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Marine seismic reflection data have been collected for decades and since the mid-to late- 1980s much of this data is positioned relatively accurately. This older data provides a valuable archive, however, it is mainly stored on paper records that do not allow easy integration with other datasets. A method for converting these records to digital SEGY format has been reported previously, although the accuracy and reliability has not been documented. Using 3.5 kHz pinger, bathymetric and side scan sonar data we test the accuracy and data resolution of converted paper seismic records on the surface and shallow-subsurface of the Barra Fan, NE Atlantic Ocean. Frequencies of navigational updates and printed fix marks are vital in determining positional accuracy as interpolation between fixes, which may be 30 minutes apart, is a significant source of potential error. Vertical data resolution of the converted records is primarily governed by the dimensions of the printed record, with order of magnitude differences noted between the scanned BGS and NOC pinger records. Positional accuracy of pinger data is observed to be within the resolution of the bathymetric grid. BGS 1985 pinger data is located within 40 m of bathymetric constrained locations at 635 m below mean sea level and NOC 1998 pinger data within 25 m of bathymetric locations at 1180 m below mean sea level. This paper-to-digital conversion is not a replacement for modern data acquisition, but it does provide a valuable complement to such data. Where appropriate archival paper data is available for conversion it could be used to assist efficiency of forthcoming surveys and may be used to provide time series evidence of seabed processes. [ABSTRACT FROM AUTHOR]

The knowledge of Green House Gases GHGs fluxes at the air--sea interface at high resolution is crucial to accurately quantify the role of the ocean in the absorption and emission of GHGs. In this paper we present a novel method to reconstruct maps of surface ocean partial pressure of CO2, pCO2, and air--sea CO2 fluxes at super resolution (4 km) using Sea Surface Temperature (SST) and Ocean Colour (OC) data at this resolution, and CarbonTracker CO2 fluxes data at low resolution (110 km). Inference of super-resolution of pCO2, and air--sea CO2 fluxes is performed using novel nonlinear signal processing methodologies that prove efficient in the context of oceanography. The theoretical background comes from the Microcanonical Multifractal Formalism which unlocks the geometrical determination of cascading properties of physical intensive variables. As a consequence, a multiresolution analysis performed on the signal of the so-called singularity exponents allows the correct and near optimal cross-scale inference of GHGs fluxes, as the inference suits the geometric realization of the cascade. We apply such a methodology to the study offshore of the Benguela area. The inferred representation of oceanic partial pressure of CO2 improves and enhances the description provided by CarbonTracker, capturing the small scale variability. We examine different combinations of Ocean Colour and Sea Surface Temperature products in order to increase the number of valid points and the quality of the inferred pCO2 field. The methodology is validated using in-situ measurements by means of statistical errors. We obtain that mean absolute and relative errors in the inferred values of pCO2 with respect to in-situ measurements are smaller than for CarbonTracker. [ABSTRACT FROM AUTHOR]

We use an eddy-resolving, regional ocean biogeochemical model to investigate the main variables and processes responsible for the climatological spatio-temporal variability of pCO2 and the air-sea CO2 fluxes in the southwestern Atlantic Ocean. Overall, the region acts as sink of atmospheric CO2 south of 30° S, and is close to equilibrium with the atmospheric CO2 to the north. On the shelves, the ocean acts as a weak source of CO2, except for the mid/outer shelves of Patagonia, which act as sinks. In contrast, the inner shelves and the low latitude open ocean of the southwestern Atlantic represent source regions. Observed nearshore-to-offshore and meridional pCO2 gradients are well represented by our simulation. A sensitivity analysis shows the importance of the counteracting effects of temperature and dissolved inorganic carbon (DIC) in controlling the seasonal variability of pCO2. Biological production and solubility are the main processes regulating pCO2, with biological production being particularly important on the shelf regions. The role of mixing/stratification in modulating DIC, and therefore surface pCO2 is shown in a vertical profile at the location of the Ocean Observatories Initiative (OOI) site in the Argentine Basin (42° S, 42° W). [ABSTRACT FROM AUTHOR]

Oceans are a net source of molecular hydrogen (H2) to the atmosphere. The production of marine H2 is assumed to be mainly biological by N2 fixation, but photochemical pathways are also discussed. We present measurements of mole fraction and isotopic composition of dissolved and atmospheric H2 from the southern and northern Atlantic between 2008 and 2010. In total almost 400 samples were taken during five cruises along a transect between Punta Arenas (Chile) and Bremerhaven (Germany), as well as at the coast of Mauretania. The isotopic source signatures of dissolved H2 extracted from surface water are highly deuterium-depleted and correlate negatively with temperature, showing dD values of (-629 ± 54) ‰ for water temperatures at (27 ± 3) °C and (-249 ± 88) ‰ below (19 ± 1) °C. The results for warmer water masses are consistent with biological production of H2. This is the first time that marine H2 excess has been directly attributed to biological production by isotope measurements. However, the isotope values obtained in the colder water masses indicate that beside possible biological production a significant different source should be considered. The atmospheric measurements show distinct differences between both hemispheres as well as between seasons. Results from the global chemistry transport model TM5 reproduce the measured H2 mole fractions and isotopic composition well. The climatological global oceanic emissions from the GEMS database are in line with our data and previously published flux calculations. The good agreement between measurements and model results demonstrates that both the magnitude and the isotopic signature of the main components of the marine H2 cycle are in general adequately represented in current atmospheric models despite a proposed source different from biological production or a substantial underestimation of nitrogen fixation by several authors. [ABSTRACT FROM AUTHOR]

The paper provides a basin assessment of the spatial distribution of ocean alkalinity in the Mediterranean Sea. The assessment is made using a 3-D transport-biogeochemical-carbonate model to integrate the available experimental findings, which also constrains model output. The results indicate that the Mediterranean Sea shows alkalinity values that are much higher than those observed in the Atlantic Ocean on a basin-wide scale. A marked west-to-east surface gradient of alkalinity is reproduced as a response to the terrestrial discharges, the mixing effect with the Atlantic water entering from the Gibraltar Strait and the Black Sea water from Dardanelles, and the surface flux of evaporation minus precipitation. Dense water production in marginal seas (Adriatic and Aegean Seas), where alkaline inputs are relevant, and the Mediterranean thermohaline circulation sustains the west-to-east gradient along the entire water column. In the surface layers, alkalinity has a relevant seasonal cycle (up to 40 µmol kg-1) that is driven both by physical and biological processes. A comparison of alkalinity vs. salinity indicates that different regions present different relationships. In regions of freshwater influence, the two measures are negatively correlated due to riverine alkalinity input, whereas they are positively correlated in open seas. Alkalinity always is much higher than in the Atlantic waters, which might indicate a higher than usual buffering capacity towards ocean acidification, even at high concentrations of dissolved inorganic carbon. [ABSTRACT FROM AUTHOR]

This work presents the quantitative study of climatological distributions of mid-depth SourceWater Types in the NE Atlantic by the Optimum Multiparameter analysis (OMP), merging a number of regional results from particular synoptic sections. The cores of the Mediterranean Water (MW), the modified Antarctic Intermediate Water (mAAIW) and the Subarctic Intermediate Water (SAIW) are detected and spatial variations of their depth/density are obtained: as expected, spreading of the source water types is predominantly isopycnic and follows the major mid-depth circulation patterns. In some areas the turbulent transport should also be considered. The MW in the Atlantic spreads as 3 cores of different density: the upper MW core (northwest of the first transition line between 28° W, 35° N and 14° W, 44° N) is found in the neutral density range of 27.65-27.70 kg m-3 and depths of 900-1000 m; the main MW core (northwest of the second transition line between 35° W, 28° N and 10° W, 37° N) has neutral density around 27.75 kg m-3 and is found at 1000-1100 m; the lower MW core (southeast of the second transition) has neutral density around 27.80 kg m-3 and is found at 1250-1350 m. The upper MW core has comparatively low MW contents (below 30%) and is speculated to be transported by the mean flow from the northern Iberian Peninsula and the Bay of Biscay to the northern Azores. The main MW core contains the most of the MW. It primarily originates from the MUC between Cape St. Vincent and Estremadura Promontory, where the strongest local decrease of the topographic ß-effect is detected and is transported west by a flow at around 39° N. The lower MW core originates in the Gulf of Cadiz and is translated southwestwards by dominating flows. The SAIW (the core between 27.70 and 27.75 kg m-3) is found to spread south along both slopes of the MAR. The SAIW east of the MAR mixes with the upper and the main MW cores and re-circulates in a cyclonic gyre at 15-25° W and 34-39° N as far south as the Azores Current. The northernmost spreading limit of the mAAIW (the core between 27.60 and 27.65 kg m-3) is at 25-29° N, but its influence reaches 32° N east and west of the Canary Islands. Its maximum concentration is found south of the Canaries, from where the mAAIW is transported westwards, parallel to the westward transport of the deep fraction of the MW. [ABSTRACT FROM AUTHOR]

The polar front separates the warm and saline AtlanticWaters encountered in the western part of the Barents Sea from the cold and fresh Arctic Waters situated in the northern part. These water masses can mix together, mainly in the eastern part of the Barents Sea, generating dense waters in winter which can cascade into the Arctic Ocean to form the Artic Intermediate Waters. To study the interannual variability and evolution of these water masses and the fronts, we have merged data from the International Council for the Exploration of the Sea and the Arctic and Antarctic Research Institute and have built a new database which covers the period 1980-2011. The summer data is interpolated on a regular grid and a "Probability Density Function" method is used to show that the polar front splits into two branches east of 32° E where the topographic constraint weakens. Two fronts can then be defined: the "Northern Polar Front" is associated with strong salinity gradients and the "Southern Polar Front" with temperature gradients. They enclose the dense Barents SeaWater. The interannual variability of the 15 water masses is apparent in the observed data and is linked to that of the ice cover. In contrast, the link with the Arctic Oscillation is not clear. However, results from a general circulation model suggest that such a link could be found if winter data were taken into account. A strong trend, which amplifies during the last decade, is also found: the AtlanticWater occupies a larger volume of the Barents Sea. This "Atlantification" could be accompanied by a northwards displacement of the southern polar front in the eastern part of the Barents Sea (which is suggested by a model based study) and a decrease of the volume occupied by the Arctic Waters. [ABSTRACT FROM AUTHOR]

Fluxes of organic and inorganic carbon within the Amazon basin are considerably controlled by annual flooding, which triggers the export of terrigenous organic material to the river and ultimately to the Atlantic Ocean. The amount of carbon imported to the river and the further conversion, transport and export of it, depend on terrestrial productivity and discharge, as well as temperature and atmospheric CO2. Both terrestrial productivity and discharge are influenced by climate and land use change. To assess the impact of these changes on the riverine carbon dynamics, the coupled model system of LPJmL and RivCM (Langerwisch et al., 2015) has been used. Vegetation dynamics (in LPJmL) as well as export and conversion of terrigenous carbon to and within the river (RivCM) are included. The model system has been applied for the years 1901 to 2099 under two deforestation scenarios and with climate forcing of three SRES emission scenarios, each for five climate models. The results suggest that, following deforestation, riverine particulate and dissolved organic carbon will strongly decrease by up to 90 % until the end of the current century. In parallel, discharge increases, leading to roughly unchanged net carbon transport during the first decades of the century, as long as a sufficient area is still forested. During the following decades the amount of transported carbon will decrease drastically. In contrast to the riverine organic carbon, the amount of riverine inorganic carbon is only determined by climate change forcing, namely increased temperature and atmospheric CO2 concentration. Mainly due to the higher atmospheric CO2 it leads to an increase in riverine inorganic carbon by up to 20 % (SRES A2). The changes in riverine carbon fluxes have direct effects on the export of carbon, either to the atmosphere via outgassing, or to the Atlantic Ocean via discharge. Basin-wide the outgassed carbon will increase slightly, but can be regionally reduced by up to 60 % due to deforestation. The discharge of organic carbon to the ocean will be reduced by about 40 % under the most severe deforestation and climate change scenario. The changes would have local and regional consequences on the carbon balance and habitat characteristics in the Amazon basin itself but also in the adjacent Atlantic Ocean. [ABSTRACT FROM AUTHOR]

The stable carbon isotope composition of dissolved inorganic carbon (δ13CDIC) in seawater was measured in samples collected during two cruises in the Northeastern Atlantic and Nordic Seas from June to August 2012. One cruise was part of the UK Ocean Acidification research programme, and the other was a repeat hydrographic transect of the Extended Ellett Line. In combination with measurements made of various other variables on these and other cruises, these data can be used to constrain the anthropogenic component of DIC in the interior ocean, and also assist in determining the influence of biological carbon uptake on surface ocean carbonate chemistry. The measurements have been processed, quality-controlled and submitted to an in-preparation global compilation of seawater δ13CDIC data, and are available from the British Oceanographic Data Centre. The observed δ13CDIC values fall in a range from -0.58 to +2.37%0, relative to the Vienna Peedee Belemnite standard. From duplicate samples collected during both cruises, the precision for the 552 results is 0.07‰, which is similar to other published studies of this kind. Data doi:10.5285/09760a3a-c2b5-250b-e053-6c86abc037c0 (Northeastern Atlantic), doi:10.5285/09511dd0-51db-0e21-e053-6c86abc09b95 (Nordic Seas). [ABSTRACT FROM AUTHOR]

The objective of this study was to estimate the reproductive parameters of porbeagle shark in the Southwest Atlantic Ocean and thus characterize the adult fraction of this population. Therefore, 1012 specimens were measured by scientific observers on board the commercial trawl fleet operating south of 50° S. The size range of the specimens was from 77 to 292 cm fork length (L F ). The mean size at maturity was estimated to be 153 cm L F for males and 172 cm L F for females. Porbeagle shark catches were recorded throughout the year, with the highest frequency occurring between November and June. The presence of pregnant females was observed from December to July, along with an increase in the average size of embryos in each litter. The information presented in this study improves the knowledge of the reproductive biology and allows to propose a migratory pattern of adult porbeagle females in the Southwest Atlantic Ocean. The likely seasonal increase in vulnerability of this shark to austral trawl fishery, despite all conservation management measures established in Argentina, underscores the importance of promoting its proper management and conservation given the need to improve understanding of porbeagle population dynamics in the Southern Hemisphere., (© 2024 Fisheries Society of the British Isles.)

We introduce a new class of zero-or-one inflated power logit (IPL) regression models, which serve as a versatile tool for analyzing bounded continuous data with observations at a boundary. These models are applied to explore the effects of climate changes on the distribution of tropical tuna within the North Atlantic Ocean. Our findings suggest that our modeling approach is adequate and capable of handling the outliers in the data. It exhibited superior performance compared to rival models in both diagnostic analysis and regarding the inference robustness. We offer a user-friendly method for fitting IPL regression models in practical applications., (© 2024 Wiley‐VCH GmbH.)

This study delves into the foraging ecology of the cookiecutter shark (Isistius brasiliensis) in the Saint Peter and Saint Paul Archipelago (SPSPA), assessing bite marks on pelagic fishes collected between March and September 2018. Examination of 200 individuals from five species revealed the shark's predilection for targeting adult fish, ensuring efficient removal of energy-rich tissue layers. However, a notable exception is Thunnus albacares, preyed on predominantly during its juvenile stage, possibly due to vertical spatial segregation. Recent bites were pervasive across species, with wahoo displaying a distinctive pattern. Cookiecutter shark bites predominantly targeted the lateral body portion (>55%) except for yellowfin tuna, which exhibited a preference for the ventral region (95%). The estimated length distribution suggests the SPSPA as a potential nursery area for cookiecutter sharks. Bite mark positions and frequencies may be linked to fish behavior, swimming velocity, and fishing gear strategy, highlighting the complex interplay in pelagic ecosystems., (© 2024 Fisheries Society of the British Isles.)

Beginning with the purchase of the schooner Nellie May and concluding with the docking of the schooner Ernestina in the Port of New Bedford, Cape Verdeans in southeastern New England and on the Cape Verde islands off the West African coast purchased and refurbished old, decommissioned ships from New Bedford's bygone whaling and fishing era. Between 1892 and 1965, this fleet of ships, named the Cape Verdean Packet Trade, specialized in the transportation of goods, people, and news between the United States and the Cape Verde islands. The packet trade was a large-scale effort that transformed the Atlantic into a highway for Cape Verdean trade, communication, emigration, and family reunification. Cape Verdeans' radical repurposing of the packet vessels converted the Atlantic Ocean from a site of dispossession, enslavement, and immobility to a reimagined zone of possibility and freedom through mobility for African-descended peoples. These Cape Verdean–owned and operated packets assisted Cape Verdean Americans in maintaining long-term connections to loved ones separated by the Atlantic. In this way, the Cape Verdean Packet Trade's more than 1,200 voyages connected the United States to Cape Verde as part of a transnational social field and single economic universe for more than seventy years. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

The oceanography of the Labrador Sea is well studied because of its globally important deep-water convection that oxygenates the deep ocean and drives climate-regulating ocean currents. However, little is known about the fish communities that inhabit this area, particularly beyond the depths accessible to standard research surveys and commercial fishing activities. We used baited longline surveys to characterize important components of demersal fish communities across a depth gradient of 200-3000 m and compared these data to a similar dataset collected c. 1200 km to the south in the Flemish Cap Region. We found demersal fish communities in the Labrador Sea to be similar to those of the Flemish Cap Region despite unique oceanography and lower primary productivity in the Labrador Sea. Moreover, both areas had high abundance, biomass, and species richness at intermediate depths that suggests factors beyond depth drive community structure in the deep ocean. These data are important for identifying high-value areas for potential protective measures in the northwest Atlantic and provide necessary data with which to assess potential environmental impacts of extractive industries that are expanding north and to deeper waters., (© 2023 His Majesty the King in Right of Canada and The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles. Reproduced with the permission of the Minister of Fisheries and Oceans.)

Every sailor, at the back of his or her mind, is aware that the nearest land is likely to be directly beneath the ship's keel and he or she is interested to know just how near. For over two thousand years, mariners measured depth of water by using a sounding rod in shallow areas and the lead and line in deeper water. This paper considers how, during the “Dark Ages”, sailors in the North Sea might have navigated, including the use of sounding rods and lead lines for way-finding during a time when no other navigational instruments were available. Because of the lack of contemporary records the authors firstly consider the use of depth finding in earlier and later times to shed light on how the early North Sea sailors might have operated. The latter part of this paper takes account of the earlier discussion, together with some records of North Sea voyaging, to suggest how “Dark Age” sailors might have used sounding rods, the lead and line, and other techniques to navigate around and across the North Sea. [ABSTRACT FROM AUTHOR]

The Atlantic meridional overturning circulation (AMOC) plays a critical role in the climate system and is responsible for much of the meridional heat transported by the ocean. In this paper, the potential of using AMOC observations from the 26 $$^{\circ }$$ N RAPID array to predict North Atlantic sea surface temperatures is investigated for the first time. Using spatial correlations and a composite method, the AMOC anomaly is used as a precursor of North Atlantic sea-surface temperature anomalies (SSTAs). The results show that the AMOC leads a dipolar SSTA with maximum correlations between 2 and 5 months. The physical mechanism explaining the link between AMOC and SSTA is described as a seesaw mechanism where a strong AMOC anomaly increases the amount of heat advected north of 26 $$^{\circ }$$ N as well as the SSTA, and decreases the heat content and the SSTA south of this section. In order to further understand the origins of this SSTA dipole, the respective contributions of the heat advected by the AMOC versus the Ekman transport and air-sea fluxes have been assessed. We found that at a 5-month lag, the Ekman component mainly contributes to the southern part of the dipole and cumulative air-sea fluxes only explain a small fraction of the SSTA variability. Given that the southern part of the SSTA dipole encompasses the main development region for Atlantic hurricanes, our results therefore suggest the potential for AMOC observations from 26 $$^\circ$$ N to be used to complement existing seasonal hurricane forecasts in the Atlantic. [ABSTRACT FROM AUTHOR]

The occurrence of pinnipeds in areas distant from their reproductive sites is a well-known phenomenon, which could be influenced by oceanographic anomalies in a changing environment. In the present paper, we present an extra-limital record in deep pelagic waters of a young fur seal (Arctocephalus sp.) in the North Atlantic Ocean. The individual was recorded alive in March/April 2013 in the vicinity of the São Pedro and São Paulo Archipelago (ca. 00°56′N; 29°22′W), which is about 1010 km away from the Brazilian mainland, just above the equatorial line. The specimen was apparently healthy, and it was feeding upon flying fish (Cheilopogon cyanopterus). We hypothesized it to be one of the three main potential species (Arctocephalus tropicalis, Arctocephalus australis, and Arctocephalus pusillus pusillus), suggested their possible routes of arrival, and highlighted it as the northernmost record of a fur seal in the Atlantic Ocean. [ABSTRACT FROM AUTHOR]

Preindustrial control simulations with the third Hadley Centre Global Environmental Model, run in the Global Coupled configuration 3.1 of the Met Office Unified Model (HadGEM3‐GC3.1) are presented at two resolutions. These are N216ORCA025, which has a horizontal resolution of 60 km in the atmosphere and 0.25° in the ocean, and N96ORCA1, which has a horizontal resolution of 130 km in the atmosphere and 1° in the ocean. The aim of this study is to document the climate variability in these simulations, make comparisons against present‐day observations (albeit under different forcing), and discuss differences arising due to resolution. In terms of interannual variability in the leading modes of climate variability the two resolutions behave generally very similarly. Notable differences are in the westward extent of El Niño and the pattern of Atlantic multidecadal variability, in which N216ORCA025 compares more favorably to observations, and in the Antarctic Circumpolar Current, which is far too weak in N216ORCA025. In the North Atlantic region, N216ORCA025 has a stronger and deeper Atlantic Meridional Overturning Circulation, which compares well against observations, and reduced biases in temperature and salinity in the North Atlantic subpolar gyre. These simulations are being provided to the sixth Coupled Model Intercomparison Project (CMIP6) and provide a baseline against which further forced experiments may be assessed. Plain Language Summary: In this paper, we present the latest computer models of the joint atmosphere and ocean system. These models were developed at the U.K. Met Office Hadley Centre. They are designed to simulate the climate of the past, present, and future and to be used in scientific analysis and decision making. In this study, the are intended to simulate a continuous preindustrial state, to provide a reference level for future experiments and analysis. We present two resolutions of the same model, where the resolution is analogous to the number of pixels on, for example, a smartphone display. We find that the model with greater resolution also simulates many aspects of the global climate better than the model with lower resolution. These include El Niño, sea surface temperature variability in the Atlantic Ocean, and the depth of the AMOC in the North Atlantic. However, in other aspects, such as the strength of the major current circling Antarctica, this version is worse. Key Points: Preindustrial control simulations for CMIP6 with HadGEM3‐GC3.1 are presented using two model resolutionsOur evaluation focuses on interannual variability in key climate indicesThe high‐resolution model shows improvements in ENSO, AMV, and in the depth structure of the AMOC. However, the ACC strength is worse [ABSTRACT FROM AUTHOR]

Predicting North Atlantic hurricane activity months in advance is of great potential societal significance. The ocean temperature, both in terms of North Atlantic/tropical averages and upper ocean heat content, is demonstrated to be a significant predictor. To investigate the relationship between the thermal state of the Atlantic Ocean and the tropical cyclone (TC) activity in terms of accumulated cyclone energy (ACE), we use observed 1980-2015 TC records and a 1/4° resolution global ocean reanalysis. This paper highlights the nonlocal effect associated with eastern Atlantic Ocean temperature, via a reduction of wind shear, and provides additional predictive skill of TC activity, when considering subsurface temperature instead of sea surface temperature (SST) only. The most active TC seasons occur for lower than normal wind shear conditions over the main development region, which is also driven by reduced trade wind strength. A significant step toward operationally reliable TC activity predictions is gained after including upper ocean mean temperatures over the eastern Atlantic domain. Remote effects are found to provide potential skill of ACE up to 3 months in advance. These results indicate that consideration of the upper 40-m ocean average temperature improves upon a prediction of September Atlantic hurricane activity using only SST. [ABSTRACT FROM AUTHOR]

Recent increases in resolution of coupled ocean‐atmosphere models have the potential to improve the representation of poleward heat transport within the climate system. Here we examine the interplay between model resolution‐dependent changes in Atlantic Ocean heat transport (AOHT) and surface heat fluxes. The different roles of changes in atmospheric and ocean resolution are isolated using three different climate models (The Centro Euro‐Mediterraneo sui Cambiamenti Climatici Climate Model 2, Hadley Centre Global Environmental Model 3 – Global Coupled configuration 2, and European Community Earth‐System Model 3.1) and comparing runs in which (a) only the ocean resolution changes, (b) only the atmosphere resolution changes, and (c) both change. Enhancing ocean resolution from eddy parameterized to eddy permitting increases the AOHT throughout the basin, values changing from 1.0 to 1.2 PW at 26°N, bringing the AOHT into the range of estimates from the RAPID observing array. This increase in AOHT is associated with higher North Atlantic sea surface temperatures and increased ocean heat loss to the atmosphere. Increasing the atmospheric resolution alone has little impact on the AOHT due to regionally compensating changes in the components of the net heat flux. Finally, in a fourth experiment the impact of resolution changes in both components and the transition to an eddy‐resolving ocean is assessed. This additional resolution increase is accompanied by a further change in the AOHT and improves agreement with observations in the tropics but not the subpolar regions. However, unlike with the increase to the eddy‐permitting ocean, when the greatest AOHT change occurs in the subtropics and subpolar region, the most significant increase now occurs in the tropics. Plain Language Summary: The ocean and atmosphere export large amounts of heat from the tropics toward more poleward latitudes. In the Northern Hemisphere about 25% of this export is accomplished by the movement of water in the Atlantic Ocean. It is therefore important for climate models to accurately simulate this Atlantic Ocean heat transport (AOHT). However, historically climate models have typically underestimated AOHT relative to our best observations. This paper investigates how changing the size of the grid cells in the model changes both AOHT and the ocean‐to‐atmosphere exchange of heat in the model. Reducing the size of the grid cells in the models is referred to as increasing the resolution. Increasing the resolution of the ocean component of the model to 1/4° latitude and longitude increases AOHT, making agreement with observations better in the subtropics but slightly worse in subpolar regions. Increasing the resolution of the atmospheric part of the model had little effect on AOHT, instead bringing changes to different parts of the ocean‐to‐atmosphere heat exchange that compensate each other. Finally, we examined the AOHT in one of the newest climate models with even higher resolution (1/12° ocean and 25‐km atmosphere). Additional improvements in the simulation of AOHT were found. Key Points: Model resolution‐dependent changes in Atlantic Ocean heat transport and surface heat fluxes are determined using three climate modelsIncreasing ocean resolution to eddy‐permitting raises Atlantic heat transport; changing atmospheric resolution only impacts surface fluxesEnhancing ocean resolution to eddy‐resolving results in a further increase in Atlantic Heat Transport and the best observational agreement [ABSTRACT FROM AUTHOR]

Mesopelagic fishes play a central role in marine food webs linking primary consumers to top predators. In this study, measures of direct calorimetry were used to analyse the energy density (ED) of 34 mesopelagic species collected at 12 stations in the equatorial and tropical Atlantic. Mean ED ranged from 2.7 kJ g -1 wet weight (WW) for the lanterfish Lampanyctus nobilis to 8.7 kJ g -1 WW for the lanterfish Benthosema glaciale. This study includes species of the orders Myctophiformes and Stomiiformes and represents migrants, non-migrants and partial-migrants species. The majority of the species were grouped into the medium-energy quality category (ED from 4 to 6 kJ g -1 ); Myctophiformes showed higher energetic values than the Stomiiformes. For the different species, the ED values were discussed in relation to spawning period and energy allocation strategies for reproduction and growth and feeding and migratory behaviour, as well as the ecoregion of study. These values will be useful for future assessment of energetic transfer between trophic levels and energetic modelling of Atlantic ecosystems., (© 2023 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

The Galician coast (NW Spain) is a region that is strongly influenced by the presence of low pressure systems in the mid-Atlantic Ocean and the periodic passage of storms that give rise to severe sea states. Since its wave climate is one of the most energetic in Europe, the objectives of this paper were twofold. The first objective was to characterize the most extreme wave height events in Galicia over the wintertime of a two-year period (2015-2016) by using reliable high-frequency radar wave parameters in concert with predictions from a regional wave (WAV) forecasting system running operationally in the Iberia-Biscay-Ireland (IBI) area, denominated IBI-WAV. The second objective was to showcase the application of satellite wave altimetry (in particular, remote-sensed three-hourly wave height estimations) for the daily skill assessment of the IBI-WAV model product. Special attention was focused on monitoring Ophelia-one of the major hurricanes on record in the easternmost Atlantic-during its 3-day track over Ireland and the UK (15-17 October 2017). Overall, the results reveal the significant accuracy of IBI-WAV forecasts and prove that a combined observational and modeling approach can provide a comprehensive characterization of severe wave conditions in coastal areas and shows the benefits from the complementary nature of both systems. [ABSTRACT FROM AUTHOR]

The intra-annual variability of the tropical Atlantic Ocean north of the equator is investigated with satellite altimetry mean sea level anomaly data and with an algorithm based on empirical mode decomposition (EMD) methods. Two regions of high variability are identified. The first region, between 3° and 12°N, is characterized by the presence of westward-propagating eddies linked to the North Brazil Current (NBC) retroflection in the vicinity of the Brazilian coast. They show a strong annual cycle. In this paper the EMD algorithm points out that this signal is frequency modulated shifting from large length-scale structures in October to smaller ones in March. Consequently, the number of 'eddies' per year can be aliased, according to the time and location of sampling, and can impact the percentage they explain of the interhemispheric exchange of mass and heat associated with the meridional overturning circulation's upper limb. A scenario concerning this dynamics is proposed. The second region reveals the presence of westward-propagating instability waves centered north of the equator (3°-7°N) between 50° and 10°W. These instability waves are also frequency modulated and show a strong seasonal cycle with maximum amplitude around August. [ABSTRACT FROM AUTHOR]

The blue shark Prionace glauca is a top predator with one of the widest geographical distributions of any shark species. It is classified as Critically Endangered in the Mediterranean Sea, and Near Threatened globally. Previous genetic studies did not reject the null hypothesis of a single global population. The blue shark was proposed as a possible archetype of the "grey zone of population differentiation," coined to designate cases where population structure may be too recent or too faint to be detected using a limited set of markers. Here, blue shark samples collected throughout its global range were sequenced using a specific RAD method (DArTseq), which recovered 37,655 genome-wide single nucleotide polymorphisms (SNPs). Two main groups emerged, with Mediterranean Sea and northern Atlantic samples (Northern population) differentiated significantly from the Indo-west Pacific samples (Southern population). Significant pairwise F ST values indicated further genetic differentiation within the Atlantic Ocean, and between the Atlantic Ocean and the Mediterranean Sea. Reconstruction of recent demographic history suggested divergence between Northern and Southern populations occurred about 500 generations ago and revealed a drastic reduction in effective population size from a large ancestral population. Our results illustrate the power of genome scans to detect population structure and reconstruct demographic history in highly migratory marine species. Given that the management plans of the blue shark (targeted or bycatch) fisheries currently assume panmictic regional stocks, we strongly recommend that the results presented here be considered in future stock assessments and conservation strategies., (© 2022 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.)

This paper examines the difference in the Atlantic Meridional Overturning Circulation (AMOC) mean state between free and assimilative simulations of a common ocean model using a common interannual atmospheric forcing. In the assimilative simulation, the reproduction of cold cores in the Nordic Seas, which is absent in the free simulation, enhances the overflow to the North Atlantic and improves AMOC with enhanced transport of the deeper part of the southward return flow. This improvement also induces an enhanced supply of North Atlantic Deep Water (NADW) and causes better representation of the Atlantic deep layer despite the fact that correction by the data assimilation is applied only to temperature and salinity above a depth of 1750 m. It also affects Circumpolar Deep Water in the Southern Ocean. Although the earliest influence of the improvement propagated by coastal waves reaches the Southern Ocean in 10-15 years, substantial influence associated with the arrival of the renewed NADW propagates across the Atlantic Basin in several decades. Although the result demonstrates that data assimilation is able to improve the deep ocean state even if there is no data there, it also indicates that long-term integration is required to reproduce variability in the deep ocean originating from variations in the upper ocean. This study thus provides insights on the reliability of AMOC and the ocean state in the Atlantic deep layer reproduced by data assimilation systems. [ABSTRACT FROM AUTHOR]

This review provides an inventory of the biodiversity of the anisakid species identified so far from fish and marine mammals of the NE Atlantic Ocean. The paper reviews and discusses various taxonomical and epidemiological aspects related to biodiversity assessment, with emphasis on: (1) taxa recognized as 'biological species' based on molecular/genetic markers; (2) current molecular/genetic approaches to identify the species at different developmental stages; (3) ecological data related to the actual geographical distribution and definitive host preferences of the species; (4) their distribution in various, commercially important fish species in northern European waters; (5) their possible occurrence in farmed fish; and, finally, (6) an update of their zoonotic potential as causative agents of anisakidosis in humans. [ABSTRACT FROM AUTHOR]

Comparative tectonic analysis of passive margins of the Atlantic Ocean has been performed. Tectonotypes of both volcanic and nonvolcanic margins are described, and their comparison with other passive Atlantic margins is given. The structural features of margins, peculiarities of magmatism, its sources and reasons for geochemical enrichment of melts are discussed. The important role of melting of the continental lithosphere in the development of magmatism is demonstrated. Enriched EM I and EM II sources are determined for the lower parts of the volcanic section, and a depleted or poorly enriched source is determined for the upper parts of the volcanic section based on isotope data. The conclusions of the paper relate to tectonic settings of the initial occurrence of magmatism and rifting and breakup during the period of opening of the Mesozoic Ocean. It was found out that breakup and magmatism at proximal margins led only to insignificant structural transformations and reduction of the thickness of the ancient continental crust, while very important magmatic events happened later in the distal zone. New growth of magmatic crust at the stage of continental breakup is determined as a typical feature of distal zones of the margins under study. The relationship of development of margins with the impact of deep plumes as the source of magmatic material or a heat source only is discussed. Progradation of the zone of extension and breakup into the areas of cold lithosphere of the Atlantic and the formation of a single tectonomagmatic system of the ocean are under consideration. [ABSTRACT FROM AUTHOR]

Petermann Gletscher in North Greenland features the second largest floating ice shelf in the Northern Hemisphere. This paper describes the history of its exploration and presents new ocean and glacier observations. We find that the floating ice shelf is strongly coupled to the ocean below and to Nares Strait at time scales from tidal to interannual. Our observations cover the 2012 to 2016 period after two large calving events took place in 2010 and 2012 that reduced the ice shelf area by 380 km² to about 870 km² today. A potential third breakup, of an additional 150 km², is anticipated by a large fracture that extends from the margin to the center of the glacier. [ABSTRACT FROM AUTHOR]

This paper reports new data on the trace metal composition of planktonic foraminifer shells from surface sediments and cores (fraction >0.1 mm) in the central part of the Atlantic Ocean. This investigation has made it possible to identify a considerable accumulation of trace elements from water due to calcite entering into the crystal lattice under biomineralization and adsorption on the shell surface and pores, despite the fact that the shells are depleted in trace elements relative to pelagic clays. The trace element content in planktonic foraminifer microfossils is characterized by temporal variability, which is the most pronounced in long cores (Holocene-Upper Pleistocene) and reflects the sedimentation paleoenvironment in the ocean. [ABSTRACT FROM AUTHOR]

Catch, bycatch and discard information is important for the assessment and management of fisheries. Using Chinese pelagic tuna longline observer data from 2010 to 2018, we studied the catch composition in the Chinese pelagic tuna longline fisheries in Atlantic targeting bigeye tuna (Thunnus obesus) and bluefin tuna (Thunnus thynnus), and analyzed the survival status and discard rates of common bycatch species. A total of 55 species, including tunas, billfishes, sharks, sea turtles, cetaceans, seabirds, and other pelagic species, were observed. The results indicated that the catch composition of the Chinese pelagic tuna longline fishery targeting bigeye tuna was significantly different from that targeting bluefin tuna. The annual discard rates of common species decreased over this period. Discard rate by length and discard mortality for common species were varied among species. This is the first study to estimate catch, bycatch, and discard using Chinese pelagic tuna longline observer data in the Atlantic Ocean, which is important for the management of Chinese tuna longline fisheries in Atlantic Ocean. [ABSTRACT FROM AUTHOR]

The aim of this paper was to explore egg-laying areas of oviparous chondrichthyans occurring in the northern part of the Southwest Atlantic Ocean (36°S–41°S) at between 50 and 200 metres depth and the Mar del Plata Canyon (from 200 to 3447 m). A total of 515 capsules were collected corresponding to 10 species. Four species accounted for 87.6% of the total catch:Psammobatis normani,Bathyraja macloviana,Amblyraja doellojuradoiandBathyraja brachyurops.The remaining corresponded toSchroederichthys bivius,Psammobatis rudis,Zearaja chilensis,Bathyraja albomaculata,Psammobatis lentiginosaandBathyrajasp.Most hauls were monospecific and relatively few hauls contained four or five species (southern part of the area, in sites located at 75 and 94–105 m depth). No egg capsules were recorded between 1712 m and 3447 m. Highest densities (>3000 capsules/km2) were mainly found between 39°46.2′ and 40°29.9′S from 85 to 105 m and they were also recorded near the Mar del Plata Canyon at 37°59.7′S and at 852 m. The highest value recorded was 12,326 capsules/km2(located at 40°18.9′S and 85.4 m). The highest densities for each of the most abundant species are discussed. The finding of high densities of egg cases near the Argentine shelf-break front indicates that many skate species use this area as a nursery site. The egg-laying areas explored here are the first reported sites of this kind in the Southwest Atlantic Ocean. Recognizing and protecting egg-laying habitats may be important steps to a long-term conservation of oviparous chondrichthyan populations. [ABSTRACT FROM AUTHOR]

This paper explores the role of Hispania in the Atlantic route in Roman times. We analyse the different Atlantic Iberian territories along this route, based on recent archaeological advances and discoveries related to trade as well as the shipping infrastructure. The aim is to explain the origin and evolution of a new maritime area that was completely integrated with the political and commercial structure of the Empire, with trade routes that followed the coastal areas of the Iberian Peninsula all the way to the Mediterranean. [ABSTRACT FROM AUTHOR]

This paper aims to describe the spatial-temporal variability in catch of the main fishery resources of the Amazon River and floodplain lakes of the Lower Amazon, as well as relating the Catch per Unit of Effort with anomalies of some of the Amazon River, atmosphere and Atlantic Ocean system variables, determining the influence of the environment on the Amazonian fishery resources. Finfish landings data from the towns and villages of the Lower Amazon for the fisheries of three sites (Óbidos, Santarém and Monte Alegre), were obtained for the period between January 1993 and December 2004. Analysis of variance, detrended correspondence analysis, redundancy analysis and multiple regression techniques were used for the statistical analysis of the distinct time series. Fisheries production in the Lower Amazon presents differences between the Amazon River and the floodplain lakes. Production in the Amazon River is approximately half of the one of the floodplain lakes. This variability occurs both along the Lower Amazon River region (longitudinal gradient) and laterally (latitudinal gradient) for every fishing ground studied here. The distinct environmental variables alone or in association act differently on the fishery stocks and the success of catches in each fishery group studied here. Important variables are the flooding events; the soil the sea surface temperatures; the humidity; the wind and the occurence of El Niño-Southern Oscillation events. Fishery productivity presents a large difference in quantity and distribution patterns between the river and floodplain lakes. This variability occurs in the region of the Lower Amazon as well as laterally for each fishery group studied, being dependent on the ecological characteristics and life strategies of each fish group considered here. [ABSTRACT FROM AUTHOR]

The paper is devoted to salt tectonics in marginal oceanic salt-dome basins and is based on a wide synthesis of the literature and the author's data. For the first time, the general pattern of global distribution of these basins has been illustrated by a map. Their localization and structure, tectonic position and evolution, and peculiar morphokinematic features of salt tectonics are characterized and compared with the attributes of salt tectonics inherent to continental regions. The geodynamic settings of the initial formation of marginal oceanic basins and their present-day arrangement have been refined, as well as the onset of salt tectonics therein, manifested in various styles. It has been shown that the geodynamic type of basin and stages of its geodynamic evolution determine the morphokinematic type of salt tectonics, character of its manifestation, and dislocations in host sedimentary complexes, and, therefore, they are auxiliary indicators of geodynamic regimes. The mechanisms of salt tectonics, its effect on the structure of overlying sedimentary sequences, and localization of hydrocarbon fields are discussed. [ABSTRACT FROM AUTHOR]

This paper investigates the Atlantic Ocean influence on equatorial Pacific decadal variability. Using an ensemble of simulations, where the ICTPAGCM ('SPEEDY') is coupled to the NEMO/OPA ocean model in the Indo-Pacific region and forced by observed sea surface temperatures in the Atlantic region, it is shown that the Atlantic Multidecadal Oscillation (AMO) has had a substantial influence on the equatorial Pacific decadal variability. According to AMO phases we have identified three periods with strong Atlantic forcing of equatorial Pacific changes, namely (1) 1931-1950 minus 1910-1929, (2) 1970-1989 minus 1931-1950 and (3) 1994-2013 minus 1970-1989. Both observations and the model show easterly surface wind anomalies in the central Pacific, cooling in the central-eastern Pacific and warming in the western Pacific/Indian Ocean region in events (1) and (3) and the opposite signals in event (2). The physical mechanism for these responses is related to a modification of the Walker circulation because a positive (negative) AMO leads to an overall warmer (cooler) tropical Atlantic. The warmer (cooler) tropical Atlantic modifies the Walker circulation, leading to rising (sinking) and upper-level divergence (convergence) motion in the Atlantic region and sinking (rising) motion and upper-level convergence (divergence) in the central Pacific region. [ABSTRACT FROM AUTHOR]

Acoustics have been used in underwater communication and environmental sensing for a century. Sound waves propagate well in water; however, the marine environment poses many challenges to this phenomenon. Designing and deploying an underwater acoustic sensor network has always been a challenge due to the inhomogeneity of the propagation medium. In this paper, a background theory of the underwater sound propagation is provided followed by practical observations and insights into innovative ideas achieved in a lab-scale prototype which assisted in overcoming these challenges. These observations are used to propose a large-scale deployment strategy in the Northwest Atlantic region. Bellhop simulation results provide evidence of the effectiveness of a large-scale system design. This work is focused on finding optimal positioning of the acoustic sensors in the sea while minimizing the multipath effect at the receiver. In addition, the process for precise current speed measurement in a laboratory environment has been explained which elaborates on the practical aspects of a large-scale network deployment in the ocean. The Doppler effect, caused by the motion of the transducers due to wave motion in the sea, is also considered and analyzed for signal processing needs. [ABSTRACT FROM AUTHOR]

The antecedent atmospheric conditions at midmorning (1200 UTC or 0900 LST) related to subsequent squall-line (SL) initiation in the late afternoon or early evening over the northern coast of Brazil (NCB) were obtained for a specific month (July) when the SL initiation is independent of the strong synoptic forcing related to the intertropical convergence zone. The cases of SL and sparse deep convection in the late afternoon or early evening over the NCB were identified both objectively and subjectively, and grouped into either the SL category (SLC) or the no-convection category (NOC). For the central area of the NCB, the vertical profiles at midmorning for SLC and NOC, computed from radiosonde and ERA-Interim data spanning 9 years (2004-12), were compared. By focusing on the significant differences for both datasets, it was found that two midmorning conditions are favorable to SL initiation in July: a moister layer between 850 and 350 hPa, and a northeasterly flow at 350 hPa. These regional conditions are part of a larger-scale pattern: moister (drier) conditions over the whole NCB (southeastern South America) at 700 hPa and more intense anticyclonic circulation over the Atlantic Ocean close to northeastern Brazil at 350 hPa. The paper's findings have the potential to aid weather forecasting activities, such as those focused on the prediction of SL-related precipitation 6-12 h ahead. [ABSTRACT FROM AUTHOR]

This paper presents transport of a mixture of cohesive sediments and sand in the Paranagua Estuarine Complex in the south of Brazil. The estuary houses a navigation channel from the Atlantic Ocean to a busy harbour. The channel requires frequent dredging owing to sediment deposition to maintain navigable depth for vessels. A three-dimensional process-based model for sediment transport coupled with wave-current models based on the Delft3D modelling system is constructed for the estuary. Extensive field data concerning current velocity, water level, salinity and suspended sediment concentration were collected. The flow model that is necessary to run the sediment transport model was calibrated and validated using field measurements. In this paper only the results concerning the sediment motion are presented. Calibration and validation of the numerical model show that the results of sediment transport represent the field conditions well. Additional support for the validity of the computed results is provided by field data pertaining to bathymetry acquired in 2005 and 2006. The present study gives insight into the motion of cohesive sediments and the morphological behaviour of the estuary, and should help operators maintain the channel for navigation. [ABSTRACT FROM AUTHOR]

Simulations with a very high resolution (~25 km) global climate model indicate that more severe Autumn storms will impact Europe in a warmer future climate. The observed increase is mainly attributed to storms with a tropical origin, especially in the later part of the twentyfirst century. As their genesis region expands, tropical cyclones become more intense and their chances of reaching Europe increase. This paper investigates the properties and evolution of such storms and clarifies the future changes. The studied tropical cyclones feature a typical evolution of tropical development, extratropical transition and a re-intensification. A reduction of the transit area between regions of tropical and extratropical cyclogenesis increases the probability of re-intensification. Many of the modelled storms exhibit hybrid properties in a considerable part of their life cycle during which they exhibit the hazards of both tropical and extratropical systems. In addition to tropical cyclones, other systems such as cold core extratropical storms mainly originating over the Gulf Stream region also increasingly impact Western Europe. Despite their different history, all of the studied storms have one striking similarity: they form a warm seclusion. The structure, intensity and frequency of storms in the present climate are compared to observations using the MERRA and IBTrACS datasets. Damaging winds associated with the occurrence of a sting jet are observed in a large fraction of the cyclones during their final stage. Baroclinic instability is of great importance for the (re-)intensification of the storms. Furthermore, so-called atmospheric rivers providing tropical air prove to be vital for the intensification through diabatic heating and will increase considerably in strength in the future, as will the associated flooding risks. [ABSTRACT FROM AUTHOR]

This paper analyzes the sea surface height dataset from the TOPEX, Jason-1, and Jason-2 satellites of a 19-yr time series in order to extract the tide harmonic constituents for the region limited by latitude 5°N-35°S and longitude 55°-20°W. The harmonic analysis results implemented here were compared with the tidal constituents estimated by three classical tidal models [i.e., TOPEX/Poseidon Global Inverse Solution 7.2 (TPXO7.2), Global Ocean Tide 4.7 (GOT4.7), and Finite Element Solution 2102 (FES2102)] and also with those extracted from in situ measurements. The Courtier criterion was used to define the tide regimes and regionally they are classified as semidiurnal between the latitude range from approximately 5°N to 22°S, semidiurnal with diurnal inequality from 22° to about 29°S, and mixed southward of latitude 22°S. The comparison results among all tide approaches were done by analyzing the root-sum-square misfit (RSSmisfit) value. Generally, the RSSmisfit difference values are not higher than 12 cm among them in deep-water regions. On the other hand, in shallow water, all models have presented quite similar performance, and the RSSmisfit values have presented higher variance than the previous region, as expected. The major discrepancy results were particularly noted for two tide gauges located in the latitude range from 5°N to 2°S. The latter was investigated and conclusions have mainly pointed to the influence of the mouth of the Amazon River and the considerable distance between tide measurements and the satellite reference point, which make it quite hard to compare those results. In summary, the results have showed that all models presently generate quite reliable results for deep water; however, further study should done in order to improve them in shallow-water regions too. [ABSTRACT FROM AUTHOR]

In this paper author depicts the results of the sea trials of the operational test of a Hiload technology at sea waves with the numerical analysis for the dynamic forces and operational risk. The research was carried out on board MT "Navion Anglia" which was engaged in a towing operation through the Atlantic Ocean with a "Hiload DP1" prototype unit docked on her portside alongside, with different ship's draft and in different weather conditions. Additionally in this paper author presents the methods that can be used for estimating the safety factor SF against sliding and/or operational risk for the towing and/or manoeuvring operation with a "Hiload DP1" unit docked alongside at the open sea. [ABSTRACT FROM AUTHOR]

Oscillatory behavior of the Atlantic meridional overturning circulation (MOC) is thought to underlie Atlantic multidecadal climate variability. While the energy sources and sinks driving the mean MOC have received intense scrutiny over the last decade, the governing energetics of the modes of variability of the MOC have not been addressed to the same degree. This paper examines the energy conversion processes associated with this variability in an idealized North Atlantic Ocean model. In this model, the multidecadal variability arises through an instability associated with a so-called thermal Rossby mode, which involves westward propagation of temperature anomalies. Applying the available potential energy (APE) framework from stratified turbulence to the idealized ocean model simulations, the authors study the multidecadal variability from an energetics viewpoint. The analysis explains how the propagation of the temperature anomalies leads to changes in APE, which are subsequently converted into the kinetic energy changes associated with variations in the MOC. Thus, changes in the rate of generation of APE by surface buoyancy forcing provide the kinetic energy to sustain the multidecadal mode of variability. [ABSTRACT FROM AUTHOR]

The northern Mid-Atlantic Ridge, from Iceland to the Azores (MAR), is the largest topographical feature in the Atlantic Ocean. Despite its size, few studies have described dietary patterns of pelagic fishes along the MAR. MAR-ECO, a Census of Marine Life field project, aimed to describe the food web structure of abundant fish species along the ridge through a series of research expeditions to the MAR. Among the midwater fishes sampled during the MAR-ECO project, Bathylagus euryops (Osmeriformes: Bathylagidae) was the biomass-dominant pelagic species and ranked third in total abundance. In this paper, we describe the dietary composition of B. euryops along the MAR. Overall, copepods represented the dominant prey group consumed by B. euryops . Multivariate analyses, including a cluster analysis and a canonical correspondence analysis, revealed that fish size significantly influenced the diet of B. euryops with ostracods representing the most important prey group at small sizes (<95 mm) and decapod shrimp and calanoid copepods becoming more important with increasing fish size. Due to the high abundance and biomass observed along the MAR combined with its role as a link for energy transfer between zooplankton and higher trophic level predators, B. euryops appears to be an ecologically important species in the oceanic food web of the North Atlantic Ocean. [ABSTRACT FROM AUTHOR]

This article reports on new archaeological data obtained in 2018 from the coastal region of the Kongo Central province of the Democratic Republic of Congo (DRC). The area's ancient history is virtually unknown but is potentially of paramount importance in the context of the development of early village communities in Central Africa. The article focuses on the Muanda 6 site, dated to ⁓ 1400 BP, and offers a multidisciplinary analysis of the finds uncovered there. The site's pottery is associated with shell and stone beads, ironworking remains, a stone quern, and biological remains testifying to a mixed subsistence system that took advantage of the region's ecological diversity. The Early Iron Age occupants of Muanda 6 practiced ocean and mangrove fishing, gathered beach and mangrove gastropods and bivalves, hunted, and exploited oil palms. The article also discusses the Muanda 13 site, which is more recent (⁓ 1100 BP), and the results of the profile sampling at the Katala village. Both Muanda 6 and Muanda 13 yielded different ceramic types. Other pottery styles, surface collected between the Congo River and the Angolan province of Cabinda and probably of more recent date, are briefly described. The results provide new perspectives about the Iron Age in the DRC, providing further evidence of the cultural diversity in the Lower Congo region and an outline of the cultural sequence along the Atlantic Ocean coast. Résumé: Cet article rend compte de nouvelles données archéologiques obtenues en 2018 dans la région côtière de la Province du Kongo-Central en République démocratique du Congo. L'histoire ancienne de cette région est pratiquement inconnue, mais elle est potentiellement d'une importance capitale dans le contexte de l'installation des premiers villages en Afrique centrale. Les travaux se concentrent sur le site de Muanda 6, daté vers 1400 BP, dont les trouvailles sont étudiées dans une perspective multidisciplinaire. La poterie de ce site est associée à des perles de coquillages et de pierre, à des traces de travail du fer, et à une meule en pierre ainsi qu'à des restes biologiques témoignant d'un système de subsistance mixte reposant sur divers écotones. Les occupants de l'Age du Fer Ancien de Muanda 6 pratiquaient la pêche en mer et dans la mangrove, la collecte de gastéropodes et de bivalves sur la plage et dans la mangrove, la chasse et l'exploitation des palmiers à huile. Le site plus récent de Muanda 13 (vers 1100 BP), ainsi qu'une collecte stratigraphique dans la berge du village de Katala, ont permis de découvrir un autre type de céramique. L'article décrit un dernier style de poterie probablement plus récent et découvert en surface entre le fleuve Congo et la frontière de la province angolaise de Cabinda. Les résultats présentés ici offrent de nouvelles perspectives à l'Age du Fer sur la diversité culturelle dans la région du Bas-Congo et propose l'esquisse d'une séquence culturelle au long de la côte de l'Océan Atlantique. [ABSTRACT FROM AUTHOR]

Abstract: In recent decades there has been steady progress towards a risk-based management approach for fisheries. An important first step in a risk analysis framework is scoping to identify, describe and catalog the sources of uncertainty that might have an impact on a fishery. This paper introduces a methodology based on a range of tools to formalize the process of elicitation of uncertainties, from both experts and stakeholders, for the International Commission for the Conservation of Atlantic Tunas (ICCAT). ICCAT is a regional fisheries management organization responsible for the conservation of tunas and other highly migratory fish in the Atlantic Ocean and its adjacent seas. The aim of the elicitation was to identify and prioritize uncertainties for inclusion in Operating Models for Management Strategy Evaluation (MSE). The tool presented in this paper supports the qualitative prioritization of uncertainties, while also visualizing the degree of consensus among stakeholders on particular issues. Perceptions of uncertainty in fisheries often vary widely among scientists, industry and other interest groups, so tools that can facilitate inclusion and representation of different opinions are useful where decision-making depends on broad agreement and more generally, where effective management depends on commitment from stakeholders. [Copyright &y& Elsevier]

Since 1850, the rise in global mean surface temperatures (GMSTs) from increasing atmospheric concentrations of greenhouse gases (GHGs) has exhibited three ~30-year hiatus (surface cooling) episodes. The current hiatus is often thought to be generated by similar cooling episodes in Pacific or Atlantic ocean basins. However, GMSTs as well as reconstructed Atlantic and Pacific ocean basin surface temperatures show the presence of similar multidecadal components generated from a three-dimensional analysis of differential gravitational (tidal) forcing from the sun and moon. This paper hypothesizes that these episodes are all caused by external tidal forcing that generates alternating ~30-year zonal and meridional circulation regimes, which respectively increase and decrease GMSTs through tidal effects on sequestration (deep ocean heat storage) and energy redistribution. Hiatus episodes consequently coincide with meridional regimes. The current meridional regime affecting GMSTs is predicted to continue to the mid-2030s but have limited tendency to decrease GMSTs from sequestration because of continuing increases in radiative forcing from increasing atmospheric GHGs. The tidal formulation also generates bidecadal oscillations, which may generate shorter ~12-year hiatus periods in global and ocean basin temperatures. The formulation appears to assimilate findings from disciplines as disparate as geophysics and biology. [ABSTRACT FROM AUTHOR]

Abstract Knowledge of population spatial structure is essential in fisheries management. The study of morphological variation patterns in fishes can indicate differences in growth and maturation rates, and thus provide information on group dynamics that should be modelled and managed separately. Identification of intraspecific groups which have different life history features is necessary for understanding population dynamics and achieving a sustainable harvest. The black seabream, Spondyliosoma cantharus , has an extensive distribution along the eastern Atlantic Ocean and is an important commercial fish, exploited in European waters by recreational and commercial fishers. In this paper, body geometric morphometrics was used in order to discriminate among black seabream geographical populations caught in seven different geographical areas. The results showed the existence of intraspecific groups of black seabream across the eastern Atlantic Ocean, with Canary and Angola having clear distinct morphotypes and at least four populations in the European Coast (English Channel, Galicia, Peniche and Algarve) that present stable body shape differences. These populations should be considered to be separate and studies on life history parameters should be enhanced and updated. [ABSTRACT FROM AUTHOR]