Upwelling

The Regional Ocean Modeling System (ROMS) is used to systematically investigate equilibrium conditions and seasonal variations of the Benguela system at a resolution of 9 km, including both the large-scale offshore flow regime and the economically and ecologically important coastal upwelling regime. A shelf-edge poleward flow exists in the northern Benguela region (i.e., north of ∼28°S) and is driven primarily by the wind stress curl via the Sverdrup relation. As such, it is strongly seasonal and is most intense during spring and summer, when the wind stress curl is most negative. The poleward flow deepens as it moves southward; between ∼25° and 27°S, much of it veers offshore because of the nature of the wind stress curl and its interaction with the northwestward path of the Benguela Current, which is influenced by alongshore topographical variations. The Benguela Current is driven by nonlinear interactions of passing Agulhas rings and eddies and does not have a striking seasonal s...

Jordan is well known for its Cretaceous phosphorite deposits. These comprise the phosphorite-bearing sediments which overlie the main chert facies of the Amman Formation. Phosphorites have been mined since the 1950s in north and central Jordan. Tectonic 'windows' or 'inliers' reveal the Upper Cretaceous sequence in the SE desert of Jordan in several localities underlying the main chert facies. These newly discovered phosphorite deposits are sandy with P 2 O 5 ranging from less than 1% to more than 33%. They form a belt extending in a NE-SW direction for about 200 km, and into NW Saudi Arabia. The equivalent sequence in western Jordan is fully calcareous and devoid of phosphorites. The southern segment of this belt (about 80 km) may have as much as 4 billion tonnes of phosphorite containing more than 20% P 2 O 5. These phosphorites are postulated to have been deposited in a restricted nearshore environment by local upwelling around the Sirhan Arch, a mid Cretaceous positive feature in the study area which also served as the source for sand.

The distribution of nepheloid layers across the outer shelf and upper continental slope off Namibia was studied during a cruise with R.V. Meteor in late austral summer 2003. Optical measurements, carried out with a transmissometer and a backscattering fluorometer, are correlated with suspended particulate matter (SPM) and particulate organic carbon (POC) values from water sample filtration. Conductivity-temperature-depth and oxygen data are used to relate the nepheloid layers to hydrographic structures. The particle content of surface water at the continental slope is controlled primarily by the offshore extension of highly productive upwelling filaments. A pronounced bottom nepheloid layer (BNL) covers the entire area of study with maximum intensity above the outer shelf and at the shelf break-an area where erosional forces dominate. The detachment of this BNL at the shelf break feeds a major intermediate nepheloid layer (INL) at 25.51S. This INL is positioned at 250-400 m depth, at the lower boundary of an oxygen minimum zone, and is likely connected to the poleward flow of South Atlantic Central Water (SACW) across the shelf break. Together, these strong subsurface nepheloid layers are indicators of intensive lateral particle transport from the outer shelf towards a depocenter of organic matter on the upper continental slope. r

The Upper Campanian Mishash Formation of southern Israel was deposited within the southern Tethys upwelling belt, with sea floors beneath this system characterized by poorly ventilated sediments approaching anoxia. This study was aimed at tracking the oxygen-poor gradient using benthic foraminiferal assemblages of organic-rich carbonates that are devoid of benthic macro-invertebrates and trace fossils.Quantitative data were gathered on foraminiferal faunas

Global climate change is expected to intensify hypoxic conditions during coastal upwelling events along the west coast of North America, but the potential effects on nearshore fishes are not well understood. Viviparous rockfishes (genus Sebastes) that gestate and give birth during the upwelling season, such as gopher rockfish (S. carnatus), may be among the most affected. We tested the transgenerational effects of future hypoxic conditions on the metabolic status of gopher rockfish larvae. Four pregnant females were held during gestation in either ambient conditions (DO~8 mg/L) or a hypoxic treatment (DO~4 mg/L). A subset of larvae was sampled immediately post-parturition and remaining larvae were then split into two groups and placed in either control or hypoxic conditions for five days and sampled again. Citrate synthase (CS) and lactate dehydrogenase (LDH), proxies for aerobic and anaerobic metabolism, respectively, were assayed in pooled larval samples from all treatments. We expected that larvae would exhibit relatively greater reliance on aerobic metabolism (e.g., higher CS/LDH ratios) if exposure to hypoxia during pregnancy enhances larval performance to hypoxia post-parturition, compared with larvae from control mothers. We also expected that larvae from control mothers would exhibit relatively greater reliance on anaerobic metabolism if exposed to hypoxic post-parturition. Lastly, we hypothesized that larvae from hypoxic mothers would rely more on anaerobic metabolism immediately post-parturition. At birth, we found larvae from hypoxic mothers were more anaerobic compared to those from control mothers, but after five days we found trends that larvae from hypoxic mothers that continued developing in hypoxic conditions were more aerobic compared to those from control mothers. Our findings suggest the potential for larval gopher rockfish to exhibit a more aerobic phenotype when gestated during hypoxic conditions and placed in similar conditions post-parturition.

A three-dimensional (3D) numerical model using the finite element method was used to diagnose coastal currents off Antofagasta, in the upwelling region of northern Chile. The diagnosis was emphasized in the nearshore zone off Peninsula Mejillones (23°S), a well-known upwelling site off northern Chile. Water density fields, available from seasonal climatologies of the region, were used to predict currents for the austral winter, and summer conditions. Steady-state conditions were simulated under absence of wind, with a constant southwest wind of 10 knots (5.14 m s−1), which is the dominant upwelling-favorable wind in the zone, and with a constant north wind of 10 knots. Spatial variability of winds was examined by using historical wind fields for the region. A 3D particle tracking program was further used to diagnose expected particle trajectories over a 72 h steady-state period. Coastal circulation was dominated by alongshore currents, and presence of reversal currents and coastal eddies. Wind forcing accelerated the flow of the nearsurface layer in most cases, but did not considerably alter the circulation pattern of the average water column. Simulation of passive particle drift showed that the whole nearshore zone might act as an efficient retention area. It was concluded that, as a result of the interactions among distinct water masses, upwelling plumes, and alongshore currents, physical barriers may develop and give rise to semi-enclosed habitats. Physical structuring may have important ecological implications for the upwelling ecosystem.

Geologic studies indicate that prior to --40 Ma the Drake Passage was closed and the Central American Isthmus was open. The effect of these changes has been examined in an ocean general circulation model. Several sensitivity experiments were conducted, all with atmospheric forcing and other boundary conditions from the present climate, but with different combinations of closed and open gateways. In the first experiment, the only change involved closure of the Drake Passage. In agreement with earlier studies the barrier modified the geostrophic balance that now maintains the circumpolar flow in the southern ocean, with the net effect being decreased transport of the Antarctic Current and an approximate fourfold increase in outflow of Antarctic deep-bottom waters. The very large increase in Antarctic outflow suppresses North Atlantic Deep Water (NADW) formation. In addition to corroboration of results from earlier studies, our simulations provide several new insights into the role of a closed Drake Passage. A more geologically realistic closed Drake/open central American isthmus experiment produces essentially the same pattern of deepwater circulation from the first experiment, except that Antarctic outflow is about 20% less than the first experiment. The resultant unipolar deepwater circulation pattern for the second experiment is consistent with paleoceanographic observations from the early Cenozoic. A third Copyright 1993 by the American Geophysical Union. Paper number 93PA00893. 0883-8305/93/93PA-00893510.00 experiment involved an open Drake and open central American isthmus. In this experiment, Antarctic outflow is diminished to slightly above present levels but NADW production is still low due to free exchange of low-salinity surface water between the North Pacific and North Atlantic. The low level of thermohaline overturn should have reduced oceanic productivity in the Oligocene (.--30 Ma), a result in agreement with geologic observations. Finally, simulations with an energy balance model demonstrate that the changes in surface heat flux south of 60øS due to breaching of the Drake barrier do not result in temperature changes large enough to have triggered Antarctic glaciation. This last result suggests that some other factor (CO27) may be required for Antarctic ice sheet expansion in the Oligocene (-•30-34 Ma). Our results lend further support to the concept that even in the absence of changing boundary conditions due to ice sheet growth, variations in the geometry of the ocean basins can significantly influence ocean circulation patterns and the sediment record. The results also suggest that the primary polarities of the Cenozoic deepwater circulation may have been controlled by opening and closing of these two gateways. Cox, M.D., An idealized model of the world ocean, Part I, The global-scale water masses, J. Phys. Climate model comparison of Gondwanan and Laurentide glaciations, J. Geophys. Res., 96, 9217-9226, 1991.

Eastern boundary current systems are among the most productive and lucrative ecosystems on Earth because they benefit from upwelling currents. Upwelling currents subsidize the base of the coastal food web by bringing deep, cold and nutrient-rich water to the surface. As upwelling is driven by large-scale atmospheric patterns, global climate change has the potential to affect a wide range of significant ecological processes through changes in water chemistry, water temperature, and the transport processes that influence species dispersal and recruitment. We examined long-term trends in the frequency, duration, and strength of continuous upwelling events for the Oregon and California regions of the California Current System in the eastern Pacific Ocean. We then associated event-scale upwelling with up to 21 years of barnacle and mussel recruitment, and water temperature data measured at rocky intertidal field sites along the Oregon coast. Our analyses suggest that upwelling events are...

According to the new proposed model, in addition to the anthropogenic carbon dioxide (CO2) due to land -use change and fossil fuel burning, significant emissions of CO2 are released from the ocean at sites of upwelling currents, which connect the global overturning circulation with the sea surface, as exemplified by the upwelling currents along the Antarctic Circumpolar Current (ACC). Carbon dioxide was sequestered in deep oceanic layers which were disturbed through detonations of the nuclear bomb tests early in the1960s as confirmed by multiple time series of temperature and geochemical records. New features contributed to this article are
• the abrupt and vigorous change of the climate since about 1960, by contrast to the mild and gradual warming since the beginning of the Industrial Era, a period of adaptation after the cold Little Ice Age
• the identification of the temporal coincidence of the initiation of the severe climate change in the 1960s with the bomb tests associated with geochemical anomalies and steady temperature increase,
• the outrageous rate of CO2 emission, five times higher than similar extreme events in the geological past,
• the function of the Southern Ocean both as sink and as source of CO2 with prevailing outgassing currently,
• the heat engine along the boundary of the Antarctica Lithospheric Plate which stimulates upwelling and causes widespread continental warming of the West Antarctic climate, confirmed since 1958.
Therefore, apart from the Greenhouse Effect, we are currently confronted with the Nuclear Bomb Effect, a much more severe likelihood. It is not argued that the Bomb Effect is a proven fact, but only that there are strong indications for it and therefore it is an emergency for the scientific community to accelerate the investigations by absolute priority, which requires significant international support.
The evidence for the climatic change predominantly is based on measurements of the temperature globally and the increase of the carbon dioxide in the atmosphere and the oceans. The relevant data are reconsidered based on the latest results and their current interpretation. Multiple time series are correlated, including the temperature, the greenhouse gases, the isotopic values of the radiocarbon (14C) and the stable isotope 13C. Furthermore, it is suggested that field surveys and modeling applications in the latest couple of years indicate that the Southern Ocean surrounding Antarctica is very likely a source of carbon dioxide from deep oceanic waters in tandem with CO2 intake at the ocean surface from the atmosphere. It is not considered a coincidence that the increase of temperature and the geochemical anomalies start simultaneously with the nuclear bomb spike, approximately in 1960, as highlighted in the following.
The temperature increase is still in the expected range of warming after the cold period of the Little Ice age from 1570 to 1900 AD in the Northern Hemisphere. However, the CO2 increase is beyond any geological record, continues, and will persist so for some time, even after zeroing the fossil fuel burning. The reason is that a proportion of the CO2 in the atmosphere comes from sequestered gases in the ocean which travel southwards along the Global Overturning Circulation to join the Antarctic Circumpolar Current, where they upwell heated by the oceanic ridge of the Antarctic Lithospheric Plate and the elevated relief of the ridge.
It is not argued that the Bomb Effect is a proven fact, but only that there are reliable indications for it and therefore it is an emergency for the scientific community to accelerate the investigations in Antarctica by absolute priority which requires international support and coordination.

This work encompasses three years of nocturnal zooplankton samplings in the Ría de Vigo (2008-2009), as well as two oceanographic surveys over the shelf and continental slope off NW Iberian Peninsula (CAIBEX-I) and NW Africa (CAIBEX-III). Its aim was to understand basic aspects of the the planktonic paralarvae of Octopus vulgaris like their diet in the wild, their vertical and horizontal distributions in upwelling areas, its interactions with the zooplankton and their mortality. Secondary aims were: to study the ecology of other cephalopod species found together with O. vulgaris in the Ría de Vigo, as well as to compare the assemblage of cephalopod paralarvae and macrozooplankton found in two contrasting coastal areas, one with a seasonal upwelling like Cape Silleiro (CAIBEX-I) and the other with a quasi-permanent upwelling like Cape Ghir (CAIBEX-III). Finally, we aimed to identify the potential predators of cephalopod paralarvae among the macrozooplankton of the pelagic realm. Octo...

Data from field observations and numerical model simulations are used to understand and quantify the pathways by which passive tracers penetrate into the Black Sea intermediate and deep layers. Chlorofluorocarbon (CFC) concentrations measured during the1988 R.V. Knorr cruise show strong decrease with increasing density in the Black Sea and illustrate the very slow rate of ventilation of deep water in this basin. We develop a 3D numerical model based on the Modular Ocean Model (MOM), and calibrate it in a way to produce consistent simulations of observed temperature, salinity and CFCs. One important feature is the implementation of a special parameterization for convection, which is an alternative of the convective adjustment in MOM and handles the penetration of the Bosporus plume into the halocline. The model forcing includes interannually variable wind, heat and water fluxes constructed from Comprehensive Ocean-Atmosphere Data Set and ECMWF atmospheric analysis data and river runoff data. The analysis of observations and simulated data are focused on correlations between thermohaline and tracer fields, dynamic control of ventilation, and the relative contributions of sources at the sea surface and outflow from the Bosporus Strait in the formation of intermediate and deep waters. A simple theory is developed which incorporates the outflow from the strait along with the vertical circulation (vertical turbulent mixing and Ekman upwelling) and reveals their mutual adjustment. The analyses of simulated and observed CFCs demonstrate that most of the CFC penetrating the deep layers has its source at the sea surface within the Black Sea rather than from the Marmara Sea via the Bosporus undercurrent. Under present-day conditions, the surface CFC signals have reached only the upper halocline. Intrusions below 600 m are not simulated. The major pathways of penetration of CFCs are associated with cold-water ARTICLE IN PRESS www.elsevier.com/locate/dsr 0967-0637/$ -see front matter r mass formation sites, Bosporus effluent, as well as with the diapycnal mixing in the area of Rim Current. Future CFC sampling strategies coherent with the unique conditions in the Black Sea are discussed. r

Resumo: As datas de radiocarbono obtidas a partir de amostras de biosfera marinha não têm sido tão utilizadas como as determinadas a partir de amostras da biosfera terrestre para a construção de cronologias absolutas, dado que factores oceanográficos podem levar a interpretações ou usos incorrectos dessas datas. Contudo, os moluscos marinhos foram utilizados abundantemente na dieta pré-histórica, designadamente a partir do início do Holocénico, e as suas conchas encontram-se em grande quantidade em muitos sítios arqueológicos. É, por conseguinte, necessária uma investigação prévia, no que se refere às condições oceanográficas e ao efeito de reservatório marinho para uma determinada região oceanográfica, se se quiser utilizar datas de amostras da biosfera marinha dessa região na construção de cronologias absolutas rigorosas e fiáveis. Investigações desse tipo têm já sido levadas a cabo para algumas regiões, nomeadamente para a Ibéria Atlântica. Foram, assim, determinados valores do parâmetro ΔR -denominado efeito de reservatório marinho ou oceânico para o radiocarbono -para as águas que banham as costas atlânticas da Península Ibérica, o que permite a construção de cronologias absolutas para estas regiões fazendo uso de datas de radiocarbono marinhas. Além disso, a investigação realizada permite algumas inferências paleoambientais: i) durante o Holocénico têm ocorrido importantes variações nos valores do efeito de reservatório marinho para as costas atlânticas da Península Ibérica; ii) essas variações deverão estar correlacionadas com modificações das condições oceanográficas regionais, designadamente com modificações da intensidade do upwelling costeiro; iii) essas variações sugerem algum tipo de variabilidade dos factores climáticos que estão por detrás do upwelling existente nas costas atlânticas da Península Ibérica.

Observations along ten shelf transects in 2012 near 10°N in the southeastern Arabian Sea revealed the usual warm oligotrophic conditions during the winter monsoon (WM) and upwelling of oxygen-deficient, nutrient-rich cool water during the summer monsoon (SM). By changing an oligotrophic to a nutrient-replete condition, the upwelling is the major process that regulates the biogeochemistry of this shelf. Its onset is perceptible at 100 m depth between January and March. The upwelling reaches the surface layer in May and intensifies during June-July but withdraws completely and abruptly by October. Despite the nutrient injection, the primary production during SM, integrated for euphotic zone is comparable to that during the preceding spring intermonsoon (SIM). Again as usual the high oxygen demand coupled with low concentration in the upwelled subsurface waters causes severe oxygen depletion below the shallow pycnocline. The oxygen concentrations/ saturations of 2012 on the mid-shelf are similar from those of mid-1958 to early 1960, except for marginally higher values during the peak upwelling period due to relatively weak upwelling in 2012. This implies little anthropogenic influence on coastal hypoxia unlike many other coastal regions. In 2012, the inner shelf system shifted from net autotrophy in SIM to net heterotrophy in SM but on an annual basis it was net-autotrophic (gross primary production to community respiration ratio, GPP/R: 1.11 ± 0.84) as organic production exceeded consumption.

Effective conservation and management of natural resources requires accurate predictions of ecosystem responses to future climate change, but environmental science has largely failed to produce these reliable forecasts. The future response of Pacific salmon (Oncorhynchus spp.) to a changing environment and continued anthropogenic disturbance is of particular interest to the public because of their high economic, social, and cultural value. While numerous retrospective analyses show a strong correlation between past changes in the ocean environment and salmon production within the north Pacific, these correlations rarely make good predictions. Using a Bayesian timeseries model to make successive 1-yr-ahead forecasts, we predicted changes in the ocean survival of Snake River spring/summer chinook salmon (O. tshawytscha) from indices of coastal ocean upwelling with a high degree of certainty (R 2 ¼ 0.71). Furthermore, another form of the dynamic times-series model that used all of the available data indicated an even stronger coupling between smolt-to-adult survival and ocean upwelling in the spring and fall (R 2 ¼ 0.96). This suggests that management policies directed at conserving this threatened stock of salmon need to explicitly address the important role of the ocean in driving future salmon survival.

A three-dimensional (3D) numerical model using the finite element method was used to diagnose coastal currents off Antofagasta, in the upwelling region of northern Chile. The diagnosis was emphasized in the nearshore zone off Peninsula Mejillones (23 S), a well-known upwelling site off northern Chile. Water density fields, available from seasonal climatologies of the region, were used to predict currents for the austral winter, and summer conditions. Steady-state conditions were simulated under absence of wind, with a constant southwest wind of 10 knots (5.14 m s À1), which is the dominant upwelling-favorable wind in the zone, and with a constant north wind of 10 knots. Spatial variability of winds was examined by using historical wind fields for the region. A 3D particle tracking program was further used to diagnose expected particle trajectories over a 72 h steady-state period. Coastal circulation was dominated by alongshore currents, and presence of reversal currents and coastal eddies. Wind forcing accelerated the flow of the nearsurface layer in most cases, but did not considerably alter the circulation pattern of the average water column. Simulation of passive particle drift showed that the whole nearshore zone might act as an efficient retention area. It was concluded that, as a result of the interactions among distinct water masses, upwelling plumes, and alongshore currents, physical barriers may develop and give rise to semi-enclosed habitats. Physical structuring may have important ecological implications for the upwelling ecosystem.

The Guinea Current Large Marine Ecosystem (GCLME) extending from Bissagos Island (Guinea Bissau) in the north to Cabinda (Angola) in the south defines the shared transboundary waters off the coast of western Africa, which embodies some of the major coastal upwelling sub-ecosystems of the world and is an important centre of marine biodiversity and marine food production. The GCLME is characterized by distinctive bathymetry, hydrography, chemistry, and trophodynamics and represents the number 28 Large Marine Ecosystem (LME) ranked among the most productive coastal and offshore waters in the world with rich fishery resources. However, over-exploitation of fisheries, pollution from domestic and industry sources, habitat destruction and poorly planned and managed coastal developments and near-shore activities are resulting in a rapid depletion of the rich fisheries resources and degradation of vulnerable coastal and offshore habitats putting the economies, productivity and health of the populace at risk. Recognizing the urgency of the fisheries decline and the environmental and socio-economic consequences for the region, the 16 countries bordering the ecosystem have mobilized complementary resources to the funding from the Global Environment Facility and United Nations Industrial Development Organization to implement priority management actions agreed in the preliminary Strategic Action Programme for the recovery of depleted fish stocks and restoration of degraded habitats for the advancement of the achievement of the World Summit on Sustainable Development (WSSD) Johannesburg Plan of Implementation targets for recovery of fish stocks.

RESUMEN. En este estudio se caracterizaron los patrones de circulación en el interior del Golfo de Arauco (37°10'S -36°45'S, Chile) que están asociados a períodos de intensificación y relajación de la surgencia costera durante un período de transición verano-otoño. Se analizaron imágenes satelitales de TSM (10, 16, 22 y 27 de marzo), series de corrientes (a 10 y 28 m) provenientes de tres fondeos de correntómetros y series de viento. Los resultados muestran que la marea semidiurna, las fluctuaciones diurnas del viento S-SW y los procesos de surgencia y de hundimiento en la plataforma adyacente al Golfo, son factores importantes en la determinación de la circulación al interior de éste. La discusión se centró en fluctuaciones del orden de tres a diez días identificándose, durante el período de estudio, 4 eventos de relajación (9-13, 19-20, 23-24, y 30-31 de marzo) y 4 de surgencia (2-8, 14-18, 21-22 y 25-29 de marzo) adyacentes al Golfo. El viento S-SW, favorable a surgencia, forzó una circulación antihoraria de una sola capa durante el máximo desarrollo de la surgencia. Durante viento N, en cambio, la circulación mostró una tendencia horaria durante procesos de hundimiento fuera del Golfo. En períodos de transición o debilitamiento del viento, ya sea de viento S-SW o N, la circulación mostró un sistema de doble capa: superficial antihoraria y subsuperficial horaria. Se propone un esquema conceptual de la circulación del Golfo de Arauco en períodos de Surgencia-Relajación basado en el patrón de circulación subinercial. Este patrón dependió, principalmente, de las fluctuaciones de la intensidad y dirección del viento y de la entrada de agua hacia el interior del Golfo a través de su "Boca Grande".

The middle Miocene marly sediments in the southwestern Paratethys (Central Europe) have been studied
for calcareous nannofossil assemblages. Palaeoecological and palaeogeographic parameters, based on
siliceous microfossils (diatom and silicoflagellate), are emended into the palaeoecological preferences
of coccoliths, as are data from their modern analogies, giving more precise results. This study deals with
complex shallow and deep water marine systems and the regional and global events that influenced the
changes of the marginal part of study area and its species diversity. The link between the middle Miocene
tectonic events and Paratethyan gateways resulted in a changing of environments and marine circulations,
and their concomitant effects on the paleoclimate. These impacts induced the (earlier) appearance
of specific and endemic species (Calcidiscus pataecus, Noelaerhabdus bozinovicae, Isolithus semenenko,
Amaurolithus group) and a reduced diversity in the highly fluctuating marine environments. For the first
time, the termination of the Earth’s most recent major warm episode (the mid-Miocene climate optimum)
is observed in the early to mid-Sarmatian transition in the North Croatian and Vienna Basins via
observations of the changing of the local climate and circulation (upwelling) systems. Based on the
palaeoecological data of the r-selected strategies that dominate the assemblages, it was possible to reconstruct
the short-term, small-scale variations of the temperature, salinity, primary productivity, nutrient
supply, freshwater influx and relative sea level changes in the highly dynamic nearshore setting. The similarities
and differences between the Paratethyan basins, together with their palaeoecological interpretations,
contribute to the broader picture of Paratethyan evolution, climate change and its connectivity
with other marine areas.

Two sediment cores retrieved from the continental slope in the Benguela Upwelling System, GeoB 1706 (19°33.7'S 1 l°10.5'E) and GeoB 1711 (23°18.9'S, 12°22.6'E), reveal striking variations in planktonic foraminiferal abundances during the last 160,000 years. These fluctuations are investigated to assess changes in the intensity and position of the upwelling centres off Namibia. Four species make up over 95% of the variation within the core, and enable the record to be divided into episodes characterized by particular planktonic foraminiferal assemblages. The fossil assemblages have meaningful ecological significance when compared to those of the modern day and the relationship to their environment. The cold-water planktonic foraminifer, Neogloboquadrina pachyderma sinistral [N. pachyderma (s)], dominates the modern-day, coastal upwelling centres, and Neogloboquadrina pachyderma dextral and Globigerina bulloides characterize the fringes of the upwelling cells. Globorotalia inflata is representative of the offshore boundary between newly upwelled waters and the transitional, reduced nutrient levels of the subtropical waters. In the fossil record, episodes of high N. pachyderma (s) abundances are interpreted as evidence of increased upwelling intensity, and the associated increase in nutrients. The N. pachyderma (s) record suggests temporal shifts in the intensity of upwelling, and corresponding trophic domains, that do not follow the typical glacial-interglacial pattern. Periods of high N. pachyderma (s) abundance describe rapid, discrete events dominating isotope stages 3 and 2. The timing of these events correlates to the temporal shifts of the Angola-Benguela Front situated to the north of the Walvis Ridge. Absence of high abundances of N. pachyderma (s) from the continental slope of the southern Cape Basin indicates that Southern Ocean surface water advection has not exerted a major influence on the Benguela Current System. The coincidence of increased upwelling intensity with the movement of the Angola-Benguela Front can be interpreted mainly by changes in strength and zonality of the trade wind system.

This study analyzes the characteristics of upwelling events during the northeast monsoon, as
well as El-Niño impacts towards upwelling in the northwest Sabah, which is located in southern
part of the South China Sea by combining remote sensing, reanalysis, and modeling data. The
data used in this study obtained from Moderate Resolution Imaging Spectroradiometer (MODIS)
Aqua satellite for the sea surface temperature (SST) and chlorophyll a concentration data, Hybrid
Coordinate Ocean Model (HYCOM) for the vertical cross section of temperature and salinity
data, and European Centre for Medium-range Weather Forecast (ECMWF) Interim Reanalysis
(ERA-Interim) for the wind data, as well as Ekman transport and Ekman pumping analysis during
December to April 2003-2016. The monthly mean of the climatological data were analyzed and
the results showed that the MODIS-Aqua satellite indicates the presence of cooler sea surface
temperature (SST) and higher chlorophyll-a concentration along the inshore region of northwest
Sabah during the northeast monsoon, indicating the existence of upwelling. Cross-sectional
temperature profiles obtained from the HYCOM further confirmed the existence of upwelling as
the thermohaline was uplifted from the deeper layer and reached the surface during the northeast
monsoon. Ekman transport and Ekman pumping derived from the ECMWF showed an upwelling
favorable condition during the northeast monsoon. Comparison between climatological data and
El-Niño year in 2016 represented that El-Niño events somehow increase the upwelling intensity
due to the intensification of Ekman transport and Ekman pumping.

Tropical cyclones (TCs) often change intensity as they move over mesoscale oceanic features, as a function of the oceanic mixed layer (OML) thermal response (cooling) to the storm's wind stress. For example, observational evidence indicates that TCs in the Gulf of Mexico rapidly weaken over cyclonic cold core eddies (CCEs) where the cooling response is enhanced, and they rapidly intensify over anticyclonic warm features such as the Loop Current (LC) and Warm Core Eddies (WCEs) where OML cooling is reduced. Understanding this contrasting thermal response has important implications for oceanic feedback to TCs' intensity in forecasting models. Based on numerical experimentation and data acquired during hurricanes Katrina and Rita, this dissertation delineates the contrasting velocity and thermal response to TCs in mesoscale oceanic eddies. Observational evidence and model results indicate that, during the forced stage, the wind-driven horizontal current divergence under the sto...

We examine the genetics of marine diversification along the West Coast of North America in relation to the Late Neogene geology and climate of the region. Trophically important components of the diverse West Coast fauna, including kelp, alcid birds (e.g., auks, puffins), salmon, rockfish, abalone, and Cancer crabs, appear to have radiated during peaks of upwelling primarily in the Late Miocene and in some cases secondarily in the Pleistocene. Phylogeographic barriers associated with Mio-Pliocene estuaries of the mid-California coast, the Pliocene opening of the Gulf of California, tectonic and eustatic evolution of the California Bight, as well as the influence of Pleistocene and Holocene climate change on genetic structure are assessed in a geologic context. Comparisons to East Coast and western freshwater systems, as well as upwelling systems around the globe, provide perspective for the survey.

The sediments in the upwelling area off central Vietnam are totally bioturbated and display a low-diverse assemblage of bioturbational structures. During interglacial times (Marine Isotope Stage MIS 1, 5a, 5c, 5e), summer monsoon leads to pronounced upwelling and seasonally pulsed arrival of organic matter on the seafloor.
These deposits are characterized by a 4-tier bioturbated zone with Zoophycos. Zoophycos producers used this seasonal food source and show a cache behavioral strategy. During glacial periods upwelling was weak and oxygenation of bottom water decreased as evidenced by bioturbational structures that show a decrease in size, penetration depth and diversity. Enlarged freshwater influx during glacial times fuelled primary production and led to estuarine circulation. The resultant oxygen minimum layer favored an increased deposition of organic matter that in turn affected sediment properties. During MIS 2 and 5b oxygenation was probably a little lower than today. During MIS 3 and 5d Chondrites-like burrows point to a stronger oxygen deficiency.
During MIS 4 bottom water oxygenation was even lower and only biodeformational structures occur in soft sediment rich in benthic food. Based on these findings an ichnofabric model for food-rich, fairly soft deposits experiencing oxygen deficiency is suggested having biodeformational structures as low-oxygen end member.

Unusual large-scale accumulations of phytoplankton occurred across 10,000 km of the equatorial Pacific during the 1998 transition from El Niño to La Niña. The forcing and dynamics of these phytoplankton blooms were studied using satellite-based observations of sea surface height, temperature and chlorophyll, and mooring-based observations of winds, hydrography and ocean currents. During the bloom period, the thermocline (nutricline) was anomalously shallow across the equatorial Pacific. The relative importance of processes that enhanced nutrient flux into the euphotic zone differed between the western and eastern regions of the blooms. In the western bloom region, the important vertical processes were turbulent vertical mixing and wind-driven upwelling. In contrast, the important processes in the eastern bloom region were wave-forced shoaling of nutrient source waters directly into the euphotic zone, along-isopycnal upwelling, and wind-driven upwelling. Advection by the Equatorial Undercurrent spread the largest bloom 4500 km east of where it began, and advection by meridional currents of tropical instability waves transported the bloom hundreds of kilometers north and south of the equator. Many processes influenced the intricate development of these massive biological events. Diverse observations and novel analysis methods of this work advance the conceptual framework for understanding the complex dynamics and ecology of the equatorial Pacific.

1] The offshore propagation of mesoscale eddies contributes significantly to expanding the area of high chlorophyll concentration beyond the coastal upwelling center as shown by satellite data of chlorophyll, wind stress, sea level anomalies between (1997 -2003) off central Chile. Mesoscale eddies ($6.45 Â 10 3 km 2 ) formed near the coastal zone in spring-summer have mean seaward speeds of $1.68 km d À1 and reach $500 km offshore in winter. Chlorophyll concentrations along eddy paths are elevated by nutrient pumping and by nutrients and/or chlorophyll transported from the coastal zone. Eddies make up >50% of the winter (weak upwelling) chlorophyll peak in the coastal transition zone. Coupling between eddies and upwelling extends central Chile's high productivity area offshore and prolongs it towards winter.

The Queen Charlotte Islands, Canada, lie at the northern extreme of the coastal upwelling system of the eastern North Pacific Ocean (51–54°N). In this study, the first observations of spatial and inter-annual patterns in nutrient inventories, chlorophyll (Chl) a and phytoplankton assemblages are reported and related to oceanographic conditions in near-shore waters of the island archipelago. Stronger and more persistent upwelling in 2002 coincided with higher nutrient and Chl a standing stocks compared to 2001 and a higher proportion of diatoms. Dinoflagellates were more prevalent in 2001, including several potentially harmful species. At sub-seasonal scales, Chl a concentrations were greatest during downwelling conditions and smallest during upwelling conditions. On the west coast, weak water column stratification, high relative proportions of diatoms and large nutrient inventories accompanied upwelling-favourable conditions, whereas on the east coast, there was no direct relationship between the Bakun Upwelling Index and water column stability. According to redundancy analysis, variability in species composition was best explained by sea surface temperature, the depth of the euphotic zone and nutrient inventories. The east coast supported blooms of coccolithophores within protected bays, confirming previous satellite observations that showed bright patches in these areas. The data illustrate that moderate upwelling can have an important influence on near-shore algal standing stocks and species composition at the northern extreme of the upwelling system off the west coast of North America, and that topographical complexity may be important for the development of phytoplankton blooms.

The NW Mediterranean has a number of structural features in common with upwelling ecosystems. Therefore, an ecological model representing a NW Mediterranean exploited ecosystem was standardized and compared with four previously standardized models from coastal upwelling ecosystems: the Northern and Southern Humboldt (Chile and Peru upwelling systems) and the Northern and Southern Benguela (Namibia and South Africa upwelling systems). Results from biomasses, flows and trophic levels indicated important differences between ecosystems, mainly caused by differences in primary production, which was smallest in the NW Mediterranean Sea. However, principal component analysis (PCA) of biomasses and flows suggested a similar pattern between the NW Mediterranean and the South African systems due to the inclusion of an important fraction of the continental shelf in both ecological models representing these areas. At the same time, diets of commercial species from the NW Mediterranean were more similar to Benguela than Humboldt species.However, the relatively heavy fishing pressure in the NW Mediterranean ecosystem was highlighted relative to its primary production, and was evident from the large catches and small primary production, largest flows from TL 1 required to sustain the fishery (%PPR), the low trophic level of the catch (TLc), high exploitation rates (F/Z), largest values in the trophic spectra portraying catch: biomass ratio, the FIB index and the demersal: total catch ration. Comparisons of %PPR, the trophic level of the community (TLco), the biomass of consumers and F/Z ratios seemed to capture the ecosystem effects of fishing: large in the NW Mediterranean, Namibia and Peru upwelling systems. Small pelagic fish were the most important component of the fisheries in the NW Mediterranean and Peruvian systems. However, the smaller production and biomass ratios from the NW Mediterranean could be an indirect indicator of intense fishing pressure on small pelagic fish, also in line with results from consumption of small pelagic fish by the fishery, F/Z ratios and trophic spectra. Moreover, similarities between the NW Mediterranean and Namibian systems were found, mainly related to the demersal: total catch ratios, the FIB index, the relevance of gelatinous zooplankton in the consumption of production and the importance of pelagic-demersal coupling, in remarkable contrast to the other ecosystems. These similarities should be interpreted in terms of dynamic trajectories that the Namibian system has shown due to the collapse of its pelagic ecosystem, partly due to fishing intensity, and the signs that the NW Mediterranean could follow suit in the future.

Using distributions of benthic Foraminifera and bottom-water variables (depth, salinity, temperature, oxygen, suspended matter, organic matter, phosphate, silicate, nitrite, and nitrate), we investigated movements of water masses on the South Brazilian Shelf (27-301S) and assessed the seasonality of continental runoff on the distribution of shelf water masses. The data were obtained from water and sediment samples collected in the austral winter of 2003 and austral summer of 2004 in three transects. The terrestrial nutrient input was significantly reduced at stations away from the coast, but high values of nutrients were maintained in subsurface waters due the presence of South Atlantic Central Water (SACW) at greater depths. At shallow sampling stations the influence of freshwater runoff was related to (1) the dominance of calcareous benthic Foraminifera, such as lagoon-related Pseudononion atlanticum, Hanzawaia boueana, Bulimina marginata, Bolivina striatula, Elphidium poeyanum, together with several agglutinated species, including Arenoparrella mexicana, Gaudryina exilis, and Trochammina spp., common in coastal environments subject to wide salinity fluctuations. In contrast, smaller forms and higher species diversity characterized the assemblage at offshore stations. In winter, the presence of Buccella peruviana and Uvigerina peregrina at Santa Marta Cape suggest the possible transport of those species of Subantarctic Shelf Waters (SASW) origin. Foraminifera associated to Subtropical Shelf Water (STSW) were dominated by Globocassidulina subglobosa in both seasons. In summer, the occurrence of U. peregrina in the shallower stations suggested the influence of SACW nutrients brought up by upwelling of deeper waters.

Cyanobacterial blooms are common in the Baltic Sea. They are dominated by Aphanizomenon flos-aquae and Nodularia spumigena and take place in July-August. Investigations of bloom development using different approaches have been carried out in the Gulf of Finland during recent years. The ship-of-opportunity technique allows to observe the upper layer dynamics from meso-to basin-wide scale with high temporal and spatial frequency at low cost. Unattended measurements on board a commercial ferry along a transect between Tallinn and Helsinki have been conducted for 3 years (1997)(1998)(1999). The influence of weather conditions-temperature and wind-on the cyanobacterial bloom development was investigated. The formation of cyanobacterial blooms was favoured by warm and calm weather, while in cold and windy conditions other species formed mass occurrences. Water temperature has been found to be the main factor controlling the initiation of the bloom, in general, while vertical stratification appeared to be the critical factor determining the intensity of the bloom at species level. The spatial distribution of the cyanobacterial bloom was determined rather by the wind-forced advection than by the possible vertical transport of nutrients in the areas of the observed upwelling events.

The authors investigated the response to experimentally elevated water temperature in genotypes of PociUopora damicornis from three coral reefs in the upwelling Gulf of Panama and four coral reefs in the non-upwelling Gulf of Chiriqui, Panamanian Pacific. Sea-surface temperature in the Gulf of Panama declines below 20 °C during seasonal upwelHng, while in the thermally stable Gulf of Chiriqui, the temperature ranges from 27 to 29 °C. Genotypes of P. damicornis from the seven locations were determined by allozyme electrophoresis. The most abundant genotype at each location was selected for a thermal tolerance experiment where corals were exposed to water temperature of 30 °C (1 °C above ambient) for 43 days. Four site coral genotypes can be uniquely differentiated by the GPI locus, two by the LGG-2 locus, and two by a combination of the MDH-1, LGG-2, and LTY-3 loci. A visual assessment of the coral condition after exposure to an elevated temperature showed that corals from localities in the non-upwelling environment retained a normal to slightly pale appearance, while corals from the upwelling environment bleached and their polyps were mostly retracted. A two-way ANO VA confirmed that corals were significantly affected by water temperature and locality. The zooxanthellae were also significantly affected by the interaction of elevated temperature and locahty of the Communicated by K.S.

An exceptional Early Aquitanian Konservat-Lagerstätte with well-preserved vertebrate and invertebrate fossil assemblages has been studied in the North Alpine Foreland Basin of Upper Austria. The finely laminated sediments were deposited along the northern shelf of the Central Paratethys Sea. Micropaleontological (foraminifers, dinoflagellates) and geochemical (organic carbon, sulphur, carbonate content, biomarker, stable isotopes) proxies indicate intense upwelling. In addition, episodically increased coastal runoff provided large amounts of nutrients stimulating primary productivity. All evidence suggests deposition within dysoxic-anoxic bottom waters of an oxygen minimum zone along the outer shelf and upper slope. Fossil assemblages show specific planktic and nektic associations in distinct intervals of the section. Various mechanisms are discussed to explain their origin: (1) blooms of pteropods and calcareous nannoplankton reflect short-term peaks in primary productivity. Increased coastal runoff and/or intensified upwelling activity are considered as trigger mechanisms for providing the nutrients. (2) Allochthonous associations of the cephalopod Aturia with brown algae suggest a two-fold transport mechanism: shells of the offshoreliving cephalopods were transported post mortem to the coast by surface currents and/or wind currents. Episodic flooding events and storms mixed the accumulated shells with the algae and moved them offshore. The latter process also seems to apply to several pipefish accumulations observed in the section.

The history of the Somali upwelling during the last 18.5 ka has been reconstructed using biogenic silica fluxes estimated from a sediment core retrieved from the western Arabian Sea. The reconstructed record demonstrates periodic weakening and strengthening of the Somali upwelling during the past 18.5 ka. Variations in biogenic silica fluxes suggest weak upwelling during the last glacial period (18.5-15 ka BP). Strengthened upwelling during the Bølling-Allerød period (15-10 13 ka BP) points to post-glacial onset of the southwest monsoon. The Younger Dryas (13-11 ka BP) is again marked by reduced upwelling strength. Intensification of the Somali upwelling at the beginning of the Holocene and a decline at 8 ka BP are observed. Increases in upwelling strength recorded since 8 ka BP suggest strengthening of the southwest monsoon during the latter part of the Holocene. Linking these upwelling variations with southwest monsoon precipitation, a major shift in the relationship between the strength of the Somali upwelling and southwest monsoon rainfall from positive to negative has 15 occurred during the pre-Holocene to the Holocene. The observed shift is attributed to the variation in the southwest monsoon strength due to the latitudinal shift of the Intertropical Convergence Zone (ITCZ) associated with changes in moisture sources. 1 Introduction The greater part of the world's population inhabits the tropical region, where climate is mainly controlled by monsoon rainfall. Understanding the causes of past changes thus plays a critical role in deciphering past, present and future monsoon variability. 20 The economy of India, which is a tropical country that contains a significant part of the world's population, is dependent to a large extent on the southwest monsoon (SWM) rainfall; hence, slight changes in SWM rainfall can lead to immense societal impacts. Several attempts have been made to identify the factors responsible for SWM rainfall variations. SWM rainfall variability is correlated with several global phenomena, such as ENSO (

An exceptional Early Aquitanian Konservat-Lagerstätte with well-preserved vertebrate and invertebrate fossil assemblages has been studied in the North Alpine Foreland Basin of Upper Austria. The finely laminated sediments were deposited along the northern shelf of the Central Paratethys Sea. Micropaleontological (foraminifers, dinoflagellates) and geochemical (organic carbon, sulphur, carbonate content, biomarker, stable isotopes) proxies indicate intense upwelling. In addition, episodically increased coastal runoff provided large amounts of nutrients stimulating primary productivity. All evidence suggests deposition within dysoxic-anoxic bottom waters of an oxygen minimum zone along the outer shelf and upper slope. Fossil assemblages show specific planktic and nektic associations in distinct intervals of the section. Various mechanisms are discussed to explain their origin: (1) blooms of pteropods and calcareous nannoplankton reflect short-term peaks in primary productivity. Increased coastal runoff and/or intensified upwelling activity are considered as trigger mechanisms for providing the nutrients. (2) Allochthonous associations of the cephalopod Aturia with brown algae suggest a two-fold transport mechanism: shells of the offshoreliving cephalopods were transported post mortem to the coast by surface currents and/or wind currents. Episodic flooding events and storms mixed the accumulated shells with the algae and moved them offshore. The latter process also seems to apply to several pipefish accumulations observed in the section.