533)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144533 includes Surface underway data collected from LAURENCE M. GOULD in the North Pacific Ocean, South Atlantic Ocean, South Pacific Ocean and...

O mínimo de oxigênio na costa leste do Brasil entre 7-22ºS The minimum oxygen concentration in easthern Brasilian coast between 7-22ºS

Directory of Open Access Journals (Sweden)

Argeo Magliocca

1978-01-01

Full Text Available In the South Atlantic nearly the Brazilian coast, at low latitudes, the layer of minimum oxygen concentration shows distinct values between the Equatorial region (7ºS and the region limited by latitudes of 18-22ºS. In the vicinity of the Equator the minimum concentration is remarkably clear (2,0 ml/l at 7ºS and at 22ºS the minima values raise up to 4.0-4.5 ml/l. The minimum oxygen layer follows the isopynics surfaces (σt = 26.8-27.2 in depths of 300-400 m (7ºS and 600-800 m (22ºS . The oxygen concentration in this area results from a biochemical and physical processes, due to the presence of poor water Brazil Current southward and the rich one Intermediate Antartic water flowing northward.

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from NOAA Ship RONALD H. BROWN in the North Atlantic Ocean and South Atlantic Ocean from 2003-06-04 to 2003-08-11 (NODC Accession 0108061)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108061 includes discrete sample and profile data collected from NOAA Ship RONALD H. BROWN in the North Atlantic Ocean and South Atlantic Ocean from...

Analysis of a general circulation model. II - Distribution of kinetic energy in the South Atlantic and Kuroshio/Oyashio systems

Science.gov (United States)

Garraffo, Zulema; Garzoli, Silvia L.; Haxby, William; Olson, Donald

1992-01-01

It was found (Garzoli et al., 1992) that the general circulation model of Semtner and Chervin (1992) provides accurate descriptions of the Brazil-Malvinas and the Kuroshio/Oyashio confluence systems, except for the fact that the model prediction shows less variability than that present in observations. This paper investigates the problem of model variability by analyzing the mean and the eddy kinetic energy from the model and comparing the values with the Geosat altimeter observations for the South Atlantic Ocean and for the Kuroshio system. It is found that, while the model shows transient eddy activity in the areas that overlap the Geosat observations, the energy level of the model transient motions is considerably smaller following an arch along the bottom topography. The same was found from the comparisons made with values obtained from FGGE and surface drifters. It is suggested that the model is poorly resolving instabilities in the confluence front, and is not resolving other transients appearing in regions of marked topography.

Pan-Atlantic analysis of the overlap of a highly migratory species, the leatherback turtle, with pelagic longline fisheries

Science.gov (United States)

Fossette, S.; Witt, M. J.; Miller, P.; Nalovic, M. A.; Albareda, D.; Almeida, A. P.; Broderick, A. C.; Chacón-Chaverri, D.; Coyne, M. S.; Domingo, A.; Eckert, S.; Evans, D.; Fallabrino, A.; Ferraroli, S.; Formia, A.; Giffoni, B.; Hays, G. C.; Hughes, G.; Kelle, L.; Leslie, A.; López-Mendilaharsu, M.; Luschi, P.; Prosdocimi, L.; Rodriguez-Heredia, S.; Turny, A.; Verhage, S.; Godley, B. J.

2014-01-01

Large oceanic migrants play important roles in ecosystems, yet many species are of conservation concern as a result of anthropogenic threats, of which incidental capture by fisheries is frequently identified. The last large populations of the leatherback turtle, Dermochelys coriacea, occur in the Atlantic Ocean, but interactions with industrial fisheries could jeopardize recent positive population trends, making bycatch mitigation a priority. Here, we perform the first pan-Atlantic analysis of spatio-temporal distribution of the leatherback turtle and ascertain overlap with longline fishing effort. Data suggest that the Atlantic probably consists of two regional management units: northern and southern (the latter including turtles breeding in South Africa). Although turtles and fisheries show highly diverse distributions, we highlight nine areas of high susceptibility to potential bycatch (four in the northern Atlantic and five in the southern/equatorial Atlantic) that are worthy of further targeted investigation and mitigation. These are reinforced by reports of leatherback bycatch at eight of these sites. International collaborative efforts are needed, especially from nations hosting regions where susceptibility to bycatch is likely to be high within their exclusive economic zone (northern Atlantic: Cape Verde, Gambia, Guinea Bissau, Mauritania, Senegal, Spain, USA and Western Sahara; southern Atlantic: Angola, Brazil, Namibia and UK) and from nations fishing in these high-susceptibility areas, including those located in international waters. PMID:24523271

Egg cases of the graytail skate Bathyraja griseocauda and the cuphead skate Bathyraja scaphiops from the south-west Atlantic Ocean.

Science.gov (United States)

Mabragaña, E; Vazquez, D M; Gabbanelli, V; Sabadin, D; Barbini, S A; Lucifora, L O

2017-09-01

Egg cases of Bathyraja griseocauda were larger (140-142 mm in length) than those of Bathyraja scaphiops (88-90 mm in length) and their surface was relatively smooth, without denticles, prickles or any ornamentation. Egg cases of B. scaphiops had a relative coarse surface, covered with prickles of similar size. An identification key for the all described egg cases from Bathyraja occurring in the south-west Atlantic Ocean is provided. © 2017 The Fisheries Society of the British Isles.

Parameterization of synoptic weather systems in the South Atlantic Bight for modeling applications

Science.gov (United States)

Wu, Xiaodong; Voulgaris, George; Kumar, Nirnimesh

2017-10-01

An event based, long-term, climatological analysis is presented that allows the creation of coastal ocean atmospheric forcing on the coastal ocean that preserves both frequency of occurrence and event time history. An algorithm is developed that identifies individual storm event (cold fronts, warm fronts, and tropical storms) from meteorological records. The algorithm has been applied to a location along the South Atlantic Bight, off South Carolina, an area prone to cyclogenesis occurrence and passages of atmospheric fronts. Comparison against daily weather maps confirms that the algorithm is efficient in identifying cold fronts and warm fronts, while the identification of tropical storms is less successful. The average state of the storm events and their variability are represented by the temporal evolution of atmospheric pressure, air temperature, wind velocity, and wave directional spectral energy. The use of uncorrected algorithm-detected events provides climatologies that show a little deviation from those derived using corrected events. The effectiveness of this analysis method is further verified by numerically simulating the wave conditions driven by the characteristic wind forcing and comparing the results with the wave climatology that corresponds to each storm type. A high level of consistency found in the comparison indicates that this analysis method can be used for accurately characterizing event-based oceanic processes and long-term storm-induced morphodynamic processes on wind-dominated coasts.

Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the METEOR in the Caribbean Sea, North Atlantic Ocean and South Atlantic Ocean from 2002-06-07 to 2002-07-04 (NODC Accession 0115586)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115586 includes chemical, discrete sample, physical and profile data collected from METEOR in the Caribbean Sea, North Atlantic Ocean and South...

Temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the SONNE in the Caribbean Sea, North Atlantic Ocean and South Atlantic Ocean from 2003-05-25 to 2003-06-13 (NODC Accession 0116705)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116705 includes chemical, discrete sample, physical and profile data collected from SONNE in the Caribbean Sea, North Atlantic Ocean and South...

Interhemispheric Changes in Atlantic Ocean Heat Content and Their Link to Global Monsoons

Science.gov (United States)

Lopez, H.; Lee, S. K.; Dong, S.; Goni, G. J.

2015-12-01

This study tested the hypothesis whether low frequency decadal variability of the South Atlantic meridional heat transport (SAMHT) influences decadal variability of the global monsoons. A multi-century run from a state-of-the-art coupled general circulation model is used as basis for the analysis. Our findings indicate that multi-decadal variability of the South Atlantic Ocean plays a key role in modulating atmospheric circulation via interhemispheric changes in Atlantic Ocean heat content. Weaker SAMHT produces anomalous ocean heat divergence over the South Atlantic resulting in negative ocean heat content anomaly about 15 years later. This, in turn, forces a thermally direct anomalous interhemispheric Hadley circulation in the atmosphere, transporting heat from the northern hemisphere (NH) to the southern hemisphere (SH) and moisture from the SH to the NH, thereby intensify (weaken) summer (winter) monsoon in the NH and winter (summer) monsoon in the SH. Results also show that anomalous atmospheric eddies, both transient and stationary, transport heat northward in both hemispheres producing eddy heat flux convergence (divergence) in the NH (SH) around 15-30°, reinforcing the anomalous Hadley circulation. The effect of eddies on the NH (SH) poleward of 30° is opposite with heat flux divergence (convergence), which must be balanced by sinking (rising) motion, consistent with a poleward (equatorward) displacement of the jet stream and mean storm track. The mechanism described here could easily be interpreted for the case of strong SAMHT, with the reverse influence on the interhemispheric atmospheric circulation and monsoons. Overall, SAMHT decadal variability leads its atmospheric response by about 15 years, suggesting that the South Atlantic is a potential predictor of global climate variability.

Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from RRS JAMES COOK in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2009-02-03 to 2009-03-03 (NODC Accession 0110379)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0110379 includes discrete sample and profile data collected from RRS JAMES COOK in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans...

Macro and trace elements in Paracentrotus lividus gonads from South West Atlantic areas

DEFF Research Database (Denmark)

Camacho, Carolina; Rocha, A. Cristina; Barbosa, Vera L.

2018-01-01

Sea urchin represents one of the most valuable seafood product being harvested and explored for their edible part, the gonads or roe. This species is generally considered a sentinel organism for ecotoxicological studies being widely used in monitoring programs to assess coastal aquatic environments...... quality, because is directly exposed to anthropogenic contaminants in their habitat. In this context, the aim of this study is to evaluate the concentrations of macro (Cl, K, P, Ca, S) and trace (Zn, Br, Fe, Sr, I, Se, Rb, Cu, Cr, Ni, As, iAs, Cd, Pb, Hg) elements in Paracentrotus lividus gonads from...... three South West Atlantic production areas subjected to distinct environmental and anthropogenic pressures. In all studied areas, the elements profile in sea urchin gonads was Cl > K > P > Ca > S > Zn > Br > Fe > Sr > I > Rb > Cu > Se > Cr > Ni, suggesting an element guide profile with special interest...

76 FR 66273 - Snapper-Grouper Fishery Off the Southern Atlantic States and Coral and Coral Reefs Fishery in the...

Science.gov (United States)

2011-10-26

...-Grouper Fishery Off the Southern Atlantic States and Coral and Coral Reefs Fishery in the South Atlantic... the South Atlantic Region and the FMP for Coral, Coral Reefs, and Live/Hard Bottom Habitats of the... Aquariums to collect, with certain conditions, various species of reef fish and live rock in Federal waters...

Turbidity distribution in the Atlantic Ocean

Science.gov (United States)

Eittreim, S.; Thorndike, E.M.; Sullivan, L.

1976-01-01

The regional coverage of Lamont nephelometer data in the North and South Atlantic can be used to map seawater turbidity at all depths. At the level of the clearest water, in the mid-depth regions, the turbidity distribution primarily reflects the pattern of productivity in the surface waters. This suggests that the 'background' turbidity level in the oceans is largely a function of biogenic fallout. The bottom waters of the western Atlantic generally exhibit large increases in turbidity. The most intense benthic nepheloid layers are in the southwestern Argentine basin and northern North American basin; the lowest bottom water turbidity in the western Atlantic is in the equatorial regions. Both the Argentine and North American basin bottom waters appear to derive their high turbidity largely from local resuspension of terrigenous input in these basins. In contrast to the west, the eastern Atlantic basins show very low turbidities with the exception of three regions: the Mediterranean outflow area, the Cape basin, and the West European basin. ?? 1976.

Tropical Dominance of N2 Fixation in the North Atlantic Ocean

Science.gov (United States)

Marconi, Dario; Sigman, Daniel M.; Casciotti, Karen L.; Campbell, Ethan C.; Alexandra Weigand, M.; Fawcett, Sarah E.; Knapp, Angela N.; Rafter, Patrick A.; Ward, Bess B.; Haug, Gerald H.

2017-10-01

To investigate the controls on N2 fixation and the role of the Atlantic in the global ocean's fixed nitrogen (N) budget, Atlantic N2 fixation is calculated by combining meridional nitrate fluxes across World Ocean Circulation Experiment sections with observed nitrate 15N/14N differences between northward and southward transported nitrate. N2 fixation inputs of 27.1 ± 4.3 Tg N/yr and 3.0 ± 0.5 Tg N/yr are estimated north of 11°S and 24°N, respectively. That is, 90% of the N2 fixation in the Atlantic north of 11°S occurs south of 24°N in a region with upwelling that imports phosphorus (P) in excess of N relative to phytoplankton requirements. This suggests that, under the modern iron-rich conditions of the equatorial and North Atlantic, N2 fixation occurs predominantly in response to P-bearing, N-poor conditions. We estimate a N2 fixation rate of 30.5 ± 4.9 Tg N/yr north of 30°S, implying only 3 Tg N/yr between 30° and 11°S, despite evidence of P-bearing, N-poor surface waters in this region as well; this is consistent with iron limitation of N2 fixation in the South Atlantic. Since the ocean flows through the Atlantic surface in Pacific basins.

Tropical North Atlantic ocean-atmosphere interactions synchronize forest carbon losses from hurricanes and Amazon fires

OpenAIRE

Chen, Y; Randerson, JT; Morton, DC

2015-01-01

©2015. American Geophysical Union. All Rights Reserved. We describe a climate mode synchronizing forest carbon losses from North and South America by analyzing time series of tropical North Atlantic sea surface temperatures (SSTs), landfall hurricanes and tropical storms, and Amazon fires during 1995-2013. Years with anomalously high tropical North Atlantic SSTs during March-June were often followed by a more active hurricane season and a larger number of satellite-detected fires in the south...

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the METEOR in the South Atlantic Ocean and South Pacific Ocean from 1990-01-23 to 1990-03-08 (NODC Accession 0115021)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115021 includes chemical, discrete sample, physical and profile data collected from METEOR in the South Atlantic Ocean and South Pacific Ocean from...

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from Surface underway, discrete sample and profile observations using CTD, Carbon dioxide (CO2) gas analyzer and other instruments from MAURICE EWING in the North Atlantic Ocean and South Atlantic Ocean from 1994-01-04 to 1994-03-21 (NODC Accession 0115157)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0115157 includes Surface underway, discrete sample and profile data collected from MAURICE EWING in the North Atlantic Ocean and South Atlantic Ocean...

Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the S. A. AGULHAS in the South Atlantic Ocean from 1997-12-04 to 1998-02-06 (NODC Accession 0113247)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113247 includes chemical, discrete sample, physical and profile data collected from S. A. AGULHAS in the South Atlantic Ocean from 1997-12-04 to...

Ocean station data collected using bottle from the PROFESSOR W. BESNARD in the South Atlantic Ocean from 1969-01-17 to 1987-12-16 (NODC Accession 9000030)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Ocean station data were collected using bottle in the South Atlantic Ocean. Data were submitted by the LCDR Persio Soares Souto of Directoria de Hidrografia e...

Deep-sea dives reveal an unexpected hexactinellid sponge garden on the Rio Grande Rise (SW Atlantic). A mimicking habitat?

Science.gov (United States)

Hajdu, Eduardo; Castello-Branco, Cristiana; Lopes, Daniela A.; Sumida, Paulo Yukio Gomes; Perez, Jose Angel Alvarez

2017-12-01

Long overlooked, sponge grounds are now recognised as important habitats which support high biodiversity. Some of these deep-sea sponge aggregations are formed by hexactinellids, in varying densities, which can occur on both soft and hard substrates. Despite their ecological importance as habitat framework building taxa, hexactinellids have been little studied and only 33 species in this Class were reported from the entire South Atlantic until now. Most of this knowledge was gained from studies conducted on the eastern South America continental slope. Here we report a new hexactinellid sponge garden found by the Shinkai 6500 manned submersible on the Rio Grande Rise, a prominent topographic feature of the deep SW Atlantic. This is the first sponge garden worldwide found to be dominated by the stiff, often dichotomously branching, Sarostegia oculata which may occur in densities of over 5 individuals per square meter. This sponge, of uncertain familial allocation, seems to always carry epibiotic zoanthids, thus mimicking the 3D skeletal framework of actual coral gardens

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from surface underway observations using Carbon dioxide (CO2) gas analyzer and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2012-12-31 to 2013-12-19 (NCEI Accession 0163187)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0163187 includes chemical, meteorological, physical and surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2009-12-29 to 2010-12-20 (NCEI Accession 0156926)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0156926 includes Surface underway, chemical, meteorological and physical data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South...

76 FR 56120 - Atlantic Highly Migratory Species; North and South Atlantic Swordfish Quotas

Science.gov (United States)

2011-09-12

... recreational fishing for swordfish in the Atlantic Ocean, including the Caribbean Sea and Gulf of Mexico, by... http://www.iccat.int/en/ . One swordfish measure adopted at the 2010 meeting, and one swordfish measure...

Dispersion in North Atlantic Deep Water transfer between the northern source region and the South Atlantic

Energy Technology Data Exchange (ETDEWEB)

Huhn, Oliver; Roether, Wolfgang [Institut fuer Umweltphysik, Universitaet Bremen (Germany)

2007-07-01

North Atlantic Deep Water (NADW) represents the Atlantic part of the deep, southward return arm of the oceanic 'conveyor belt', which moderates Europe's climate and effects most of the water transfer from the ocean surface into the deep waters globally. The transfer starts from the NADW formation regions, which in the case of upper NADW (approx. 1500-2000 m depth) is the Labrador Sea (far NW Atlantic). NADW is found concentrated toward the continental slope of the Americas, but subject to meandering, and to recirculation into, and mixing with, the waters of the interior Atlantic. Individual water parcels thus follow a complex ensemble of trajectories. We have obtained characteristics of that ensemble by fitting the free parameters of a suitable function using extensive observations of the transient tracers CFC-11, CFC-12, CCl{sub 4}, and tritium. A tracer transfer function of ocean-surface concentrations to those in newly formed NADW was derived as a precursory step. In the upper NADW we obtain RMS transfer-time dispersions on the way from the Labrador Sea of 31 years at 6 N rising to 53 years at 20 S, compared to mean transfer times ranging 46 to 79 years ({+-}20 %); furthermore, approximately 10 % to 40 % of the water is old, tracer-free water admixed on the way. Similar results have been obtained for lower NADW (approx. 2500-4000 m). The combination of tritium and CFC observations is particularly suited to constrain the dispersion, since it acts on the concentrations of these tracers in an opposite way. The tracer-adjusted transfer functions allow quantification of the NADW transport of pollutants and other compounds delivered to the NADW formation region. The results can furthermore check mean transfer times and large-scale dispersion of the NADW part of dynamic ocean circulation models.

Temperature profile collected using XBT casts in the North/South Atlantic Ocean from NOAA Ship RESEARCHER from 1977-11-05 to 1979-02-13 (NODC Accession 7900324)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile were collected using BT and XBT casts from NOAA Ship RESEARCHER in North/South Atlantic Ocean from 05 November 1977 to 13 February 1979. Data...

Ocean station data collected using bottle casts from the ALMIRANTE SALDANHA in the South Atlantic Ocean from 1984-02-19 to 1984-03-26 (NODC Accession 9000034)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Ocean station data were collected using seechi disk, meteorological sensors, and bottle casts in the South Atlantic Ocean from 19 February 1984 to 26 March 1984. The...

Particle precipitation events in the South Atlantic Magnetic Anomaly (SAMA) and geomagnetic field

International Nuclear Information System (INIS)

Sanchez Bettucci, L.; Caraballo, R.; Da Silva Barbosa, C.

2003-01-01

Particle precipitation events in the South Atlantic Magnetic Anomaly (SAMA) have been correlated with impulses in the H component of the geomagnetic field. Sudden changes in the H component of the geomagnetic field can produce high intensity peaks in geomagnetic induced currents (GIC) at the Earth’s surface. The effects related to electron precipitation on the upper and middle atmosphere are still not well understood, especially in the area of the SAMA. This study focuses on the Halloween magnetic storm (29-31 October 2003) and two of the largest magnetic storms occurred in 2011. Data from POES and DMSP satellites have been contrasted with the Vassoura s magnetic observatory records and the GIC in a H V transformer neutral at Itumbiara substation (central Brazilian area) to look for possible correlations between d H, the GIC and the precipitation flux of ultrarelativistic electrons. The observations suggest some overlap between episodes of intense precipitation of electrons in the inner radiation belt and impulsive changes in these variables

Carapidae larvae (Acanthomorpha, Paracanthopterygii, Ophidiiformes) from the oceanic region of the southwest Atlantic Ocean off Brazil (12 22°S)

Science.gov (United States)

Namiki, C.; Bonecker, A. C. T.; de Castro, M. S.

2007-02-01

We report the occurrence and distribution of Carapidae larvae in the southwest Atlantic Ocean, between Real River (12°S) and São Tomé Cape (22°S), off Brazil. Carapidae larvae were collected during three oceanographic cruises: spring 1998, winter 1999 and autumn 2000. The hauls were conducted obliquely from a maximum depth of 200 m, during day and night, with bongo nets 330- and 500-μm mesh size. Three species were recorded in this study: Carapus bermudensis, Echiodon dawsoni and Snyderidia canina. Only one C. bermudensis was collected during the winter cruise off the Salvador coast (13°S). Twenty-one larvae of E. dawsoni were collected during the three cruises between 14.5° and 22°S, including some at the banks of Vitória-Trindade Ridge. One S. canina larva occurred, during the spring in the north coast of Rio de Janeiro (22°S).

Central Atlantic Break-up: A competition between CAMP Hotspot and thinning rate.

Science.gov (United States)

Sapin, F.; Maurin, T.

2017-12-01

The break-up of the Central Atlantic is known to have ended at about 190Myrs while the CAMP (Central Atlantic Magmatic Province) was still active. Several seismic lines, acquired recently in the deep offshore Senegal and Mauritanian domain, provide detailed images of continent-ocean transition and the oceanic crust architecture. Their interpretation is the opportunity to describe the progressive interaction between the hot spot activity, the architecture and timing of break up and the oceanic crust production. In the North, seismic data and gravity/magnetic inversions suggest an extremely thinned continental crust with possible mantle exhumation. In the South, the continental crust is thick and the transition to oceanic crust is sharp. In addition, three oceanic crust facies were described along the margin in an extremely slow spreading ridge setting ( 0.8cm/yr during the first 20Myrs): facies (1) with a poorly imaged Moho and a strongly faulted thin oceanic crust or exhumed mantle; facies (2) with an extensively faulted 6km thick oceanic crust; facies (3) with abnormally thick (9km) oceanic crust marked by SDR-type reflections. They are diachronous from North to South and the two first one disappear southwards and (facies 3) being younger toward the North. Only a single very thick oceanic crust (12-14km) remains in front of the Guinea Plateau. We concluded that, in the South, the break-up had been forced through a thick or thickened continental crust due to the remnant activity of the CAMP Hotspot. In the North, the magmatic pulse arrived far after the break-up during the spreading and the thinning of the continental crust could lead to hyper extension. This evolution emphasizes that the architecture, and thus processes leading to the break-up can vary a lot considering the influence of thermal vertical forces (mantle dynamics/hotspot/magmatism) and mechanical horizontal forces (plate movement/faulting/spreading), both of them being necessary for a rift to succeed.

The Partitioning of Carbon Biomass among the Pico- and Nano-plankton Community in the South Brazilian Bight during a Strong Summer Intrusion of South Atlantic Central Water

Directory of Open Access Journals (Sweden)

Natascha M. Bergo

2017-07-01

Full Text Available To investigate how pico- and nano-plankton respond to oceanographic conditions in the Southwestern Atlantic Ocean, we assessed the influence of a summer intrusion of the South Atlantic Central Water (SACW on the spatial and vertical dynamics of planktonic abundance and carbon biomass across environmental gradients. Seawater samples were collected from six depths within the euphotic zone at nine oceanographic stations in a transect on the Brazilian continental shelf in January 2013. The abundance of pico- and nano-plankton populations was determined by flow cytometry, and carbon biomass was calculated based on conversion factors from the literature. The autotrophic Synechococcus spp., picoeukaryotes, and nanoeukaryotes were more abundant in the surface layers of the innermost stations influenced by Coastal Water (maximum of 1.19 × 105, 1.5 × 104, and 8.61 × 103 cell·mL−1, respectively, whereas Prochlorococcus spp. dominated (max. of 6.57 × 104 cell·mL−1 at the outermost stations influenced by Tropical Water and in the uplifting layers of the SACW around a depth of 100 m. Numerically, heterotrophic bacterial populations were predominant, with maximum concentrations (2.11 × 106 cell·mL−1 recorded in the surface layers of the inner and mid shelves in Coastal Water and the upper limits of the SACW. Nutrient-rich (high silicate and phosphate and relatively less saline waters enhanced the picoeukaryotic biomass, while Synechococcus and heterotrophic bacteria were linked to higher temperatures, lower salinities, and higher inputs of ammonia and dissolved organic carbon. The relative importance of each group to carbon biomass partitioning under upwelling conditions is led by heterotrophic bacteria, followed by picoeukaryotes, Synechococcus and Prochlorococcus, and when the SACW is not as influential, the relative contribution of each phytoplanktonic group is more evenly distributed. In addition to habitat preferences, the physical structure

Millennial-scale precipitation variability over Easter Island (South Pacific) during MIS 3: inter-hemispheric teleconnections with North Atlantic abrupt cold events

Science.gov (United States)

Margalef, O.; Cacho, I.; Pla-Rabes, S.; Cañellas-Boltà, N.; Pueyo, J. J.; Sáez, A.; Pena, L. D.; Valero-Garcés, B. L.; Rull, V.; Giralt, S.

2015-04-01

Marine Isotope Stage 3 (MIS 3, 59.4-27.8 kyr BP) is characterized by the occurrence of rapid millennial-scale climate oscillations known as Dansgaard-Oeschger cycles (DO) and by abrupt cooling events in the North Atlantic known as Heinrich events. Although both the timing and dynamics of these events have been broadly explored in North Atlantic records, the response of the tropical and subtropical latitudes to these rapid climatic excursions, particularly in the Southern Hemisphere, still remains unclear. The Rano Aroi peat record (Easter Island, 27° S) provides a unique opportunity to understand atmospheric and oceanic changes in the South Pacific during these DO cycles because of its singular location, which is influenced by the South Pacific Anticyclone (SPA), the Southern Westerlies (SW), and the Intertropical Convergence Zone (ITCZ) linked to the South Pacific Convergence Zone (SPCZ). The Rano Aroi sequence records 6 major events of enhanced precipitation between 38 and 65 kyr BP. These events are compared with other hydrological records from the tropical and subtropical band supporting a coherent regional picture, with the dominance of humid conditions in Southern Hemisphere tropical band during Heinrich Stadials (HS) 5, 5a and 6 and other Stadials while dry conditions prevailed in the Northern tropics. This antiphased hydrological pattern between hemispheres has been attributed to ITCZ migration, which in turn might be associated with an eastward expansion of the SPCZ storm track, leading to an increased intensity of cyclogenic storms reaching Easter Island. Low Pacific Sea Surface Temperature (SST) gradients across the Equator were coincident with the here-defined Rano Aroi humid events and consistent with a reorganization of Southern Pacific atmospheric and oceanic circulation also at higher latitudes during Heinrich and Dansgaard-Oeschger stadials.

Freshening of Antarctic Intermediate Water in the South Atlantic Ocean in 2005-2014

Science.gov (United States)

Yao, Wenjun; Shi, Jiuxin; Zhao, Xiaolong

2017-07-01

Basin-scale freshening of Antarctic Intermediate Water (AAIW) is reported to have occurred in the South Atlantic Ocean during the period from 2005 to 2014, as shown by the gridded monthly means of the Array for Real-time Geostrophic Oceanography (Argo) data. This phenomenon was also revealed by two repeated transects along a section at 30° S, performed during the World Ocean Circulation Experiment Hydrographic Program. Freshening of the AAIW was compensated for by a salinity increase of thermocline water, indicating a hydrological cycle intensification. This was supported by the precipitation-minus-evaporation change in the Southern Hemisphere from 2000 to 2014. Freshwater input from atmosphere to ocean surface increased in the subpolar high-precipitation region and vice versa in the subtropical high-evaporation region. Against the background of hydrological cycle changes, a decrease in the transport of Agulhas Leakage (AL), which was revealed by the simulated velocity field, was proposed to be a contributor to the associated freshening of AAIW. Further calculation showed that such a decrease could account for approximately 53 % of the observed freshening (mean salinity reduction of about 0.012 over the AAIW layer). The estimated variability of AL was inferred from a weakening of wind stress over the South Indian Ocean since the beginning of the 2000s, which would facilitate freshwater input from the source region. The mechanical analysis of wind data here was qualitative, but it is contended that this study would be helpful to validate and test predictably coupled sea-air model simulations.

Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KNORR in the Caribbean Sea, North Atlantic Ocean and South Atlantic Ocean from 1982-12-01 to 1983-02-18 (NODC Accession 0116706)

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National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116706 includes chemical, discrete sample, physical and profile data collected from KNORR in the Caribbean Sea, North Atlantic Ocean and South...

A deforestation-induced tipping point for the South American monsoon system

Science.gov (United States)

Boers, Niklas; Marwan, Norbert; Barbosa, Henrique M. J.; Kurths, Jürgen

2017-01-01

The Amazon rainforest has been proposed as a tipping element of the earth system, with the possibility of a dieback of the entire ecosystem due to deforestation only of parts of the rainforest. Possible physical mechanisms behind such a transition are still subject to ongoing debates. Here, we use a specifically designed model to analyse the nonlinear couplings between the Amazon rainforest and the atmospheric moisture transport from the Atlantic to the South American continent. These couplings are associated with a westward cascade of precipitation and evapotranspiration across the Amazon. We investigate impacts of deforestation on the South American monsoonal circulation with particular focus on a previously neglected positive feedback related to condensational latent heating over the rainforest, which strongly enhances atmospheric moisture inflow from the Atlantic. Our results indicate the existence of a tipping point. In our model setup, crossing the tipping point causes precipitation reductions of up to 40% in non-deforested parts of the western Amazon and regions further downstream. The responsible mechanism is the breakdown of the aforementioned feedback, which occurs when deforestation reduces transpiration to a point where the available atmospheric moisture does not suffice anymore to release the latent heat needed to maintain the feedback.

Temperature profile data collected using CTD casts from the JAMES CLARK ROSS in the South Atlantic Ocean from 15 November 1996 to 20 November 1996 (NODC Accession 0000874)

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National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using CTD casts in the South Atlantic Ocean from JAMES CLARK ROSS. Data were collected from 15 November 1996 to 20 November...

Temperature profile data collected using CTD casts from the JAMES CLARK ROSS in the South Atlantic Ocean from 15 November 1994 to 21 November 1994 (NODC Accession 0000873)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using CTD casts in the South Atlantic Ocean from JAMES CLARK ROSS. Data were collected from 15 November 1994 to 21 November...

Turbidity, SOLAR RADIATION - ATMOSPHERIC and other data from UNKNOWN PLATFORMS OF AUSTRALIA in the South Atlantic Ocean from 1972-02-01 to 1977-11-15 (NCEI Accession 9000036)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains ocean station and current data collected by Water & Sewerage Board in South Atlantic Ocean and submitted by Mr.K.H.J. Robin. The physical...

Synthetic aperture radar for maritime domain awareness: Ship detection in a South African context

CSIR Research Space (South Africa)

Schwegmann, CP

2014-10-01

Full Text Available , people, cargo, and vessels and other conveyances,” (DoD 2005). Each country is required to monitor its own Exclusive Economic Zone (EEZ) for actions that may negatively affect the country’s environment, commerce or security... covers a larger area than its land and it is positioned at a maritime choke point in that it is surrounded by three oceans – the Indian, South Atlantic and Southern Ocean. In this way the improvement of South Africa’s own MDA is important to ensure...

A record of the last 460 thousand years of upper ocean stratification from the central Walvis Ridge, South Atlantic

NARCIS (Netherlands)

Scussolini, P.; Peeters, F.J.C.

2013-01-01

The upper branch of the Atlantic Meridional Overturning Circulation predominantly enters the Atlantic Ocean through the southeast, where the subtropical gyre is exposed to the influence of the Agulhas leakage (AL). To understand how the transfer of Indian Ocean waters via the AL affected the upper

Phytoplankton biomass dynamics and environmental variables around the Rocas Atoll Biological Reserve, South Atlantic

Directory of Open Access Journals (Sweden)

Marina Cavalcanti Jales

2015-12-01

Full Text Available Abstract The Rocas Atoll Biological Reserve is located in the Atlantic Ocean, at 3º 51' S and 33º 49' W. It lies 143 nautical miles from the City of Natal, Rio Grande do Norte (Brazil. The purpose of this study was to analyze the hydrology, water masses, currents and chlorophyll a content to determine the dynamics of phytoplankton biomass around the Rocas Atoll. Samples were collected in July 2010 in the area around the Atoll, using the Research Vessel Cruzeiro do Sul of the Brazilian Navy. Two transects were established according to the surface currents, one of which at the southeast of the Atoll (SE and the other at norwest (NW. Three collection points were determined on each of these transects. Samples were collected at different depths (surface and DCM - Deep Chlorophyll Maximum and different times (day and night. According to PCA (Principal Component Analysis, the nutrients analyzed, DIN (dissolved inorganic nitrogen, DIP (dissolved inorganic phosphorus and silicate, were inversely correlated with temperature and dissolved oxygen. Most environmental variables showed a significant increase due to the turbulence on the Northwest transect. There was an increase in the concentration of chlorophyll a and nutrients when the temperature and oxygen in the mixed layer was reduced due to the influence of the SACW (South Atlantic Central Water. Despite the increase observed in some variables such as nutrient salts and chlorophyll a, the temperature in the mixed layer attained a mean value of 23.23 ºC due to the predominance of Tropical Water. The increase of the phytoplankton biomass on the NW transect was, therefore, caused by the "island effect" and not by upwelling.

Determination of deep water circulation in the East Atlantic Ocean by means of a box-model based evaluation of C-14 measurements and other tracer data

International Nuclear Information System (INIS)

Schlitzer, R.

1984-01-01

Radiocarbon (C-14) measurements proved to be an efficient means of determining the average, large-area deep water circulation in the Atlantic Ocean. The thesis under review explains and discusses measurements carried out in the equatorial West Atlantic and North Atlantic Ocean. The samples have been taken during mission 56 of the RS 'meteor' in spring 1981. The gas has been obtained by vacuum extraction and the measurements have been performed in proportional counter tubes, the error to be accounted for amounting to 2per mille. These measured data, together with measurements of the potential temperatures, the silicate and CO 2 concentrations, and measured data from the South-East Atlantic Ocean, have been used to calculate on the basis of a box model of the Atlantic Ocean the deep water flow from the West to the East Atlantic Ocean, the deep water circulation between the various East Atlantic basins, and the turbulent diffusion coefficients required to parameterize the deep water mixing processes. (orig./HP) [de

Study of X-rays at the atmosphere of the South Atlantic Magnetic Anomaly

International Nuclear Information System (INIS)

Pinto Junior, O.

1985-06-01

A study of X-rays at the atmosphere of the South Atlantic Magnetic Anomaly is presented in this work, in which an analysis of all existing balloon measurements carried out at this region has been done. It is concluded that the X-ray flux due to electron precipitation depends strongly on geomagnetic activity, reaching at Sao Jose dos Campos a maximum doward flux of 10 -2 photons/cm 2 .sec.KeV for 4g/cm 2 and for the energy range of 30-150KeV. The related flux of precipitating electrons was computed by Monte Carlo method with values of about 500 electrons/cm 2 .sec and energy espectra of the type e -T/200 . This electron flux is shown to represent the main ionization flux for the atmosphere at about 60 Km height. Furthermore, the atmospheric and diffuse components were determined at balloon altitudes (approximately 5g/cm 2 ) of Sao Jose dos campos (λ m = 11 0 S) to be of the same order. (author) [pt

The Relationships between Tropical Pacific and Atlantic SST and Northeast Brazil Monthly Precipitation.

Science.gov (United States)

Bertacchi Uvo, Cintia; Repelli, Carlos A.; Zebiak, Stephen E.; Kushnir, Yochanan

1998-04-01

The monthly patterns of northeast Brazil (NEB) precipitation are analyzed in relation to sea surface temperature (SST) in the tropical Pacific and Atlantic Oceans, using singular value decomposition. It is found that the relationships between precipitation and SST in both basins vary considerably throughout the rainy season (February-May). In January, equatorial Pacific SST is weakly correlated with precipitation in small areas of southern NEB, but Atlantic SST shows no significant correlation with regional precipitation. In February, Pacific SST is not well related to precipitation, but south equatorial Atlantic SST is positively correlated with precipitation over the northern Nordeste, the latter most likely reflecting an anomalously early (or late) southward migration of the ITCZ precipitation zone. During March, equatorial Pacific SST is negatively correlated with Nordeste precipitation, but no consistent relationship between precipitation and Atlantic SST is found. Atlantic SST-precipitation correlations for April and May are the strongest found among all months or either ocean. Precipitation in the Nordeste is positively correlated with SST in the south tropical Atlantic and negatively correlated with SST in the north tropical Atlantic. These relationships are strong enough to determine the structure of the seasonal mean SST-precipitation correlations, even though the corresponding patterns for the earlier months of the season are quite different. Pacific SST-precipitation correlations for April and May are similar to those for March. Extreme wet (dry) years for the Nordeste occur when both Pacific and Atlantic SST patterns for April and May occur simultaneously. A separate analysis reinforces previous findings in showing that SST in the tropical Pacific and the northern tropical Atlantic are positively correlated and that tropical Pacific-south Atlantic correlations are negligible.Time-lagged analyses show the potential for forecasting either seasonal mean

Post-Gondwana Africa and the vertebrate history of the Angolan Atlantic Coast

NARCIS (Netherlands)

Jacobs, Louis L.; Polcyn, Michael J.; Mateus, Octávio; Schulp, Anne S.; Gonçalves, António Olímpio; Morais, Maria Luísa

2016-01-01

The separation of Africa from South America and the growth of the South Atlantic are recorded in rocks exposed along the coast of Angola. Tectonic processes that led to the formation of Africa as a continent also controlled sedimentary basins that preserve fossils. The vertebrate fossil record in

A new species of Nidalia Gray, 1835 from Mid-Atlantic seamounts (Octocorallia, Alcyonacea, Nidaliidae)

Science.gov (United States)

López-González, Pablo J.; Gili, Josep-Maria

2008-12-01

A new soft coral species of the genus Nidalia, from seamounts to the south of the Azores Archipelago is described. The main features of Nidalia aurantia n. sp. are as following: colony torch-like, a capitulum light orange in colour, not laterally flattened, dome-shaped and not distinctly projecting beyond the stalk, an introvert with sparse sclerites transversally placed, and an anthocodial crown with 13 17 sclerite rows. The new species is compared with its closest congeners. This is the first time that a species of Nidalia has been located in the Mid-Atlantic Ocean.

75 FR 61094 - Drawbridge Operation Regulation; Atlantic Intracoastal Waterway, Beaufort, SC

Science.gov (United States)

2010-10-04

.... Highway 21, Sea Island Parkway Bridge at mile marker 536 over the Beaufort River (Atlantic Intracoastal... Bridge, which is across the Atlantic Intracoastal Waterway at mile 539.0 in Port Royal, South Carolina... Bridge, across the Beaufort River, Mile 536.0 at Beaufort. The draw shall operate as follows: (1) On...

Evolutionary diversity among Atlantic coast mangroves

Science.gov (United States)

Dodd, Richard S.; Rafii, Zara A.; Fromard, François; Blasco, François

1998-06-01

Current knowledge of intraspecific variation of mangrove species is limited in terms of rangewide distributions and is mostly restricted to morphological analyses, which have indicated a high degree of homogeneity. However, our analyses of the aliphatic hydrocarbon and triterpenoid fraction of foliar waxes (by gas chromatography and mass spectroscopy) of mangrove species ( Rhizophora mangle, Avicennia germinans and Laguncularia racemosa) from Gabon in West Africa and French Guiana in South America show significant genetic differentiation between eastern and western Atlantic provenances. The greater diversity in lipid composition, and the tendency for longer carbon chain lengths in all taxa from Africa, may suggest that American mangroves exhibit derived characteristics. A consequence of this hypothesis would be that Atlantic mangroves are unlikely to have dispersed from the Tethys via the Pacific, as has been proposed by some authors. More widespread sampling within the Atlantic and east Pacific region is needed to support and confirm these results.

First record of a digenean from invasive lionfish, Pterois cf. volitans, (Scorpaeniformes: Scorpaenidae) in the northwestern Atlantic Ocean.

Science.gov (United States)

Bullard, S A; Barse, A M; Curran, S S; Morris, J A

2011-10-01

Adults of Lecithochirium floridense (Digenea: Hemiuridae) parasitized the stomach in each of 22 necropsied lionfish, Pterois cf. volitans (Scorpaeniformes: Scorpaenidae) (prevalence  =  100%, mean intensity  =  11), captured in the northwestern Atlantic Ocean off Beaufort, North Carolina (34°14.83'N, 76°35.25'W). This is the first report of a digenean from the invasive lionfish and that of L. floridense from a species of Pterois. The leech specimen previously identified as Myzobdella lugubris from P. volitans in the northwestern Atlantic Ocean is re-identified as Trachelobdella lubrica based on a study of the original voucher specimen.

Continental breakup of the Central Atlantic and the initiation of the southern Central Atlantic Magmatic Province: revisiting the role of a mantle plume

Science.gov (United States)

Rohrman, M.

2017-12-01

Central Atlantic breakup is strongly associated with magmatism of the Central Atlantic Magmatic Province (CAMP), although the exact mechanism, as well as the temporal and spatial relations, have so far been poorly constrained. Here, I propose a mantle plume origin for the 200 Ma southern Central Atlantic Province (CAMP), based on an original plume conduit location off southeastern Florida, linking Early Jurassic rift systems: One rift arm is defined by the Takutu rift in present-day Guyana and Brazil, extending all the way past the Demerara Rise. This rift is linking up with a second arm from the Bahamas basin to the Blake Plateau basin. Finally, there is the third, failed rift between the Demerara Rise and the Guinea Plateau. This rift system post-dates earlier Triassic rift systems along the US eastcoast and in the subsurface of Arkansas, Texas, the Gulf of Mexico and northern South America. Chronostratigraphic analysis of outcrop, wells and seismic data near the proposed conduit, suggest initial Rhaetian uplift, followed by dike/sill intrusions feeding flood basalts and the initiation of igneous centers at the triple point. The latter resulted in various subsequent uplift and subsidence events, as a result of volcanic construction and erosion. The load of the volcanic edifice generated a point of weakness, allowing favorable plate stresses to generate rift systems, propagating away from the rift junction and eventually break up Pangea. The breakup is marked by the magmatic breakup (un)conformity on seismic data, separating hotspot/plume sourced Seaward Dipping reflectors (SDRs) within the continental rift system, from early ocean spreading sourced SDRs. As ocean spreading continued, the volcanic construction evolved into a hotspot track, now recognized as the Bahamas island trail. Time progression of this hotspot track resembles the present-day Iceland hotspot track, as suggested by plate reconstructions (Figure 1). Based on melting depth estimates from Sm

Paleoliquefaction investigations along the Atlantic seaboard implications for long-term seismic hazard

International Nuclear Information System (INIS)

Amick, D.; Gelinas, R.; Marauth, G.; Cannon, R.

1989-01-01

Within the past five years, investigations by the USGS, the University of South Carolina, and Ebasco Services Incorporated have documented the existence of liquefaction features caused by the 1886 Charleston earthquake and at least three large prehistoric earthquakes of magnitudes similar to the 1886 event. For the past three years the US Nuclear Regulatory Commission has supported a search for seismically induced paleoliquefaction features along the Atlantic Seaboard. These investigations are designed to determine in a systematic fashion whether or not seismically induced prehistoric liquefaction features, such as those associated with the 1886 Charleston, South Carolina earthquake, are present elsewhere in young sediments of the Atlantic Coastal Plain. The discovery of similar liquefaction features in other areas along the Atlantic Seaboard could indicate that large potentially damaging earthquakes have not been restricted to the Charleston area in the recent geologic past. Conversely, if at the conclusion of this systematic search no evidence of similar paleoliquefaction features are discovered outside the Coastal Plain of South Carolina, then the uniqueness of this area in the context of eastern US seismicity would tend to be confirmed. Initial phases of this study focused on developing a comprehensive control data set based on the evaluation of liquefaction sites and features located in the Charleston, S.C. area. A total of over 100 probable liquefaction sites were identified on the basis of the detailed review of historical accounts of the 1886 earthquake, and results of more recent studies conducted by investigators from the USGS, the University of South Carolina, and the authors. Based on these results, Ebasco is presently conducting a systematic search for similar seismically induced paleoliquefaction features in other parts of the Atlantic Coastal Plain

A Reassessment of the Integrated Impact of Tropical Cyclones on Surface Chlorophyll in the Western Subtropical North Atlantic

Energy Technology Data Exchange (ETDEWEB)

Foltz, Gregory R.; Balaguru, Karthik; Leung, Lai-Yung R.

2015-02-28

The impact of tropical cyclones on surface chlorophyll concentration is assessed in the western subtropical North Atlantic Ocean during 1998–2011. Previous studies in this area focused on individual cyclones and gave mixed results regarding the importance of tropical cyclone-induced mixing for changes in surface chlorophyll. Using a more integrated and comprehensive approach that includes quantification of cyclone-induced changes in mixed layer depth, here it is shown that accumulated cyclone energy explains 22% of the interannual variability in seasonally-averaged (June–November) chlorophyll concentration in the western subtropical North Atlantic, after removing the influence of the North Atlantic Oscillation (NAO). The variance explained by tropical cyclones is thus about 70% of that explained by the NAO, which has well-known impacts in this region. It is therefore likely that tropical cyclones contribute significantly to interannual variations of primary productivity in the western subtropical North Atlantic during the hurricane season.

The distribution of 226Ra in the Atlantic Ocean

International Nuclear Information System (INIS)

Broecker, W.S.; Goddard, J.; Sarmiento, J.L.

1976-01-01

Based on results obtained during the GEOSECS program the primary features of the distribution of 226 Ra in the Atlantic Ocean can be defined. Outside the Antarctic no significant variation has been found in the 226 Ra content of surface waters. Eighty samples yield an average of 7.4 dpm/100 kg (normalized to a salinity of 35.00%). Deep waters in the central Atlantic have 226 Ra contents several dpm/100 kg higher than expected from the mixing of Antarctic Bottom Water (21.3 dpm/100 kg) and basal North Atlantic Deep Water (10.3 dpm/100 kg). These excesses correlate well with deficiencies in O 2 and excesses in SiO 2 . The intermediate water 226 Ra maximum in the South Atlantic is associated with the inflow of low-oxygen Circumpolar Intermediate Water beneath the Antarctic Intermediate Water. (Auth.)

Biological, chemical, and temperature profile data collected using bottle casts from the ALMIRANTE SALDANHA in South Atlantic Ocean from 07 February 1957 to 04 December 1957 (NODC Accession 7601281)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Biological and chemical data were collected using net and bottle casts from the ALMIRANTE SALDANHA off the coastal waters of Brazil in South Atlantic Ocean from 07...

Lead isotopic compositions of South Sandwich Island volcanic rocks and their bearing on magmagenesis in intra-oceanic island arcs

International Nuclear Information System (INIS)

Barreiro, B.

1983-01-01

Pb isotope ratios have been measured in 12 volcanic rocks from the South Sandwich Islands. The results are reported. In 207 Pb/ 204 Pb- 206 Pb/ 204 Pb and 208 Pb/ 204 Pb- 206 Pb/ 204 Pb correlation diagrams, the South Sandwich data plot distinctly above the fields for ocean ridge basalts, and yield trends showing apparent mixing with a sedimentary end member similar to South Atlantic pelagic sediments as reported by Chow and Patterson (1962) and this study. Armstrong and Cooper (1971) have likewise shown that volcanics from the Lesser Antilles show mixing trends with North Atlantic sediments in Pb isotope correlation diagrams. The North Atlantic sediments have distinctly higher 206 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios compared to the South Atlantic sediments. The parallel relationships between sediments and volcanic island arc rocks of the North and South Atlantic provide strong evidence for a component of Pb from subducted sediments in the lavas of the west Atlantic basin. In contrast to these data, lavas from the Mariana Arc in the western Pacific show little or no component of Pb from pelagic sediments. The reason for the different behaviors in the two settings is speculative. (author)

Single nucleotide polymorphisms in native South American Atlantic coast populations of smooth shelled mussels: hybridization with invasive European Mytilus galloprovincialis.

Science.gov (United States)

Zbawicka, Małgorzata; Trucco, María I; Wenne, Roman

2018-02-22

Throughout the world, harvesting of mussels Mytilus spp. is based on the exploitation of natural populations and aquaculture. Aquaculture activities include transfers of spat and live adult mussels between various geographic locations, which may result in large-scale changes in the world distribution of Mytilus taxa. Mytilus taxa are morphologically similar and difficult to distinguish. In spite of much research on taxonomy, evolution and geographic distribution, the native Mytilus taxa of the Southern Hemisphere are poorly understood. Recently, single nucleotide polymorphisms (SNPs) have been used to clarify the taxonomic status of populations of smooth shelled mussels from the Pacific coast of South America. In this paper, we used a set of SNPs to characterize, for the first time, populations of smooth shelled mussels Mytilus from the Atlantic coast of South America. Mytilus spp. samples were collected from eastern South America. Six reference samples from the Northern Hemisphere were used: Mytilus edulis from USA and Northern Ireland, Mytilus trossulus from Canada, and Mytilus galloprovincialis from Spain and Italy. Two other reference samples from the Southern Hemisphere were included: M. galloprovincialis from New Zealand and Mytilus chilensis from Chile. Fifty-five SNPs were successfully genotyped, of which 51 were polymorphic. Population genetic analyses using the STRUCTURE program revealed the clustering of eight populations from Argentina (Mytilus platensis) and the clustering of the sample from Ushuaia with M. chilensis from Chile. All individuals in the Puerto Madryn (Argentina) sample were identified as M. platensis × M. galloprovincialis F2 (88.89%) hybrids, except one that was classified as Mediterranean M. galloprovincialis. No F1 hybrids were observed. We demonstrate that M. platensis (or Mytilus edulis platensis) and M. chilensis are distinct native taxa in South America, which indicates that the evolutionary histories of Mytilus taxa along the

Similar mid-depth Atlantic water mass provenance during the Last Glacial Maximum and Heinrich Stadial 1

Science.gov (United States)

Howe, Jacob N. W.; Huang, Kuo-Fang; Oppo, Delia W.; Chiessi, Cristiano M.; Mulitza, Stefan; Blusztajn, Jurek; Piotrowski, Alexander M.

2018-05-01

The delivery of freshwater to the North Atlantic during Heinrich Stadial 1 (HS1) is thought to have fundamentally altered the operation of Atlantic meridional overturning circulation (AMOC). Although benthic foraminiferal carbon isotope records from the mid-depth Atlantic show a pronounced excursion to lower values during HS1, whether these shifts correspond to changes in water mass proportions, advection, or shifts in the carbon cycle remains unclear. Here we present new deglacial records of authigenic neodymium isotopes - a water mass tracer that is independent of the carbon cycle - from two cores in the mid-depth South Atlantic. We find no change in neodymium isotopic composition, and thus water mass proportions, between the Last Glacial Maximum (LGM) and HS1, despite large decreases in carbon isotope values at the onset of HS1 in the same cores. We suggest that the excursions of carbon isotopes to lower values were likely caused by the accumulation of respired organic matter due to slow overturning circulation, rather than to increased southern-sourced water, as typically assumed. The finding that there was little change in water mass provenance in the mid-depth South Atlantic between the LGM and HS1, despite decreased overturning, suggests that the rate of production of mid-depth southern-sourced water mass decreased in concert with decreased production of northern-sourced intermediate water at the onset of HS1. Consequently, we propose that even drastic changes in the strength of AMOC need not cause a significant change in South Atlantic mid-depth water mass proportions.

Aerosol-Radiation-Cloud Interactions in the South-East Atlantic: Results from the ORACLES-2016 Deployment and a First Look at ORACLES-2017 and Beyond

Science.gov (United States)

Redemann, Jens; Wood, R.; Zuidema, P.

2018-01-01

Seasonal biomass burning (BB) in Southern Africa during the Southern hemisphere spring produces almost a third of the Earth's BB aerosol particles. These particles are lofted into the mid-troposphere and transported westward over the South-East (SE) Atlantic, where they interact with one of the three semi-permanent subtropical stratocumulus (Sc) cloud decks in the world. These interactions include adjustments to aerosol-induced solar heating and microphysical effects. The representation of these interactions in climate models remains highly uncertain, because of the scarcity of observational constraints on both, the aerosol and cloud properties, and the governing physical processes. The first deployment of the NASA P-3 and ER-2 aircraft in the ORACLES (ObseRvations of Aerosols Above Clouds and Their IntEractionS) project in August/September of 2016 has started to fill this observational gap by providing an unprecedented look at the SE Atlantic cloud-aerosol system. We provide an overview of the first deployment, highlighting aerosol absorptive and cloud-nucleating properties, their vertical distribution relative to clouds, the locations and degree of aerosol mixing into clouds, cloud changes in response to such mixing, and cloud top stability relationships to the aerosol. We also expect to describe preliminary results of the second ORACLES deployment from Sao Tome and Pri­ncipe in August 2017. We will make an initial assessment of the differences and similarities of the BB plume and cloud properties as observed from a deployment site near the plume's northern edge. We will conclude with an outlook for the third ORACLES deployment in October 2018.

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2011-02-19 to 2011-04-23 (NODC Accession 0109933)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0109933 includes discrete sample and profile data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern...

Heavy Rainfall Episodes in the Eastern Northeast Brazil Linked to Large-Scale Ocean-Atmosphere Conditions in the Tropical Atlantic

Directory of Open Access Journals (Sweden)

Yves K. Kouadio

2012-01-01

Full Text Available Relationships between simultaneous occurrences of distinctive atmospheric easterly wave (EW signatures that cross the south-equatorial Atlantic, intense mesoscale convective systems (lifespan > 2 hour that propagate westward over the western south-equatorial Atlantic, and subsequent strong rainfall episodes (anomaly > 10 mm·day−1 that occur in eastern Northeast Brazil (ENEB are investigated. Using a simple diagnostic analysis, twelve cases with EW lifespan ranging between 3 and 8 days and a mean velocity of 8 m·s−1 were selected and documented during each rainy season of 2004, 2005, and 2006. These cases, which represent 50% of the total number of strong rainfall episodes and 60% of the rainfall amount over the ENEB, were concomitant with an acceleration of the trade winds over the south-equatorial Atlantic, an excess of moisture transported westward from Africa to America, and a strengthening of the convective activity in the oceanic region close to Brazil. Most of these episodes occurred during positive sea surface temperature anomaly patterns over the entire south-equatorial Atlantic and low-frequency warm conditions within the oceanic mixing layer. A real-time monitoring and the simulation of this ocean-atmosphere relationship could help in forecasting such dramatic rainfall events.

Dissolved inorganic carbon, alkalinity, salinity and SEA SURFACE TEMPERATURE collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the ANTEA in the Gulf of Guinea, North Atlantic Ocean and South Atlantic Ocean from 2005-09-04 to 2005-09-26 (NODC Accession 0108087)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108087 includes chemical, discrete sample, physical and profile data collected from ANTEA in the Gulf of Guinea, North Atlantic Ocean and South...

Dissolved inorganic carbon, alkalinity, salinity and SEA SURFACE TEMPERATURE collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the ANTEA in the Gulf of Guinea, North Atlantic Ocean and South Atlantic Ocean from 2007-06-06 to 2007-07-03 (NODC Accession 0108090)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108090 includes chemical, discrete sample, physical and profile data collected from ANTEA in the Gulf of Guinea, North Atlantic Ocean and South...

Dissolved inorganic carbon, alkalinity, salinity and SEA SURFACE TEMPERATURE collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the ANTEA in the Gulf of Guinea, North Atlantic Ocean and South Atlantic Ocean from 2006-11-01 to 2006-11-30 (NODC Accession 0108089)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108089 includes chemical, discrete sample, physical and profile data collected from ANTEA in the Gulf of Guinea, North Atlantic Ocean and South...

Dissolved inorganic carbon, alkalinity, salinity and SEA SURFACE TEMPERATURE collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the ANTEA in the Gulf of Guinea, North Atlantic Ocean and South Atlantic Ocean from 2007-09-03 to 2007-09-24 (NODC Accession 0108091)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108091 includes chemical, discrete sample, physical and profile data collected from ANTEA in the Gulf of Guinea, North Atlantic Ocean and South...

Temperature profile and nutrients data collected using bottle and CTD casts from the HESPERIDES in the South Atlantic Ocean from 11 February 1995 to 20 February 1995 (NODC Accession 0000870)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and nutrients data were collected using bottle and CTD casts in the South Atlantic Ocean from HESPERIDES. Data were collected from 11 February...

Temperature profile and nutrients data collected using bottle and CTD casts from the HESPERIDES in the South Atlantic Ocean from 15 February 1996 to 21 February 1996 (NODC Accession 0000871)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and nutrients data were collected using bottle and CTD casts in the South Atlantic Ocean from HESPERIDES. Data were collected from 15 February...

Will the Traditional Health Practitioners Act (Act No 22, 2007 challenge the holy grails of South African medical doctors?

Directory of Open Access Journals (Sweden)

Gabriel Louw

2017-02-01

Full Text Available Background The South African healthcare establishment is primarily managed and overseen by medical doctors. This powerbase was established over many years, especially after the early 1930s. World War II gave doctors the final approval to take this supervisory and sole decision-making role regarding healthcare training, practice models and other health workers in South Africa. This phenomenon led initially to doctors having a certain jurisdiction to set the pace and to make the rules. This jurisdiction became more comprehensive and extent with time in South Africa to include a collection of unique medical traditions, customs, privileges, habits, healthcare rights and empowerment as well as exclusive medical training and practice models to become known as the holy grails of the South African medical doctors. The power of these holy grails has become untouchable to anyone outside the medical domain. Since the 1980s, some powers vested in these holy grails have been lost to the allied health professions and to other insiders of the HPCSA brotherhood itself. The recognition of traditional healers by means of the Traditional Health Practitioners Act (Act No 22, 2007 seems to challenge these holy grails of medical doctors. This may also create internal conflict in the South African medical brotherhood that can cost medical doctors more ground. Aims The study aimed to determine if the Traditional Health Practitioners Act No 22 (2007 challenges the holy grails of South African medical doctors, subsequently affecting the long-established management and guardian system of the medical field within South Africa or the practice rights of medical doctors. Methods This is an exploratory and descriptive study that makes use of an historical approach by means of investigation and a literature review. The emphasis is on using current documentation like articles, books and newspapers as primary sources to reflect on the possible effect of the Traditional Health

Aerosol-Radiation-Cloud Interactions in the South-East Atlantic: Future Suborbital Activities to Address Knowledge Gaps in Satellite and Model Assessments

Science.gov (United States)

Redemann, Jens; Wood, R.; Zuidema, P.; Haywood, J.; Piketh, S.; Formenti, P.; L'Ecuyer, T.; Kacenelenbogen, M.; Segal-Rosenheimer, M.; Shinozuka, Y.;

Aerosol-radiation-cloud interactions in the South-East Atlantic: first results from the ORACLES-2016 deployment and plans for future activities

Science.gov (United States)

Redemann, J.; Wood, R.; Zuidema, P.; Haywood, J. M.; Piketh, S.; Formenti, P.; Abel, S.

2016-12-01

Southern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles. Particles lofted into the mid-troposphere are transported westward over the South-East (SE) Atlantic, home to one of the three permanent subtropical stratocumulus (Sc) cloud decks in the world. The SE Atlantic stratocumulus deck interacts with the dense layers of BB aerosols that initially overlay the cloud deck, but later subside and may mix into the clouds. These interactions include adjustments to aerosol-induced solar heating and microphysical effects, and their global representation in climate models remains one of the largest uncertainties in estimates of future climate. Hence, new observations over the SE Atlantic have significant implications for regional and global climate change predictions. Our understanding of aerosol-cloud interactions in the SE Atlantic is severely limited. Most notably, we are missing knowledge on the absorptive and cloud nucleating properties of aerosols, including their vertical distribution relative to clouds, on the locations and degree of aerosol mixing into clouds, on the processes that govern cloud property adjustments, and on the importance of aerosol effects on clouds relative to co-varying synoptic scale meteorology. We describe first results from various synergistic, international research activities aimed at studying aerosol-cloud interactions in the region: NASA's airborne ORACLES (ObseRvations of Aerosols Above Clouds and Their IntEractionS) deployment in August/September of 2016, the DoE's LASIC (Layered Atlantic Smoke Interactions with Clouds) deployment of the ARM Mobile Facility to Ascension Island (June 2016 - October 2017), the ground-based components of CNRS' AEROCLO-sA (Aerosols Clouds and Fog over the west coast of southern Africa), and ongoing regional-scale integrative, process-oriented science efforts as part of SEALS-sA (Sea Earth Atmosphere Linkages Study in southern Africa). We expect to describe experimental

Freshening of Antarctic Intermediate Water in the South Atlantic Ocean in 2005–2014

Directory of Open Access Journals (Sweden)

W. Yao

2017-07-01

Full Text Available Basin-scale freshening of Antarctic Intermediate Water (AAIW is reported to have occurred in the South Atlantic Ocean during the period from 2005 to 2014, as shown by the gridded monthly means of the Array for Real-time Geostrophic Oceanography (Argo data. This phenomenon was also revealed by two repeated transects along a section at 30° S, performed during the World Ocean Circulation Experiment Hydrographic Program. Freshening of the AAIW was compensated for by a salinity increase of thermocline water, indicating a hydrological cycle intensification. This was supported by the precipitation-minus-evaporation change in the Southern Hemisphere from 2000 to 2014. Freshwater input from atmosphere to ocean surface increased in the subpolar high-precipitation region and vice versa in the subtropical high-evaporation region. Against the background of hydrological cycle changes, a decrease in the transport of Agulhas Leakage (AL, which was revealed by the simulated velocity field, was proposed to be a contributor to the associated freshening of AAIW. Further calculation showed that such a decrease could account for approximately 53 % of the observed freshening (mean salinity reduction of about 0.012 over the AAIW layer. The estimated variability of AL was inferred from a weakening of wind stress over the South Indian Ocean since the beginning of the 2000s, which would facilitate freshwater input from the source region. The mechanical analysis of wind data here was qualitative, but it is contended that this study would be helpful to validate and test predictably coupled sea–air model simulations.

Biogeographic links between southern Atlantic Forest and western South America: Rediscovery, re-description, and phylogenetic relationships of two rare montane anole lizards from Brazil.

Science.gov (United States)

Prates, Ivan; Melo-Sampaio, Paulo Roberto; Drummond, Leandro de Oliveira; Teixeira, Mauro; Rodrigues, Miguel Trefaut; Carnaval, Ana Carolina

2017-08-01

Data on species ranges and phylogenetic relationships are key in historical biogeographical inference. In South America, our understanding of the evolutionary processes that underlie biodiversity patterns varies greatly across regions. Little is known, for instance, about the drivers of high endemism in the southern montane region of the Atlantic Rainforest. In this region, former biogeographic connections with other South American ecosystems have been invoked to explain the phylogenetic affinities of a number of endemic taxa. This may also be the case of the montane anole lizards Anolis nasofrontalis and A. pseudotigrinus, known from few specimens collected more than 40years ago. We combine new genetic data with published sequences of species in the Dactyloa clade of Anolis to investigate the phylogenetic relationships of A. nasofrontalis and A. pseudotigrinus, as well as estimate divergence times from their closest relatives. Based on newly sampled and previously overlooked specimens, we provide a taxonomic re-description of those two taxa. Our phylogenetic analysis recovered six main clades within Dactyloa, five of which were previously referred to as species series (aequatorialis, heterodermus, latifrons, punctatus, roquet). A sixth clade clustered A. nasofrontalis and A. pseudotigrinus with A. dissimilis from western Amazonia, A. calimae from the Andes, A. neblininus from the Guiana Shield, and two undescribed Andean taxa. We therefore define a sixth species series within Dactyloa: the neblininus series. Close phylogenetic relationships between highly disjunct, narrowly-distributed anoles suggest that patches of suitable habitat connected the southern Atlantic Forest to western South America during the Miocene, in agreement with the age of former connections between the central Andes and the Brazilian Shield as a result of Andean orogeny. The data also support the view of recurrent evolution (or loss) of a twig anole-like phenotype in mainland anoles, in

Compendium of NASA data base for the global tropospheric experiment's Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE-A)

Science.gov (United States)

Gregory, Gerald L.; Scott, A. Donald, Jr.

1995-01-01

This compendium describes aircraft data that are available from NASA's Transport and Atmospheric Chemistry near the Equator - Atlantic (TRACE-A) conducted in September/October 1992. The broad objectives of TRACE-A were to study chemical processes and long-range transport associated with South American and African continental outflow during periods of widespread vegetation burning, and to understand the ozone enhancements observed from satellite data measured over the southern tropical Atlantic Ocean during the September/October time period. Flight experiments were conducted from Brazil, South Africa, Namibia, and the Ascension Island. This document provides a representation of aircraft data that are available from NASA Langley's Distributed Active Archive Center (DAAC). The data format of time series and altitude profile plots is not intended to support original analyses, but to assist the reader in identifying data that are of interest. This compendium is for only the NASA aircraft data. The DAAC data base includes numerous supporting data-meteorological products, results from surface studies, satellite observations, and data from sonde releases.

(Ceramiales, Rhodophyta) from the Canary Islands, eastern Atlantic

African Journals Online (AJOL)

The genus Osmundea is a strongly supported monophyletic group within the Laurencia complex and shows a disjunct distribution occurring in the North-East and South-West Pacific, the Indian and Atlantic oceans and the Mediterranean Sea. Its phenotypic plasticity on the Canary Islands may be the result of the high ...

19 CFR 122.23 - Certain aircraft arriving from areas south of the U.S.

Science.gov (United States)

2010-04-01

... inner boundary of the Atlantic (Coastal) Air Defense Identification Zone (ADIZ) south of 30 degrees... 33 degrees north latitude, or from the Gulf of Mexico and Atlantic Coasts from a place in the Western Hemisphere south of 30 degrees north latitude, from any place in Mexico, from the U.S. Virgin Islands, or...

Are mangroves in the tropical Atlantic ripe for invasion? Exotic mangrove trees in the forests of South Florida

Science.gov (United States)

Fourqurean, James W.; Smith, Thomas J.; Possley, Jennifer; Collins, Timothy M.; Lee, David; Namoff, Sandra

2010-01-01

Two species of mangrove trees of Indo-Pacific origin have naturalized in tropical Atlantic mangrove forests in South Florida after they were planted and nurtured in botanic gardens. Two Bruguiera gymnorrhiza trees that were planted in the intertidal zone in 1940 have given rise to a population of at least 86 trees growing interspersed with native mangrove species Rhizophora mangle, Avicennia germinans and Laguncularia racemosa along 100 m of shoreline; the population is expanding at a rate of 5.6% year−1. Molecular genetic analyses confirm very low genetic diversity, as expected from a population founded by two individuals. The maximum number of alleles at any locus was three, and we measured reduced heterozygosity compared to native-range populations. Lumnitzera racemosa was introduced multiple times during the 1960s and 1970s, it has spread rapidly into a forest composed of native R. mangle, A. germinans, Laguncularia racemosa and Conocarpus erectus and now occupies 60,500 m2 of mangrove forest with stem densities of 24,735 ha−1. We estimate the population growth rate of Lumnitzera racemosa to be between 17 and 23% year−1. Populations of both species of naturalized mangroves are dominated by young individuals. Given the long life and water-dispersed nature of propagules of the two exotic species, it is likely that they have spread beyond our survey area. We argue that the species-depauperate nature of tropical Atlantic mangrove forests and close taxonomic relatives in the more species-rich Indo-Pacific region result in the susceptibility of tropical Atlantic mangrove forests to invasion by Indo-Pacific mangrove species.

76 FR 35086 - Atlantic Bank & Trust, Charleston, SC; Notice of Appointment of Receiver

Science.gov (United States)

2011-06-15

... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Atlantic Bank & Trust, Charleston, SC... section 5(d)(2) of the Home Owners' Loan Act, the Office of Thrift Supervision has duly appointed the Federal Deposit Insurance Corporation as sole Receiver for Atlantic Bank & Trust, Charleston, South...

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from KNORR in the North Atlantic Ocean and South Atlantic Ocean from 1987-11-24 to 1989-04-12 (NODC Accession 0117501)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0117501 includes chemical, discrete sample, meteorological, physical and profile data collected from KNORR in the North Atlantic Ocean and South...

Antarctica: Arena for South American Cooperation or Conflict.

Science.gov (United States)

Child, Jack

A number of converging circumstances suggest that Antarctica may be a major object of geopolitical attention in South America in the decade to come. The Malvinas/Falklands crisis focused geopolitical attention on the South Atlantic and the chain of Southern (Austral) Islands which link the southern tip of South America to the Antarctic Peninsula.…

Breeding of White-tailed Tropicbirds (Phaethon lepturus) in the western South Atlantic.

Science.gov (United States)

Leal, G R; Serafini, P P; Simão-Neto, I; Ladle, R J; Efe, M A

2016-04-19

Basic information on natural history is crucial for assessing the viability of populations, but is often lacking for many species of conservation concern. One such species is the White-tailed Tropicbird, Phaethon lepturus (Mathews, 1915). Here, we address this shortfall by providing detailed information on reproductive biology, distribution and threats on the Fernando de Noronha archipelago, Brazil - the largest colony of P. lepturus in the South Atlantic. We assessed reproduction from August 2011 to January 2012 by monitoring tropicbird nests and their contents. A population estimate was obtained through a combination of active searches for nests and by census at sea between 2010 and 2012. Breeding success was calculated by traditional methods. The growth curve of chicks and life table were also calculated. Additional information on nest and mate fidelity and on age of breeding birds was obtained from the banded birds. Our results indicate that the unusual nest form (limestone pinnacles) and predation by crabs may be responsible for the observed patterns of hatching and fledging success. Although the Fernando de Noronha population appears to be stable (at between 100-300 birds), a long term monitoring program would be desirable to assess fluctuations in this globally important population. Conservation strategies should focus on controlling predation by land crabs and tegu lizards.

First insights into genus level diversity and biogeography of deep sea benthopelagic calanoid copepods in the South Atlantic and Southern Ocean

Science.gov (United States)

Renz, Jasmin; Markhaseva, Elena L.

2015-11-01

Calanoid copepods constitute the most numerous organisms not only in the pelagic realm, but also in the benthic boundary layer, which gives them an important role in the turnover of organic matter in the benthopelagic habitat. During seven expeditions to the South Atlantic and Southern Ocean, the diversity and biogeography of deep-sea benthopelagic calanoid copepods were studied. The communities of calanoids living in the vicinity of the seabed were characterized by high diversity comparable to many pelagic habitats, but low abundance of individuals. Members of the taxon Clausocalanoidea dominated the communities, and within this taxon most individuals belonged to detritivore calanoids characterized by sensory setae on the second maxillae or aetideid copepods. 73% of all genera classified as obligate or predominantly benthopelagic copepods detected during these expeditions were new to science and a vast number of genera and species have been described since then. Comparing the communities of calanoid genera between different regions, the assemblages in the Southern Ocean differed significantly from the Southeast and Southwest Atlantic. A latitudinal diversity gradient could be observed, with highest numbers of genera in the Southwest Atlantic and low numbers at stations in the Southern Ocean. Reviewing the literature, endemism for benthopelagic calanoids appeared to be low on a latitudinal range caused by connectivity in benthopelagic habitats through spreading water masses. However, considering the habitats structuring the water column vertically, a high number of genera are endemic in the benthopelagial and specialized to living within the vicinity of the seabed.

Aerosol-Cloud Interactions in the South-East Atlantic: Knowledge Gaps, Planned Observations to Address Them, and Implications for Global Climate Change Modeling

Science.gov (United States)

Redemann, Jens; Wood, R.; Zuidema, P.; Haywood, J.; Luna, B.; Abel, S.

2015-01-01

Southern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. Particles lofted into the mid-troposphere are transported westward over the South-East (SE) Atlantic, home to one of the three permanent subtropical Stratocumulus (Sc) cloud decks in the world. The stratocumulus "climate radiators" are critical to the regional and global climate system. They interact with dense layers of BB aerosols that initially overlay the cloud deck, but later subside and are mixed into the clouds. These interactions include adjustments to aerosol-induced solar heating and microphysical effects. As emphasized in the latest IPCC report, the global representation of these aerosol-cloud interaction processes in climate models is one of the largest uncertainty in estimates of future climate. Hence, new observations over the SE Atlantic have significant implications for global climate change scenarios. We discuss the current knowledge of aerosol and cloud property distributions based on satellite observations and sparse suborbital sampling, and describe planned field campaigns in the region. Specifically, we describe the scientific objectives and implementation of the following four synergistic, international research activities aimed at providing a process-level understanding of aerosol-cloud interactions over the SE Atlantic: 1) ORACLES (Observations of Aerosols above Clouds and their interactions), a five-year investigation between 2015 and 2019 with three Intensive Observation Periods (IOP), recently funded by the NASA Earth-Venture Suborbital Program, 2) CLARIFY-2016 (Cloud-Aerosol-Radiation Interactions and Forcing: Year 2016), a comprehensive observational and modeling programme funded by the UK's Natural Environment Research Council (NERC), and supported by the UK Met Office. 3) LASIC (Layered Atlantic Smoke Interactions with Clouds), a funded

The nematode community in the Atlantic rainforest lizard Enyalius perditus Jackson, from south-eastern Brazil.

Science.gov (United States)

Barreto-Lima, A F; Toledo, G M; Anjos, L A

2012-12-01

Studies focusing on communities of helminths from Brazilian lizards are increasing, but there are many blanks in the knowledge of parasitic fauna of wild fauna. This lack of knowledge hampers understanding of ecological and parasitological aspects of involved species. Moreover, the majority of research has focused on parasitic fauna of lizards from families Tropiduridae and Scincidae. Only a few studies have looked at lizards from the family Leiosauridae, including some species of Enyalius. This study presents data on the gastrointestinal parasite fauna of Enyalius perditus and their relationships with ecological aspects of hosts in a disturbed Atlantic rainforest area in the state of Minas Gerais, south-eastern Brazil. Two nematode species, Oswaldocruzia burseyi [(Molineidae) and Strongyluris oscari (Heterakidae) were found. Nematode species showed an aggregated distribution in this host population, with O. burseyi being more aggregated than S. oscari. The present study extends the range of occurrence of O. burseyi to the Brazilian continental area.

The Mediterranean Water content in the Northeast Atlantic

Science.gov (United States)

Nascimento, Angela; Bashmachnikov, Igor; Neves, Filipe

2014-05-01

slope, and further gradually decreased to the west and to the south. To the west it reached about 10% at 35-40º W, over the subptropical section of the Mid-Atlantic ridge, and to the south it totally disappeared around 25o N, south of the Canary islands. Following the values of the maximum percentage of the MW, we got that at 700 m depth its preferred path was to the north along the Iberian continental margin and further on, reaching 24% at 45 - 50o N. At 900- 1300 m depth the MW preferably moved west and west-south-west. Below 1500 m level the MW still had a significant percentage and moved south-west.

Temperature profile and other data collected using CTD casts in the North Atlantic Ocean from NOAA Ship RESEARCHER from 1980-01-22 to 1980-02-03 (NODC Accession 8900302)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and other data were collected using CTD casts from NOAA Ship RESEARCHER in the North Atlantic Ocean from 22 January 1980 to 03 February 1980....

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2013-01-03 to 2013-11-15 (NCEI Accession 0157348)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157348 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2014-12-30 to 2015-12-27 (NCEI Accession 0148769)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148769 includes Surface underway, chemical, meteorological and physical data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2008-01-09 to 2008-08-06 (NCEI Accession 0157386)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157386 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2012-03-14 to 2012-09-02 (NCEI Accession 0157397)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157397 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2005-12-17 to 2006-12-15 (NCEI Accession 0157311)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157311 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 1999-03-06 to 2000-02-10 (NCEI Accession 0157370)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157370 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2010-01-02 to 2011-01-16 (NCEI Accession 0157259)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157259 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from NATHANIEL B. PALMER in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2005-01-28 to 2005-12-12 (NCEI Accession 0157262)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157262 includes Surface underway, chemical, meteorological and physical data collected from NATHANIEL B. PALMER in the South Atlantic Ocean, South...

Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from L'ATALANTE in the Gulf of Guinea, North Atlantic Ocean and South Atlantic Ocean from 1995-01-13 to 1995-04-02 (NODC Accession 0115764)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0115764 includes chemical, discrete sample, physical and profile data collected from L'ATALANTE in the Gulf of Guinea, North Atlantic Ocean and South...

76 FR 53413 - South Atlantic Fishery Management Council Meeting

Science.gov (United States)

2011-08-26

...; fax: (843) 769-4520; e-mail: [email protected] . SUPPLEMENTARY INFORMATION: Meeting Dates 1. Joint... terms of reference (TOR) and appointments for the SEDAR 28 stock assessment for Atlantic and Gulf...

Small scale endemism in Brazil's Atlantic Forest: 14 new species of Mesabolivar (Araneae, Pholcidae), each known from a single locality.

Science.gov (United States)

Huber, Bernhard A

2015-04-07

In an ongoing mega-transect project that aims at analyzing pholcid spider diversity and distribution in the Atlantic Forest of Brazil, many species appear restricted to small geographic ranges. Of the 84 species collected between 2003 and 2011 at 17 sites between Bahia and Santa Catarina, 51 species (61%) were found at only one locality. The present paper focuses on such species in the genus Mesabolivar, and compares diversity and distribution patterns of this genus within and outside the Atlantic Forest. The percentage of species known from single localities is higher in the Atlantic Forest (34 of 52 species; 65%) than outside the Atlantic Forest (10 of 25; 40%). Distribution rages of species in the Atlantic Forest are significantly smaller than of species outside the Atlantic Forest (mean maximum distances between localities: 184 versus 541 km; medians: 10 km versus 220 km). The following species are newly described (arranged from north to south), each currently known from the respective type locality only: M. caipora; M. kathrinae; M. bonita; M. pau (Bahia); M. monteverde; M. perezi (Espírito Santo); M. giupponii; M. goitaca; M. sai (Rio de Janeiro); M. tamoio; M. unicornis; M. gabettae; M. inornatus (São Paulo); M. itapoa (Santa Catarina).

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2007-01-02 to 2007-12-20 (NCEI Accession 0148773)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148773 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2011-12-30 to 2012-12-23 (NCEI Accession 0148774)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148774 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2007-12-31 to 2008-10-27 (NCEI Accession 0148763)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148763 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2011-01-02 to 2011-12-18 (NCEI Accession 0148767)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148767 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2006-01-01 to 2006-12-27 (NCEI Accession 0144535)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144535 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2014-12-30 to 2015-07-01 (NCEI Accession 0144343)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144343 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2011-01-02 to 2011-12-19 (NCEI Accession 0144354)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144354 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2007-12-30 to 2008-10-28 (NCEI Accession 0144348)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144348 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2002-03-07 to 2002-12-23 (NCEI Accession 0144356)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144356 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2011-12-30 to 2012-12-24 (NCEI Accession 0144349)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144349 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2013-12-31 to 2014-12-20 (NCEI Accession 0144532)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144532 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2006-01-02 to 2006-12-26 (NCEI Accession 0148764)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148764 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2002-12-29 to 2003-11-30 (NCEI Accession 0144351)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144351 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2012-12-31 to 2013-11-15 (NCEI Accession 0144529)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144529 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2002-03-23 to 2002-12-23 (NCEI Accession 0148766)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148766 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2014-01-01 to 2014-12-20 (NCEI Accession 0145200)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0145200 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2003-01-01 to 2003-12-29 (NCEI Accession 0148770)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148770 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2010-01-01 to 2011-12-19 (NCEI Accession 0148765)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0148765 includes Surface underway data collected from LAURENCE M. GOULD in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans (> 60...

Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from POLARSTERN in the South Atlantic Ocean and Southern Oceans from 1998-03-28 to 1998-05-23 (NODC Accession 0113595)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0113595 includes discrete sample and profile data collected from POLARSTERN in the South Atlantic Ocean and Southern Oceans (> 60 degrees South)...

A Database and Meta-Analysis of Ecological Responses to Flow in the South Atlantic Region

Energy Technology Data Exchange (ETDEWEB)

McManamay, Ryan A [ORNL; Orth, Dr. Donald J [Virginia Polytechnic Institute and State University (Virginia Tech); Davis, Dr, Mary [Southeastern Aquatic Resources Partnership; Kauffman, John [John Kauffman LLC.

2013-01-01

Generalized and quantitative relationships between flow and ecology are pivotal to developing environmental flow standards based on socially acceptable ecological conditions. Informing management at regional scales requires compiling sufficient hydrologic and ecological sources of information, identifying information gaps, and creating a framework for hypothesis development and testing. We compiled studies of empirical and theoretical relationships between flow and ecology in the South Atlantic region (SAR) of the United States to evaluate their utility for the development of environmental flow standards. Using database searches, internet searches, and agency contacts, we gathered 186 sources of information that provided a qualitative or quantitative relationship between flow and ecology within states encompassing the SAR. A total of 109 of the 186 sources had sufficient information to support quantitative analyses. Ecological responses to natural changes in flow magnitude, frequency, and duration were highly variable regardless of the direction and magnitude of changes in flow. In contrast, the majority of ecological responses to anthropogenic-induced flow alterations were negative. Fish consistently showed negative responses to anthropogenic flow alterations whereas other ecological groups showed somewhat variable responses (e.g. macroinvertebrates and riparian vegetation) and even positive responses (e.g. algae). Fish and organic matter had sufficient sample sizes to stratify natural flow-ecology relationships by specific flow categories (e.g. high flow, baseflows) or by region (e.g. coastal plain, uplands). After stratifying relationships, we found that significant correlations existed between changes in natural flow and ecological responses. In addition, a regression tree explained 57% of the variation in fish responses to anthropogenic and natural changes in flow. Because of some ambiguity in interpreting the directionality in ecological responses, we

Tropical North Atlantic ocean-atmosphere interactions synchronize forest carbon losses from hurricanes and Amazon fires

Science.gov (United States)

Chen, Yang; Randerson, James T.; Morton, Douglas C.

2015-08-01

We describe a climate mode synchronizing forest carbon losses from North and South America by analyzing time series of tropical North Atlantic sea surface temperatures (SSTs), landfall hurricanes and tropical storms, and Amazon fires during 1995-2013. Years with anomalously high tropical North Atlantic SSTs during March-June were often followed by a more active hurricane season and a larger number of satellite-detected fires in the southern Amazon during June-November. The relationship between North Atlantic tropical cyclones and southern Amazon fires (r = 0.61, p forests.

Post-Glacial Development of Western North Atlantic - Labrador Sea Oceanographic Circulation

DEFF Research Database (Denmark)

Sheldon, Christina

2015-01-01

The subpolar North Atlantic Ocean – Labrador Sea region is an important site for both oceanographic and atmospheric circulation. The convergence of ocean currents causes downwelling of cold, saline water in the subpolar gyre, helping to drive the world-wide thermohaline circulation system. The main......, the subpolar gyre weakened, which carried less Gulf Stream-derived water to the western North Atlantic Ocean via the West Greenland Current and the Slopewater Current, south of Newfoundland. Changes in the subpolar gyre circulation had developed to be analogous to the modern climate by approximately 2 cal kyr...... surface currents involved in the gyre are the south-flowing, cold and relatively fresh Labrador Current and the north-flowing, warm and relatively saline Gulf Stream. The oceanic front between these two major currents moves north and south, dependent on the relative strengths of the currents, impacting...

Convective lofting links Indian Ocean air pollution to paradoxical South Atlantic ozone maxima

Science.gov (United States)

Chatfield, R. B.; Guan, H.; Thompson, A. M.; Witte, J. C.

2005-01-01

We describe a broad resolution of the Atlantic Parado concerning the seasonal and geographic distribution, of tropical tropospheric ozone. We highlight periods of significant maximum tropospheric O3 for Jan.- April, 1999, exploiting satellite estimates and SHADOZ (Southern Hemisphere Additional Ozonesondes). Trajectory analyses connecting sondes and Total Tropospheric Ozone (TTO) maps suggest a complex influence from the Indian Ocean: beginning with mixed combustion sources, then low level transport, cumulonimbus venting, possible stratospheric input, and finally high-level transport to the west, with possible mixing over Africa. For the Jan.-March highest column-O3 periods in the Atlantic, distinct sounding peaks trace to specific NO sources, especially lightning, while in the same episodes, recurring every 20-50 days, more diffuse buildups of Indian-to-Atlantic pollution make important contributions.

Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, Barometric pressure sensor and other instruments from NOAA Ship RONALD H. BROWN in the South Atlantic Ocean, South Pacific Ocean and Southern Oceans from 2005-01-11 to 2005-02-24 (NODC Accession 0108153)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108153 includes discrete sample and profile data collected from NOAA Ship RONALD H. BROWN in the South Atlantic Ocean, South Pacific Ocean and...

PRESSURE - WATER and Other Data from NOAA Ship ALBATROSS IV and Other Platforms From NW Atlantic (limit-40 W) from 1992-05-22 to 1997-05-21 (NODC Accession 9800002)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, light transmission, and fluorescence profiles were collected from CTD casts in the NW Atlantic Ocean (limit-40w) from 22 May 1992 to 21 May...

An Anatomy of the 1960s Atlantic Cooling.

Science.gov (United States)

Hodson, Dan; Robson, Jon; Sutton, Rowan

2014-05-01

North Atlantic Sea Surface Temperatures (SSTs) exhibited pronounced multidecadal variability during the 20th Century. In particular, the North Atlantic SSTs exhibited a rapid warming between 1920 and 1940 followed by a rapid cooling between 1960 and 1980. SSTs outside the North Atlantic display a much smaller level of decadal variability over the 20th Century. This pattern of North Atlantic warming and cooling has been linked to subsequent changes in rainfall over the Sahel and Nordeste Brazil, Summertime North American Climate and Atlantic Hurricane Genesis. Several hypotheses for the rapid 1960s Atlantic cooling have been proposed, including a reduction in northward ocean heat transport due to a reduced Atlantic Meridional Overturning Circulation (AMOC) and the significant rise in anthropogenic sulphur dioxide emissions during the latter half of the 20th century. Here we examine the observed 1960s Atlantic cooling in more detail. We describe the evolution of the rapid cooling by constructing a detailed multivariate anatomy of the cooling period in order to illuminate the possible explanations and mechanisms involved. We show that the observed 1960s cooling began around 1964-68 in the Greenland-Iceland-Norway (GIN) seas, later spreading to the Atlantic Sub Polar Gyre and much of the subtropical Atlantic. This initial cooling of the Sub Polar Gyre is associated with a marked reduction in salinity (the Great Salinity Anomaly). The cooling peaked between 1972-76, extending into the Tropical North Atlantic. This period also saw the development of a significant Winter North-South Dipole Mean Sea Level Pressure dipole pattern reminiscent of a positive NAO (High over the Azores, Low over Iceland). The cooling then retreated back to higher latitudes during 1976:80. Our analysis demonstrates that the cooling of the North Atlantic during the 1960s cannot be understood as a simple thermodynamic response to aerosol induced reductions in shortwave radiation. Dynamical changes