WorldWideScience

Sample records for chilean coastal upwelling

  1. Coastal Upwelling.

    Science.gov (United States)

    Clark, Steve

    1998-01-01

    Features a three-part activity designed to teach students about coastal upwelling, the upward movement of cooler, more nutrient-rich water along a coast. Activity includes a mapping exercise, a graphing exercise, and questions for analyzing the map and graph. (Author/WRM)

  2. How depositional conditions control input, composition, and degradation of organic matter in sediments from the Chilean coastal upwelling region

    DEFF Research Database (Denmark)

    Niggemann, Jutta; Ferdelman, Timothy G.; Lomstein, Bente Aagaard;

    2007-01-01

    the Chilean coastal upwelling system and have an extended oxygen minimum zone in the water column. However, the northern site (23°S) borders the Atacama Desert, while the southern site (36°S) has a humid hinterland. Eight surface sediment cores (up to 30 cm long) from water depths of 126‑1350 m were...... m‑2 d‑1), which was partly due to the greater water depth of most of the sediments investigated in the northern region and consistent with a lower quality of the sedimentary OM at 23°S. Reaction rate constants for TOC degradation that were obtained from measured SRR (kSRR; 0.0004‑0.0022 yr‑1) showed...

  3. VOCALS-CUpEx: the Chilean Upwelling Experiment

    Science.gov (United States)

    Garreaud, R. D.; Rutllant, J. A.; Muñoz, R. C.; Rahn, D. A.; Ramos, M.; Figueroa, D.

    2011-03-01

    The VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) was a major field experiment conducted in spring of 2008 off southern Peru and northern Chile, aimed at better understanding the coupled climate systems of the southeast Pacific. Because of logistical constrains, the coastal area around 30° S was not sampled during VOCALS-REx. This area not only marks the poleward edge of the subtropical stratocumulus cloud regime (thus acting as a source of transient disturbances) but is also one of the most active upwelling centers and source of surface ocean kinetic energy along the Chilean coast. To fill such an observational gap, a small, brief, but highly focused field experiment was conducted in late spring 2009 in the near-shore region around 30° S. The Chilean Upwelling Experiment (CUpEx) was endorsed by VOCALS as a regional component. CUpEx included long-term monitoring, an intensive two-week field campaign and off-shore research flights. Our goal was to obtain an atmospheric/oceanic dataset with enough temporal and spatial coverage to be able to document (a) the mean diurnal cycles of the lower-troposphere and upper-ocean in a region of complex topography and coastline geometry, and (b) the ocean-atmosphere response to the rapid changes in coastal winds from strong, upwelling-favorable equatorward flow (southerly winds) to downwelling-favorable poleward flow (northerly winds). In this paper we describe the measurement platforms and sampling strategy, and provide an observational overview, highlighting some key mean-state and transient features.

  4. (abstract) Seasonal Variability in Coastal Upwelling: A Comparison of Four Coastal Upwelling Sites from Space

    Science.gov (United States)

    Carr, Mary-Elena

    1996-01-01

    Coastal upwelling of subsurface nutrient-rich water occurs along the eastern boundary of the ocean basins and leads to high primary production and fish catches. In this study satellite observations are used to compare the seasonal cycle in wind forcing and in the oceanic and biological response of the major coastal upwelling regions associated with the Canary, Benguela, California, and Humboldt Currents.

  5. Coastal Upwelling Drives Intertidal Assemblage Structure and Trophic Ecology

    OpenAIRE

    Reddin, Carl J.; Felipe Docmac; Nessa E O'Connor; Bothwell, John H; Chris Harrod

    2015-01-01

    Similar environmental driving forces can produce similarity among geographically distant ecosystems. Coastal oceanic upwelling, for example, has been associated with elevated biomass and abundance patterns of certain functional groups, e.g., corticated macroalgae. In the upwelling system of Northern Chile, we examined measures of intertidal macrobenthic composition, structure and trophic ecology across eighteen shores varying in their proximity to two coastal upwelling centres, in a hierarchi...

  6. How will Somali coastal upwelling evolve under future warming scenarios?

    Science.gov (United States)

    Decastro, M.; Sousa, M. C.; Santos, F.; Dias, J. M.; Gómez-Gesteira, M.

    2016-07-01

    Somali upwelling system, the fifth in the world, presents some unique features compared with the other major upwelling systems: 1) it is a Western Boundary Upwelling System located near the Equator and 2) upwelling affects the moisture responsible for monsoon rainfall. The intensity of Somali coastal upwelling during summer was projected for the twenty first century by means of an ensemble of Global Climate Models and Regional Climate Models within the framework of CMIP5 and CORDEX projects, respectively. Regardless global or regional circulation models and the chosen greenhouse warming scenario, the strengthening of Somali coastal upwelling, which increases with latitude, is even higher than observed for the Eastern Boundary Upwelling System. In addition, coastal upwelling strengthening is mainly due to Ekman transport since Ekman pumping shows no clear trend for most of the latitudes. Projected land-sea air temperature and pressure show a clear intensification of land-sea thermal and pressure gradient as a consequence of the global warming, which is likely to affect the strengthening of Somali upwelling verifying the hypothesis of Bakun. As a consequence, projected sea surface temperature warming is less intense nearshore than at oceanic locations, especially at latitudes where upwelling strengthening is more intense.

  7. How will Somali coastal upwelling evolve under future warming scenarios?

    Science.gov (United States)

    deCastro, M; Sousa, M C; Santos, F; Dias, J M; Gómez-Gesteira, M

    2016-01-01

    Somali upwelling system, the fifth in the world, presents some unique features compared with the other major upwelling systems: 1) it is a Western Boundary Upwelling System located near the Equator and 2) upwelling affects the moisture responsible for monsoon rainfall. The intensity of Somali coastal upwelling during summer was projected for the twenty first century by means of an ensemble of Global Climate Models and Regional Climate Models within the framework of CMIP5 and CORDEX projects, respectively. Regardless global or regional circulation models and the chosen greenhouse warming scenario, the strengthening of Somali coastal upwelling, which increases with latitude, is even higher than observed for the Eastern Boundary Upwelling System. In addition, coastal upwelling strengthening is mainly due to Ekman transport since Ekman pumping shows no clear trend for most of the latitudes. Projected land-sea air temperature and pressure show a clear intensification of land-sea thermal and pressure gradient as a consequence of the global warming, which is likely to affect the strengthening of Somali upwelling verifying the hypothesis of Bakun. As a consequence, projected sea surface temperature warming is less intense nearshore than at oceanic locations, especially at latitudes where upwelling strengthening is more intense. PMID:27440455

  8. Amino acid biogeo- and stereochemistry in coastal Chilean sediments

    DEFF Research Database (Denmark)

    Lomstein, Bente Aagaard; Jørgensen, Bo Barker; Schubert, Carsten J.;

    2006-01-01

    The spatial distribution of total hydrolysable amino acids (THAA) and amino acid enantiomers (D- and L-forms) was investigated in sediments underlying two contrasting Chilean upwelling regions,: at ~23°S off Antofagasta and at ~36°S off Concepcion. The contribution of amino acids to total organic...

  9. Chemical hydrography of coastal upwelling in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    WANG Baodong; WANG Xiulin

    2007-01-01

    Based on the field data obtained during cruises on the shelf of the East China Sea from 1997 to 1999, seasonal variations of coastal upwelling on the inner shelf are discussed by using cross-shelf transect profiles and horizontal distributions of chemical and hydrographic variables. Results show that the coastal upwelling was year-round, but the areas and intensities of the upwelling were quite different in season. The coastal upwelling occurred in all of the coastal areas of the region in spring and summer, but in autumn only in the area off Zhejiang Province, and in winter in the area off Fujian Province. It was the strongest in summer and the weakest in winter. Geographically, it was the strongest in the area off Zhejiang Province and the weakest in the southmost or northmost parts of the East China Sea.The estimated nutrient fluxes upward into euphotic zone through coastal upwelling were quite large, especially for phosphate, which contributed significantly to primary production and improved the nutrient structure of the coastal ecosystem in the East China Sea.

  10. Interannual variability in the PFEG coastal upwelling indices

    OpenAIRE

    Parker, Heather A.

    1996-01-01

    Numerous studies examine decadal-scale variability in basin-scale parameters in the Northern Pacific. Characterizing such interannual-to-interdecadal variability is essential to identifying long-term climate changes. The Pacific Fisheries Environmental Group (PFEG) coastal upwelling indices display variability on these time scales and may help explain the mechanisms responsible for such climate variability. ... In this study, examination of 49-year time series of monthly mean upwelling indice...

  11. Coastal upwelling observed by multi-satellite sensors

    Institute of Scientific and Technical Information of China (English)

    LI XiaoMing; LI XiaoFeng; HE MingXia

    2009-01-01

    Coastal upwelling phenomenon along the China coast in the Yellow Sea during August 2007 is studied using ENVISAT Advanced Synthetic Aperture Radar (ASAR) data, NOAA Advanced AVHRR series Sea Surface Temperature (SST) data, and NASA QuikSCAT Scatterometer ocean surface wind data. A dark pattern in an ASAR image is interpreted as coastal upwelling. This is because the natural biogenic slicks associated with coastal upwelling damp the Bragg waves on the sea surface and thus make the surface smoother. Most of the incoming radar energy is reflected in the forward direction. As a result, the radar backscatter signal is very weak. Analyzing the concurrent AVHRR SST Image, we find that the dark pattern in the ASAR image is indeed corresponding to the low SST area. The wind retrieval in the slicks dominant region is biased due to the low Normaliced Radar Cross Section (NRCS) associated with the coastal upwelling. We applied a SST correction to the NRCS values to improve the accuracy of wind retrieval from ASAR data.

  12. Coastal upwelling observed by multi-satellite sensors

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Coastal upwelling phenomenon along the China coast in the Yellow Sea during August 2007 is studied using ENVISAT Advanced Synthetic Aperture Radar (ASAR) data, NOAA Advanced AVHRR series Sea Surface Temperature (SST) data,and NASA QuikSCAT Scatterometer ocean surface wind data. A dark pattern in an ASAR image is interpreted as coastal upwelling. This is because the natural biogenic slicks associated with coastal upwelling damp the Bragg waves on the sea surface and thus make the surface smoother. Most of the incoming radar energy is reflected in the forward direction. As a result, the radar backscatter signal is very weak. Analyzing the concurrent AVHRR SST image, we find that the dark pattern in the ASAR image is indeed corresponding to the low SST area. The wind retrieval in the slicks dominant region is biased due to the low Normalised Radar Cross Section (NRCS) associated with the coastal upwelling. We applied a SST correction to the NRCS values to improve the accuracy of wind retrieval from ASAR data.

  13. What shapes mesoscale wind anomalies in coastal upwelling zones?

    Energy Technology Data Exchange (ETDEWEB)

    Boe, Julien [University of California, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA (United States); CNRS/CERFACS, URA 1875, Toulouse (France); Hall, Alex; Qu, Xin; Kapnick, Sarah B. [University of California, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA (United States); Colas, Francois; McWilliams, James C.; Kurian, Jaison [University of California, Institute of Geophysics and Planetary Physics, Los Angeles, CA (United States)

    2011-06-15

    Observational studies have shown that mesoscale variations in sea surface temperature may induce mesoscale variations in wind. In eastern subtropical upwelling regions such as the California coast, this mechanism could be of great importance for the mean state and variability of the climate system. In coastal regions orography also creates mesoscale variations in wind, and the orographic effect may extend more than 100 km offshore. The respective roles of SST/wind links and coastal orography in shaping mesoscale wind variations in nearshore regions is not clear. We address this question in the context of the California Upwelling System, using a high-resolution regional numerical modeling system coupling the WRF atmospheric model to the ROMS oceanic model, as well as additional uncoupled experiments to quantify and separate the effects of SST/wind links and coastal orography on mesoscale wind variations. After taking into account potential biases in the representation of the strength of SST/wind links by the model, our results suggest that the magnitude of mesoscale wind variations arising from the orographic effects is roughly twice that of wind variations associated with mesoscale SST anomalies. This indicates that even in this region where coastal orography is complex and leaves a strong imprint on coastal winds, the role of SST/winds links in shaping coastal circulation and climate cannot be neglected. (orig.)

  14. Offshore Wind Farm Wake Effect on Stratification and Coastal Upwelling

    OpenAIRE

    Bakhoday Paskyabi, Mostafa

    2015-01-01

    In this study, the interactions between an offshore wind farm, upper-ocean currents, and stratification are examined under shallow water conditions from a two-dimensional modeling standpoint. The modeling results from two numerical simulation runs provide new insights on the formation of downwind vortex streets and the adjustment of coastal processes, such as upwelling and stratification. The distorted farm-induced wind deficits are calculated by the concept of single- and multiple-wake model...

  15. Coastal upwelling activity on the Pacific shelf of the Baja California Peninsula

    OpenAIRE

    O. Zaytsev; Cervantes Duarte, Rafael; Montante, Orzo; Gallegos García, A.

    2003-01-01

    High primary productivity on the Pacific coast of the Baja California Peninsula is usually related to coastal upwelling activity that injects nutrients into the euphotic zone in response to prevailing longshore winds (from the northwest to north). The upwelling process has maximum intensity from April to June, with the coastal upwelling index varying from 50 to 300 m3/s per 100 m of coastline. Along the entire coast of the peninsula, the upwelling intensity changes in accordance with local wi...

  16. Domoic acid production near California coastal upwelling zones, June 1998

    Energy Technology Data Exchange (ETDEWEB)

    Trainer, V L.(National Marine Fisheries Service); Adams, Nicolaus G.(National Marine Fisheries Service); Bill, Brian D.(National Marine Fisheries Service); Stehr, Carla M.(National Marine Fisheries Service); Wekell, John C.(National Marine Fisheries Service); Moeller, Peter (National Ocean Service, Marine Biotoxins Program); Busman, Mark (National Ocean Service, Marine Biotoxins Program); Woodruff, Dana L.(BATTELLE (PACIFIC NW LAB))

    2000-01-01

    Sea lion mortalities in central California during May and June 1998 were traced to their ingestion of sardines and anchovies that had accumulated the neurotoxin domoic acid. The detection of toxin in urine, feces, and stomach contents of several sea lions represents the first proven occurrence of domoic acid transfer through the food chain to a marine mammal. The pennate diatoms, Pseudo-nitzschia multiseries and P. australis, were the dominant, toxin-producing phytoplankton constituting algal blooms near Monterey Bay, Half Moon Bay, and Oceano Dunes, areas where sea lions with neurological symptoms stranded. Toxic Pseudo-nitzschia were also found near Morrow Bay, Point Conception, Point Arguello, and Santa Barbara, demonstrating that these species were widespread along the central California coast in June 1998. Measurements of domoic acid during three cruises in early June showed the highest cellular toxin levels in P. multiseries near Point A?o Nuevo and in P. australis from Morro w Bay. Maximum cellular domoic acid levels were observed within 20 km of the coast between 0 and 5 m depth, although toxin was also measured to depths of 40 m. Hydrographic data indicated that the highest toxin levels and greatest numbers of toxic cells were positioned in water masses associated with upwelling zones near coastal headlands. Nutrient levels at these sites were less than those typically measured during periods of active upwelling, due to the 1998 El Ni?o event. The flow of cells and/or nutrients from coastal headlands into embayments where cells can multiply in a stratified environment is a possible mechanism of bloom development along the central California coast. This coupling of toxic Pseudo-nitzschia growth near upwelling zones with physical processes involved in cell transport will be understood only when long-term measurements are made at several key coastal locations, aiding in our capability to predict domoic-acid producing algal blooms.

  17. Coastal Upwelling and Deep Fog: 50-year Worldwide Climatology

    Science.gov (United States)

    Koracin, D. R.

    2015-12-01

    An analysis is presented of the marine fog distribution based upon the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) ship observations taken during 1950-2007. Deep fog occurrence is reported in routine weather reports that are encoded in an ICOADS ship observation. Occurrence is estimated by the number of deep fog observations divided by the total present weather observations in a one-degree area centered on latitude and longitude grid point intersections. The mean fog occurrence for the summer (June-July-August) 1950-2007 was computed for each one degree point for the world. There are five major world locations with coastal SST minimums due to wind driven upwelling. Four of these are during the local summer on the eastern side of a semi-permanent anticyclone on eastern sides of northern and southern mid-latitudes of the Pacifica and the Atlantic. The fifth is during the SW monsoon in the Indian Ocean. For all five of these locations, the deep fog occurrence is at maximum during the upwelling season, with the greatest occurrences concentrated along the coast and isolated over the SST minimum. For the five coastal fog maxima, the greatest and longest duration occurrence along coast occurrence is associated with the coldest sea surface temperature and longest along coast occurrence, which is along N. California- S. Oregon. In contrast, the lowest occurrence of fog and the least along coast occurrence is associated with the warmest sea surface temperatures and least along coast occurrence along the SE Arabian Peninsula. The remaining three zones, Peru-Chile, NW Africa, and SW Africa are between the two extremes in fog occurrence, along coast coverage and sea surface temperature. Peru-Chile is more complex than the others as the Peru upwelling and fog appears the more dominant although ship observations are sparse along Chile.

  18. Delayed upwelling alters nearshore coastal ocean ecosystems in the northern California current

    OpenAIRE

    John A. Barth; Menge, Bruce A.; Lubchenco, Jane; Chan, Francis; Bane, John M.; Kirincich, Anthony R.; McManus, Margaret A.; Nielsen, Karina J.; Pierce, Stephen D.; Washburn, Libe

    2007-01-01

    Wind-driven coastal ocean upwelling supplies nutrients to the euphotic zone near the coast. Nutrients fuel the growth of phytoplankton, the base of a very productive coastal marine ecosystem [Pauly D, Christensen V (1995) Nature 374:255–257]. Because nutrient supply and phytoplankton biomass in shelf waters are highly sensitive to variation in upwelling-driven circulation, shifts in the timing and strength of upwelling may alter basic nutrient and carbon fluxes through marine food webs. We sh...

  19. Spatial and temporal seasonal trends in coastal upwelling off Northwest Africa, 1981-2012

    OpenAIRE

    Cropper, T.E; Hanna, E; Bigg, G.R.

    2014-01-01

    Seasonal coastal upwelling was analyzed along the NW African coastline (11-35°N) from 1981 to 2012. Upwelling magnitudes are calculated by wind speed indices, sea-surface temperature indices and inferred from meteorological station, sea-surface height and vertical water column transport data. A permanent annual upwelling regime is documented across 21-35°N and a seasonal regime across 12-19°N, in accordance with the climatology of previous studies. Upwelling regions were split into three zone...

  20. Remote sensing and ichthyoplankton ecology of coastal upwelling fronts off central California

    Science.gov (United States)

    Bjorkstedt, Eric Peter

    1998-11-01

    Recruitment to many marine populations is determined by processes affecting survival and transport of planktonic larvae. Coastal upwelling poses a trade-off between larval access to high productivity supported by upwelled nutrients and increased risk of offshore transport and failure to return to coastal habitats. I used plankton surveys, remote sensing, and a simple model to investigate the role of coastal upwelling fronts and behavior in pelagic ecology and recruitment success, focussing on rockfish (Sebastes spp.) off central California. Distributions of early stage larvae suggest that coastal upwelling fronts reduce offshore transport of rockfish larvae, in contrast to distributions of taxa with life histories that minimize larval exposure to strong upwelling. Coincident distributions of larval fish, prey (i.e., small copepods and invertebrate eggs) and phytoplankton patches indicate that coastal upwelling fronts provide enhanced foraging conditions for larvae. Thus, coastal upwelling fronts may allow coastal taxa to successfully exploit high productivity during the upwelling season while reducing the risk of offshore transport. I developed a novel method for utilizing a single HF radar to resolve currents and detect fronts that matched sea surface temperature fronts generated by coastal upwelling. Fronts and currents detected with NF radar affect distributions and transport of planktonic larval fish and intertidal barnacle larvae, demonstrating that remote sensing with HF radar can support field and modelling research on ecological dynamics in coastal marine systems. I used an empirically-based model that incorporated the advection-foraging trade-off and long-distance swimming as an active settlement behavior to investigate optimal settlement strategies as a function of pelagic transport and growth. For parameters loosely describing pelagic stages of rockfish, the model predicts optimal settling strategies (ages and sizes) for pelagic juveniles that roughly

  1. Retention controls on-shelf hypoxia in coastal upwelling systems

    Science.gov (United States)

    Harrison, C. S.; Long, M. C.; Hales, B. R.; Siedlecki, S. A.; Samelson, R. M.

    2015-12-01

    A maximally simple, coupled physical-biogeochemical box model is used to examine interactions controlling seasonal hypoxia over the continental shelf in an idealized Eastern Boundary upwelling system (EBUS). On-shelf bottom oxygen drawdown is controlled by the balance between flushing with offshore source waters and the degree to which surface particulate organic carbon (POC) production and its subsequent sinking and respiration are retained over the shelf and focused on the bottom. In the model, POC production is controlled by wind-driven upwelling of a generic nutrient to the surface, balanced by respiration and sinking. The degree to which this production occurs over shelf is a balance between the net POC growth rate η, and the upwelling driven shelf flushing rate λ, equivalent to the Ekman upwelling index scaled by the shelf width and surface layer depth. Initial oxygen drawdown follows this exponential rate of surface POC accumulation over shelf (α=η-λ), and so is slower for rapid upwelling (large λ) or nutrient limited conditions (small η). Retention efficiency indicates that up to 40% or more of upwelled nutrients can be retained over the shelf and contribute to oxygen drawdown. Fluctuations in the amplitude of the upwelling forcing can systematically reduce the potential for oxygen depletion below these estimates, especially when surface sinking export is rapid or forcing is strong.

  2. Cross-shelf structure of coastal upwelling : a two - dimensional extension of Ekman's theory and a mechanism for inner shelf upwelling shut down

    OpenAIRE

    Estrade, P.; Marchesiello, Patrick; Verdière de, A. C.; Roy, Claude

    2008-01-01

    Sea-surface temperature images of the coastal upwelling regions off Northwest Africa show that the core of upwelling is sometimes located far from the coast. This has been documented in three regions that share a common feature, namely a wide and shallow continental shelf. This upwelling feature plays a key role in the ecology of the Canary Current System. It creates an innerfront which provides retention for biological material, e.g. fish eggs and larvae, in the highly productive nearshore e...

  3. Trends in coastal upwelling intensity during the late 20th century

    Directory of Open Access Journals (Sweden)

    N. Narayan

    2010-02-01

    Full Text Available This study presents linear trends of coastal upwelling intensity in the later part of the 20th century (1960–2001 employing various indices of upwelling, derived from meridional wind stress and sea surface temperature. The analysis was conducted in the four major coastal upwelling regions in the world, which are off North-West Africa, Lüderitz, California and Peru respectively. The trends in meridional wind stress showed a steady increase of intensity from 1960–2001, which was also reflected in the SST index calculated for the same time period. The steady cooling observed in the instrumental records of SST off California substantiated this observation further. Correlation analysis showed that basin-scale oscillations like the Atlantic Multidecadal Oscillation (AMO and the Pacific Decadal Oscillation (PDO could not be directly linked to the observed increase of upwelling intensity off NW Africa and California respectively. The relationship of the North Atlantic Oscillation (NAO with coastal upwelling off NW Africa turned out to be ambiguous due to a negative correlation between the NAO index and the meridional wind stress and a lack of correlation with the SST index. Our results give additional support to the hypothesis that the coastal upwelling intensity increases globally because of raising greenhouse gas concentrations in the atmosphere and an associated increase of the land-sea pressure gradient and meridional wind stress.

  4. Trends in coastal upwelling intensity during the late 20th century

    Directory of Open Access Journals (Sweden)

    N. Narayan

    2010-09-01

    Full Text Available This study presents linear trends of coastal upwelling intensity in the later part of the 20th century (1960–2001 employing various indices of upwelling, derived from meridional wind stress and sea surface temperature. The analysis was conducted in the four major coastal upwelling regions in the world, which are off North-West Africa, Lüderitz, California and Peru. The trends in meridional wind stress showed a steady increase of intensity from 1960–2001, which was also reflected in the SST index calculated for the same time period. The steady cooling observed in the instrumental records of SST off California substantiated this observation further. It was also noted that the trends in meridional wind stress obtained from different datasets differ substantially from each other. Correlation analysis showed that basin-scale oscillations like the Atlantic Multidecadal Oscillation (AMO and the Pacific Decadal Oscillation (PDO could not be directly linked to the observed increase of upwelling intensity off NW Africa and California respectively. The relationship of the North Atlantic Oscillation (NAO with coastal upwelling off NW Africa turned out to be ambiguous due to a negative correlation between the NAO index and the meridional wind stress and a lack of correlation with the SST index. Our results give additional support to the hypothesis that the coastal upwelling intensity increases globally because of raising greenhouse gas concentrations in the atmosphere and an associated increase of the land-sea pressure gradient and meridional wind stress.

  5. Imprint of external climate forcing on coastal upwelling in past and future climate

    Directory of Open Access Journals (Sweden)

    N. Tim

    2015-11-01

    Full Text Available The Eastern Boundary Upwelling Systems are the major coastal upwelling regions. The trade winds are driving these upwelling regimes located in the subtropics at the eastern boundary of the Atlantic and Pacific Ocean. Here we analyse the impact of the external climate forcing, e.g. the greenhouse gas concentration, solar activity and volcano eruptions, on these upwelling systems in simulations of ensembles of two Earth System Models. The ensembles contain three simulations for each time period which cover the past millennium (900–1850, the 20th century (1850–2005 and the near future (2006–2100. Using a set of simulations, differing only in their initial conditions, enables us to detect whether the variability is driven internally or externally. Our analysis shows that the variability of the simulated upwelling is to the most driven internally and that there are no significant trends except for the scenario with the most dramatic increase of greenhouse gas concentrations.

  6. Modelling shelf-ocean exchange and its biogeochemical consequences in coastal upwelling systems

    DEFF Research Database (Denmark)

    Muchamad, Al Azhar

    The biogeochemical cycles of organic carbon, nutrients, oxygen, and sulfur in the oceans have been suggested to dominantly occur across the shelf–ocean transition over the continental margin, although this zone represents only a small percentage of the global ocean area. Coastal upwelling zones...... in eastern boundary upwelling systems is an example of the most productive ocean waters over continental margins where intense supply of nutrients occur from deeper ocean waters. Interesting questions arise related to the biogeochemical cycles in such upwelling systems; such as 1) how the recently observed...... these questions centering on shelf–ocean exchange and biogeochemical cycle in the coastal upwelling systems under oxic and anoxic conditions. Firstly, I developed a new biogeochemical model which resolves coupling between cycles of the elements nitrogen, oxygen, phosphate, and sulfur by considering several key...

  7. Amino acid biogeo- and stereochemistry in coastal Chilean sediments

    Science.gov (United States)

    Lomstein, Bente Aa.; Jørgensen, Bo B.; Schubert, Carsten J.; Niggemann, Jutta

    2006-06-01

    The spatial distribution of total hydrolysable amino acids (THAA) and amino acid enantiomers ( D- and L-forms) was investigated in sediments underlying two contrasting Chilean upwelling regions: at ˜23 °S off Antofagasta and at ˜36 °S off Concepción. The contribution of amino acids to total organic carbon (%T AAC: 7-14%) and total nitrogen (%T AAN: 23-38%) in surface sediments decreased with increasing water depth (from 126 to 1350 m) indicating that organic matter becomes increasingly decomposed in surface sediments at greater water depth. Changes in the ratio between the protein amino acid aspartate and its non-protein degradation product β-alanine confirmed this observation. Furthermore, estimates of THAA mineralization showed that sedimentary amino acid reactivity decreased with both increasing water depth as well as progressive degradation status of the organic matter that was incorporated into the sediment. Reactivity of organic matter in the sediment was also assessed using the Degradation Index (DI) developed by [Dauwe, B., Middelburg, J.J., 1998. Amino acids and hexosamines as indicators of organic matter degradation state in North Sea sediments. Limnol. Oceanogr.43, pp. 782-798.]. Off Concepción, DI was successfully applied to examine the degradation status of sedimentary organic matter at different water depths. However, unexpected results were obtained at the Antofagasta stations as DI increased with sediment depth, suggesting more degraded organic matter at the surface than deeper in the cores. The contribution of peptidoglycan amino acids to THAA was estimated from the concentrations of D-aspartate, D-glutamic acid, D-serine, and D-alanine. Peptidoglycan amino acids accounted for >18% of THAA in all investigated samples. In surface sediments peptidoglycan amino acids accounted for a progressively larger fraction of THAA at increasing water depths (up to >26%). Further, the contribution of peptidoglycan amino acids to THAA increased with

  8. Tidally induced upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    MASNUM wave-tide-circulation coupled numerical model (MASNUM coupled model, hereinafter) is de-veloped based on the Princeton Ocean Model (POM). Both POM and MASNUM coupled model are ap-plied in the numerical simulation of the upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer. The upwelling mechanisms are analyzed from the viewpoint of tide, and a new mechanism is proposed. The study suggests that the tidally inducing mechanism of the upwelling in-cludes two dynamic aspects: the barotropic and the baroclinic process. On the one hand, the residual currents induced by barotropic tides converge near the seabed, and upwelling is generated to maintain mass conservation. The climbing of the residual currents along the sea bottom slope also contributes to the upwelling. On the other hand, tidal mixing plays a very important role in inducing the upwelling in the baroclinic sea circumstances. Strong tidal mixing leads to conspicuous front in the coastal waters. The considerable horizontal density gradient across the front elicits a secondary circulation clinging to the tidal front, and the upwelling branch appears near the frontal zone. Numerical experiments are de-signed to determine the importance of tide in inducing the upwelling. The results indicate that tide is a key and dominant inducement of the upwelling. Experiments also show that coupling calculation of the four main tidal constituents (M2, S2, K1, and O1), rather than dealing with the single M2 constituent, im-proves the modeling precision of the barotropic tide-induced upwelling.

  9. Tidally induced upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer

    Institute of Scientific and Technical Information of China (English)

    L(ü) XinGang; QIAO FangLi; XIA ChangShui; YUAN YeLi

    2007-01-01

    MASNUM wave-tide-circulation coupled numerical model(MASNUM coupled model,hereinafter)is developed based on the Princeton Ocean Model (POM).Both POM and MASNUM coupled model are applied in the numerical simulation of the upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer.The upwelling mechanisms are analyzed from the viewpoint of tide,and a new mechanism is proposed.The study suggests that the tidally inducing mechanism of the upwelling includes two dynamic aspects:the barotropic and the baroclinic process.On the one hand,the residual currents induced by barotropic tides converge near the seabed,and upwelling is generated to maintain mass conservation.The climbing of the residual currents along the sea bottom slope also contributes to the upwelling.On the other hand,tidal mixing plays a very important role in inducing the upwelling in the baroclinic sea circumstances.Strong tidal mixing leads to conspicuous front in the coastal waters.The considerable horizontal density gradient across the front elicits a secondary circulation clinging to the tidal front,and the upwelling branch appears near the frontal zone.Numerical experiments are designed to determine the importance of tide in inducing the upwelling.The results indicate that tide is a key and dominant inducement of the upwelling.Experiments also show that coupling calculation of the four main tidal constituents (M2,S2,K1,and O1),rather than dealing with the single M2 constituent,improves the modeling precision of the barotropic tide-induced upwelling.

  10. An Efficient Tool for Automatic Delimitation of Moroccan Coastal Upwelling Using SST Images

    OpenAIRE

    Tamim, Ayoub; Minaoui, Khalid; Daoudi, Khalid; Yahia, Hussein; Atillah, Abderrahman; Aboutajdine, Driss

    2014-01-01

    International audience An unsupervised classification method is developed for the coarse segmentation of Moroccan coastal upwelling using the Sea Surface Temperature (SST) satellite images. The algorithm is started with the generation of c-partitioned labeled image using Otsu's method for the purpose of finding regions of homogenous temperatures. Then two well-known validity indices are used to select the c-partition which best reproduce the shape of upwelling area. A region-growing algori...

  11. Controls on Primary Productivity and its Measurement in Coastal Upwelling Systems

    OpenAIRE

    Jacox, Michael

    2012-01-01

    Eastern Boundary Current systems, running along the west coasts of Africa and the Americas, are among the most biologically productive oceanic ecosystems. Their disproportionately large contributions to global marine primary productivity (photosynthesis) and fish catch are supported by upwelling of deep, nutrient rich water, a process driven by the interaction of surface winds and Earth's rotation. Upwelling in these systems may be forced by two mechanisms: equatorward winds at the coastal bo...

  12. Combined impact of ocean acidification and corrosive waters in a river-influenced coastal upwelling area off Central Chile

    Science.gov (United States)

    Vargas, C.; De La Hoz, M.; San Martin, V.; Contreras, P.; Navarro, J. M.; Lagos, N. A.; Lardies, M.; Manríquez, P. H.; Torres, R.

    2012-12-01

    organic matter due to natural or anthropogenically stimulated respiration processes within river basin may impact the coastal ocean. Furthermore, the upwelling of corrosive subsurface waters might also undersaturate coastal waters with respect to aragonite. In addition, by using a mesocosm system to simulate different pH and CO2 levels we have evaluate under controlled conditions the effect of ocean acidification on the larval stage of an economically-important gastropod species (Concholepas concholepas). In this presentation, we show some preliminary results using multi-source data from different research projects dealing with the carbon cycle and OA processes along Chilean coast. Funded by Project RIVOM (Fondecyt 1095069), Project TOA-SPACE (Fondecyt 1090624), and Project Anillo ACT132 (CONICYT).

  13. Winter conditioning of the Cascadian margin upwelling system: Remote forcing and coastal river influences (Invited)

    Science.gov (United States)

    Hales, B. R.; Goni, M. A.; Evans, W.; Harris, K. E.; Siedlecki, S. A.; Skyllingstad, E. D.; Wall, C.; Wetz, M.; White, A. E.

    2013-12-01

    The Cascadian margin stretches along the North American Pacific coast from Cape Mendocino to Vancouver Island, and across the land-ocean margin from the crest of the coastal mountains to the California Current. Carbonate system chemistry in these coastal waters is among the most dynamic in the world, with high net community productivity driving the system to a regionally important CO2 sink, while upwelled, respiration-influenced waters carry such elevated CO2 that they are often corrosive to biogenic carbonates. Most of the focus on this ecosystem has been on the influence of the seasonal upwelling and interaction with the upper thermocline of the ocean interior; recently, however, the downwelling-season has been recognized as critical in shaping the carbon cycling of the ecosystem. We present a combination of in-water survey and mooring data from river, estuary, and shelf waters; remote-sensing of coastal surface waters and watershed precipitation; and modeling results describing the physics of coastal circulation and storm-event precipitation and river discharge that shows how the winter conditions control carbon cycling. Coastally-trapped internal waves propagating northward from remote upwelling regions to the south lead to shoaling of the pycnocline such that upwelled source waters are present far inshore of the shelfbreak months before the onset of upwelling favorable winds. The close proximity of upwelled source waters to inner shelf upwelling locations leads to rapid transition in response to late winter and early spring upwelling favorable wind events. Winter storms and closely coupled flooding events deliver regionally significant amounts of nutrient-rich, low-CO2 fresh waters to the coastal ocean during downwelling conditions that retain these inputs on the shelf, and this fuels phytoplankton blooms that are a significant contribution to the annual net community production. These blooms and river influences maintain low coastal surface water pCO2 during

  14. Intraseasonal coastal upwelling signal along the southern coast of Java observed using Indonesian tidal station data

    Science.gov (United States)

    Horii, Takanori; Ueki, Iwao; Syamsudin, Fadli; Sofian, Ibnu; Ando, Kentaro

    2016-04-01

    Sea level variations along the coasts of Sumatra and Java were investigated to determine the coastal upwelling signal that is linked to local sea surface temperature (SST) variability. We used Indonesian tidal station data together with satellite SST data and atmospheric reanalysis data. The sea level variations along the southern coast of Java have a significant coherence with remote wind, local wind, and local SST variations, with an intraseasonal time scale of 20-50 days. Assuming that a coastal upwelling signal would appear as a sea level drop (SLD), we focused on intraseasonal-scale SLD events in the data. Significant upwelling signals are frequently observed during both the boreal summer and winter. To evaluate the impact of the coastal upwelling on local SST, we examined statistical relationships between sea level and SST variations. The results demonstrated that events that occurred during April-August were associated with local SST cooling. The horizontal distribution of the SST cooling was analogous with annual mean SST, suggesting the importance of intraseasonal-scale coastal upwelling in forming the climatic conditions of the southeastern tropical Indian Ocean.

  15. Winter coastal upwelling off northwest Borneo in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    YAN Yunwei; LING Zheng; CHEN Changlin

    2015-01-01

    Winter coastal upwelling off northwest Borneo in the South China Sea (SCS) is investigated by using satellite data, climatological temperature and salinity fields and reanalysis data. The upwelling forms in Decem-ber, matures in January, starts to decay in February and almost disappears in March. Both Ekman trans-port induced by the alongshore winter monsoon and Ekman pumping due to orographic wind stress curl are favorable for the upwelling. Transport estimates demonstrate that the month-to-month variability of Ekman transport and Ekman pumping are both consistent with that of winter coastal upwelling, but Ek-man transport is two times larger than Ekman pumping in January and February. Under the influence of El Niño-Southern Oscillation (ENSO), the upwelling shows remarkable interannual variability: during winter of El Niño (La Niña) years, an anticyclonic (a cyclonic) wind anomaly is established in the SCS, which behaves a northeasterly (southwesterly) anomaly and a positive (negative) wind stress curl anomaly off the north-west Borneo coast, enhancing (reducing) the upwelling and causing anomalous surface cooling (warming) and higher (lower) chlorophyll concentration. The sea surface temperature anomaly (SSTA) associated with ENSO off the northwest Borneo coast has an opposite phase to that off southeast Vietnam, resulting in a SSTA seesaw pattern in the southern SCS in winter.

  16. Spatio-temporal trends in coastal upwelling across NW Africa, 1981-2010

    Science.gov (United States)

    Cropper, Thomas; Hanna, Edward; Bigg, Grant

    2013-04-01

    In the early 1990's it was hypothesized that coastal upwelling across the eastern boundary currents may increase as a result of global warming. Since then, numerous studies have sought to elucidate the spatial and temporal trends in coastal upwelling intensity. Across the Canary Current (10-36°N), a conflicting signal (i.e. a positive/negative/no trend) in published results has emerged. We surmise this to be the consequence of (1) minor methodological differences, (2) differences in the temporal periods considered (intra- and inter-annual) and (3) the use of different data sets/sources. Here, we present seasonal upwelling estimates across the most recent 30-year climatic 'normal' period (1981-2010) based on the more commonly used wind stress and sea-surface temperature (SST) methodologies, and reinforce this analysis with traditionally 'lesser-used' sources (including sea-surface height, horizontal current velocity and vertical water column motion). For the wind-stress upwelling index we use six data sources (ERA-Interim, NCEP/NCAR, 20CR, PFEL, ICOADS and MERRA) and for the SST index we use three (HadISST, Reynolds OISST and ICOADS). We also utilize the sparse coastal meteorological and tide-gauge stations scattered across the NW African coastline. Additionally, we examine sea-surface height data from four sources (AVISO, GODAS, SODA and GRACE), horizontal current velocity from two sources (GODAS, SODA) and vertical water column motion from the GODAS dataset as further proxies for upwelling estimation. Generally, across summer, the numerous indices correlate reasonably well and display consistent spatial patterns and the same year-to-year oscillations, although the trend directions across the entire period sometimes diverge. Nevertheless, we conclude there is enough corroborating evidence to suggest there is a positive (negative) tendency in upwelling poleward (equatorward) of 20°N, but are cautious that these trends aren't ubiquitously significant. We suggest

  17. Aragonite saturation state dynamics in a coastal upwelling zone

    Science.gov (United States)

    Harris, Katherine E.; Degrandpre, Michael D.; Hales, Burke

    2013-06-01

    upwelling zones may be at enhanced risk from ocean acidification as upwelling brings low aragonite saturation state (ΩAr) waters to the surface that are further suppressed by anthropogenic CO2. ΩAr was calculated with pH, pCO2, and salinity-derived alkalinity time series data from autonomous pH and pCO2 instruments moored on the Oregon shelf and shelf break during different seasons from 2007 to 2011. Surface ΩAr values ranged between 0.66 ± 0.04 and 3.9 ± 0.04 compared to an estimated pre-industrial range of 1.0 ± 0.1 to 4.7 ± 0.1. Upwelling of high-CO2 water and subsequent removal of CO2 by phytoplankton imparts a dynamic range to ΩAr from ~1.0 to ~4.0 between spring and autumn. Freshwater input also suppresses saturation states during the spring. Winter ΩAr is less variable than during other seasons and is controlled primarily by mixing of the water column.

  18. Arabian Sea upwelling - A comparison between coastal and open ocean regions

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; PrasannaKumar, S.

    The response of the eastern Arabian Sea to prevailing winds during an upwelling event, in the peak of southwest monsoon, was studied at both coastal and open ocean environment based on the data collected as a part of the Indian Joint Global Ocean...

  19. UPWELLING EFFECTS ON THE DISTRIBUTION OF NITRATE IN YAQUINA BAY, A COASTAL OREGON ESTUARY

    Science.gov (United States)

    Coastal Oregon in the summer is dominated by northwesterly winds. Upwelling of nutrient-rich water into the nearshore is controlled by the velocity and duration of these summer winds. Yaquina Bay estuary is a mesotidal drowned river valley that is typically vertically well-mixed ...

  20. Influence of Coastal Upwelling on SST Trends along the South Coast of Java.

    Science.gov (United States)

    Varela, R; Santos, F; Gómez-Gesteira, M; Álvarez, I; Costoya, X; Días, J M

    2016-01-01

    The south coast of Java has warmed at a much lower rate than adjacent ocean locations over the last three decades (1982-2015). This behavior can be observed during the upwelling season (July-October) and it is especially patent in August and September when upwelling attains the highest values. Although different warming rates (ocean-coast) had been previously observed in other areas around the world, this behavior was always linked to situations where upwelling increased or remained unchanged. South Java warming is observed at ocean locations and cooling near shore but under a scenario of decreasing upwelling (~30% in some cases). The origin of coastal cooling is due to changes in the vertical structure of the water column. A vein of subsurface water, which has cooled at a rate higher than 0.3°C per decade, is observed to enter from the northwestern part of the study area following the South Java Current. This water only manifests at surface near coast, where it is pumped up by coastal upwelling. PMID:27606676

  1. The future of coastal upwelling ecosystems: the impact of potential wind changes on ocean acidification and coastal hypoxia

    Science.gov (United States)

    Lachkar, Z.; Gruber, N.

    2012-04-01

    The upwelling of deep, low pH, and low oxygen water to the surface makes eastern boundary upwelling systems (EBUS) naturally prone to global change induced perturbations such as ocean acidification and ocean deoxygentation related to decreased ocean ventilation. The severity of these chemical perturbations may further be exacerbated in EBUS by the potential increase in upwelling favorable winds induced by global warming. Here, we explore the impact of upwelling-favorable wind changes on modern and future ocean acidification and coastal hypoxia through a comparative study of the California Current System (California CS) and the Canary Current System (Canary CS). To this end, we undertook a series of idealized wind perturbation studies for present-day and year 2050 conditions with eddy-resolving setups of the Regional Oceanic Modeling System - ROMS- to which a nitrogen-based Nutrient-Phytoplankton-Detritus-Zooplankton (NPDZ) biogeochemical model was coupled. Our results show that the increase of upwelling favorable winds leads to a substantial shoaling of the hypoxic boundary in the California CS, while the same wind perturbation results in a reduction of the hypoxic water volume in the Canary CS. This is because coastal hypoxia is driven by local remineralization of organic matter on the shelf in the Canary CS, while it is essentially driven by large-scale advection of low oxygen water in the California CS. The intensification of upwelling tends to acerbate ocean acidification in the surface ocean, but mediates it below it, leading to complex change pattern reflecting the intricate interplay between biologically and physically -driven changes in calcium carbonate saturation state. Additionally, our results reveal differential biogeochemical responses to upwelling intensification in the water column and on the continental shelf with, therefore, contrasting implications for the benthic and the pelagic communities of these ecosystems.

  2. Diatoms Si uptake capacity drives carbon export in coastal upwelling systems

    Science.gov (United States)

    Abrantes, Fatima; Cermeno, Pedro; Lopes, Cristina; Romero, Oscar; Matos, Lélia; Van Iperen, Jolanda; Rufino, Marta; Magalhães, Vitor

    2016-07-01

    Coastal upwelling systems account for approximately half of global ocean primary production and contribute disproportionately to biologically driven carbon sequestration. Diatoms, silica-precipitating microalgae, constitute the dominant phytoplankton in these productive regions, and their abundance and assemblage composition in the sedimentary record is considered one of the best proxies for primary production. The study of the sedimentary diatom abundance (SDA) and total organic carbon content (TOC) in the five most important coastal upwelling systems of the modern ocean (Iberia-Canary, Benguela, Peru-Humboldt, California, and Somalia-Oman) reveals a global-scale positive relationship between diatom production and organic carbon burial. The analysis of SDA in conjunction with environmental variables of coastal upwelling systems such as upwelling strength, satellite-derived net primary production, and surface water nutrient concentrations shows different relations between SDA and primary production on the regional scale. On the global scale, SDA appears modulated by the capacity of diatoms to take up silicic acid, which ultimately sets an upper limit to global export production in these ocean regions.

  3. Coastal upwelling fluxes of O2, N2O, and CO2 assessed from continuous atmospheric observations at Trinidad, California

    Directory of Open Access Journals (Sweden)

    T. J. Lueker

    2004-01-01

    Full Text Available Continuous atmospheric records of O2/N2, CO2 and N2O obtained at Trinidad, California document the effects of air-sea exchange during coastal upwelling and plankton bloom events. The atmospheric records provide continuous observations of air-sea fluxes related to synoptic scale upwelling events over several upwelling seasons. Combined with satellite, buoy and local meteorology data, calculated anomalies in O2/N2 and N2O were utilized in a simple atmospheric transport model to compute air-sea fluxes during coastal upwelling. CO2 fluxes were linked to the oceanic component of the O2 fluxes through local hydrographic data and estimated as a function of upwelling intensity (surface ocean temperature and wind speed. Regional air-sea fluxes of O2/N2, N2O, and CO2 during coastal upwelling were estimated with the aid of satellite wind and SST data. Upwelling CO2 fluxes were found to represent ~10% of export production along the northwest coast of North America. Synoptic scale upwelling events impact the net exchange of atmospheric CO2 along the coastal margin, and will vary in response to the frequency and duration of alongshore winds that are subject to climate change.

  4. Fish larvae retention linked to abrupt bathymetry at Mejillones Bay (northern Chile during coastal upwelling events

    Directory of Open Access Journals (Sweden)

    Pablo M Rojas

    2014-11-01

    Full Text Available The influence of oceanic circulation and bathymetry on the fish larvae retention inside Mejillones Bay, northern Chile, was examined. Fish larvae were collected during two coastal upwelling events in November 1999 and January 2000. An elevated fish larvae accumulation was found near an oceanic front and a zone of low-speed currents. Three groups of fish larvae were identified: the coastal species (Engraulis ringens and Sardinops sagax, associated with high chlorophyll-a levels; larvae from the families Phosichthyidae (Vinciguerria lucetia and Myctophidae (Diogenichthys laternatus and Triphoturus oculeus, associated with the thermocline (12°C, and finally, larvae of the families Myctophidae (Diogenichthys atlanticus and Bathylagidae (Bathylagus nigrigenys, associated with high values of temperature and salinity. The presence of a seamount and submarine canyon inside Mejillones Bay appears to play an important role in the circulation during seasonal upwelling events. We propose a conceptual model of circulation and particles retention into Mejillones Bay. The assumption is that during strong upwelling conditions the flows that move along the canyon emerge in the centre of Mejillones Bay, producing a fish larvae retention zone. Understanding the biophysical interactions responsible to trap and/or concentrate particles is essential to protect these fragile upwelling ecosystems.

  5. Numerical modeling experiments of coastal upwelling at the field of Arctic fjords.

    Science.gov (United States)

    Kosecki, Szymon; Dzierzbicka-Głowacka, Lidia

    2016-04-01

    Coastal upwelling is a well described, known phenomenon in theory. Nowadays there is more and more both environmental and modeling studies about it. Upwelling especially in the Arctic fjords is a process that strongly affects hydrodynamics and even more ecosystems. It is so important, that it brings detailed question about effects and needed wind driven forcing parameters. My modeling experiment studies were strongly different than the studies that are typically carried out using numerical models. Instead of searching for this phenomenon in modeled analysis or environmental data, I did several case scenarios simulations. For those I used statistically selected wind data measured in-stiu. The hi-resolution coastal mapping, the flexible mesh discretization method and the sigma-layered three dimensional model MIKE 3 by DHI allowed me to explore this phenomenon with very good accuracy. This studies have been done in Institute of Oceanology PAS in Sopot, as a part of Centre for Polar Studies.

  6. Coastal upwelling linked to toxic Pseudo-nitzschia australis blooms in Los Angeles coastal waters, 2005-2007

    KAUST Repository

    Schnetzer, Astrid

    2013-06-10

    Harmful algal blooms dominated by the diatom Pseudo-nitzschia spp. have become a perennial but variable event within surface waters near the greater Los Angeles area. Toxic blooms during spring seasons from 2005 to 2007 varied strongly in their overall toxicity and duration. Differences in bloom dynamics were linked to differences in storm-induced river discharge following episodic rain events and coastal upwelling, both major coastal processes that led to the injection of nutrients into coastal surface waters. Heavy river runoff during early 2005, a record-rainfall year, favored a phytoplankton community mainly comprised of algal taxa other than Pseudo-nitzschia. The spring bloom during 2005 was associated with low domoic acid surface concentrations and minor contributions of (mainly) P. delicatissima to the diatom assemblage. In contrast, highly toxic P. australis-dominated blooms during spring seasons of 2006 and 2007 were linked to strong upwelling events. River discharge quotas in 2006 and 2007, in contrast to 2005, fell well below annual averages for the region. Surface toxin levels were linked to colder, more saline (i.e. upwelled) water over the 3-year study, but no such consistent relationship between domoic acid levels and other physiochemical parameters, such as macronutrient concentrations or nutrient ratios, was observed. © The Author 2013. Published by Oxford University Press. All rights reserved.

  7. Phytoplankton community and environmental correlates in a coastal upwelling zone along western Taiwan Strait

    Science.gov (United States)

    Wang, Yu; Kang, Jian-hua; Ye, You-yin; Lin, Geng-ming; Yang, Qing-liang; Lin, Mao

    2016-02-01

    Upwelling system in western Taiwan Strait is important for facilitating the fishery production. This study investigated hydro-chemical properties, phytoplankton biomass, phytoplankton species composition, three-dimensional (horizontal, vertical and transect) distribution of phytoplankton abundance, as well as phytoplankton annual variation and the correlation of phytoplankton community with the upwelling of underlying current and nutrients according to samples of Fujian-Guangdong coastal upwelling zone in western Taiwan Strait from August 27 to September 8, 2009. The results manifest that the nutrient-rich cold and high salinity current on the continental shelf of South China Sea upwells to the Fujian-Guangdong coastal waters through Taiwan Bank and the surging strength to surface is weak while strong at 30-m layer. The thermohaline center of coastal upwelling shifts to the east of Dongshan Island and expanded to offshore waters in comparison with previous records. A total of 137 phytoplankton species belonging to 59 genera in 4 phyla are identified excluding the unidentified species. Diatom is the first major group and followed by dinoflagellate. Cyanobacteria mainly composed by three Trichodesmium species account for a certain proportions, while Chrysophyta are only found in offshore waters. The dominant species include Thalassionema nitzschioides, Pseudo-nitzschia pungens, Thalassionema frauenfeldii, Pseudo-nitzschia delicatissima, Rhizosolenia styliformis, Chaetoceros curvisetus, Diplopsalis lenticula and Trichodesmium thiebautii. Phytoplankton community mainly consists of eurythermal and eurytopic species, followed by warm-water species, tropic high-salinity species and oceanic eurythermic species in order. Phytoplankton abundance ranges from 1.00 × 102 ind./L ~ 437.22 × 102 ind./L with an average of 47.36 × 102 ind./L. For vertical distribution, maximum abundance is found at 30 m-depth and the surface comes second. Besides, the abundance below 30 m

  8. Influence of external climate forcing on coastal upwelling systems analysed in ensemble of past millennium climate simulations

    Science.gov (United States)

    Tim, Nele; Zorita, Eduardo; Hünicke, Birgit; Yi, Xin; Emeis, Kay

    2016-04-01

    Eastern Boundary Upwelling Systems are highly productive coastal ocean areas where nutrient rich, cold water upwells by the action of favorable winds. Observations over the 20th century and ocean sediment records, which may be indicative of upwelling, display an intensification due to stronger external climate forcing, such as increasing greenhouse gas concentrations or changes in solar irradiance. This intensification is compatible with the hypothesis put forward by Bakun (1990) that a stronger external radiative forcing should lead to a more intense coastal upwelling. Here, we analyze ensemble of simulations covering the past millennium with the aim of identifying and quantifying the role of external climate forcing on upwelling in the major Eastern Boundary Upwelling System. We analyse the decadal variability and centennial trends of upwelling in ensemble of simulations with the global climate model MPI-ESM covering the past millennium, the last 150 years and the next 100 years. The future simulations were driven by three IPCC scenarios of concentrations of anthropogenic greenhouse gases, RCP2.5, RCP4.5 and RCP 8.5. For the past millennium and the last 150 years, coastal upwelling does not show any imprint of external forcing. This result indicates that chaotic internal variability has dominated upwelling intensity in major upwelling regions over the last thousand years and even since industrialisation up to present. For the 21st century, all ensemble members show a consistent and significant intensification of upwelling in the strongest scenario RCP8.5 for the Benguela upwelling region, consistent and significant weakening for Morocco and California, and no significant change for the Peruvian upwelling. Weaker scenarios do not produce consistent long-term trends that are replicated in all ensemble members. The results are confirmed by analysing another ensemble of past millennium simulations with the model CESM-CAM5 (Community Earth System Model

  9. Wind-driven coastal upwelling and westward circulation in the Yucatan shelf

    Science.gov (United States)

    Ruiz-Castillo, Eugenio; Gomez-Valdes, Jose; Sheinbaum, Julio; Rioja-Nieto, Rodolfo

    2016-04-01

    The wind-driven circulation and wind-induced coastal upwelling in a large shelf sea with a zonally oriented coast are examined. The Yucatan shelf is located to the north of the Yucatan peninsula in the eastern Gulf of Mexico. This area is a tropical shallow body of water with a smooth sloping bottom and is one of the largest shelves in the world. This study describes the wind-driven circulation and wind-induced coastal upwelling in the Yucatan shelf, which is forced by easterly winds throughout the year. Data obtained from hydrographic surveys, acoustic current profilers and environmental satellites are used in the analysis. Hydrographic data was analyzed and geostrophic currents were calculated in each survey. In addition an analytical model was applied to reproduce the currents. The results of a general circulation model were used with an empirical orthogonal function analysis to study the variability of the currents. The study area is divided in two regions: from the 40 m to the 200 m isobaths (outer shelf) and from the coast to the 40 m isobath (inner shelf). At the outer shelf, observations revealed upwelling events throughout the year, and a westward current with velocities of approximately 0.2 m s-1 was calculated from the numerical model output and hydrographic data. In addition, the theory developed by Pedlosky (2007) for a stratified fluid along a sloping bottom adequately explains the current's primary characteristics. The momentum of the current comes from the wind, and the stratification is an important factor in its dynamics. At the inner shelf, observations and numerical model output show a wind-driven westward current with maximum velocities of 0.20 m s-1. The momentum balance in this region is between local acceleration and friction. A cold-water band is developed during the period of maximum upwelling.

  10. Navigating transformations in governance of Chilean marine coastal resources

    NARCIS (Netherlands)

    Gelcich, S.; Hughes, T.P.; Olsson, P.; Folke, C.; Defeo, O.; Fernandez, M.; Foale, S.; Gunderson, L.H.; Rodriguez-Sickert, C.; Scheffer, M.; Steneck, R.S.; Castilla, J.C.

    2010-01-01

    Marine ecosystems are in decline. New transformational changes in governance are urgently required to cope with overfishing, pollution, global changes, and other drivers of degradation. Here we explore social, political, and ecological aspects of a transformation in governance of Chile's coastal mar

  11. Biological consequences of environmental changes related to coastal upwelling: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Howe, S.O.

    1979-05-01

    Two simulation models of marine ecosystem dynamics are formulated and applied to field data. The first is a time-dependent model of phytoplankton growth in nutrient-enriched batch cultures where spatial gradients of dependent variables and the effects of higher tropic level processes are not included. Rates of photosynthesis, nutrient uptake, chlorophyll synthesis and cell division for a single phytoplankton functional group are simulated as functions of photosynthetically active solar radiation, dissolved nutrient concentrations and cell quotas of carbon, nitrogen and silica. The second model combines the phytoplankton growth model with a time dependent, two-dimensional model of coastal upwelling off northwest Africa.

  12. An improved coastal upwelling index from sea surface temperature using satellite-based approach : the case of the Canary Current upwelling system

    OpenAIRE

    Benazzouz, A.; Mordane, S.; Orbi, A.; Chagdali, M.; Hilmi, K; A. Atillah; Pelegri, J. L.; Demarcq, Hervé

    2014-01-01

    A new methodology to derive an SST-based upwelling index was based on a rigorous spatial analysis of satellite SST fields and their variability, by referring to previous works, from Wooster et al. (1976) to Santos et al. (2011). The data was precautiously processed by considering data quality aspects (including cloud cover) and the best way to derive accurate coastal SST and its offshore reference. The relevance of the developed index was evaluated by comparing its spatial and seasonal consis...

  13. Lagrangian studies of phytoplankton growth and grazing relationships in a coastal upwelling ecosystem off Southern California

    Science.gov (United States)

    Landry, Michael R.; Ohman, Mark D.; Goericke, Ralf; Stukel, Michael R.; Tsyrklevich, Kate

    2009-12-01

    Experimental studies of phytoplankton growth and grazing processes were conducted in the coastal upwelling system off Point Conception, California to test the hypothesis that phytoplankton growth and grazing losses determine, to first order, the local dynamics of phytoplankton in the upwelling circulation. Eight experiments of 3-5 days each were conducted over the course of two cruises in May-June 2006 and April 2007 following the trajectories of satellite-tracked drifters. Rates of phytoplankton growth and microzooplankton grazing were determined by daily in situ dilution incubations at 8 depths spanning the euphotic zone. Mesozooplankton grazing was assessed by gut fluorescence analysis of animals collected from net tows through the euphotic zone. We compared directly the net rates of change observed for the ambient phytoplankton community to the net growth rates predicted from experimental determinations of each process rate. The resulting relationship accounted for 91% of the variability observed, providing strong support for the growth-grazing hypothesis. In addition, grazing by mesozooplankton was unexpectedly high and variable, driving a substantial positive to negative shift in phytoplankton net rate of change between years despite comparable environmental conditions and similar high growth rates and suggesting strong top-down control potential. The demonstrated agreement between net ambient and experimental community changes is an important point of validation for using field data to parameterize models. Data sets of this type may provide an important source of new information and rate constraints for developing better coupled biological-physical models of upwelling system dynamics.

  14. Influence of coastal upwelling on the air-sea gas exchange of CO2 in a Baltic Sea Basin

    OpenAIRE

    Norman, Maria; Raj Parampil, Sindu; Rutgersson, Anna; Sahlée, Erik

    2013-01-01

    During coastal upwelling cold water from the ocean interior with high CO2 concentration is brought up to the surface, allowing this water to interact with the atmosphere. This sets the stage for events with potentially altered sea–air CO2 fluxes. Four upwelling events off the east coast of Gotland in the Baltic Sea were analyzed to assess the impact of upwelling on the air–sea exchange of CO2. For each event, the observed pCO2 were found to be a function of sea-surface temperature (SST) in th...

  15. Particle fluxes in the NW Iberian coastal upwelling system: Hydrodynamical and biological control

    Science.gov (United States)

    Zúñiga, D.; Villacieros-Robineau, N.; Salgueiro, E.; Alonso-Pérez, F.; Rosón, G.; Abrantes, F.; Castro, C. G.

    2016-07-01

    To better understand sources and transport of particulate material in the NW Iberian coastal upwelling system, a mooring line dotted with an automated PPS 4/3 sediment trap was deployed off Cape Silleiro at the base of the photic zone. The samples were collected from November 2008 through June 2012 over sampling periods of 4-12 days. Our study represents the first automated sediment trap database for the NW Iberian margin. The magnitude and composition of the settling material showed strong seasonal variability with the highest fluxes during the poleward and winter mixing periods (averages of 12.9±9.6 g m-2 d-1 and 5.6±5.6 g m-2 d-1 respectively), and comparatively lower fluxes (3.6±4.1 g m-2 d-1) for the upwelling season. Intensive deposition events registered during poleward and winter mixing periods were dominated by the lithogenic fraction (80±3%). They were associated to high energy wave-driven resuspension processes, due to the occurrence of south-westerly storms, and intense riverine inputs of terrestrial material from Minho and Douro rivers. On the other hand, during the spring - summer upwelling season, the share of biogenic compounds (organic matter, calcium carbonate (CaCO3), biogenic silica (bSiO2)) to downward fluxes was higher, reflecting an increase in pelagic sedimentation due to the seasonal intensification of primary production and negligible river inputs and wave-driven resuspended material. Otherwise, the large variations of biogenic settling particles were mainly modulated by upwelling intensity, which by means of upwelling filaments ultimately controlled the offshore transport of the organic carbon fixed by primary producers towards the adjacent ocean. Based on the average downward flux of organic carbon (212 mg C m-2 d-1) and considering an average primary production of 1013 mg C m-2 d-1 from literature, we estimated that about 21% of the fixed carbon is vertically exported during the upwelling season.

  16. Changing Chilean coastal currents could drive aquatic evolution

    Science.gov (United States)

    Schultz, Colin

    2012-01-01

    For invertebrate and fish species that spend most of their lives in rich coastal waters rather than migrating freely throughout the open ocean, the formation of island populations and the associated risk of genetic diversity loss are threats to long-term population health. Many species cope through a spawning mechanism whereby larvae are released en masse into near-shore ocean currents, like pollen adrift in the wind. The larvae are viable in open waters from days to months, but only those that find their way back to shore can settle and develop. To increase their chances, different species' larvae often use particular swimming behaviors, for example, varying their depth in the water column throughout the day.

  17. A model-based insight into the coupling of nitrogen and sulfur cycles in a coastal upwelling system

    DEFF Research Database (Denmark)

    Muchamad, Al Azhar; Canfield, Donald Eugene; Fennel, Katja;

    2014-01-01

    The biogeochemical cycling in oxygen-minimum zones (OMZs) is dominated by the interactions of microbial nitrogen transformations and, as recently observed in the Chilean upwelling system, also through the energetically less favorable remineralization of sulfate reduction. The latter process...... detritus, to quantify the nitrogen and sulfur cycles in the Chilean OMZ. A new biogeochemical submodule was developed and coupled to the Regional Ocean Model System (ROMS). The model results generally agree with the observed distribution of reactive species and the measured process rates. Modeled...... is masked, however, by rapid sulfide oxidation, most likely through nitrate reduction. Thus, the cryptic sulfur cycle links with the nitrogen cycle in OMZ settings. Here, we model the physical-chemical water column structure and the observed process rates as driven by formation and sinking of organic...

  18. Long-term Variability of NorthWest African coastal upwelling

    Science.gov (United States)

    Wade, Malick; Rodríguez-Fonseca, Belen; Lazar, Alban

    2014-05-01

    The NorthWest African sea surface temperature variability can be due to changes in the coastal upwelling system, which in turn can be due to alterations in local winds, global winds induced by teleconnections and propagation of waves from wind burst in remote regions. The two last processes could be due in turn to changes in the sea surface temperature in extended regions remote from the upwelling region, as changes in Pacific SSTs associated with ENSO, or in the Equatorial Atlantic SSTs. This work demonstrates that the whole signal cannot be explained by local wind/Ekman pumping and large scale winds induced by teleconnections play an important role. Using observational data of SSTs and winds from atmospheric reanalysis, and applying different statistical technics, as correlation analysis, filtering and discriminant analysis, the different influences and its stationarity along the observational period are tested pointing to the non stationarity of El Niño influence in FMA and to other possible predictors influencing in the region.

  19. Joint effect of freshwater plume and coastal upwelling on phytoplankton growth off the Changjiang River

    Directory of Open Access Journals (Sweden)

    Y.-F. Tseng

    2013-06-01

    Full Text Available Changjiang River discharges vast amount of unbalanced nutrients (dissolved inorganic nitrogen (N and phosphorus (P with N / P > 80 in general into the East China Sea during summertime. To explore nutrient dynamics and P stress potential for phytoplankton, a cruise was conducted in the Changjiang plume during summer 2011. With 3-D observations of nutrients, chlorophyll a (Chl a, and bulk alkaline phosphatase activity (APA, we concluded that the Changjiang Diluted Water (CDW and coastal upwelling significantly influenced the horizontal and vertical heterogeneities of phytoplankton P-deficiency in the plume. Allochthonous APA was detected at nutrient-enriched freshwater end. Excessive N (~10 to 112 µM was obserevd throughout the entire plume surface. In the plume fringe where featured by stratification and excess N, diapycnal phosphate supply was blocked to stimulate APA for phytoplankton growth. We observed upwelling outcrops just attaching the turbidity front at seaward side, where Chl a peaked yet much less APA was detected. An external phosphate supply from subsurface, which stimulated phytoplankton growth but inhibited APA, was suggested and the supply was likely sourced from the Nearshore Kuroshio Branch Current. In such hydrographically complicated Changjiang plume, phosphate supply instead of its concentration was more important determining the expression of APA. Meanwhile, allochthounous APA may also alter the usefulness of APA as a P-stress indicator.

  20. Regulation of bacterial sulfate reduction and hydrogen sulfide fluxes in the central Namibian coastal upwelling zone

    DEFF Research Database (Denmark)

    Bruchert, V.; Jørgensen, BB; Neumann, K.;

    2003-01-01

    and the low capacity to oxidize and trap sulfide. The inner shelf break marks the seaward border of sulfidic bottom waters, and separates two different regimes of bacterial sulfate reduction. In the sulfidic bottom waters on the shelf, up to 55% of sulfide oxidation is mediated by the large nitrate......The coastal upwelling system off central Namibia is one of the most productive regions of the oceans and is characterized by frequently occurring shelf anoxia with severe effects for the benthic life and fisheries. We present data on water column dissolved oxygen, sulfide, nitrate and nitrite, pore...... water profiles for dissolved,sulfide and sulfate, S-35-sulfate reduction rates, as well as bacterial counts of large sulfur bacteria from 20 stations across the continental shelf and slope. The stations covered two transects and included the inner shelf with its anoxic and extremely oxygen...

  1. Biological and physical oceanographic observations pertaining to the trawl fishery in a region of persistent coastal upwelling

    Science.gov (United States)

    Howe, J. T.; Gibson, D. B.; Evans, T. O.; Breaker, L.; Wrigley, R. C.; Broenkow, W. W.

    1981-01-01

    An upwelling episode in the Point Sal region of the central California coast is examined by using data obtained by a data buoy. The episodes was interrupted by the abrupt abatement of the strong wind which promotes coastal upwelling. The mean hourly upwelling index is calculated to be higher than the 20 year mean monthly value. During 3 days of light wind commercial bottom trawl operations were possible. Shipboard estimates of chlorophyll content in surface waters during trawling show the high concentrations that are indicative of a rich biomass of phytoplankton, a result of the upwelling episode. Satellite imagery shows the extent of the upwelling water to be of the order of 100 km offshore; the result of many upwelling episodes. Shipboard echo sounder data show the presence of various delmersal species and of zooplakton; the latter graze on the phytoplankton in the upper euphotic layers. The fish catch data are recorded according to species for 2 days of trawling, and the catch per trawl hour is recorded.

  2. The importance of external climate forcing for the variability and trends of coastal upwelling in past and future climate

    Science.gov (United States)

    Tim, Nele; Zorita, Eduardo; Hünicke, Birgit; Yi, Xing; Emeis, Kay-Christian

    2016-06-01

    The eastern boundary upwelling systems, located in the subtropics at the eastern boundary of the Atlantic and Pacific oceans and mainly driven by the trade winds, are the major coastal upwelling regions. Previous studies have suggested that the intensity of upwelling in these areas in the past centuries may have been influenced by the external radiative forcing, for instance by changes in solar irradiance, and it will also be influenced in the future by the increasing atmospheric greenhouse gases. Here, we analyse the impact of the external climate forcing on these upwelling systems in ensembles of simulations of two Earth system models. The ensembles contain three simulations for each period covering the past millennium (900-1849) and the 20th century (1850-2005). One of these Earth system models additionally includes the near future (2006-2100). Using a set of simulations, differing only in their initial conditions, enables us to test whether the observed variability and trends are driven by the external radiative forcing. Our analysis shows that the variability of the simulated upwelling is largely not affected by the external forcing and that, generally, there are no significant trends in the periods covering the past and future. Only in future simulations with the strongest increase of greenhouse gas concentrations the upwelling trends are significant and appear in all members of the ensemble.

  3. Microzooplankton feeding impact in a coastal upwelling system on the NW Iberian margin: The Ría de Vigo

    Science.gov (United States)

    Teixeira, Isabel G.; Figueiras, Francisco G.; Crespo, Bibiana G.; Piedracoba, Sílvia

    2011-01-01

    The dilution technique, combined with identification and enumeration of pico-, nano- and micro-plankton by microscopy, was used to estimate microzooplankton impact on the microbial community in surface waters of a coastal embayment on the NW Iberian upwelling system. Microzooplankton were important consumers of autotrophic and heterotrophic plankton in this system, feeding up to 93% of standing stock and more than 100% of production of several groups. Heterotrophic bacteria and heterotrophic picoflagellates experienced the highest and constant impact, with 75-84% of their standing stocks and 85-102% of their production being channelled through the microbial food web. Pico- and nano-phytoplankton were also consumed, although maximum grazing occurred on diatoms during upwelling events, coinciding with highest primary production. Predation on pico-nano-heterotrophs was especially relevant under downwelling conditions, when consumption of total carbon and particularly autotrophic carbon was considerably lower than during upwelling. The results suggest that the existence of a multivorous food web, extending from the microbial loop to the herbivorous food web, could be a major feature in this coastal upwelling system. The microbial loop, which occurs as a permanent background in the system, would contribute to sustain the microbial food web during downwelling, whereas the herbivorous food web could coexist with a microbial food web based on large diatoms during upwelling. The multivorous food web would partially divert diatoms from sinking and hence favour the retention of organic matter in the water column. This could enhance the energy transfer to higher pelagic trophic levels in coastal upwelling systems.

  4. Habitat characteristics influence macrofaunal communities in coralline turf more than mesoscale coastal upwelling on the coast of Northern Chile

    Science.gov (United States)

    Kelaher, Brendan P.; Carlos Castilla, Juan

    2005-04-01

    Rocky shore communities are often influenced by near-shore coastal upwelling. For macrofauna in algal turf, these effects may be caused directly by well-studied bottom-up mechanisms or indirectly via changes in habitat structure provided by algal turf associated high nutrient loads. Here, we investigated possible interactions between upwelling and habitat structure by sampling diverse faunal assemblages in coralline algal turf on seven rocky intertidal shores in northern Chile, ranging from El Cobre [23°17'1″S, 70°31'40″W] to La Lobería [23°03'40″S, 70°33'14″W]. Some of these shores were located adjacent to strong upwelling centers, while others were in areas rarely affected. On each shore, we sampled four (2 × 2 m) sites separated by 15-50 m. In each site, we collected three replicate cores (80 mm in diameter) from which we measured macrofauna greater than 850 μm, biomass of sediment and epiphytes, frond density and average frond length. We used mean water temperature and its variation at 1-1.5 m water depth (below Extreme Low Water Spring, ELWS) to represent local upwelling intensity because long-term data have shown that these variables make excellent indicators for this region. In total, we found 94 macrofaunal taxa in coralline turf, which is almost three times higher than has previously been reported in Chile. Although macrofaunal assemblages varied significantly among shores, there were no patterns to suggest mesoscale variation in upwelling intensity affected either faunal assemblages or local habitat characteristics. In contrast, multivariate and univariate correlations highlighted sediment and frond density as strong determinants of community structure. We therefore conclude that traditionally studied habitat characteristics, such as structural complexity and habitat heterogeneity, have greater influence on faunal assemblages in mat-like habitats on rocky shores than environmental variables associated with mesoscale coastal upwelling.

  5. Variability of coastal water hydrodynamics in the southern Baltic - hindcast modelling of an upwelling event along the Polish coast

    Directory of Open Access Journals (Sweden)

    Andrzej Jankowski

    2002-12-01

    Full Text Available This paper presents the results of an attempt to reproduce, with theaid of a numerical circulation model, the hydrological conditions observedin the coastal area of the southern Baltic in September 1989.A large fall in surface layer seawater temperature was recordedin September 1989 at two coastal stations in the vicinity ofKolobrzeg and Wladyslawowo. This upwelling-like phenomenon was assumed tobe related to the specific anemobaric situation in September 1989,however typical of this phenomenon to occur along the Polish Baltic coast(Malicki & Mietus 1994. A three-dimensional (3-D sigma-coordinatebaroclinic model of the Baltic Sea, with a horizontal resolution of~5 km and 24 sigma-levels in the vertical, was applied to investigatewater circulation and thermohaline variability. Hindcastnumerical simulation showed that the model provided a good reproductionof the temporal history of the surface seawater temperature and theduration of the upwelling-like fall, but that the model results wereunderestimated. The maxima of this large fall in the surface layertemperature at both coastal stations are closely related to the phase ofchange of the upwelling-favourable wind direction to the opposite one.The results of simulation runs showed details of upwelling developmentdue to wind field fluctuations in time and differences in shaping thetemperature and current patterns in conjunction with the variations intopography and coastline features in some areas along the Polish coast.Two different hydrodynamic regimes of water movements along the coastresulting from topographical features (the Slupsk Bank can be distinguished.From the model simulation the specific conditions for the occurrence anddevelopment of upwelling at the eastern end of the Polish coast(in the vicinity of Wladyslawowo can be deduced.

  6. A Numerical Study of the Effect of Periodic Nutrient Supply on Pathways of Carbon in a Coastal Upwelling Regime

    Science.gov (United States)

    Carr, Mary-Elena

    1998-01-01

    A size-based ecosystem model was modified to include periodic upwelling events and used to evaluate the effect of episodic nutrient supply on the standing stock, carbon uptake, and carbon flow into mesozooplankton grazing and sinking flux in a coastal upwelling regime. Two ecosystem configurations were compared: a single food chain made up of net phytoplankton and mesozooplankton (one autotroph and one heterotroph, A1H1), and three interconnected food chains plus bacteria (three autotrophs and four heterotrophs, A3H4). The carbon pathways in the A1H1 simulations were under stronger physical control than those of the A3H4 runs, where the small size classes are not affected by frequent upwelling events. In the more complex food web simulations, the microbial pathway determines the total carbon uptake and grazing rates, and regenerated nitrogen accounts for more than half of the total primary production for periods of 20 days or longer between events. By contrast, new production, export of carbon through sinking and mesozooplankton grazing are more important in the A1H1 simulations. In the A3H4 simulations, the turnover time scale of the autotroph biomass increases as the period between upwelling events increases, because of the larger contribution of slow-growing net phytoplankton. The upwelling period was characterized for three upwelling sites from the alongshore wind speed measured by the NASA Scatterometer (NSCAT) and the corresponding model output compared with literature data. This validation exercise for three upwelling sites and a downstream embayment suggests that standing stock, carbon uptake and size fractionation were best supported by the A3H4 simulations, while the simulated sinking fluxes are not distinguishable in the two configurations.

  7. Coastal upwelling fluxes of O2, N2O, and CO2 assessed from continuous atmospheric observations at Trinidad,California

    Directory of Open Access Journals (Sweden)

    T. J. Lueker

    2004-08-01

    Full Text Available Continuous atmospheric records of O2/N2, CO2 and N2O obtained at Trinidad, California document the effects of air-sea exchange during coastal upwelling and plankton bloom events. The atmospheric records provide continuous observations of air-sea fluxes related to synoptic scale upwelling events over several upwelling seasons. Combined with satellite, buoy and local meteorology data, calculated anomalies in O2/N2 and N2O were utilized in a simple atmospheric transport model to compute air-sea fluxes during coastal upwelling. CO2 fluxes were linked to the oceanic component of the O2 fluxes through local hydrographic data and estimated as a function of upwelling intensity (surface ocean temperature and wind speed. Regional air-sea fluxes of O2/N2O, and CO2 during coastal upwelling were estimated with the aid of satellite wind and SST data. Upwelling CO2 fluxes were found to represent ~10% of export production along the northwest coast of North America. Synoptic scale upwelling events impact the net exchange of atmospheric CO2 along the coastal margin, and will vary in response to the frequency and duration of alongshore winds that are subject to climate change.

  8. What controls biological production in coastal upwelling systems? Insights from a comparative modeling study

    OpenAIRE

    Z. Lachkar; Gruber, N.

    2011-01-01

    The magnitude of net primary production (NPP) in Eastern Boundary Upwelling Systems (EBUS) is traditionally viewed as directly reflecting the wind-driven upwelling intensity. Yet, different EBUS show different sensitivities of NPP to upwelling-favorable winds (Carr and Kearns, 2003). Here, using a comparative modeling study of the California Current System (California CS) and Canary Current System (Canary CS), we show how physical and environmental factors, such as light,...

  9. What controls biological productivity in coastal upwelling systems? Insights from a comparative modeling study

    OpenAIRE

    Z. Lachkar; Gruber, N.

    2011-01-01

    The magnitude of the biological productivity in Eastern Boundary Upwelling Systems (EBUS) is traditionally viewed as directly reflecting the upwelling intensity. Yet, different EBUS show different sensitivities of productivity to upwelling-favorable winds (Carr and Kearns, 2003). Here, using a comparative modeling study of the California Current System (California CS) and Canary Current System (Canary CS), we show how physical and environmental factors, such as light, temperature and c...

  10. Upwelling-Induced Primary Productivity in Coastal Waters of the Black Sea: Impact on Algorithms for Remote Sensing

    Science.gov (United States)

    Goldman, Joel C.; Brink, Kenneth K.; Gawarkiewicz, Glen; Sosik, Heidi M.

    1997-01-01

    This research program was a collaborative effort to investigate the impact of rapid changes in the water column during coastal upwelling, on biological and optical properties. These properties are important for constructing region or event-specific algorithms for remote sensing of pigment concentration and primary productivity and for comparing these algorithms with those used for the development of large scale maps from ocean color. We successfully achieved the primary objective of this research project which was to study in situ the dynamics of rapid spatial and temporal changes in properties of the water column during, coastal upwelling off the Crimean Coast in the Black Sea. The work was a collaborative effort between a group of biological and physical oceanographers from the Woods Hole Oceanographic Institution and from two oceanographic research institutions in the Crimea, Ukraine, located near the study site, the Marine Hydrophysical Institute (MHI) and the Institute of Biology of the Southern Seas (IBSS). The site was an ideal experimental model, both from a technical and economic standpoint, because of the predictable summer upwelling that occurs in the region and because of the availability of both a ship on call and laboratory and remote sensing facilities at the nearby marine institutes. We used a combination of shipboard measurements and remote sensing to investigate the physical evolution of rapid upwelling events and their impact on photoplankton and water column optical properties. The field work involved a two day cruise for mooring, deployment and a three day baseline survey cruise, followed by an eleven day primary cruise during, a summer upwelling event (anticipated by monitoring local winds and tracked by remote sensing imaging). An MHI ship was outfitted and used for these purposes.

  11. Mesoscale eddies in the coastal upwelling region of the tropical northeast Atlantic Ocean

    Science.gov (United States)

    Schütte, Florian; Brandt, Peter; Karstensen, Johannes

    2014-05-01

    The mesoscale variability in the tropical northeast Atlantic (between 12°N - 22°N and 15°W - 26°W) is examined and characterised. We applied two automated methods for eddy identification to 16 years of satellite altimetry measurements: the geometrical method, based on closed streamlines around eddy cores, and the Okubo-Weiß method, based on the relationship between vorticity and the strain tensors. In general, both methods agree well. On average about 125 (±11) eddies per year were identified, separating in 52% cyclones and 48% anticylones. We found an average radius of about 50 (±20) km, a westward propagation speed of about 2.8 (±1.2) km/d and an average lifetime of about 40 days. Several eddies (more anticylones than cyclones) were detectable up to 300 days. Three main eddy formation regions in the coastal upwelling region that can be associated with headlands of the coast are detectable. This suggests that dynamic instability of the along-shore current is an important generation mechanism. We identified that cyclones are produced predominantly during boreal winter, especially in January, whereas anticyclones are generated predominantly during boreal summer. From the three eddy generation areas, almost all eddies propagate westward along distinct corridors with a small polarity depending meridional deflection (anticyclones - equatorward, cyclones - poleward). Considering occupied area and number of eddies, about 17% of the tropical northeast Atlantic region under investigation was occupied by eddies in every moment in time. About 30 (±5) eddies per year originate from the upwelling region off Senegal and Mauretania. Considering in-situ temperature and salinity observations (Argo, ship, mooring data) within and outside of eddies detected by the algorithms the mean vertical structure of the mesoscale eddies were determined. From together 2191 Profiles, 106 (144) profiles were within anticyclonic (cyclonic) mesoscale eddies. On average the maximum

  12. Seasonality in Planktic Foraminifera of the Central California Coastal Upwelling Region

    OpenAIRE

    Davis, C.V.; Russell, A. D.; Gaylord, B. P.; Jahncke, J.; Hill, T M

    2016-01-01

    The association between planktic foraminiferal assemblages and local hydrography make foraminifera invaluable proxies for environmental conditions. Modern foraminiferal seasonality is important for interpreting fossil distributions and shell geochemistry as paleoclimate proxies. Understanding this seasonality in an active upwelling area is also critical for anticipating which species may be vulnerable to future changes in upwelling intensity and ocean acidification. Two ye...

  13. Chilean coastal orographic precipitation experiment: A tale of two rain regimes

    Science.gov (United States)

    Massmann, Adam K.

    The Chilean Coastal Orographic Precipitation Experiment Pilot Project (CCOPE-2015) was an exploratory field campaign to better understand the mechanisms of orographic precipitation enhancement in the Nahuelbuta Mountains of Southern Chile (38 deg. S.). Observations collected include: (1) surface rainfall from a network of 10 data logging rain gauges, (2) vertical precipitation profiles from a pair of K-band Micro Rain Radars, (3) rain drop size distributions from an optical disdrometer, (4) upstream wind and thermodynamic profiles from radiosonde launches, and (5) aerosol number concentration and size distribution measurements from a condensation particle counter and an ultra-high sensitivity aerosol spectrometer. An overview of observations collected during CCOPE-2015 is presented. The character of precipitation over the Nahuelbuta is contrasted between periods of ice-initiated and warm rain. Thirty-four percent of rainfall fell during warm rain periods, while fifty-two percent of rainfall fell during ice-initiated periods. Warm rain drop size distributions are characterized by many more and relatively smaller drops than ice-initiated drop size distributions. Both the portion and properties of ice-initiated and warm rainfall compare favorably with observations of coastal mountain rainfall at a similar latitude in California. Observations suggest that enhancement is stronger during warm rain periods, but uncertainty precludes declarations of significance. Additionally, the skill of satellite-based quantitative precipitation estimation is assessed for each rain regime. A cutting-edge NASA Global Precipitation Measurement mission algorithm severely underestimates orographic enhancement of precipitation in the Nahuelbuta mountains, but performs better in the lee and upwind of the mountains. Much of the error in estimating orographic rain is during warm rain periods, while performance is much improved during ice-initiated rain periods.

  14. Northern Monterey Bay upwelling shadow front: Observations of a coastally and surface-trapped buoyant plume

    Science.gov (United States)

    Woodson, C.B.; Washburn, L.; Barth, J.A.; Hoover, D.J.; Kirincich, A.R.; McManus, M.A.; Ryan, J.P.; Tyburczy, J.

    2009-01-01

    During the upwelling season in central California, northwesterly winds along the coast produce a strong upwelling jet that originates at Point A??o Nuevo and flows southward across the mouth of Monterey Bay. A convergent front with a mean temperature change of 3.77 ?? 0.29??C develops between the warm interior waters and the cold offshore upwelling jet. To examine the forcing mechanisms driving the location and movement of the upwelling shadow front and its effects on biological communities in northern Monterey Bay, oceanographic conditions were monitored using cross-shelf mooring arrays, drifters, and hydrographic surveys along a 20 km stretch of coast extending northwestward from Santa Cruz, California, during the upwelling season of 2007 (May-September). The alongshore location of the upwelling shadow front at the northern edge of the bay was driven by: regional wind forcing, through an alongshore pressure gradient; buoyancy forces due to the temperature change across the front; and local wind forcing (the diurnal sea breeze). The upwelling shadow front behaved as a surface-trapped buoyant current, which is superimposed on a poleward barotropic current, moving up and down the coast up to several kilometers each day. We surmise that the front is advected poleward by a preexisting northward barotropic current of 0.10 m s-1 that arises due to an alongshore pressure gradient caused by focused upwelling at Point A??o Nuevo. The frontal circulation (onshore surface currents) breaks the typical two-dimensional wind-driven, cross-shelf circulation (offshore surface currents) and introduces another way for water, and the material it contains (e.g., pollutants, larvae), to go across the shelf toward shore.Copyright 2009 by the American Geophysical Union.

  15. Detection of Moroccan Coastal Upwelling in SST images using the Expectation-Maximization

    OpenAIRE

    Tamim, Ayoub; Minaoui, Khalid; Daoudi, Khalid; Atillah, Abderrahman; Aboutajdine, Driss

    2014-01-01

    International audience This paper proposes an unsupervised algorithm for automatic detection and segmentation of upwelling region in Moroccan Atlantic coast using the Sea Surface Temperature (SST) satellite images. This has been done by exploring the Expectation-Maximization algorithm. The good number of clus- ters that best reproduces the shape of upwelling areas is selected by using the two popular Davies-Bouldin and Dunn indices. Area opening technique is developed that is used to remov...

  16. What controls biological productivity in coastal upwelling systems? Insights from a comparative modeling study

    Directory of Open Access Journals (Sweden)

    Z. Lachkar

    2011-06-01

    Full Text Available The magnitude of the biological productivity in Eastern Boundary Upwelling Systems (EBUS is traditionally viewed as directly reflecting the upwelling intensity. Yet, different EBUS show different sensitivities of productivity to upwelling-favorable winds (Carr and Kearns, 2003. Here, using a comparative modeling study of the California Current System (California CS and Canary Current System (Canary CS, we show how physical and environmental factors, such as light, temperature and cross-shore circulation modulate the response of biological productivity to upwelling strength. To this end, we made a series of eddy-resolving simulations of the California CS and Canary CS using the Regional Ocean Modeling System (ROMS, coupled to a nitrogen based Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD ecosystem model. We find the nutrient content of the euphotic zone to be 20 % smaller in the Canary CS relative to the California CS. Yet, the biological productivity is 50 % smaller in the latter. This is due to: (1 a faster nutrient-replete growth in the Canary CS relative to the California CS, related to a more favorable light and temperature conditions in the Canary CS, and (2 the longer nearshore water residence times in the Canary CS which lead to larger buildup of biomass in the upwelling zone, thereby enhancing the productivity. The longer residence times in the Canary CS appear to be associated with the wider continental shelves and the lower eddy activity characterizing this upwelling system. This results in a weaker offshore export of nutrients and organic matter, thereby increasing local nutrient recycling and enhancing the coupling between new and export production in the Northwest African system. Our results suggest that climate change induced perturbations such as upwelling favorable wind intensification might lead to contrasting biological responses in the California CS and the Canary CS, with major implications for the biogeochemical cycles

  17. Salares versus coastal ecotypes of quinoa: Salinity responses in Chilean landraces from contrasting habitats.

    Science.gov (United States)

    Ruiz, Karina B; Aloisi, Iris; Del Duca, Stefano; Canelo, Valentina; Torrigiani, Patrizia; Silva, Herman; Biondi, Stefania

    2016-04-01

    Quinoa (Chenopodium quinoa Willd.) is a highly salt-tolerant species subdivided into five ecotypes and exhibiting broad intra-specific differences in tolerance levels. In a greenhouse study, Chilean landraces belonging either to the salares (R49) or coastal lowlands (VI-1, Villarrica) ecotype with contrasting agro-ecological origins were investigated for their responses to high salinity. The effects of two levels of salinity, 100 (T1) and 300 (T2) mM NaCl, on plant growth and on some physiological parameters were measured. Leaf and root Na(+) accumulation differed among landraces. T2 reduced growth and seed yield in all landraces with maximum inhibition relative to controls in R49. Salinity negatively affected chlorophyll and total polyphenol content (TPC) in VI-1 and Villarrica but not R49. Germination on saline or control media of seeds harvested from plants treated or not with NaCl was sometimes different; the best performing landrace was R49 insofar as 45-65% of seeds germinated on 500 mM NaCl-containing medium. In all landraces, average seedling root length declined strongly with increasing NaCl concentration, but roots of R49 were significantly longer than those of VI-1 and Villarrica up to 300 mM NaCl. Salt caused increases in seed TPC relative to controls, but radical scavenging capacity was higher only in seeds from T2 plants of R49. Total SDS-extractable seed proteins were resolved into distinct bands (10-70 kDa) with some evident differences between landraces. Salt-induced changes in protein patterns were landrace-specific. The responses to salinity of the salares landrace are discussed in relation to its better adaptation to an extreme environment. PMID:26841266

  18. [Community composition of phytoplankton in Fujian-Guangdong coastal upwelling region in summer and related affecting factors].

    Science.gov (United States)

    Wang, Yu; Lin, Mao; Lin, Geng-Ming; Xiang, Peng

    2011-02-01

    Based on the investigation data of 133 samples from 30 grid stations in the Fujian-Guangdong coastal upwelling region (21.6 degrees - 24.3 degrees N,115.7 degrees -118.7 degrees E) in 11-16 June 2009, this paper studied the phytoplankton species composition and cell abundance in the region in three dimensions (vertical, horizontal, and sectional), and approached their relations with major environmental factors. A total of 159 taxa belonging to 85 genera of 4 phyla were identified, among which, diatom was predominant, followed by dinoflagellate. Cyanophyceae mainly composed of Trichodesmium also occupied a greater proportion, but Chrysophyceae was only checked out in the upper 10 m water layer at coastal stations. The dominant species were Rhizosolenia alata f. gracillma, Thalassionema nitzschioides, Pseudonitzschia pungens, Skeletonema costatum, Thalassionema frauenfeldii, Paralia sulcata, Guinadia striata, Trichodesmium thiebautii, Ceratium fusus, and Gyrodinium spirale. Most of the phytoplankton taxa were cosmopolitan species, followed by warm-water species, while tropic high-salinity or oceanic eurythermal species were lesser. The cell abundance of the phytoplankton was average of 67.59 x10(2) ind x L(-1). In vertical profile, the cell abundance of the phytoplankton was the highest in surface water, and decreased with water depth. In horizontal and sectional profiles, the cell abundance had no definite patterns, but the high abundance region was in Nanao Island water area, being anastomosed with the center of upwelling region, which indicated that the weak and small intensity of deep-sea water upwelling caused lesser phytoplankton cell abundance and superposition. The comparatively high phytoplankton cell abundance in the four sections (B, C, D, E) along Nanao-Zhangpu was resulted from the upwelling from Taiwan Bank. The phytoplankton cell abundance had a significant positive correlation with the PO4(3-) concentration in the upper 10 m water layer, but no

  19. Influences of riverine and upwelling waters on the coastal carbonate system off Central Chile and their ocean acidification implications

    Science.gov (United States)

    Vargas, Cristian A.; Contreras, Paulina Y.; Pérez, Claudia A.; Sobarzo, Marcus; Saldías, Gonzalo S.; Salisbury, Joe

    2016-06-01

    A combined data set, combining data from field campaigns and oceanographic cruises, was used to ascertain the influence of both river discharges and upwelling processes, covering spatial and temporal variation in dissolved inorganic carbon (DIC) and aragonite saturation state. This work was conducted in one of the most productive river-influenced upwelling areas in the South Pacific coasts (36°S). Additionally, further work was also conducted to ascertain the contribution of different DIC sources, influencing the dynamics of DIC along the land-ocean range. Six sampling campaigns were conducted across seven stations at the Biobío River basin, covering approximately 200 km. Three research cruises were undertaken simultaneously, covering the adjacent continental shelf, including 12 sampling stations for hydrographic measurements. Additionally, six stations were also sampled for chemical analyses, covering summer, winter, and spring conditions over 2010 and 2011. Our results evidenced that seaward extent of the river plume was more evident during the winter field campaign, when highest riverine DIC fluxes were observed. The carbonate system along the river-ocean continuum was very heterogeneous varying over spatial and temporal scales. High DIC and pCO2 were observed in river areas with larger anthropogenic effects. CO2 supersaturation at the river plume was observed during all campaigns due to the influence of low pH river waters in winter/spring and high-pCO2 upwelling waters in summer. δ13CDIC evidenced that main DIC sources along the river and river plume corresponded to the respiration of terrestrial organic matter. We have linked this natural process to the carbonate saturation on the adjacent river-influenced coastal area, suggesting that Ωaragonite undersaturation in surface/subsurface waters is largely modulated by the influence of both river discharge and coastal upwelling events in this productive coastal area. Conditions of low Ωaragonite might impact

  20. Slip Distribution and Seismic Moment of the 2010 and 1960 Chilean Earthquakes Inferred from Tsunami Waveforms and Coastal Geodetic Data

    Science.gov (United States)

    Fujii, Yushiro; Satake, Kenji

    2013-09-01

    The slip distribution and seismic moment of the 2010 and 1960 Chilean earthquakes were estimated from tsunami and coastal geodetic data. These two earthquakes generated transoceanic tsunamis, and the waveforms were recorded around the Pacific Ocean. In addition, coseismic coastal uplift and subsidence were measured around the source areas. For the 27 February 2010 Maule earthquake, inversion of the tsunami waveforms recorded at nearby coastal tide gauge and Deep Ocean Assessment and Reporting of Tsunamis (DART) stations combined with coastal geodetic data suggest two asperities: a northern one beneath the coast of Constitucion and a southern one around the Arauco Peninsula. The total fault length is approximately 400 km with seismic moment of 1.7 × 1022 Nm (Mw 8.8). The offshore DART tsunami waveforms require fault slips beneath the coasts, but the exact locations are better estimated by coastal geodetic data. The 22 May 1960 earthquake produced very large, ~30 m, slip off Valdivia. Joint inversion of tsunami waveforms, at tide gauge stations in South America, with coastal geodetic and leveling data shows total fault length of ~800 km and seismic moment of 7.2 × 1022 Nm (Mw 9.2). The seismic moment estimated from tsunami or joint inversion is similar to previous estimates from geodetic data, but much smaller than the results from seismic data analysis.

  1. What controls biological production in coastal upwelling systems? Insights from a comparative modeling study

    Directory of Open Access Journals (Sweden)

    Z. Lachkar

    2011-10-01

    Full Text Available The magnitude of net primary production (NPP in Eastern Boundary Upwelling Systems (EBUS is traditionally viewed as directly reflecting the wind-driven upwelling intensity. Yet, different EBUS show different sensitivities of NPP to upwelling-favorable winds (Carr and Kearns, 2003. Here, using a comparative modeling study of the California Current System (California CS and Canary Current System (Canary CS, we show how physical and environmental factors, such as light, temperature and cross-shore circulation modulate the response of NPP to upwelling strength. To this end, we made a series of eddy-resolving simulations of the two upwelling systems using the Regional Oceanic Modeling System (ROMS, coupled to a nitrogen-based Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD ecosystem model. Using identical ecological/biogeochemical parameters, our coupled model simulates a level of NPP in the California CS that is 50 % smaller than that in the Canary CS, in agreement with observationally based estimates. We find this much lower NPP in the California CS despite phytoplankton in this system having nearly 20 % higher nutrient concentrations available to fuel their growth. This conundrum can be explained by: (1 phytoplankton having a faster nutrient-replete growth in the Canary CS relative to the California CS; a consequence of more favorable light and temperature conditions in the Canary CS, and (2 the longer nearshore water residence times in the Canary CS, which permit a larger buildup of biomass in the upwelling zone, thereby enhancing NPP. The longer residence times in the Canary CS appear to be a result of the wider continental shelves and the lower mesoscale activity characterizing this upwelling system. This results in a weaker offshore export of nutrients and organic matter, thereby increasing local nutrient recycling and reducing the spatial decoupling between new and export production in the Canary CS. Our results suggest that climate change

  2. 10Be and 26Al dating of marine terraces to quantifying the uplift of Peruvian and Chilean coastal areas

    International Nuclear Information System (INIS)

    Full text: Along most of the Southern Peru and Northern Chilean coasts, discontinuous uplifts are recorded by marine terraces and marine abrasion surfaces; they have thus preserved a record of eustatic sea level changes and the uplift history of the coastal area in the Andean forearc. One approach to study the tectonic history of the Andean forearc is to identify its effects in marine sedimentation or erosion patterns along the coastal area. To investigate these processes, the Neogene marine formations are studied in various coastal sections either in southern Peru or in Chile, in order to sample possibly different response of the continental plate to the subduction process. Differential GPS and cosmogenic datations (10Be and 26Al) are pursued to propose thorough ages on these sites and subtract the effects of eustatic sea-level changes from local curves, identifying tectonic uplifts. We chose this method in order to obtain absolute ages for each sampled terrace and because it is under application and calibration in the southern Peru on alluvial terraces. 10Be and 26Al samples analyzes in laboratory (with the collaboration of the UCSC and the Lawrence Livermore National Laboratory, USA) are still under way but already gave determinant ages. Indeed, there are four observable terraces along the Chilean coast (+7 m, +40 m, +184 m et +370 m), all of which we have sampled. We obtained an average age for two of them: 231 Ka ± 14.9 for the +40 m terrace and 330 Ka ± 1.34 for the +184 m one. So the +40 m terrace corresponds to the 7th isotopic stage and the +184 m terrace corresponds to the 9th isotopic stage, which is younger than predicted by previous authors. We can thus expect that the 5th isotopic stage corresponds to the +7 m terrace and the 11th isotopic stage to the +370 m terrace. This hypothesis will be confirmed by the very next analyzes. The terrace of the 5th isotopic stage is lower and less developed than waited. The uplift rate is not constant: we

  3. Coastal circulation and upwelling index along the east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Suryanarayana, A.; Rao, D.P.

    . From the upwelling index derived from the winds obtained from the IDWRs (Indian Daily Weather Reports) the entire coast is divided into three zones, characterisEd. by (1) negative index in the northern zone (2) both positive and negative indices of less...

  4. Insights into the Microbial and Viral Dynamics of a Coastal Downwelling-Upwelling Transition.

    Directory of Open Access Journals (Sweden)

    Gustavo Bueno Gregoracci

    Full Text Available Although previous studies have described opposing states in upwelling regions, i.e., the rise of cold nutrient-rich waters and prevalence of surface warm nutrient-poor waters, few have addressed the transition from one state to the other. This study aimed to describe the microbial and viral structure during this transition and was able to obtain the taxonomic and metabolic compositions as well as physical-chemical data. This integrated approach allowed for a better understanding of the dynamics of the downwelling upwelling transition, suggesting that a wealth of metabolic processes and ecological interactions are occurring in the minute fractions of the plankton (femto, pico, nano. These processes and interactions included evidence of microbial predominance during downwelling (with nitrogen recycling and aerobic anoxygenic photosynthesis, different viral predation pressures over primary production in different states (cyanobacteria vs eukaryotes, and a predominance of diatoms and selected bacterial and archaeal groups during upwelling (with the occurrence of a wealth of nitrogen metabolism involving ammonia. Thus, the results provided insights into which microbes, viruses and microbial-mediated processes are probably important in the functioning of upwelling systems.

  5. Insights into the Microbial and Viral Dynamics of a Coastal Downwelling-Upwelling Transition.

    Science.gov (United States)

    Gregoracci, Gustavo Bueno; Soares, Ana Carolina Dos Santos; Miranda, Milene Dias; Coutinho, Ricardo; Thompson, Fabiano L

    2015-01-01

    Although previous studies have described opposing states in upwelling regions, i.e., the rise of cold nutrient-rich waters and prevalence of surface warm nutrient-poor waters, few have addressed the transition from one state to the other. This study aimed to describe the microbial and viral structure during this transition and was able to obtain the taxonomic and metabolic compositions as well as physical-chemical data. This integrated approach allowed for a better understanding of the dynamics of the downwelling upwelling transition, suggesting that a wealth of metabolic processes and ecological interactions are occurring in the minute fractions of the plankton (femto, pico, nano). These processes and interactions included evidence of microbial predominance during downwelling (with nitrogen recycling and aerobic anoxygenic photosynthesis), different viral predation pressures over primary production in different states (cyanobacteria vs eukaryotes), and a predominance of diatoms and selected bacterial and archaeal groups during upwelling (with the occurrence of a wealth of nitrogen metabolism involving ammonia). Thus, the results provided insights into which microbes, viruses and microbial-mediated processes are probably important in the functioning of upwelling systems. PMID:26327119

  6. Microbial diversity of a Brazilian coastal region influenced by an upwelling system and anthropogenic activity.

    Directory of Open Access Journals (Sweden)

    Juliano C Cury

    Full Text Available BACKGROUND: Upwelling systems are characterised by an intense primary biomass production in the surface (warmest water after the outcrop of the bottom (coldest water, which is rich in nutrients. Although it is known that the microbial assemblage plays an important role in the food chain of marine systems and that the upwelling systems that occur in southwest Brazil drive the complex dynamics of the food chain, little is known about the microbial composition present in this region. METHODOLOGY/PRINCIPAL FINDINGS: We carried out a molecular survey based on SSU rRNA gene from the three domains of the phylogenetic tree of life present in a tropical upwelling region (Arraial do Cabo, Rio de Janeiro, Brazil. The aim was to analyse the horizontal and vertical variations of the microbial composition in two geographically close areas influenced by anthropogenic activity (sewage disposal/port activity and upwelling phenomena, respectively. A lower estimated diversity of microorganisms of the three domains of the phylogenetic tree of life was found in the water of the area influenced by anthropogenic activity compared to the area influenced by upwelling phenomena. We observed a heterogenic distribution of the relative abundance of taxonomic groups, especially in the Archaea and Eukarya domains. The bacterial community was dominated by Proteobacteria, Cyanobacteria and Bacteroidetes phyla, whereas the microeukaryotic community was dominated by Metazoa, Fungi, Alveolata and Stramenopile. The estimated archaeal diversity was the lowest of the three domains and was dominated by uncharacterised marine Crenarchaeota that were most closely related to Marine Group I. CONCLUSIONS/SIGNIFICANCE: The variety of conditions and the presence of different microbial assemblages indicated that the area of Arraial do Cabo can be used as a model for detailed studies that contemplate the correlation between pollution-indicating parameters and the depletion of microbial

  7. The Response of Phytoplankton Size Spectra and Chlorophyll Biomass to Wind-driven Coastal Upwelling off Northern California During the CoOP-WEST Study.

    Science.gov (United States)

    Wilkerson, F. P.; Dugdale, R. C.; Marchi, A.; Hogue, V.; Lassiter, A.; Lew, K.; Lorenzi, A.

    2002-12-01

    During the WEST (Wind Events and Shelf Transport) summer studies of the coastal upwelling region off Bodega Bay, CA, chlorophyll concentrations consistently reached phytoplankton bloom levels following wind driven upwelling events that resulted in high concentrations of pCO2 and nutrients. In most coastal upwelling areas, upwelled nitrate and high rates of new production lie close to the coast in a distinct plume, and their consequences (a band of enhanced chlorophyll) are propagated seaward far beyond the point where upwelled nutrients have been exhausted. Most likely grazing on advected diatoms results in release of regenerated N (ammonium and urea) that is taken up by the small-sized phytoplankton that out-compete diatoms for ammonium and consequently carry coastal new production offshore in the upper layer current system. However in the WEST study area the growing phytoplankton (showing high rates of new production) and productivity are retained on the shelf, and apparently transported alongshore rather than offshore most of the time. The elevated chlorophyll (reaching over 30 μg/l in June 2000) is made up of mostly larger phytoplankton cells with the diatom Chaetoceros spp. dominating during the bloom events. These cells may be grazed or sink and be carried in sub surface currents and re-entrained in the undercurrent, unlike smaller cells that remain in the upper layer. Surface distributions of chlorophyll and phytoplankton size spectra and fluorescence obtained using a CytoSense flow cytometer will be compared between upwelling spring cruises and a non upwelling winter cruise to the CoOP-WEST study site off Bodega Bay, CA.

  8. The MORENA Project: Shelf-ocean exchanges and transport processes along the continental margin in the European coastal upwelling region

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, A.F.G. [Univ. de Lisboa (Portugal). Inst. de Oceanografia; Perez, F. [Inst. Investigaciones Marinas, Vigo (Spain); Johnson, J. [Univ. East Anglia (United Kingdom)] [and others

    1994-12-31

    The MORENA Project (Multidisciplinary Oceanographic Research in the Eastern Boundary of the North Atlantic) is sponsored by the CEC MAST-2 Programme and has as general objective to measure, understand and model shelf-ocean exchange in a typical coastal upwelling region of the eastern boundary layer of the subtropical ocean. This is being attained through a multidisciplinary approach aimed at the quantitative understanding of the physical, chemical and biological processes involved in the transfer of matter (including salt, particulates, nutrients, organic compounds, biomass), momentum and energy across and along the shelf, the shelf break and the slope, in the Iberian region of the European Atlantic. MORENA has the following components: Observations, Modelling and Combined Analysis.

  9. Deep ocean mass fluxes in the coastal upwelling off Mauritania from 1988 to 2012: variability on seasonal to decadal timescales

    Science.gov (United States)

    Fischer, Gerhard; Romero, Oscar; Merkel, Ute; Donner, Barbara; Iversen, Morten; Nowald, Nico; Ratmeyer, Volker; Ruhland, Götz; Klann, Marco; Wefer, Gerold

    2016-05-01

    A more than two-decadal sediment trap record from the Eastern Boundary Upwelling Ecosystem (EBUE) off Cape Blanc, Mauritania, is analysed with respect to deep ocean mass fluxes, flux components and their variability on seasonal to decadal timescales. The total mass flux revealed interannual fluctuations which were superimposed by fluctuations on decadal timescales. High winter fluxes of biogenic silica (BSi), used as a measure of marine production (mostly by diatoms) largely correspond to a positive North Atlantic Oscillation (NAO) index (December-March). However, this relationship is weak. The highest positive BSi anomaly was in winter 2004-2005 when the NAO was in a neutral state. More episodic BSi sedimentation events occurred in several summer seasons between 2001 and 2005, when the previous winter NAO was neutral or even negative. We suggest that distinct dust outbreaks and deposition in the surface ocean in winter and occasionally in summer/autumn enhanced particle sedimentation and carbon export on short timescales via the ballasting effect. Episodic perturbations of the marine carbon cycle by dust outbreaks (e.g. in 2005) might have weakened the relationships between fluxes and large-scale climatic oscillations. As phytoplankton biomass is high throughout the year, any dry (in winter) or wet (in summer) deposition of fine-grained dust particles is assumed to enhance the efficiency of the biological pump by incorporating dust into dense and fast settling organic-rich aggregates. A good correspondence between BSi and dust fluxes was observed for the dusty year 2005, following a period of rather dry conditions in the Sahara/Sahel region. Large changes of all bulk fluxes occurred during the strongest El Niño-Southern Oscillation (ENSO) in 1997-1999 where low fluxes were obtained for almost 1 year during the warm El Niño and high fluxes in the following cold La Niña phase. For decadal timescales, Bakun (1990) suggested an intensification of coastal upwelling

  10. The Role of Shelf Break Upwelling Along the East Coast of the US in the Coastal Carbon Cycle: A Model's Tale

    Science.gov (United States)

    Siedlecki, S. A.; Mahadevan, A.; Archer, D.

    2008-12-01

    The coastal ocean is highly productive because it has several sources of nutrients: rivers, sediments and the open ocean. Although the East Coast of the United States is not an upwelling regime, its continental shelf is supplied by nutrients from the open ocean. Instead of traditional upwelling, a persistent front at the continental shelf break regulates the source of nutrients by interactions with the bottom boundary layer and the winds via a mechanism referred to as "shelf break upwelling." Shelf break upwelling also leads to ventilation of carbon dioxide and methane from coastal waters. A three-dimensional, nonhydrostatic, 2km resolution model with idealized bathymetry is used to simulate the shelf and shelf-break front circulations of an archetypical passive margin off the eastern coast of the United States. The model is adapted for the coastal setting from a model developed for open ocean fronts after Mahadevan et al, (1996a) and Mahadevan et al, (1996b) and is ground-truthed using data from the Mid- Atlantic Bight. We diagnose the pathways for nutrient supply and ventilation using a series of idealized tracers including nutrient, gas and bottom boundary layer tracers We find that the location of the foot of the front determines the source waters for the shelf break upwelling. In response to Southerly winds, the foot of the front moves onshore. Conversely, the foot moves offshore in response to Northerly winds. Targeted tracer results indicate that the source waters for upwelling depend on the direction of the wind: Southerly winds bring slope bottom water to the shelf, while Northerly winds bring up shelf bottom boundary layer water. The upwelling flux is sensitive to the duration as well as the magnitude of wind events. The physics and geochemistry of the bottom boundary layer and the shelf break front are not resolved in global-scale carbon cycle models, yet they appear to play a strong role in the coastal carbon cycle. Mahadevan, A., J. Oliger, and R

  11. Offshore influence of coastal upwelling off Mauritania, NW Africa, as recorded by diatoms in sediment traps at 2195 m water depth

    Science.gov (United States)

    Lange, Carina B.; Romero, Oscar E.; Wefer, Gerold; Gabric, Albert J.

    1998-06-01

    Downward flux and taxonomic composition of diatom and silicoflagellate assemblages were determined from sediment trap samples off Cap Blanc (CB1, NW Africa) over a 1-year period (March 1988-March 1989) and compared to the assemblages in the underlying surface sedi ment. Trap content was composed of biogenic and lithogenic material. The dominant constituents of the biogenic fraction were calcium carbonate, biogenic opal, and organic matter. Coccolithophorids, planktonic foraminifera and pteropods contributed to the CaCO 3 flux; opal derived mainly from diatoms. During the sampling year prominent total flux maxima occurred in spring and summer. Highest diatom flux values were reached in March-April (20.1×10 5 valves m -2 d -1) and July-August (22.9×10 5 valves m -2 d -1) in coincidence with the total flux pattern. Radiolaria showed three distinct peaks: in autumn (16×10 4 shells m -2 d -1), spring (˜11×10 4 shells m -2 d -1) and summer (10×10 4 shells m -2 d -1). The flux pattern of silicoflagellates differed greatly from those of the other groups and from the total particle flux, with highest values between October 1988 and March 1989. For all microorganisms surveyed, September was the month of lowest production. We identified a total of 166 diatom taxa and 3 silicoflagellate species. Off Cap Blanc, upwelling occurs year-round, and "giant filaments" of relatively high pigment concentration develop and persist throughout the year with substantial seasonal and interannual variations. We show that the shifts in siliceous phytoplankton do reflect both the seaward displacement of the coastal upwelling center and the periods of relaxation when oligotrophic waters prevail. Accumulation rates in the surface sediment were calculated to be 1.36×10 8 valves m -2 yr -1 for diatoms and 1.05×10 6 skeletons m -2 yr -1 for silicoflagellates. Most of the diatoms found in the water column at 2195 m also occurred in the sediment surface, with a slight enrichement of robust

  12. Quantifying air-sea gas exchange using noble gases in a coastal upwelling zone

    Science.gov (United States)

    Manning, C. C.; Stanley, R. H. R.; Nicholson, D. P.; Squibb, M. E.

    2016-05-01

    The diffusive and bubble-mediated components of air-sea gas exchange can be quantified separately using time-series measurements of a suite of dissolved inert gases. We have evaluated the performance of four published air-sea gas exchange parameterizations using a five-day time-series of dissolved He, Ne, Ar, Kr, and Xe concentration in Monterey Bay, CA. We constructed a vertical model including surface air-sea gas exchange and vertical diffusion. Diffusivity was measured throughout the cruise from profiles of turbulent microstructure. We corrected the mixed layer gas concentrations for an upwelling event that occurred partway through the cruise. All tested parameterizations gave similar results for Ar, Kr, and Xe; their air-sea fluxes were dominated by diffusive gas exchange during our study. For He and Ne, which are less soluble, and therefore more sensitive to differences in the treatment of bubble-mediated exchange, the parameterizations gave widely different results with respect to the net gas exchange flux and the bubble flux. This study demonstrates the value of using a suite of inert gases, especially the lower solubility ones, to parameterize air-sea gas exchange.

  13. Current response to wind in the Chukchi Sea: A regional coastal upwelling event

    Science.gov (United States)

    Johnson, Walter R.

    1989-02-01

    A cruise was conducted on the NOAA ship Oceanographer in August and September 1986 in the Chukchi Sea. Four short-term moorings were instrumented with sediment traps and Aanderaa RCM4 current meters. The currents at the three moorings near the Alaskan coast indicate a reversal of the normal northeastward flow to southwestward. This reversal was produced by wind, which had begun to blow from the east-northeast at up to 4.2 m s-1. The temperature time series indicated that upwelling colder water was moving upward near the coast. The nearshore mooring had the largest amplitude variation of currents and the largest temperature variation. The amplitude of the reversal decreased offshore. The station farthest from the coast was near the ice edge and on the other side of Barrow Canyon and a subsea bank. The flow there was consistently toward the east and is only poorly related to the wind. Water mass analysis was conducted using two techniques; the first was a traditional TS diagram method, and the second was a cluster analysis on TS pairs for the surface and near-bottom waters. Based on the shapes of the TS curves and their positions on the TS diagrams, a map of the water masses was constructed. A cluster analysis was performed on the surface TS pairs from each station and separately for the bottom TS pairs. For both of these techniques, the line separating the groupings follows the temperature contours (5° at the surface and 4° at the bottom) and the bottom salinity contours (32.5 PSU).

  14. Environmental proteomics of microbial plankton in a highly productive coastal upwelling system

    Energy Technology Data Exchange (ETDEWEB)

    Sowell, Sarah [Oregon State University, Corvallis; Abraham, Paul E [ORNL; Shah, Manesh B [ORNL; Verberkmoes, Nathan C [ORNL; Smith, Daniel [Oregon State University, Corvallis; Barofsky, Douglas [Oregon State University, Corvallis; Giovannoni, Stephen [Oregon State University, Corvallis

    2011-01-01

    Metaproteomics is one of a suite of new approaches providing insights into the activities of microorganisms in natural environments. Proteins, the final products of gene expression, indicate cellular priorities, taking into account both transcriptional and posttranscriptional control mechanisms that control adaptive responses. Here, we report the proteomic composition of the o 1.2 lm fraction of a microbial community from Oregon coast summer surface waters, detected with two-dimensional liquid chromatography coupled with electrospray tandem mass spectrometry. Spectra corresponding to proteins involved in protein folding and biosynthesis, transport, and viral capsid structure were the most frequently detected. A total of 36% of all the detected proteins were best matches to the SAR11 clade, and other abundant coastal microbial clades were also well represented, including the Roseobacter clade (17%), oligotrophic marine gammaproteobacteria group (6%), OM43 clade (1%). Viral origins were attributed to 2.5% of proteins. In contrast to oligotrophic waters, phosphate transporters were not highly detected in this nutrient-rich system. However, transporters for amino acids, taurine, polyamines and glutamine synthetase were among the most highly detected proteins, supporting predictions that carbon and nitrogen are more limiting than phosphate in this environment. Intriguingly, one of the highly detected proteins was methanol dehydrogenase originating from the OM43 clade, providing further support for recent reports that the metabolism of one-carbon compounds by these streamlined methylotrophs might be an important feature of coastal ocean biogeochemistry.

  15. A numerical investigation of the atmosphere-ocean thermal contrast over the coastal upwelling region of Cabo Frio, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Dourado, M. [Departamento de Meteorologia, Universidade Federal de Pelotas, Pelotas RS (Brazil)]. E-mail: marcelo_dourado@ufpel.edu.br; Pereira de Oliveira, A. [Departamento de Ciencias Atmosfericas, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, (Brazil)

    2008-01-15

    An one-dimensional atmospheric second order closure model, coupled to an oceanic mixed layer model, is used to investigate the short term variation of the atmospheric and oceanic boundary layers in the coastal upwelling area of Cabo Frio, Brazil (23 degrees Celsius S, 42 degrees Celsius 08' W). The numerical simulations were carried out to evaluate the impact caused by the thermal contrast between atmosphere and ocean on the vertical extent and other properties of both atmospheric and oceanic boundary layers. The numerical simulations were designed taking as reference the observations carried out during the passage of a cold front that disrupted the upwelling regime in Cabo Frio in July of 1992. The simulations indicated that in 10 hours the mechanical mixing, sustained by a constant background flow of 10 m s-1, increases the atmospheric boundary layer in 214 m when the atmosphere is initially 2 K warmer than the ocean (positive thermal contrast observed during upwelling regime). For an atmosphere initially -2 K colder than the ocean (negative thermal contrast observed during passage of the cold front), the incipient thermal convection intensifies the mechanical mixing increasing the vertical extent of the atmospheric boundary layer in 360 m. The vertical evolution of the atmospheric boundary layer is consistent with the observations carried out in Cabo Frio during upwelling condition. When the upwelling is disrupted, the discrepancy between the simulated and observed atmospheric boundary layer heights in Cabo Frio during July of 1992 increases considerably. During the period of 10 hours, the simulated oceanic mixed layer deepens 2 m and 5.4 m for positive and negative thermal contrasts of 2 K and -2 K, respectively. In the latter case, the larger vertical extent of the oceanic mixed layer is due to the presence of thermal convection in the atmospheric boundary layer, which in turn is associated to the absence of upwelling caused by the passage of cold fronts

  16. Phytoplankton and nutrient distributions in a front-eddy area adjacent to the coastal upwelling zone off Concepcion (Chile): implications for ecosystem productivity.

    Science.gov (United States)

    Morales, Carmen; Anabalón, Valeria; Hormazábal, Samuel; Cornejo, Marcela; Bento, Joaquim; Silva, Nelson

    2016-04-01

    The impact that sub-mesoscale (1-10 km) to mesocale (50-100 km) oceanographic variability has on plankton and nutrient distributions (horizontal and vertical) in the coastal upwelling and transition zones off Concepcion was the focus of this study. Satellite time-series data (wind, sea-surface temperature (SST), and altimetry) were used to understand the dynamic context of in situ data derived from a short-term front survey (3 d) during the upwelling period (3-6 February, 2014). The survey included two transects perpendicular to the coast, covering the shelf and shelf-break areas just north of Punta Lavapie, a main upwelling center (˜37° S). Wind and SST time-series data indicated that the survey was undertaken just after a moderate upwelling event (end of January) which lead to a relaxation phase during early February. A submesoscale thermal front was detected previous to and during the survey and results from an eddy tracking algorithm based on altimetry data indicated that this front (F1) was flanked on its oceanic side by an anticyclonic, mesoscale eddy (M1), which was ˜25 d old at the sampling time. M1 strengthened the thermal gradient of F1 by bringing warmer oceanic water nearer to the colder coastal upwelling zone. The distributions of hydrographic variables and nutrients in the water column (<300 m depth) also denoted these two features. Phytoplankton biomass (Chl-a) and diatom abundance were highest in the surface layer (<20 m depth) between the coast and F1, with primary maxima in the latter, whereas they were highest at the subsurface (20-40 m depth) towards M1 and associated with secondary maxima. The distribution of dominant diatoms in the top layer (<100 m depth) indicated that both coastal and oceanic species were aggregated at F1 and in M1. These results suggest that the front-eddy interaction creates a complex field of submesoscale processes in the top layer, including vertical nutrient injections and lateral stirring, which contributes to the

  17. The Response of Nutrients and CO2 to Wind-Driven Coastal Upwelling Measured During the CoOP-WEST study

    Science.gov (United States)

    Marchi, A. M.; Dugdale, R. C.; Lew, K.; Hogue, V.; Lassiter, A.; Wilkerson, F.

    2002-12-01

    Newly upwelled water may have initial pCO2 concentrations two to three times higher than atmospheric values with correspondingly high nitrate and silicate concentrations. With aging of this water the biological pump plays an important role in reducing these concentrations as chlorophyll phytoplankton biomass is produced. pCO2 may be reduced to values well below atmospheric values, and nutrients depleted to near detection levels. Nutrient and pCO2 data were collected during underway surveys modes in the upwelling area near Bodega Bay, California during the CoOP WEST study. High levels of pCO2 (> 1000 μatm) and surface nutrients (nitrate > 40 μM, silicate > 50 μM) were observed during the Spring 2000 and 2002 cruises, which were characterized by persistent winds and strong upwelling. In spring 2001 upwelling was less intense with concurrently lower concentrations of pCO2 and nutrients. The winter cruise (January 2002) showed low concentrations of nutrients and no elevated pCO2 concentrations. The fate of pCO2 and nutrients in these different years will be discussed in the context of the coastal phytoplankton community.

  18. Analysis on characteristics of wind-driven coastal upwelling off the southeastern China coast using coastal upwelling index%用沿岸上升流指数分析中国东南沿岸风生上升流的特征

    Institute of Scientific and Technical Information of China (English)

    苗馨; 胡建宇

    2011-01-01

    对1968年1月到2007年12月中国东南沿海(17°N~30°N,109°E~123°E)上升流指数月平均数据进行分析,结论如下:(1)风生沿岸上升流主要在4-8月间发生于海南岛东部、雷州半岛东部、汕头以北至浙江沿岸.(2)风生沿岸上升流的强度具有时空分布变化特征,其中海南岛东部沿岸上升流最强,浙江沿岸其次;整个中国东南沿岸强度较大的风生上升流发生在6-8月.(3)风生上升流的"成长期"长于"衰减期";与海南岛东部相比,浙江沿岸风生上升流出现早,消失早.(4)海南岛东部、汕头、闽南及浙江沿岸风生上升流有逐年增大的趋势.(5)闽中以南风生上升流的显著周期为1年和半年,闽中以北为1年和4个月,过渡的闽中地区为1年、半年和4个月.%In this paper, the characteristics of wind-driven coastal upwelling off the southeastern China coast are analyzed using CUI (Coastal Upwelling Index). The following results are obtained: (1) There exists wind-driven coastal upwelling in summer off the eastern Hainan Island and the Leizhou Peninsula, and from Shantou to Zhejiang.(2) The wind-driven coastal upwelling of the eastern Hainan Island is stronger than that of the others; and the upwelling is stronger during June to August. (3) Wind-driven coastal upwelling off Zhejiang appears earlier than that off the eastern Hainan Island. (4) Wind-driven coastal upwelling off the eastern Hainan Island, Shantou and Zhejiang has a trend of intensification. (5) The wind-driven coastal upwelling off the central and southern Fujian coast as well as Guangdong and eastern Hainan Island coast has two significant periods (one year and half a year); the upwelling has two periods (one year and four months) off the northern Fujian coast and Zhejiang coast; and the upwelling off central Fujian coast has three periods (one year, half a year and 4 months).

  19. Development of a coastal upwelling front driven by advection and topographic effects in the North Sea-Baltic Sea transition

    OpenAIRE

    Lund-hansen, Lc; Vang, T

    2003-01-01

    Upwelling of cold. saline, and nutrient rich water was observed in late September 1999 along an east-west transect in the SW Kattegat. The Kattegat forms part of the transitional zone between the high saline North Sea and the low saline Baltic Sea. The upwelling occurred after an extended period of northward flow and eastern winds in the Kattegat, that changed into a southward flow as wind ceased. The upwelling was the result of a combination of high current speeds and bottom topography where...

  20. Productivity cycles in the coastal upwelling area off Concepción: The importance of diatoms and bacterioplankton in the organic carbon flux

    Science.gov (United States)

    Montero, Paulina; Daneri, Giovanni; Cuevas, L. Antonio; González, Humberto E.; Jacob, Bárbara; Lizárraga, Lorena; Menschel, Eduardo

    2007-11-01

    Recurrent coastal upwelling is recognized as one of the main factors promoting the exceptionally high productivity of the Humboldt Current System. Herein, we study time series data of gross primary production (2003-2006) and its fluctuation in relation to seasonal changes in the light and nutrient field of the Concepción upwelling ecosystem. Concurrent measurements of gross primary production, community respiration, bacterial secondary production, and sedimentation rates allowed a characterization of the main carbon fluxes and pathways in the study area. The integrated values of gross primary production were higher during the upwelling period (>1 g C m -2 d -1; October-April; that is, early spring to early austral fall). Seasonal changes in the system were also reflected in community respiration, organic matter sedimentation, and bacterial production rates, which varied along with the gross primary production. The significant correlation between gross primary production and community respiration (Spearman, r = 0.7; p 6 g C m -2 d -1) were consistently associated with maximum biomass levels of Skeletonema costatum and Thalassiosira subtilis. We observed a positive correlation between gross primary production and the sedimentation of intact diatom cells (Spearman, r = 0.5, p < 0.05, n = 17). Our data suggest that, in the Concepción upwelling ecosystem, bacteria utilize an important fraction of the gross primary production. If our interpretations are correct, they leave unanswered the question of how the system supports the extremely high fish biomass levels, therein pointing out the system’s limited capacity to buffer the evasion of CO 2 following upwelling.

  1. A Wind-Derived Upwelling Index for Lake Michigan

    OpenAIRE

    Davis, Stephen B; Essig, Rebecca; Troy, Cary

    2014-01-01

    Coastal upwelling is a phenomenon that occurs along coastlines throughout the world, and has been shown to be strongly correlated with large fish populations in these areas. Coastal upwelling occurs when strong coastal winds drive water transport away from the coast, causing colder, often nutrient-rich water to upwell in its place. While coastal upwellings can be detected with satellite imagery or in situ temperature measurements, these datasets are neither continuous nor long-term. A wind-...

  2. Upwelling in the Gulf of Lions

    OpenAIRE

    Millot, Claude; Wald, Lucien

    1981-01-01

    International audience The hydrological and meteorological characteristics of the Gulf of Lions are such that upwelling occurs with no bias due to tides or strong longshore circulation. The sky is generally cloud-free, an uncommon feature in an upwelling area that allows extensive use of satellite infrared data. The observations are adequate to compute mean maps of the sea-surface temperature during upwelling events. Undoubtedly upwelling is much more intense along straitght coastal segmen...

  3. Upwelling limitation by onshore geostrophic flow

    OpenAIRE

    Marchesiello, Patrick; Estrade, P.

    2010-01-01

    Although coastal upwelling has now been the subject of many studies. the only available dynamical upwelling index is derived from a simple relation between upwelling intensity and alongshore winds stress In this study. we first present a primitive equation model simulation of the New Caledonia island legion to show that upwelling intensity can be limited by onshore geostrophic flow Then, we propose a new analytical model accounting for the effect of onshore geostrophic flow on the structure o...

  4. Mg/Ca, Sr/Ca, and stable isotopes in modern and Holocene Protothaca staminea shells from a northern California coastal upwelling region

    Science.gov (United States)

    Takesue, R.K.; VanGeen, A.

    2004-01-01

    This study explores the potential of intertidal Protothaca staminea shells as high-resolution geochemical archives of environmental change in a coastal upwelling region. Mg/Ca and Sr/Ca ratios were analyzed by excimer laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) at sub-weekly temporal resolution in shells growing ???1 mm per month. Growth patterns of a modern P. staminea shell from Humboldt Bay, California, collected in December 1999 made it possible to infer a lifespan from 1993 to 1998. Growth hiatuses in the shell may have excluded records of extreme events. Mg/Ca ratios appeared to be partly controlled by water temperature; the correlation coefficient between temperature and Mg/Ca was r = 0.71 in one of four growth increments. Significant year-to-year differences in the sensitivity of Mg/Ca to temperature in P. staminea could not be explained, however. Sr/Ca ratios appeared to be more closely related to shell growth rate. Oxygen isotopes, measured at 2-week temporal resolution in the same shell, did not show a clear relation to local temperature in summer, possibly because temperatures were higher and less variable at the King Salmon mudflat, where the shell was collected, than in the main channel of Humboldt Bay, where water properties were monitored. Negative shell ??13C values (upwelling events. The Mg contents of P. staminea midden shells dated to ???3 ka and ???9 ka were significantly lower than in the modern shell. This may have resulted from degradation of a Mg-rich shell organic matrix and precluded quantitative interpretation of the older high-resolution records. Elevated ??13C values in the ???3 ka shell suggested that the individual grew in highly productive or stratified environment, such as a shallow coastal embayment or lagoon. Copyright ?? 2004 Elsevier Ltd.

  5. Short-term dynamics of nutrients influenced by upwelling in a small oligotrophic coastal ecosystem,Gan Bay,in the northwest Philippines

    Institute of Scientific and Technical Information of China (English)

    Yanping Xu; Minhan Dai; Weidong Zhai; Dongxing Yuan; Jinwen Liu; Zhenyu Sun; Hua Lin; Jingyu Wi

    2009-01-01

    We present a time-series analysis of nutrient and pCO2 (partial pressure of CO2) levels in an oligotrophic coastal ecosystem (Gan Bay),which was likely to be influenced by upwelled subsurface water.Gan Bay is off Currimao Harbor,in the northwest Philippines and is located at the boundary of the South China Sea (SCS).This 42-h time-series observation was conducted in December 2006.In addition to continuous observations of dissolved oxygen (DO) and pCO2,discrete samples were collected at a depth of 5 m every 3 h for measurements of nutrients,including soluble reactive phosphorus (SRP) and inorganic nitrogen (NO3- + NO2-) in order to examine their dynamics and possible physical and biological controls.We observed remarkably large short-term variations in the surface water,spanning a 10-fold change for SRP (32-330 nM) and from <0.3 μM to 4.3 μM for NO3- + NO2-.DO also varied substantially from a lower end of 171 to 205 μM O2.Surface water pCO2 changed from an equilibrium stage with the atmosphere (~386 μatm) to a stage where it was a significant source for the atmospheric CO2 (seawater pCO2~469 μatm).We found that the variation of nutrients was driven neither by tidal mixing nor by biological activities,as was suggested by the variations in the total bacterial abundance and chlorophyll a.Instead,our inverse T-S relationship suggested a two end-member mixing process during the observation period.The N:P ratio throughout the observation period was ~13.2,which is characteristic of SCS subsurface and deep waters.Moreover,pCO2 was correlated inversely with the sea surface temperature.It is likely,therefore,that an upwelled subsurface cold water with high nutrients,low-temperature and high-pCO2 existed.It should be noted that this upwelled cold water did not appear to impact the entire observation period (approximately 35 h of 42 h),which might suggest an extremely dynamic nature for this upwelled cold water mass.(C) 2009 National Natural Science Foundation of

  6. Metagenomic Analysis of Upwelling-Affected Brazilian Coastal Seawater Reveals Sequence Domains of Type I PKS and Modular NRPS.

    Science.gov (United States)

    Cuadrat, Rafael R C; Cury, Juliano C; Dávila, Alberto M R

    2015-01-01

    Marine environments harbor a wide range of microorganisms from the three domains of life. These microorganisms have great potential to enable discovery of new enzymes and bioactive compounds for industrial use. However, only ~1% of microorganisms from the environment can currently be identified through cultured isolates, limiting the discovery of new compounds. To overcome this limitation, a metagenomics approach has been widely adopted for biodiversity studies on samples from marine environments. In this study, we screened metagenomes in order to estimate the potential for new natural compound synthesis mediated by diversity in the Polyketide Synthase (PKS) and Nonribosomal Peptide Synthetase (NRPS) genes. The samples were collected from the Praia dos Anjos (Angel's Beach) surface water-Arraial do Cabo (Rio de Janeiro state, Brazil), an environment affected by upwelling. In order to evaluate the potential for screening natural products in Arraial do Cabo samples, we used KS (keto-synthase) and C (condensation) domains (from PKS and NRPS, respectively) to build Hidden Markov Models (HMM) models. From both samples, a total of 84 KS and 46 C novel domain sequences were obtained, showing the potential of this environment for the discovery of new genes of biotechnological interest. These domains were classified by phylogenetic analysis and this was the first study conducted to screen PKS and NRPS genes in an upwelling affected sample. PMID:26633360

  7. Response of zooplankton to physical changes in the environment: coastal upwelling along central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Nair, S.R.S.; Haridas, P.; Padmavati, G.

    species were supplemented by a few others such as Eucalanus attenuatus (usually dominant), Candacia pachydactyla, Pleuro- Journal of Coastal Research, Vol. 6, No.2, 1990 418 Madhupratap et af. Figure 6. Variations in depth of upper mixed layer (Al, zoo...

  8. Emergy analysis of coastal systems influenced by upwelling in northern Chile: Estimation of ecological-economic sustainability at multiple scales

    Science.gov (United States)

    Numerous studies carried out in a variety of environments have suggested that coastal marine systems generate a variety of goods and services for humanity. However, in recent decades there has been a marked degradation of these ecosystems, as well as over-exploitation of natural ...

  9. Linking the Modern and Recent Record of Cabo Frio Upwelling with Local Climate and Biogeochemical Processes in Hypersaline Coastal Lagoons, Região dos Lagos, Rio de Janeiro, Brazil

    Science.gov (United States)

    McKenzie, J. A.; Nascimento, G. S.; Albuquerque, A. L.; Belem, A. L.; Carreira, R.; Eglinton, T. I.; Vasconcelos, C.

    2015-12-01

    A unique marine and lagoonal system along the coast east of Rio de Janeiro is being investigated to understand the impact of climatic variability on the South Atlantic carbon cycle and biomineralisation processes involved in carbonate precipitation in the hypersaline coastal lagoons. The region is dominated by a semi-arid microclimate attributed to the local coastal upwelling phenomenon near Cabo Frio. The intensity of the upwelling affects the hydrology of the annual water and biogeochemical cycles in the lagoons, as well as biogeochemical signals of environmental change recorded in both onshore and offshore sediments. Preliminary results of δ18O and δD values of water samples collected monthly in Lagoa Vermelha and Brejo do Espinho from 2011 to 2014 show lower values for waters corresponding to the wet season, reflecting increased input of meteoric water. The higher values for waters collected during the dry season reflect the greater amount of evaporation with increased seasonal aridity. Radiocarbon dating of Holocene marine and lagoonal cores indicates that Mg-carbonate precipitation in the lagoons is associated with high evaporation. Modern field observations for the last 3 years suggest that the amount of carbonate precipitation is correlated with evaporitic conditions associated with the upwelling phenomenon. A calibration study of hydrogen isotopic fractionation in the modern lagoons is underway to define a relationship between δDlipid of suspended particles and δDwater of associated water. This isotopic relationship will be applied to material obtained in cores from the lagoons. Offshore cores will be studied using well-tested paleotemperature proxies to evaluate the intensity of the upwelling during the Holocene. In summary, linking the coastal upwelling with the lagoonal hydrology has the potential to furnish important insights about the relationship between the local climate and paleoceanographic circulation associated with the regional carbon cycle.

  10. 2006年夏季琼东、粤西沿岸上升流研究%Study on coastal upwelling in eastern Hainan Island and western Guangdong in summer,2006

    Institute of Scientific and Technical Information of China (English)

    许金电; 蔡尚湛; 宣莉莉; 邱云; 朱大勇

    2013-01-01

    In this paper ,the hydrographic survey data in coastal waters of Guangdong ,Hainan ,and Guangxi dur-ing the summer of 2006 ,combined with QuikSCAT wind data were used to document spatial characteristics of up-welling ,and to explore roles of the wind and wind stress curl on the upwelling ,and responses of temperature ,cur-rents ,sea level to the upwelling. The results show that the coastal upwelling regions in eastern Hainan and west-ern Guangdong are not separated but merged together below 10 m layer. The coastal upwelling in eastern Hainan is mainly driven by the southwest monsoon during summer ,and the wind stress curl also impacts the process of upwelling. The coastal upwelling in western Guangdong is mainly caused by the local wind stress curl. The inten-sity of upwelling in eastern Hainan coast was stronger than that in western Guangdong coast. In eastern Hainan coast ,the water in upper layer (<18 m) moved primarily offshore ,while the water in lower layer moved domi-nantly onshore ,with a stronger flow in upper layer. The upwelling phenomenon in eastern Hainan is intermittent , and modulated by the strength of alongshore wind. The strength of coastal upwelling in eastern Hainan was closely correlated to local sea surface height ,with variations of former lag that of later in 1-2 days.%  利用2006年夏季广东、海南、广西近海的海洋水文调查资料和卫星遥感QuikSCAT 风场资料分析琼东、粤西沿岸上升流的空间结构特征,探讨风场、风应力旋度对上升流的影响以及上升流区水温、海流、海平面对上升流的响应。结果表明:琼东、粤西沿岸上升流区并非相互独立,从10 m层以下已经连成一片。琼东沿岸上升流主要由夏季西南季风驱动而产生,风应力旋度也有一定贡献。琼东沿岸上升流的强度比粤西强。琼东沿岸海域的上层海水(18 m以浅)以离岸运动为主,中下层海水以向岸运动为主。上层的离岸流速

  11. Has upwelling strengthened along worldwide coasts over 1982-2010?

    OpenAIRE

    Varela, R; Álvarez, I.; Santos, F.;  deCastro, M.; Gómez-Gesteira, M.

    2015-01-01

    Changes in coastal upwelling strength have been widely studied since 1990 when Bakun proposed that global warming can induce the intensification of upwelling in coastal areas. Whether present wind trends support this hypothesis remains controversial, as results of previous studies seem to depend on the study area, the length of the time series, the season, and even the database used. In this study, temporal and spatial trends in the coastal upwelling regime worldwide were investigated during ...

  12. Upwelling and anthropogenic forcing on phytoplankton productivity and community structure changes in the Zhejiang coastal area over the last 100 years

    Institute of Scientific and Technical Information of China (English)

    DUAN Shanshan; XING Lei; ZHANG Hailong; FENG Xuwen; YANG Haili; ZHAO Meixun

    2014-01-01

    Phytoplankton productivity and community structure in marginal seas have been altered significantly dur-ing the past three decades, but it is still a challenge to distinguish the forcing mechanisms between climate change and anthropogenic activities. High time-resolution biomarker records of two 210Pb-dated sediment cores (#34:28.5°N, 122.272°E;CJ12-1269:28.861 9°N, 122.515 3°E) from the Min-Zhe coastal mud area were compared to reveal changes of phytoplankton productivity and community structure over the past 100 years. Phytoplankton productivity started to increase gradually from the 1970s and increased rapidly after the late 1990s at Site #34;and it started to increase gradually from the middle 1960s and increased rapidly after the late 1980s at Site CJ12-1269. Productivity of Core CJ12-1269 was higher than that of Core #34. Phy-toplankton community structure variations displayed opposite patterns in the two cores. The decreasing D/B (dinosterol/brassicasterol) ratio of Core #34 since the 1960s revealed increased diatom contribution to total productivity. In contrast, the increasing D/B ratio of Core CJ12-1269 since the 1950s indicated in-creased dinoflagellate contribution to total productivity. Both the productivity increase and the increased dinoflagellate contribution in Core CJ12-1269 since the 1950-1960s were mainly caused by anthropogenic activities, as the location was closer to the Changjiang River Estuary with higher nutrient concentration and decreasing Si/N ratios. However, increased diatom contribution in Core #34 is proposed to be caused by increased coastal upwelling, with higher nutrient concentration and higher Si/N ratios.

  13. Coastal upwelling off eastern Hainan Island observed in the summer of 2013%2013年夏季琼东海域上升流观测研究

    Institute of Scientific and Technical Information of China (English)

    汪彧; 经志友; 齐义泉

    2016-01-01

    利用2013年夏季国家自然科学基金委员会南海西部航次获得的观测资料, 并结合卫星遥感海面温度和风场资料,对琼东海域夏季上升流的空间结构及其演变过程进行了分析.研究结果表明, 在 2013 年夏季航次观测期间, 琼东海域存在显著的上升流现象, 但表层上升流信号较弱, 强上升流主要发生在 30~50m的下层海域, 上升流中心海域与外围海水在下层的温度差超过7℃, 盐度差可达到0.7‰以上.进一步分析航次期间的一次热带气旋过程对琼东上升流的影响,结果表明热带气旋破坏了上升流的上层结构, 且琼东上升流对风场变异的响应过程存在2~4d的滞后.%Based on in-situ observations supported by the National Natural Science Foundation of China during the summer of 2013 as well as satellite data, the summer coastal upwelling off eastern Hainan Island is examined in details, including its spatial structure, evolution process and the response to a tropical cyclone during the cruise. The results suggest that the upwelling anchored off eastern Hainan Island, with relatively weak signals at the sea surface. The observed strong upwelling mainly took place between the depths of 30-50 m below the surface. The temperature difference between the cooling center and the offshore non-upwelling water was more than 7°C, and the salinity difference was more than 0.7 psu. Moreover, the analysis of a tropical cyclone onset indicates that the structure of coastal upwelling in the upper ocean was completely destroyed, due to the shutdown of upwelling-favorable winds and intensive mixing induced by the tropical cyclone. Throughout these processes, the coastal upwelling lagged behind alongshore wind by 2-4 days.

  14. Population parameters and the relationships between environmental factors and abundance of the Acetes americanus shrimp (Dendrobranchiata: Sergestidae near a coastal upwelling region of Brazil

    Directory of Open Access Journals (Sweden)

    Ana Paula Freitas dos Santos

    2015-09-01

    Full Text Available AbstractThe population dynamics of Acetes americanus was investigated, focusing on the sex ratio, individual growth, longevity, recruitment and relationship between abundance and environmental factors in the region of Macaé, strongly influenced by coastal upwelling. Otter trawl net samplings were performed from July 2010 to June 2011 at two points (5 m and 15 m. Nearly 19,500 specimens, predominantly females (77.15%, were captured. Their sizes, larger than that of males, indicated sexual dimorphism. Shrimps at lower latitudes present larger sizes and longer longevity than those from higher latitudes. This difference is probably due to low temperatures and high primary productivity. Though no statistical correlation was found between abundance and environmental factors, the species was more abundant in temperatures closer to 20.0º C and in months with high chlorophyll-a levels. Due to the peculiar characteristics of this region, A. americanusshowed greater differences in size and longevity than individuals sampled in other studies undertaken in the continental shelf of Southeast Brazil.

  15. Potential contribution of planktonic components to ammonium cycling in the coastal area off central-southern Chile during non-upwelling conditions

    Science.gov (United States)

    Molina, Veronica; Morales, Carmen E.; Farías, Laura; Cornejo, Marcela; Graco, Michelle; Eissler, Yoanna; Cuevas, Luis A.

    2012-01-01

    The potential contributions of different microbial components (consumption and production, and carbon assimilation associated with photolithotrophic and chemolithoautotrophic (nitrification) metabolisms in the water column were performed. Despite low water column concentrations of ammonium in wintertime, intense ammonium transformations were registered. Prokaryotes (or bacterioplankton) contributed most to ammonium generation rates over the entire water column; these rates increased with depth (0.4-3.1 μM d -1). In surface waters (10 m depth), aerobic ammonium oxidation (potentially by Bacteria and Archaea) was the dominant consumption process (average 0.7 μM d -1) whereas in the subsurface layer (20 and 50 m depth), unexpectedly, eukaryotes accounted for most of its consumption (average 2.1 μM d -1). Nitrification oxidized an important proportion of the ammonium in both layers (from 25% to 100%) and provided regenerated nitrate. The integrated water column rates of chemosynthesis (0.005 g C m -2 d -1) represented a large proportion (51%) of the total dark carbon fixation during the non-upwelling season when integrated rates of photosynthesis are relatively low (0.42 g C m -2 d -1) and microbial food webs dominate the transfer of carbon within this coastal system.

  16. 粤东至闽南沿岸海域夏季上升流的调查研究%Observational study on summertime upwelling in coastal seas between eastern Guangdong and southern Fujian

    Institute of Scientific and Technical Information of China (English)

    许金电; 蔡尚湛; 宣莉莉; 邱云; 周喜武; 朱大勇

    2014-01-01

    Based on the summer cruise conductivity-temperature-depth (CTD) data in 2001, 2002, 2006, and 2009, this paper reveals the interannual variation of spatial structure and intensity of upwelling in eastern Guangdong and southern Fujian coastal seas. Using the QuikSCAT wind data, the current and bottom temperature data from seabed-based observations, and the sea surface temperature data at the ocean station of Nan’ao, we discuss the influence of sea surface wind and tropical cyclones on the upwelling, temporal and spatial characteristics and short-term variation of the upwelling, the evolution of the upwelling, and the source of the upwelling. We show that the range and intensity of the upwelling present an interannual variation in the coastal seas between eastern Guangdong and southern Fujian. The upwelled water only reached the surface in July-August 2009. In the border area of Guangdong and Fujian, the upwelling region was narrow, and was located mostly northeastward in July-August 2006; in contrast, it was wider in July-August 2009, and was located mostly southwestward in July-August 2001. In the eastern Guangdong coastal sea, the upwelled water reached 20 m in July-August 2006, deeper than in other years. The upwelling in the study area was stronger in July-August 2002 than on the other years. A strong vertical mixing within the upwelling area induced by a tropical cyclone warmed the middle- and bottom-layer waters rapidly, and finally led to the disruption of the upwelling. The coastal upwelling appeared earlier and was stronger in eastern Guangdong coast than in southern Fujian coast. During early and mid July, the upwelling started to appear but was not permanent. It was strengthened in mid July and early August, and became weaker from mid August to early September. Finally, it disappeared rapidly during early and mid September. The upwelled water in the coastal seas of eastern Guangdong and southern Fujian came from the lower-layer cold water in the open

  17. A statistical approach to coastal upwelling in the Baltic Sea based on the analysis of satellite data for 1990-2009

    Directory of Open Access Journals (Sweden)

    Andreas Lehmann

    2012-06-01

    Full Text Available A statistical analysis of Baltic Sea upwelling has been carried out to cover, for the first time, the entire sea area for the period 1990-2009. Weekly composite SST maps based on NOAA/AVHRR satellite data were used to evaluate the location and frequency of upwelling. The results obtained were analysed and compared with earlier studies with excellent agreement. Our study enables the most intense upwelling areas in the entire Baltic Sea to be evaluated. According to the analysis of 443 SST maps, the most common upwelling regions are found off the Swedish south and east coasts (frequency 10-25%, the Swedish coast of the Bothnian Bay (16%, the southern tip of Gotland (up to 15%, and the Finnish coast of the Gulf of Finland (up to 15%. Pronounced upwelling also occurs off the Estonian coast and the Baltic east coast (up to 15%, the Polish coast and the west coast of Rügen (10-15%; otherwise the upwelling frequency was between 5 and 10%. Additionally, simulated SST distributions derived from a Baltic Sea numerical model were analysed for the same period. Furthermore, at specific positions close to the coastline, surface winds based on the SMHI meteorological data base were analysed for the same 20-year period. Wind components parallel to the coast were discriminated into favourable and unfavourable winds forcing upwelling. The obtained frequencies of upwelling-favourable winds fit very well the observed upwelling frequencies derived from satellite SST maps. A positive trend of upwelling frequencies along the Swedish east coast and the Finnish coast of the Gulf of Finland was calculated for the period 1990-2009.

  18. Has upwelling strengthened along worldwide coasts over 1982-2010?

    Science.gov (United States)

    Varela, R.; Álvarez, I.; Santos, F.; Decastro, M.; Gómez-Gesteira, M.

    2015-05-01

    Changes in coastal upwelling strength have been widely studied since 1990 when Bakun proposed that global warming can induce the intensification of upwelling in coastal areas. Whether present wind trends support this hypothesis remains controversial, as results of previous studies seem to depend on the study area, the length of the time series, the season, and even the database used. In this study, temporal and spatial trends in the coastal upwelling regime worldwide were investigated during upwelling seasons from 1982 to 2010 using a single wind database (Climate Forecast System Reanalysis) with high spatial resolution (0.3°). Of the major upwelling systems, increasing trends were only observed in the coastal areas of Benguela, Peru, Canary, and northern California. A tendency for an increase in upwelling-favourable winds was also identified along several less studied regions, such as the western Australian and southern Caribbean coasts.

  19. A statistical approach to coastal upwelling in the Baltic Sea based on the analysis of satellite data for 1990-2009

    OpenAIRE

    Andreas Lehmann; Kai Myrberg; Katharina Höflich

    2012-01-01

    A statistical analysis of Baltic Sea upwelling has been carried out to cover, for the first time, the entire sea area for the period 1990-2009. Weekly composite SST maps based on NOAA/AVHRR satellite data were used to evaluate the location and frequency of upwelling. The results obtained were analysed and compared with earlier studies with excellent agreement. Our study enables the most intense upwelling areas in the entire Baltic Sea to be evaluated. According to the analysis of 443 SST maps...

  20. 2006年夏季粤东至闽南近岸海域上升流的特征%Characteristics of upwelling in eastern Guangdong and southern Fujian coastal waters during 2006 summer

    Institute of Scientific and Technical Information of China (English)

    蔡尚湛; 吴日升; 许金电

    2011-01-01

    利用2006年夏季粤东至闽南近岸海域海水的实测温度、盐度资料和海表温度、叶绿素a含量的卫星遥感资料,分析了该海域的上升流现象.结果表明:上升流区水体具有低温、高盐特征,其中心区域位于汕头至东山一带近岸海域.在汕头以西海域,外海深层低温高盐水沿海底地形向岸爬升形成上升流.汕头以东近岸海域的上升流为爬升至惠来近岸的外海水随沿岸流向东北方向运动,并在各地沿海底地形爬升所致.研究海域上升流区的水体属同一来源,均来自汕头西南外海.汕头以东近岸海域的上升流强度大于汕头以西,水温低于23.0℃、盐度高于34.00的外海水仅爬升至汕头以西近岸海表以下25 m左右,但可出现在汕头以东近岸10 m以浅海域.以研究海域海表温度低于27.5℃的沿岸低温区的面积来反映上升流的强度,通过对海表温度遥感数据的分析可知:7月初至7月中旬和7月28日至8月上旬,低温区域面积较大且较为稳定,上升流强度较大;7月19~ 27日期间和8月中旬以后,低温区域面积较小或短暂消失,上升流强度较弱.该上升流在2006年7~8月期间经历了强-弱-强-弱的短期变化过程.%This study analyzed the characteristics and spatial structure of the upwelling in eastern Guangdong and southern Fujian coastal waters with reference to the temperature, salinity and satellite remote sensing data of sea surface temperature (SST) and chlorophyll -a (chl-a) concentration during 2006 summer. Results showed that the upwelling water area was characterized by low temperature and high salinity, and its center was located at the coastal area between Shantou and Dongshan. In the waters west of Shantou, the deep sea water with low temperature and high salinity rised to the upper layers in coastal areas following the topographic changes and consequently induced upwelling. Because of the interference of the Taiwan Bank, the

  1. Development of coastal upwelling edge detection algorithms associated with harmful algal blooms off the Washington coast using sea surface temperature imagery.

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Nathan R.; Woodruff, Dana L.; Trainer, Vera L.

    2005-01-01

    Satellite remote sensing imagery is being used to identify and characterize upwelling conditions on the coast of Washington State, with an emphasis on detecting ocean features associated with harmful algal bloom events. Blooms of phytoplankton, including the domoic acid-producing diatom Pseudo-nitzschia, appear to be associated with a semi-permanent eddy bordering Washington and British Columbia that is observed in satellite imagery during extended upwelling events. Strong upwelling conditions may act as a barrier to movement of these blooms onshore. Using NOAA AVHRR temperature imagery, edge detection algorithms are being developed to define the strength, location and extent of the surface temperature expression of upwelling along the coast of Washington. The edge detection technique uses a simple kernel-based gradient method that compares temperatures of pixels at a user-specified distance. This allows identification of larger features with subtle edges. The resulting maximum-gradient map is then converted to a binary format with a user-specified temperature threshold. Skeletonization and edge-linking algorithms are then employed to develop final map products. The upwelling edge detection maps are being examined in relation to harmful algal bloom events that have occurred along the coast.

  2. Role of nutrient recycling in upwelling ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Whitledge, T E

    1979-01-01

    The regeneration of nitrogen is an important process that increases the efficiency of the upwelling ecosystem by enlarging their spatial scales. Ammonium regeneration was considered to contribute 42 to 72 percent of phytoplankton nitrogen requirements in the northwest Africa, Peru, and Baja California upwelling systems. Zooplankton are responsible for the largest portion of regenerated nitrogen; however, fish and benthic sediments may be nearly as large. Comparisons of the importance of ammonium regeneration in upwelling areas with coastal and open ocean regions indicate that the percentage contributions are similar. Future nutrient regeneration studies are needed to assess the recycling of benthic sediments, microzooplankton, gelatinous zooplankton, demersal fish, bacterioplankton, and mollusks.

  3. Dehumidification of Iberia by enhanced summer upwelling

    Science.gov (United States)

    Miranda, P. M.; Costa, V.; Nogueira, M.; Semedo, A.

    2015-12-01

    Dehumidification of Iberia by enhanced summer upwelling Miranda PMA, Costa V, Semedo AIDL, Faculdade de Ciências, University of LisbonA 24-year simulation of the recent Iberian climate, using the WRF model at 9km resolution forced by ERA-Interim reanalysis (1989-2012), is analysed for the decadal evolution of the upwelling forcing coastal wind and for column integrated Precipitable water vapour (PWV). Results indicate that, unlike what was found by Bakun et al. (2009) for the Peruvian region, a statistically significant trend in the upwelling favourable (northerly) wind has been accompanied by a corresponding decrease in PWV, not only inland but also over the coastal waters. Such increase is consistent with a reinforced northerly coastal jet in the maritime boundary layer contributing to atmospheric Ekman pumping of dry continental air into the coastal region. Diagnostics of the prevalence of the Iberian thermal low following Hoinka and Castro (2003) also show a positive trend in its frequency during an extended summer period (April to September). These results are consistent with recent studies indicating an upward trend in the frequency of upwelling in SW Iberia (Alves and Miranda 2013), and may be relevant for climate change applications as an increase in coastal upwelling (Miranda et al 2013) may lead to substantial regional impacts in the subtropics. Aknowledgements: Study supported by FCT Grant RECI/GEO-MET/0380/2012Alves JMR, Miranda PMA (2013) Variability of Iberian upwelling implied by ERA-40 and ERA-Interim reanalyses, Tellus A 2013, http://dx.doi.org/10.3402/tellusa.v65i0.19245.Bakun et al (2010) Greenhouse gas, upwelling-favorable winds, and the future of coastal ocean upwelling ecosystems, Global Change Biology, doi: 10.1111/j.1365-2486.2009.02094.xHoinka KP, Castro M (2003) The Iberian Peninsula thermal low. QJRMS, 129, 1491- 1511, doi: 10.1256/qj.01.189.Miranda et al (2013) Climate change and upwelling: response of Iberian upwelling to atmospheric

  4. Coastal upwelling on the east of the tropical zone of the North Atlantic and its relation to the stability of the northeast tradewind

    Science.gov (United States)

    Sorkina, A. I.

    1975-01-01

    It is shown that the intensities of deep water upwelling phenomena are correlated with seasonal features of the atmospheric circulation. Increased uprising of cold deep water is accompanied by increased stability of the tradewinds; the vertical transfer of cold water grows stronger as the tradewinds become more stable.

  5. Contribution à l'étude de l'upwelling du Pérou Chili

    OpenAIRE

    Croquette, Marie

    2007-01-01

    The upwelling and associated alongshore coastal currents variability (CPCC, Chile Peru coastal Current and PCUC, Peru-Chile Undercurrent) has been studied with satellite data and two numerical models. This study covers a large meridional extend: from Peru to Southern Chile (50°S). Variability characteristics in Peru and Chile are separated by a transition zone around 20°S where winds, upwelling and the PCUC are particularly weak. The origins of upwelling and PCUC waters have also been studied...

  6. Characterization of upwelling phenomenon along the Italian coasts

    Science.gov (United States)

    Orasi, Arianna; Morucci, Sara; Rinaldi, Eleonora; Bignami, Francesco; Inghilesi, Roberto; Santoleri, Rosalia

    2013-04-01

    In order to investigate wind-driven upwelling along the Italian coasts, preliminary wind data provided by the ISPRA Italian Tide Gauge Measurement Network (RMN) have been analyzed. In a further step, MyOcean Sea Surface Temperature (SST) data have been analyzed in order to define an SST index for wind-driven coastal upwelling assessment. At first, hourly wind data for the period 2009 - 2011 have been used in order to provide the statistical distribution and the wind rose plots at each RMN station. In particular, wind direction and speed have been selected in order to find upwelling-favorable areas and periods of time. E.g. wind directions in the sector between North and West in the Tyrrhenian Sea and between South and East in the Adriatic Sea have been defined as upwelling favorable, the wind sector being defined as the ± 30° arc around the direction parallel to the coast. Moreover only wind speeds greater than 3.0 m/s have been considered as significant for upwelling. For each location, the number of selected data has been divided by the total number of recorded wind data, thus obtaining a sort of upwelling frequency, which allows to define areas mostly exposed to upwelling. Once these areas were defined, satellite SST data have been used as a proxy to study the changes in upwelling intensity, since upwelling waters are colder than surrounding waters. So, in a given satellite SST image the upwelling event is identifiable through SST minima along the coasts. Finally, the SST upwelling index has been defined; also, this index has been "weighted" with wind intensity and direction indicating upwelling conditions obtained from the RMN wind dataset, to better distinguish between upwelling-favorable and downwelling-favorable conditions at each RMN site.

  7. A ~276 years cyclicity of western pacific coastal upwelling during Late Pleistocene (Termination I) and Holocene as revealed by the microscale facies and elemental analysis of the varved record of Saanich Inlet, BC

    Science.gov (United States)

    Kanamaru-Shinn, K.; Francus, P.; Jercinovic, M. J.

    2009-12-01

    Using core MD02-2490, recovered by the French research ship, RV Marion Dufresne, from the central basin of Saanich Inlet, BC, the last glacial-to-interglacial transition (Termination I) and Holocene laminated marine sediments of Saanich Inlet, BC, were characterized to infer the sedimentary processes responsible for their deposition, their sedimentary environments, and their provenance (i.e. source). This is achieved by examining sedimentary facies from thin-sections using backscattered scanning electron imagery (BSEI) and Energy Dispersive Spectrometry (EDS) coupled with a Scanning Electron Microscope (SEM), and an Itrax™ micro-XRF core scanner. The elemental intensities obtained by the Itrax™ micro-XRF core scanner showed - 27 abrupt changes in elemental ratios throughout the selected periods throughout the Termination I and Holocene along core MD02-2490, of which eleven peaks demonstrate abrupt increases in both Mn/Ti and Fe/Ti (10469, 100385, 10070, 9923, 8474, 8005, 7672, 5171, 4996, 4585, and 2420 C14 cal yr BP). All eleven peaks correspond with anomalous increases in Ca/Ti and Sr/Ca ratios and most of them are consistent with low gray values and Compton and Rayleigh scattering ratios (inc/coh). These chemical and physical property changes of the sediment (mineralogy and grain size-related density) suggest occurrences of deepwater flushing events associated with a basin slope failure. Indeed, in Saanich Inlet, coastal upwellings eventually cause an overturning of the bottom water, providing abundant oxygen and nutrients to the stagnant bottom water. Peaks of Mn/Ti and Fe/Ti (indicators of manganese and Iron oxides) are expected in abruptly oxygenated bottom waters, and peaks of Ca/Ti (indicators of manganese carbonate) seems to point to a abrupt enrichment of CaCO3 (only available in shallowest parts of the basin) mixed with the sediment pore water. The possible mechanisms to cause these abrupt transitions may be related to coastal upwelling. The

  8. [Chilean nuclear policy].

    Science.gov (United States)

    Bobadilla, E

    1996-06-01

    This official document is statement of the President of the Chilean Nuclear Energy Commission, Dr. Eduardo Bobadilla, about the nuclear policy of the Chilean State, Thanks to the international policy adopted by presidents Aylwin (1990-1994) and his successor Frei Ruiz Tagle (1994-), a nuclear development plan, protected by the Chilean entrance to the nuclear weapons non proliferation treaty and Tlatelolco Denuclearization treaty, has started. Chile will be able to develop without interference, an autonomous nuclear electrical system and other pacific uses of nuclear energy. Chile also supports a new international treaty to ban nuclear weapon tests.

  9. [Chilean nuclear policy].

    Science.gov (United States)

    Bobadilla, E

    1996-06-01

    This official document is statement of the President of the Chilean Nuclear Energy Commission, Dr. Eduardo Bobadilla, about the nuclear policy of the Chilean State, Thanks to the international policy adopted by presidents Aylwin (1990-1994) and his successor Frei Ruiz Tagle (1994-), a nuclear development plan, protected by the Chilean entrance to the nuclear weapons non proliferation treaty and Tlatelolco Denuclearization treaty, has started. Chile will be able to develop without interference, an autonomous nuclear electrical system and other pacific uses of nuclear energy. Chile also supports a new international treaty to ban nuclear weapon tests. PMID:9041734

  10. Spatial distribution of upwelling off the central east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.V.N.

    Rao indicates coastal upwelling. Until recently, differences in the surface temperatures of inshore and oceanic waters have been used as a criterion of coastal up- welling intensity, and this has led to conflicting con- of coastal upwelling... matter in the western Arabian Sea. Deep Sea Research 12, 199–209. Smed, J. 1982 The Oceanographic data base for the Cooperative Investigations of the Northern part of the Eastern Central Atlantic (CINECA) region. Rapport et Proces-Verbeaux des Reun- ions...

  11. Pliocene-Pleistocene variability of upwelling activity, productivity and nutrient cycle in the Benguela Upwelling System and the Eastern Equatorial Pacific

    OpenAIRE

    Etourneau, Johan

    2009-01-01

    The focus of this study is to explore the long term Plio-Pleistocene variability of coastal and open ocean upwelling systems by reconstructing for the last ~3.5 Ma, sea surface temperature (SST), primary productivity and nutrient cycling in the Benguela Upwelling System (BUS) and the Eastern Equatorial Pacific (EEP), two areas particularly sensible and influential to climate change.

  12. Zonation of bacterioplankton communities along aging upwelled water in the northern Benguela upwelling

    Directory of Open Access Journals (Sweden)

    Benjamin eBergen

    2015-06-01

    Full Text Available Upwelling areas are shaped by enhanced primary production in surface waters, accompanied by a well-investigated planktonic succession. Although bacteria play an important role in biogeochemical cycles of upwelling systems, little is known about bacterial community composition and its development during upwelling events. The aim of this study was to investigate the succession of bacterial assemblages in aging upwelled water of the Benguela upwelling from coastal to offshore sites. Water from the upper mixed layer at 12 stations was sampled along two transects from the origin of the upwelling to a distance of 220 km. 16S rRNA gene amplicon sequencing was then used in a bacterial diversity analysis and major bacterial taxa were quantified by catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH. Additionally, bacterial cell numbers and bacterial production were assessed . Community statistical analysis revealed a reproducible zonation along the two transects, with four clusters of significantly different microbial assemblages. Clustering was mainly driven by phytoplankton composition and abundance. Similar to the temporal succession that occurs during phytoplankton blooms in temperate coastal waters, operational taxonomic units (OTUs affiliated with Bacteroidetes and Gammaproteobacteria were dominant during algal blooming whereas Pelagibacterales were highly abundant in regions with low algal abundance. The most dominant heterotrophic OTU (9% of all reads was affiliated with Pelagibacterales and showed a strong negative correlation with phytoplankton. By contrast, the second most abundant heterotrophic OTU (6% of all reads was affiliated with the phylum Verrucomicrobia and correlated positively with phytoplankton. Together with the close relation of bacterial production and phytoplankton abundance, our results showed that bacterial community dynamics is strongly driven by the development and composition of the phytoplankton

  13. Trends in the number of extreme hot SST days along the Canary Upwelling System due to the influence of upwelling

    Directory of Open Access Journals (Sweden)

    Xurxo Costoya

    2014-07-01

    Full Text Available Trends in the number of extreme hot days (days with SST anomalies higher than the 95% percentile were analyzed along the Canary Upwelling Ecosystem (CUE over the period 1982- 2012 by means of SST data retrieved from NOAA OI1/4 Degree. The analysis will focus on the Atlantic Iberian sector and the Moroccan sub- region where upwelling is seasonal (spring and summer are permanent, respectively. Trends were analyzed both near coast and at the adjacent ocean where the increase in the number of extreme hot days is higher. Changes are clear at annual scale with an increment of 9.8±0.3 (9.7±0.1 days dec-1 near coast and 11.6±0.2 (13.5±0.1 days dec-1 at the ocean in the Atlantic Iberian sector (Moroccan sub-region. The differences between near shore and ocean trends are especially patent for the months under intense upwelling conditions. During that upwelling season the highest differences in the excess of extreme hot days between coastal and ocean locations (Δn(#days dec-1 occur at those regions where coastal upwelling increase is high. Actually, Δn and upwelling trends have shown to be significantly correlated in both areas, R=0.88 (p<0.01 at the Atlantic Iberian sector and R=0.67 (p<0.01 at the Moroccan sub-region.

  14. Intensification of upwelling along Oman coast in a warming scenario

    Science.gov (United States)

    Praveen, V.; Ajayamohan, R. S.; Valsala, V.; Sandeep, S.

    2016-07-01

    The oceanic impact of poleward shift in monsoon low-level jet (MLLJ) is examined using a Regional Ocean Modeling System (ROMS). Two sets of downscaling experiments were conducted using ROMS with boundary and initial conditions from six CMIP5 models. While outputs from the historical run (1981-2000) acts as forcing for the first, the second uses RCP8.5 (2080-2099). By comparing the outputs, it is found that Oman coast will experience an increase in upwelling in tune with MLLJ shift. Consistent with the changes in upwelling and zonal Ekman transport, temperature, salinity, and productivity show significant changes near the Oman coast. The changes in MLLJ causes the coastal wind to angle against the Oman coast in such a fashion that the net upwelling increases in the next century and so does the marine productivity. This study contrasts the general view of weakening of upwelling along the Arabian coasts due to the weakening of monsoon winds.

  15. Response of Mytilus edulis to enhanced phytoplankton availibility by controlled upwelling in an oligographic fjord

    NARCIS (Netherlands)

    Strohmeier, T.; Strand, Ø.; Alunno-Bruscia, M.; Duinker, A.; Rosland, R.; Jansen, H.M.

    2015-01-01

    The controlled upwelling of nutrient-rich deep water in oligotrophic coastal regions has been proposed as a means of increasing phytoplankton and, subsequently, bivalve aquaculture production. This was tested as part of a large-scale upwelling experiment in an oligotrophic environment (Lysefjord, No

  16. A Comparison of the Role of Episode Nutrient Supply on Pathways of Carbon in Upwelling Regimes

    Science.gov (United States)

    Carr, M. E.

    1997-01-01

    Nutrient supply is episode in the ocean even in regions of fairly high and continuous nutrient supply, such as coastal upwelling regimes. The structure of the ecosystem depends on nutrient availability and the different requirements of phytoplankton cells.

  17. On an upwelling front, propagation of upwelling and vertical velocity in the eastern Arabian sea during monsoon, 1987

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Unnikrishnan, A.S.

    A coastal upwelling front parallel to the coast and identifiable upto a depth of 75 m was observed between 12.5 and 16 degrees N along the eastern Arabian Sea in September, 1987 from closely spaced digital BT data. With a north-south slope...

  18. Methane emissions from the upwelling area off Mauritania (NW Africa

    Directory of Open Access Journals (Sweden)

    A. Kock

    2008-01-01

    Full Text Available Coastal upwelling regions have been indentified as sites of enhanced CH4 emissions to the atmosphere. The coastal upwelling area off Mauritania (NW Africa is one of the most biologically productive regions of the world's ocean but its CH4 emissions have not been quantified so far. More than 1000 measurements of atmospheric and dissolved CH4 in the surface layer in the upwelling area off Mauritania were performed as part of the German SOPRAN (Surface Ocean Processes in the Anthropocene study during two cruises in March/April 2005 (P320/1 and February 2007 (P348. During P348 enhanced CH4 saturations of up to 179% were found close to the coast and were associated with upwelling of South Atlantic Central Water. An area-weighted, seasonally adjusted estimate yielded overall annual CH4 emissions in the range from 0.7 to 1.4 Gg CH4. Thus the upwelling area off Mauritania represents a regional hot spot of CH4 emissions but seems to be of minor importance for the global oceanic CH4 emissions.

  19. Methane emissions from the upwelling area off Mauritania (NW Africa

    Directory of Open Access Journals (Sweden)

    A. Kock

    2008-08-01

    Full Text Available Coastal upwelling regions have been identified as sites of enhanced CH4 emissions to the atmosphere. The coastal upwelling area off Mauritania (NW Africa is one of the most biologically productive regions of the world's ocean but its CH4 emissions have not been quantified so far. More than 1000 measurements of atmospheric and dissolved CH4 in the surface layer in the upwelling area off Mauritania were performed as part of the German SOPRAN (Surface Ocean Processes in the Anthropocene study during two cruises in March/April 2005 (P320/1 and February 2007 (P348. During P348 enhanced CH4 saturations of up to 200% were found close to the coast and were associated with upwelling of South Atlantic Central Water. An area-weighted, seasonally adjusted estimate yielded overall annual CH4 emissions in the range from 1.6 to 2.9 Gg CH4. Thus the upwelling area off Mauritania represents a regional hot spot of CH4 emissions but seems to be of minor importance for the global oceanic CH4 emissions.

  20. Salinity driven oceanographic upwelling

    Science.gov (United States)

    Johnson, D.H.

    1984-08-30

    The salinity driven oceanographic upwelling is maintained in a mariculture device that includes a long main duct in the general shape of a cylinder having perforated cover plates at each end. The mariculture device is suspended vertically in the ocean such that one end of the main duct is in surface water and the other end in relatively deep water that is cold, nutrient rich and relatively fresh in comparison to the surface water which is relatively warm, relatively nutrient deficient and relatively saline. A plurality of elongated flow segregating tubes are disposed in the main duct and extend from the upper cover plate beyond the lower cover plate into a lower manifold plate. The lower manifold plate is spaced from the lower cover plate to define a deep water fluid flow path to the interior space of the main duct. Spacer tubes extend from the upper cover plate and communicate with the interior space of the main duct. The spacer tubes are received in an upper manifold plate spaced from the upper cover plate to define a surface water fluid flow path into the flow segregating tubes. A surface water-deep water counterflow is thus established with deep water flowing upwardly through the main duct interior for discharge beyond the upper manifold plate while surface water flows downwardly through the flow segregating tubes for discharge below the lower manifold plate. During such counterflow heat is transferred from the downflowing warm water to the upflowing cold water. The flow is maintained by the difference in density between the deep water and the surface water due to their differences in salinity. The upwelling of nutrient rich deep water is used for marifarming by fertilizing the nutrient deficient surface water. 1 fig.

  1. Salinity driven oceanographic upwelling

    Science.gov (United States)

    Johnson, David H.

    1986-01-01

    The salinity driven oceanographic upwelling is maintained in a mariculture device that includes a long main duct in the general shape of a cylinder having perforated cover plates at each end. The mariculture device is suspended vertically in the ocean such that one end of the main duct is in surface water and the other end in relatively deep water that is cold, nutrient rich and relatively fresh in comparison to the surface water which is relatively warm, relatively nutrient deficient and relatively saline. A plurality of elongated flow segregating tubes are disposed in the main duct and extend from the upper cover plate beyond the lower cover plate into a lower manifold plate. The lower manifold plate is spaced from the lower cover plate to define a deep water fluid flow path to the interior space of the main duct. Spacer tubes extend from the upper cover plate and communicate with the interior space of the main duct. The spacer tubes are received in an upper manifold plate spaced from the upper cover plate to define a surface water fluid flow path into the flow segregating tubes. A surface water-deep water counterflow is thus established with deep water flowing upwardly through the main duct interior for discharge beyond the upper manifold plate while surface water flows downwardly through the flow segregating tubes for discharge below the lower manifold plate. During such counterflow heat is transferred from the downflowing warm water to the upflowing cold water. The flow is maintained by the difference in density between the deep water and the surface water due to their differences in salinity. The upwelling of nutrient rich deep water is used for marifarming by fertilizing the nutrient deficient surface water.

  2. Comparaisons des systèmes productifs de l'Atlantique tropical est : dômes thermiques, upwellings côtiers et upwelling équatorial

    OpenAIRE

    Voituriez, B; Herbland, Alain

    1982-01-01

    All the high-productive systems of the Eastern tropical Atlantic between 20°N and 15°S - coastal upwelling, equatorial upwelling, and thermal domes-are partly controlled by the subsuperficial equatorial countercurrent system, which feeds all of them with Southern Atlantic Central Water. However, the enrichment processes in the systems are quite different, and thus the structures differ from one another. Two types have to be considered : 1) the quasi geostrophic ones which are two-layered syst...

  3. Mn seasonal upwellings recorded in Lake Tanganyika mussels

    Directory of Open Access Journals (Sweden)

    D. Langlet

    2006-09-01

    Full Text Available Biogenic productivity of Lake Tanganyika is highly dependent on seasonal upwellings of anoxic deep waters. We investigated the shell of freshwater bivalve Pleiodon spekii as a geochemical archive of these periodic hydrological changes tuned by the monsoon regime. The results of a 2-years-long geochemical survey of the coastal waters performed on the dissolved and particulate fractions were put in perspective against laser ablation ICP-MS profiles of Mn in five aragonitic shells from the same lake location. Skeletal Mn profiles in 3 shells are very similar and dominated by episodic peaks that matched the Mn increase recorded in surface waters during the 2002 upwelling, while a shell collected during 2003 dry season detect both 2002 and 2003 upwelling events. Larger shells showing an extremely reduced growth display more than 8Mn peaks suggesting at least an 8 years record of seasonal changes in water composition.

  4. Mn seasonal upwellings recorded in Lake Tanganyika mussels

    Science.gov (United States)

    Langlet, D.; Alleman, L. Y.; Plisnier, P.-D.; Hughes, H.; André, L.

    2006-09-01

    Biogenic productivity of Lake Tanganyika is highly dependent on seasonal upwellings of anoxic deep waters. We investigated the shell of freshwater bivalve Pleiodon spekii as a geochemical archive of these periodic hydrological changes tuned by the monsoon regime. The results of a 2-years-long geochemical survey of the coastal waters performed on the dissolved and particulate fractions were put in perspective against laser ablation ICP-MS profiles of Mn in five aragonitic shells from the same lake location. Skeletal Mn profiles in 3 shells are very similar and dominated by episodic peaks that matched the Mn increase recorded in surface waters during the 2002 upwelling, while a shell collected during 2003 dry season detect both 2002 and 2003 upwelling events. Larger shells showing an extremely reduced growth display more than 8Mn peaks suggesting at least an 8 years record of seasonal changes in water composition.

  5. Upwelling characteristics in the Gulf of Finland (Baltic Sea) as revealed by Ferrybox measurements in 2007-2013

    Science.gov (United States)

    Kikas, Villu; Lips, Urmas

    2016-07-01

    Ferrybox measurements have been carried out between Tallinn and Helsinki in the Gulf of Finland (Baltic Sea) on a regular basis since 1997. The system measures autonomously water temperature, salinity, chlorophyll a fluorescence and turbidity and takes water samples for further analyses at a predefined time interval. We aimed to show how the Ferrybox technology could be used to study the coastal upwelling events in the Gulf of Finland. Based on the introduced upwelling index and related criteria, 33 coastal upwelling events were identified in May-September 2007-2013. The number of events, as well as the frequency of their occurrence and intensity expressed as a sum of daily average temperature deviations in the 20 km wide coastal area, were almost equal near the northern and southern coasts. Nevertheless, the wind impulse, which was needed to generate upwelling events of similar intensity, differed between the northern and southern coastal areas. It is suggested that the general thermohaline structure adapted to the prevailing forcing and the estuarine character of the basin weaken the upwelling created by the westerly to southwesterly (up-estuary) winds and strengthen the upwelling created by the easterly to northeasterly (down-estuary) winds. Two types of upwelling events were identified - one characterized by a strong temperature front and the other revealing gradual decrease in temperature from the open sea to the coastal area, with maximum temperature deviation close to the shore.

  6. Initial observation of upwelling along east coast of Peninsular Malaysia musica gratis

    Science.gov (United States)

    Akhir, M.; Tanggang, F.

    2013-12-01

    There is no published evidence of upwelling in coastal area along the east coast of Peninsular Malaysia. However numbers of recent cruise data collected during the southwest monsoon found features of thermocline lifting and isolated cooler temperature water along the coast, These sign was observed along the 104°E from numbers of parallel transects. To confirm the presence of upwelling, satellite remote sensing data was used, and numerical model experiments were conducted. Cooler sea-surface temperature along the coast was observed from both in-situ and satellite data, while upward movement in the vertical profiles agreed with the location of upwelling from both in-situ and satellite data. Moreover, these data also show that the upwelled water band along the 104°E longitude stretch approximately 650 km long. Initially, southwesterly wind during this season is believed to be the important mechanism that contributed to this wind-induced Ekman upwelling. musica gratis

  7. Variability of Iberian upwelling implied by ERA-40 and ERA-Interim reanalyses

    Directory of Open Access Journals (Sweden)

    José M. R. Alves

    2013-05-01

    Full Text Available The Regional Ocean Modeling System ocean model is used to simulate the decadal evolution of the regional waters in offshore Iberia in response to atmospheric fields given by ECMWF ERA-40 (1961–2001 and ERA-Interim (1989–2008 reanalyses. The simulated sea surface temperature (SST fields are verified against satellite AVHRR SST, and they are analysed to characterise the variability and trends of coastal upwelling in the region. Opposing trends in upwelling frequency are found at the northern limit, where upwelling has been decreasing in recent decades, and at its southern edge, where there is some evidence of increased upwelling. These results confirm previous observational studies and, more importantly, indicate that observed SST trends are not only due to changes in radiative or atmospheric heat fluxes alone but also due to changes in upwelling dynamics, suggesting that such a process may be relevant in climate change scenarios.

  8. Surface circulation and upwelling patterns around Sri Lanka

    OpenAIRE

    Vos, A; Pattiaratchi, C. B.; E. M. S. Wijeratne

    2013-01-01

    Sri Lanka occupies a unique location within the equatorial belt in the northern Indian Ocean with the Arabian Sea on its western side and the Bay of Bengal on its eastern side. The region is characterised by bi-annually reversing monsoon winds resulting from seasonal differential heating and cooling of the continental land mass and the ocean. This study explored elements of the dynamics of the surface circulation and coastal upwelling in the waters around Sri Lanka using satellite imagery and...

  9. Mn seasonal upwellings recorded in Lake Tanganyika mussels

    OpenAIRE

    D. Langlet; Alleman, L. Y.; P.-D. Plisnier; Hughes, H; André, L.

    2006-01-01

    International audience Biogenic productivity of Lake Tanganyika is highly dependent on seasonal upwellings of anoxic deep waters. We investigated the shell of freshwater bivalve Pleiodon spekii as a geochemical archive of these periodic hydrological changes tuned by the monsoon regime. The results of a 2-years-long geochemical survey of the coastal waters performed on the dissolved and particulate fractions were put in perspective against laser ablation ICP-MS profiles of Mn in five aragon...

  10. Manganese content records seasonal upwelling in Lake Tanganyika mussels

    OpenAIRE

    D. Langlet; Alleman, L. Y.; Plisnier, P.-D.; Hughes, H; André, L.

    2007-01-01

    International audience Biogenic productivity of Lake Tanganyika is highly dependent on seasonal upwellings of cold, oxygen-depleted, nutrient-rich deep waters. We investigated the shell of freshwater bivalve Pleiodon spekii as a geochemical archive of these periodic hydrological changes tuned by the monsoon regime. The results of a three-year-long limnological and geochemical survey of the coastal waters performed on the dissolved and particulate fractions were compared to LA-ICP-MS profil...

  11. Modelling the impact of Baltic Sea upwelling on the atmospheric boundary layer

    OpenAIRE

    Sproson, David; Sahlée, Erik

    2014-01-01

    Coastal upwelling, with a strong sea-surface temperature (SST) signal, is extremely common in the Baltic Sea during the summer months. Although the spatial scale of upwelling is small, its high frequency of occurrence in the semi-enclosed basin may allow the SST signature to have significant feedback onto the lower atmosphere. In this paper, we develop a method to remove the signature of upwelling from SST fields, and use these modified SST fields as the lower boundary condition of an atmosph...

  12. Response of Mytilus edulis to enhanced phytoplankton availability by controlled upwelling in an oligotrophic fjord

    OpenAIRE

    Strohmeier, Tore; Strand, Oivind; ALUNNO-BRUSCIA, Marianne; Duinker, Arne; Rosland, Rune; Aure, Jan; Erga, Svein R.; Naustvoll, Lars J.; Jansen, Henrice M.; Cranford, Peter J.

    2015-01-01

    The controlled upwelling of nutrient-rich deep water in oligotrophic coastal regions has been proposed as a means of increasing phytoplankton and, subsequently, bivalve aquaculture production. This was tested as part of a large-scale upwelling experiment in an oligotrophic environment (Lysefjord, Norway). The mean chlorophyll a concentration in the upwelling area was consistently higher than at the control site (mean ± SD: 3.3 ± 1.9 and 1.5 ± 0.6 mg Chl a m-3, respectively) during the 4 mo of...

  13. Potential new production in two upwelling regions of the western Arabian Sea: Estimation and comparison

    Science.gov (United States)

    Liao, Xiaomei; Zhan, Haigang; Du, Yan

    2016-07-01

    Using satellite-derived and in situ data, the wind-driven potential new production (nitrate supply) for the 300 km wide coastal band in two upwelling regions of the western Arabian Sea (AS) during the southwest monsoon is estimated. The upward nitrate flux to the euphotic zone is generally based on the physical processes of coastal transport (Ekman transport and geostrophic transport) and offshore Ekman pumping. The coastal geostrophic current in the western AS influences the upwelling intensity and latitudinal distributions of nitrate supply. The Oman and Somalia upwelling regions have similar level of potential new production (nitrate supply) during the summer monsoon, while the satellite estimates of primary production off Oman are 2 times greater than those off Somalia. The much higher potential f-ratio in the Somalia upwelling region indicates that the primary production could be limited by availability of other macronutrients (e.g., silicate). The correlation analysis of the primary production and the aerosol optical thickness shows that the Oman upwelling region displays a stronger coupling between the atmospheric deposition and the phytoplankton abundance. The high summertime dust levels in the atmosphere are suggested to contribute to the high primary production in the Oman upwelling region.

  14. Reductions in midlatitude upwelling-favorable winds implied by weaker large-scale Pliocene SST gradients

    Science.gov (United States)

    Arnold, Nathan P.; Tziperman, Eli

    2016-01-01

    The early-to-mid Pliocene (3-5.3 Ma) is the most recent geologic period of significant global warmth. Proxy records of Pliocene sea surface temperature (SST) indicate significant and still unexplained warm anomalies of 3°C-9°C in midlatitude eastern boundary currents, where present-day cool temperatures are maintained by wind-driven upwelling. Here we quantify the effect of large-scale Pliocene-like SST patterns on the surface wind stress around the California, Humboldt, Canary, and Benguela midlatitude coastal upwelling sites. A high-resolution atmosphere model forced with Pliocene SST simulates changes in surface winds that imply reductions of 10% to 50% in both coastal upwelling, driven by alongshore wind stress, and offshore upwelling driven by wind stress curl. These changes result primarily from a reduced meridional temperature gradient which weakens the subtropical highs, and a reduction in zonal land-sea temperature contrast which weakens geostrophic alongshore winds. These results suggest that Pliocene coastal warm anomalies may result in part from atmospheric circulation changes which reduce upwelling intensity. The coastal wind stress and offshore wind stress curl are shown to respond differently to incremental changes in SST, topography, and land surface anomalies. Significant decreases in simulated cloud fraction within the subtropical highs suggest that a weaker land-sea temperature contrast could be maintained by cloud radiative feedbacks.

  15. Partial decoupling of primary productivity from upwelling in the California Current system

    Science.gov (United States)

    Renault, Lionel; Deutsch, Curtis; McWilliams, James C.; Frenzel, Hartmut; Liang, Jun-Hong; Colas, François

    2016-07-01

    Coastal winds and upwelling of deep nutrient-rich water along subtropical eastern boundaries yield some of the ocean's most productive ecosystems. Simple indices of coastal wind strength have been extensively used to estimate the timing and magnitude of biological productivity on seasonal and interannual timescales and underlie the prediction that anthropogenic climate warming will increase the productivity by making coastal winds stronger. The effect of wind patterns on regional net primary productivity is not captured by such indices and is poorly understood. Here we present evidence, using a realistic model of the California Current system and satellite measurements, that the observed slackening of the winds near the coast has little effect on near-shore phytoplankton productivity despite a large reduction in upwelling velocity. On the regional scale the wind drop-off leads to substantially higher production even when the total upwelling rate remains the same. This partial decoupling of productivity from upwelling results from the impact of wind patterns on alongshore currents and the eddies they generate. Our results imply that productivity in eastern boundary upwelling systems will be better predicted from indices of the coastal wind that account for its offshore structure.

  16. Rocket Experiment For Neutral Upwelling

    Science.gov (United States)

    Kenward, D. R.; Lessard, M.

    2015-12-01

    Observations from the CHAMP satellite from 2004 show relatively small scale heating in the thermosphere. Several different mechanisms have been proposed to explain this phenomenon. The RENU 2 rocket mission includes a suite of 14 instruments which will acquire data to help understand processes involved in neutral upwelling in the cusp. Neutral, ion, and electron measurements will be made to provide an assessment of the upwelling process. SUPERDarn measurements of large- scale Joule heating in the cusp during overflight will also be acquired. Small-scale data which could possibly be associated with Alfvén waves, will be acquired using onboard electric field measurements. In-situ measurement of precipitating electrons and all other measurements will be used in thermodynamic and electrodynamic models for comparison to the observed upwelling.

  17. Carbon dioxide in European coastal waters

    NARCIS (Netherlands)

    Borges, A.V.; Schiettecatte, L.-S.; Abril, G.; Delille, B.; Gazeau, F.P.H.

    2006-01-01

    We compiled from literature annually integrated air–water fluxes of carbon dioxide (CO2) computed from field measurements, in 20 coastal European environments that were gathered into 3 main ecosystems: inner estuaries, upwelling continental shelves and non-upwelling continental shelves. The comparis

  18. Peru-Chile upwelling dynamics under climate change

    Science.gov (United States)

    Oerder, Véra; Colas, Francois; Echevin, Vincent; Codron, Francis; Tam, Jorge; Belmadani, Ali

    2015-02-01

    The consequences of global warming on the Peru-Chile Current System (PCCS) ocean circulation are examined with a high-resolution, eddy-resolving regional oceanic model. We performed a dynamical downscaling of climate scenarios from the IPSL-CM4 Coupled General Circulation Model (CGCM), corresponding to various levels of CO2 concentrations in the atmosphere. High-resolution atmospheric forcing for the regional ocean model are obtained from the IPSL atmospheric model run on a stretched grid with increased horizontal resolution in the PCCS region. When comparing future scenarios to preindustrial (PI) conditions, the circulation along the Peru and Chile coasts is strongly modified by changes in surface winds and increased stratification caused by the regional warming. While the coastal poleward undercurrent is intensified, the surface equatorial coastal jet shoals and the nearshore mesoscale activity are reinforced. Reduction in alongshore wind stress and nearshore wind stress curl drive a year-round reduction in upwelling intensity off Peru. Modifications in geostrophic circulation mitigate this upwelling decrease in late austral summer. The depth of the upwelling source waters becomes shallower in warmer conditions, which may have a major impact on the system's biological productivity.

  19. Nimbus observation of oceanic upwelling

    Science.gov (United States)

    Szekielda, K.

    1972-01-01

    Observing the development of upwelling on the northeast coast of Africa by measuring ocean surface emission with infrared radiometers on Nimbus satellites is reported. Using the temperature of the ocean as telemetered by the satellite, the biological potential of an area is estimated, and consequently the highest potential for fisheries.

  20. Biogeochemical cycling in the ocean. Part 1: Introduction to the effects of upwelling along the west coast of North America

    Science.gov (United States)

    Howe, John T.

    1986-01-01

    Coastal upwelling is examined as it relates to the cycling of chemical species in coastal waters along the west coast of North America. The temporal and spatial features of upwelling phenomena in the Eastern boundary regions of the North Pacific Ocean are presented and discussed in terms of upwelling episodes. Climate conditions affecting upwelling include: thermal effects, wind-induced shear stress which moves surface layers, and the curl of the wind stress vector which is thought to affect the extent and nature of upwelling and the formation of offshore convergent downwelling fronts. These effects and the interaction of sunlight and upwelled nutrients which result in a biological bloom in surface waters is modeled analytically. The roles of biological and chemical species, including the effects of predation, are discussed in that context, and relevant remote sensing and in situ observations are presented. Climatological, oceanographic, biological, physical, chemical events, and processes that pertain to biogeochemical cycling are presented and described by a set of partial differential equations. Simple preliminary results are obtained and are compared with data. Thus a fairly general framework has been laid where the many facets of biogeochemical cycling in coastal upwelled waters can be examined in their relationship to one another, and to the whole, to whatever level of detail or approximation is warranted or desired.

  1. Summer upwelling and thermal fronts in the northwestern South China Sea: Observational analysis of two mesoscale mapping surveys

    Science.gov (United States)

    Jing, Zhiyou; Qi, Yiquan; Du, Yan; Zhang, Shuwen; Xie, Lingling

    2015-03-01

    Persistent coastal upwelling and upwelling-induced thermal fronts in the northwestern South China Sea are investigated using satellite measurements, two intensive mesoscale mapping surveys and three bottom-mounted ADCPs. The results indicate that pronounced surface cooling and upwelling-related fronts with a width of 20-50 km occur around Hainan Island and persist through the summer upwelling season. Driven by the prevailing southwesterly monsoon, the subsurface cooling band is ˜6°C colder than the water offshore of the East Coast, where the thermal gradients are generally more than 0.1°C/km. The cold and nutrient-rich coastal water is identified to be derived primarily from the deep water of the outer shelf. At the same time, the spatial structure of the upwelling and thermal front, as well as the upwelling-related coastal currents, is significantly regulated by wind forcing. A prominent lagged correlation between the moored temperature records and alongshore wind stress is detected in the East Coast. The correlation coefficient is -0.8 with the temperature lagging behind wind stress by 2.2 days, indicating that the cooling band off the East Coast is dominated mostly by the alongshore southwesterly monsoon during the upwelling season.

  2. Identification of upwelling areas in the Oman Sea Using Satellite Data

    Science.gov (United States)

    Moradi, Masoud

    2016-07-01

    Satellite-derived sea-surface temperature, TOPEX/POSEIDON (T/P) sea-level anomalies (SLAs), modeled wind data, and hydrodynamic data from World Ocean Database were used to characterize the upwelling along the Oman Sea coasts during 2002 - 2012. Principal Component Analysis (PCA) of the satellite-derived sea-surface temperature (SST) shows the first mode affected by upwelling processes, which represents a biannual variability. In addition, the SST shows the upwelling front moving offshore with the development of Southwest (SW) Monsoon in early June. SST shows the persistence of cold upwelling waters for nearly a month after the end of the SW Monsoon within the bays along the Oman coast. TOPEX/POSEIDON SLAs indicate that with the onset of the SW Monsoon, a 30-cm drop in height is observed along the Oman coast associated the presence of the cool upwelled waters. This drop in height sets up a horizontal pressure gradient and results in a compensating along-shore, northeastward flowing, geostrophic current (East Arabian Current) during the SW Monsoon. Similarly, the altimeter data slow an offshore decrease in height during the Northeast (NE) Monsoon, indicating a seasonal reversal in direction of the East Oman Currents with flow to the southwest. The following upwelling characteristics are identified for the Oman upwelling zone: 1- Upwelling zones have seen along Oman and Pakistan coasts and in the western coasts, like Iran, persistent upwelling zones are not available. 2- Upwelling zones along Oman coasts are more persistent and developed than in Pakistan coastal area. 3- Upwelling in the Oman and East Pakistan coasts starts with SW-Monsoon and will developed in the mid-August, adjusted with summer cooling. 4- Along Oman Sea, upwelling zones were developed between Rasal-Haddad and the southern bay. Mean SST during SW-Monsoon is about 22 °C. 5-Waters with temperature about 23°C were upwelled from depth 50-75 m along Oman coasts, and about 50 m along Pakistan coasts. 6

  3. Sea surface temperature distribution during upwelling along the Polish Baltic coast

    Directory of Open Access Journals (Sweden)

    Adam Krężel

    2005-12-01

    Full Text Available Among over 150 maps of sea surface temperature in the Polish Baltic coastal region derived from satellite data during the warm period of the year (April-October in 2000-2002, 41 cases were noted where its distribution showed characteristic features indicating the occurrence of coastal upwelling. The fundamental parameters of range, probability of occurrence and temperature modification caused by water from deeper sea layers raised by an upwelling event and spreading across the surface were established for three regions (Hel, Łeba and Kołobrzeg. The Kołobrzeg upwelling region had the largest spatial range (up to 5000 km2. The region with the smallest spatial range (Hel, up to 1400 km2 had the largest surface temperature amplitude (to 14°C, the largest maximum temperature gradient (5°C km2 and the largest average sea surface temperature decrease in the centre in relation to the background value.

  4. Does mesoscale matters in decadal changes observed in the northern Canary upwelling system?

    Science.gov (United States)

    Relvas, P.; Luís, J.; Santos, A. M. P.

    2009-04-01

    The Western Iberia constitutes the northern limb of the Canary Current Upwelling System, one of the four Eastern Boundary Upwelling Systems of the world ocean. The strong dynamic link between the atmosphere and the ocean makes these systems highly sensitive to global change, ideal to monitor and investigate its effects. In order to investigate decadal changes of the mesoscale patterns in the Northern Canary upwelling system (off Western Iberia), the field of the satellite-derived sea surface temperature (SST) trends was built at the pixel scale (4x4 km) for the period 1985-2007, based on the monthly mean data from the Advanced Very High Resolution Radiometer (AVHRR) on board NOAA series satellites, provided by the NASA Physical Oceanography Distributed Active Archive Center (PO.DAAC) at the Jet Propulsion Laboratory. The time series were limited to the nighttime passes to avoid the solar heating effect and a suite of procedures were followed to guarantee that the temperature trends were not biased towards the seasonally more abundant summer data, when the sky is considerably clear. A robust linear fit was applied to each individual pixel, crossing along the time the same pixel in all the processed monthly mean AVHRR SST images from 1985 until 2007. The field of the SST trends was created upon the slopes of the linear fits applied to each pixel. Monthly mean SST time series from the one degree enhanced International Comprehensive Ocean-Atmosphere Data Set (ICOADS) and from near-shore measurements collected on a daily basis by the Portuguese Meteorological Office (IM) are also used to compare the results and extend the analysis back until 1960. A generalized warming trend is detected in the coastal waters off Western Iberia during the last decades, no matter which data set we analyse. However, significant spatial differences in the warming rates are observed in the satellite-derived SST trends. Remarkably, off the southern part of the Western Iberia the known

  5. Environmental changes associated with monsoon induced upwelling, off central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    DeSousa, S.N.; Sawkar, K.; Rao, P.V.S.S.D.P.

    in response to prevailing equatorward winds. High salinity ocean waters of rich nutrient contents were observed at the coast in some locations. However, the effect of upwelling on the surface distribution of properties was reduced to some extent due to coastal...

  6. Comparative study of potential transfer of natural and anthropogenic cadmium to plankton communities in the North-West African upwelling

    OpenAIRE

    Auger, Pierre Amaël; Machu, Eric; Gorgues, T.; Grima, N.; Waeles, M.

    2014-01-01

    A Lagrangian approach based on a physical-biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the North-West African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is provided by phosphate industry. In our model experiment, Cd-uptake (natural or anthropogenic) in the Nor...

  7. Intense submesoscale upwelling in anticyclonic eddies

    Science.gov (United States)

    Brannigan, L.

    2016-04-01

    Observations from around the global ocean show that enhanced biological activity can be found in anticyclonic eddies. This may mean that upwelling of nutrient-rich water occurs within the eddy, but such upwelling is not captured by models that resolve mesoscale processes. High-resolution simulations presented here show intense submesoscale upwelling from the thermocline to the mixed layer in anticyclonic eddies. The properties of the upwelling are consistent with a process known as symmetric instability. A simple limiting nutrient experiment shows that this upwelling can drive much higher biological activity in anticyclonic eddies when there is a high nutrient concentration in the thermocline. An estimate for the magnitude of upwelling associated with symmetric instability in anticyclonic eddies in the Sargasso Sea shows that it may be of comparable magnitude to other processes, though further work is required to understand the full implications for basin-scale nutrient budgets.

  8. A local upwelling controls viral and microbial community structure in South Australian continental shelf waters

    Science.gov (United States)

    Paterson, James S.; Nayar, Sasi; Mitchell, James G.; Seuront, Laurent

    2012-01-01

    Despite the increasing awareness of the role of viruses and heterotrophic bacteria in microbial dynamics and biogeochemical cycles, there is still a critical lack of information on their community composition and dynamics, especially in relation to upwellings. We investigated, within surface waters and the Deep Chlorophyll Max, the community composition and dynamics of flow cytometrically defined sub-populations of heterotrophic bacteria and virus-like particles in nearby water masses that were affected and unaffected by a localised wind-driven coastal upwelling. In contrast to previous studies we uniquely identified a 4-fold increase in total viral abundance and a decrease in bacterial abundance, from upwelled to offshore waters. Individual viral sub-populations were seen to correlate significantly to both bacterial populations and chlorophyll a, suggesting the possibility of individual viral populations infecting multiple host species rather than the often assumed single host species. The percentage of HDNA bacteria was high (84.3-93.4%) within upwelled waters, in accordance with the highest recorded values within an upwelling system, and decreased down to 35.5-42.6% away from the upwelling. Additionally, changes in the community composition of individual bacterial sub-populations suggest individual populations might be better adapted to distinct environments. We suggest that each flow cytometrically defined bacterial population may possess its own environmental niche where favourable conditions for that population result in an increase in abundance, cellular activity and productivity.

  9. Dynamic features of successive upwelling events in the Baltic Sea - a numerical case study

    Directory of Open Access Journals (Sweden)

    Kai Myrberg

    2010-03-01

    Full Text Available Coastal upwelling often reveals itself during the thermal stratification season as an abrupt sea surface temperature (SST drop. Its intensity depends not only on the magnitude of an upwelling-favourablewind impulse but also on the temperature stratification of the water column during the initial stage of the event. When a "chain" of upwelling events is taking place, one event may play a part in forming the initial stratification for the next one; consequently, SST may drop significantly even with a reduced wind impulse.    Two upwelling events were simulated on the Polish coast in August 1996 using a three-dimensional, baroclinic prognostic model. The model results proved to be in good agreement with in situobservations and satellite data. Comparison of the simulated upwelling events show that the first one required a wind impulse of 28000 kg m-1 s-1 to reach its mature, full form, whereasan impulse of only 7500 kg m-1 s-1 was sufficient to bring about a significant drop in SST at the end of the second event. In practical applications like operational modelling, the initial stratification conditions prior to an upwelling event should be described with care in order to be able to simulate the coming event with very good accuracy.

  10. Meteorological constraints on oceanic halocarbons above the Peruvian upwelling

    Science.gov (United States)

    Fuhlbrügge, Steffen; Quack, Birgit; Atlas, Elliot; Fiehn, Alina; Hepach, Helmke; Krüger, Kirstin

    2016-09-01

    During a cruise of R/V METEOR in December 2012 the oceanic sources and emissions of various halogenated trace gases and their mixing ratios in the marine atmospheric boundary layer (MABL) were investigated above the Peruvian upwelling. This study presents novel observations of the three very short lived substances (VSLSs) - bromoform, dibromomethane and methyl iodide - together with high-resolution meteorological measurements, Lagrangian transport and source-loss calculations. Oceanic emissions of bromoform and dibromomethane were relatively low compared to other upwelling regions, while those for methyl iodide were very high. Radiosonde launches during the cruise revealed a low, stable MABL and a distinct trade inversion above acting as strong barriers for convection and vertical transport of trace gases in this region. Observed atmospheric VSLS abundances, sea surface temperature, relative humidity and MABL height correlated well during the cruise. We used a simple source-loss estimate to quantify the contribution of oceanic emissions along the cruise track to the observed atmospheric concentrations. This analysis showed that averaged, instantaneous emissions could not support the observed atmospheric mixing ratios of VSLSs and that the marine background abundances below the trade inversion were significantly influenced by advection of regional sources. Adding to this background, the observed maximum emissions of halocarbons in the coastal upwelling could explain the high atmospheric VSLS concentrations in combination with their accumulation under the distinct MABL and trade inversions. Stronger emissions along the nearshore coastline likely added to the elevated abundances under the steady atmospheric conditions. This study underscores the importance of oceanic upwelling and trade wind systems on the atmospheric distribution of marine VSLS emissions.

  11. Manganese content records seasonal upwelling in Lake Tanganyika mussels

    Directory of Open Access Journals (Sweden)

    D. Langlet

    2007-01-01

    Full Text Available Biogenic productivity of Lake Tanganyika is highly dependent on seasonal upwellings of cold, oxygen-depleted, nutrient-rich deep waters. We investigated the shell of freshwater bivalve Pleiodon spekii as a geochemical archive of these periodic hydrological changes tuned by the monsoon regime. The results of a three-year-long limnological and geochemical survey of the coastal waters performed on the dissolved and particulate fractions were compared to LA-ICP-MS profiles of Mn in five aragonitic shells from the same lake location. Three shells present very similar Mn/Ca profiles dominated by a peak that matched the concomitant increase of Mn and chlorophyll a in surface waters during the 2002 upwelling, while a shell collected during 2003 dry season detect both 2002 and 2003 upwelling events. Larger shells showing an extremely reduced growth display more than 8 Mn/Ca peaks suggesting at least an 8-year-record of seasonal changes in water composition. We postulate that Mn/Ca in shells record the conjunction of an increase of biological activity with supplied of dissolved Mn and nutriments in coastal waters, resulting in an enhanced assimilation of biogenic Mn-rich particles. By combining the most recent generation of laser ablation system and the powerful High Resolution ICP-MS, the spatial resolution could be improved down to 5 to 10 µm crater size and end up in a better constrain of the relative variations of the annual Mn peaks. Such an approach on P. spekii from Lake Tanganyika has definitively a great potential to provide recent and past records on primary productivity associated with the monsoon climate system.

  12. Manganese content records seasonal upwelling in Lake Tanganyika mussels

    Science.gov (United States)

    Langlet, D.; Alleman, L. Y.; Plisnier, P.-D.; Hughes, H.; André, L.

    2007-03-01

    Biogenic productivity of Lake Tanganyika is highly dependent on seasonal upwellings of cold, oxygen-depleted, nutrient-rich deep waters. We investigated the shell of freshwater bivalve Pleiodon spekii as a geochemical archive of these periodic hydrological changes tuned by the monsoon regime. The results of a three-year-long limnological and geochemical survey of the coastal waters performed on the dissolved and particulate fractions were compared to LA-ICP-MS profiles of Mn in five aragonitic shells from the same lake location. Three shells present very similar Mn/Ca profiles dominated by a peak that matched the concomitant increase of Mn and chlorophyll a in surface waters during the 2002 upwelling, while a shell collected during 2003 dry season detect both 2002 and 2003 upwelling events. Larger shells showing an extremely reduced growth display more than 8 Mn/Ca peaks suggesting at least an 8-year-record of seasonal changes in water composition. We postulate that Mn/Ca in shells record the conjunction of an increase of biological activity with supplied of dissolved Mn and nutriments in coastal waters, resulting in an enhanced assimilation of biogenic Mn-rich particles. By combining the most recent generation of laser ablation system and the powerful High Resolution ICP-MS, the spatial resolution could be improved down to 5 to 10 µm crater size and end up in a better constrain of the relative variations of the annual Mn peaks. Such an approach on P. spekii from Lake Tanganyika has definitively a great potential to provide recent and past records on primary productivity associated with the monsoon climate system.

  13. Stratigraphic modeling of organic matter distribution and preservation in deep marine environment. Case of a margin with pelagic sedimentation: the coastal upwelling system of Benguela (Namibia, Western South Africa); Modelisation stratigraphique de la distribution et de la preservation de la matiere organique en milieu marin profond. Cas d'une marge a sedimentation pelagique: systeme d'upwelling cotier du Benguela (Namibie, Afrique du Sud Ouest)

    Energy Technology Data Exchange (ETDEWEB)

    Tranier, J.

    2006-06-15

    In order to develop stratigraphic modelling of organic matter distribution and preservation in marine environment, the methodology established, uses three modelling softwares. We make use of a 3D stratigraphic model, DIONISOS, which allows to build margin thanks to sediment input and transport and thanks to basin deformation. Biogenic sediments are introduced in DIONISOS after their production modelling by two coupled models, ROMS and NPZD. ROMS is a physical model which allows to simulate upwelling dynamics thanks to wind strength exerted on ocean surface and to margin morphology. NPZD models relationships (photosynthesis, grazing, excretion, mortality, re-mineralization, etc.) between four boxes: nutrients, phytoplankton, zooplankton and detritus. Nutrients availability (model inputs) and flux intensity between boxes are controlled by upwelling dynamics, i-e ROMS. Thanks to these three softwares, organic matter can be modelled from its production to its fossilization considering the influence of various factors as upwelling intensity, nutrients availability, chemical compounds of water mass and oxygenation of water column, species competition (diatoms and coccolithophoridae), margin morphology and eustatism. After testing sensibility of the various parameters of the three models, we study their capacity for reproduce biogenic sedimentation and simulate climatic cycle effect on organic matter distribution on a passive continental margin: the Namibian margin (Southwest Africa). They are validated comparing results with core data from this margin. (author)

  14. Hypoxia in Chilean Patagonian Fjords

    Science.gov (United States)

    Silva, Nelson; Vargas, Cristian A.

    2014-12-01

    Chilean Patagonia is one of the largest estuarine systems in the world. It is characterized by a complex geography of approximately 3300 islands, a total surface area of 240,000 km2, and 84,000 km of coast line, including islands, peninsulas, channels, fjords, and sounds. The Chilean Patagonia Interior Sea is filled with a mixture of sea, estuarine, and fresh waters, and is characterized by a two layer vertical general circulation. Dissolved oxygen (DO) conditions in these fjords were analyzed based on historic salinity, dissolved oxygen and nutrient data from 1200 oceanographic stations. Horizontal advection of adjacent well oxygenated Subantarctic Waters (5-6 mL L-1) was the mayor source of DO in the deep layers of the Interior Sea. Incoming DO was consumed by the respiration of autochthonous and allochthonous particulate organic matter, as ocean water flows towards the continental fjord heads, reaching near-hypoxic (2-3 mL L-1) or hypoxic levels (2 mL L-1) and four hypoxic (<2 mL L-1), but only at their heads. None were found to be anoxic (0 mL L-1). We found these DO conditions to be permanent features of the Chilean Patagonia Interior Sea.

  15. Current, CTD, and other data from the YAQUINA and other platforms from the coastal waters of Washington/Oregon as part of the International Decade of Ocean Exploration / Coastal Upwelling Ecosystems Analysis (IDOE/CUEA) from 28 January 1975 to 01 September 1975 (NODC Accession 7800403)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current, CTD, and other data were collected from the YAQUINA and other platforms from the coastal waters of Washington/Oregon from 28 January 1975 to 01 September...

  16. Physical, chemical, and other data from bottle casts from the Coastal Waters of Washington/Oregon from the THOMAS G. THOMPSON as part of the International Decade of Ocean Exploration / Coastal Upwelling Ecosystems Analysis (IDOE/CUEA) from 11 July 1973 to 21 July 1973 (NODC Accession 7601145)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, chemical, and other data were collected from bottle casts in the Coastal Waters of Washington/Oregon from the THOMAS G. THOMPSON from 11 July 1973 to 21...

  17. Surface circulation and upwelling patterns around Sri Lanka

    Directory of Open Access Journals (Sweden)

    A. de Vos

    2013-09-01

    Full Text Available Sri Lanka occupies a unique location within the equatorial belt in the northern Indian Ocean with the Arabian Sea on its western side and the Bay of Bengal on its eastern side. The region is characterised by bi-annually reversing monsoon winds resulting from seasonal differential heating and cooling of the continental land mass and the ocean. This study explored elements of the dynamics of the surface circulation and coastal upwelling in the waters around Sri Lanka using satellite imagery and the Regional Ocean Modelling System (ROMS configured to the study region and forced with ECMWF interim data. The model was run for 2 yr to examine the seasonal and shorter term (∼10 days variability. The results confirmed the presence of the reversing current system in response to the changing wind field: the eastward flowing Southwest Monsoon Current (SMC during the Southwest (SW monsoon transporting 11.5 Sv and the westward flowing Northeast Monsoon Current (NMC transporting 9.5 Sv during the Northeast (NE monsoon, respectively. A recirculation feature located to the east of Sri Lanka during the SW monsoon, the Sri Lanka Dome, is shown to result from the interaction between the SMC and the Island of Sri Lanka. Along the eastern and western coasts, during both monsoon periods, flow is southward converging along the south coast. During the SW monsoon the Island deflects the eastward flowing SMC southward whilst along the east coast the southward flow results from the Sri Lanka Dome recirculation. The major upwelling region, during both monsoon periods, is located along the south coast and is shown to be due to flow convergence and divergence associated with offshore transport of water. Higher surface chlorophyll concentrations were observed during the SW monsoon. The location of the flow convergence and hence the upwelling centre was dependent on the relative strengths of wind driven flow along the east and west coasts: during the SW (NE monsoon the flow

  18. Cadmium in the California Current system: Tracer of past and present upwelling

    Science.gov (United States)

    VanGeen, A.; Husby, D.M.

    1996-01-01

    Over 100 samples were collected off the west coast of North America during 1991-1993 to determine the relation between wind-driven upwelling and nearshore concentrations of dissolved silicate (Si), phosphate (P), and cadmium (Cd). Highly enriched in deep water offshore, these constituents are sensitive indicators of upwelling. Coastal water was sampled from the shore in January and June 1992 at 12 sites distributed between 36?? and 48??N latitude. In January the composition of nearshore water along this transect was fairly uniform: 5-15 ??mol/kg for Si, 0.5 to 1.0 ??mol/kg for P, and 0.1-0.3 nmol/kg for Cd. In June, elevated concentrations of Si (30 ??mol/kg), P (2.0 ??mol/kg), and Cd (0.6 nmol/kg) revealed a region of intense upwelling between 38?? and 40??N. The pattern is broadly consistent with meridional gradients in coastal upwelling calculated from the long-term mean of alongshore winds compiled from ship reports. Nearshore water was also collected biweekly to monthly at two sites 3 km apart near San Francisco Bay (37.5??N) during 1991-1993. The variability seen in the time series suggests that the composition of nearshore water integrates the effect of alongshore winds over timescales of several weeks. Seasonal variations in Si (5-50 ??mol/kg), P (0.5-2.5 ??mol/kg), and Cd (0.1-0.8 nmol/kg) concentrations were consistent with upwelling during spring and summer. Maximum Si, P, and Cd concentrations reached in May 1991 were consistent with advection to the very nearshore region from a depth of about 300 m relative to a vertical profile at a distance of 200 km from the coast. Nearshore Si, P, and Cd concentrations were reduced relative to 1991 in 1992 and, to a lesser extent, in 1993 due to weaker upwelling linked to the warm phase of the El Nin???o-Southern Oscillation. During periods of weaker upwelling or downwelling, variations in P, Si, and Cd concentrations became uncoupled. There is a good correlation between the coastal Cd time series near San

  19. Diel variation in the vertical distribution of fish larvae forced by upwelling filaments off Punta Angamos (northern Chile

    Directory of Open Access Journals (Sweden)

    Pablo M Rojas

    2014-07-01

    Full Text Available The role of daily vertical migration (DVM of ichthyoplanktonic associations off Punta Angamos, in northern Chile, was examined. In September 1998 and January 1999, two oceanographic surveys were conducted during coastal upwelling events. Fish larvae were collected during the day/night in three depth strata (0-20, 20-80 and 80-200 m and inside/outside of upwelling filaments. The study area was dominated by a southward flow along 200 m depth; meanwhile, the Ekman layer did not exceed 20 m depth. The greatest accumulation of larvae was found in the middle layer (20-80 m, where the current velocity was low and did not interact with the circulation associated with upwelling the filament formation. Most fish larvae were found in non-upwelling waters in the middle stratum. Independent of the origin of water (upwelling/non-upwelling, larvae of Dioge-nichthys laternatus (Myctophidae, Engraulis ringens (Engraulidae and Bathylagus nigrigenys (Bathylagidae showed a deeper vertical distribution during the day, suggesting a daily vertical migration. This behavior can potentially increase retention of larvae near the coast in productive areas through vertical evasion of the Ekman layer during upwelling events.

  20. Late Quaternary upper-water column structure in upwelling areas of the South China Sea

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on a quantitative analysis of planktonic foraminifera in two gravity cores (17928 and 17954), the history of the upper-water structure of the eastern and western slopes of the South China Sea (SCS) over the last 220 Ka was reconstructed using the transfer function technique. Our results show that lower sea surface temperature (SST) and shallower depth of thermocline (DOT) exist at Core 17928, off Luzon, in the glacial periods; on the contrary, the same situation turned up in the interglacial at Core 17954, off Vietnam. These changes of the upper-water column structure in the two areas are induced by coastal upwelling, which in turn is driven by monsoons, namely, winter monsoon leads to upwelling at the eastern slope, and summer monsoon gives birth to upwelling on the western slope. Moreover, the intensity of upwellings is also closely related to the evolution of the East Asian monsoon. Therefore, we assume that the changes of the upwelling in the two sites indicate strengthenning of winter and su mmer monsoon during the glacial and interglacial periods, respectively.

  1. Microbial and biogeochemical responses to projected future nitrate enrichment in the California upwelling system

    Directory of Open Access Journals (Sweden)

    Katherine Rose Marie Mackey

    2014-11-01

    Full Text Available Coastal California is a dynamic upwelling region where nitrogen (N and iron (Fe can both limit productivity and influence biogeochemistry over different spatial and temporal scales. With global change, the flux of nitrate from upwelling is expected to increase over the next century, potentially driving additional oceanic regions toward Fe limitation. In this study we explored the effect of changes in Fe/N ratio on native phytoplankton from five currently Fe-replete sites near the major California upwelling centers at Bodega Bay and Monterey Bay using nutrient addition incubation experiments. Despite the high nitrate levels (13-30 M in the upwelled water, phytoplankton at three of the five sites showed increased growth when 10 M nitrate was added. None of the sites showed enhanced growth following addition of 10 nM Fe. Nitrate additions favored slow sinking single-celled diatoms over faster sinking chain-forming diatoms, suggesting that future increases in nitrate flux could affect carbon and silicate export and alter grazer populations. In particular, solitary cells of Cylindrotheca were more abundant than the toxin-producing genus Pseudonitzschia following nitrate addition. These responses suggest the biogeochemistry of coastal California could change in response to future increases in nitrate, and multiple stressors like ocean acidification and hypoxia may further result in ecosystem shifts.

  2. Iron Meteorites and Upwelling in Antarctica

    Science.gov (United States)

    Gourlay, B. S.; Behr, E.; Mardon, A.; Behr, E.

    2016-09-01

    In Antarctica, a meteorite stranding zone, stone meteorites are more common than iron. Dr. Evatt's team suggests that the heat conductivity of iron may be opposing the upwelling effects so iron meteorites sink under the ice unlike the stone ones.

  3. A survey of upwelling ion event characteristics

    Science.gov (United States)

    Pollock, C. J.; Chandler, M. O.; Moore, T. E.; Chappell, C. R.; Waite, J. H., Jr.

    1990-01-01

    Quasi-static electric field data collected by the DE-1 spacecraft were used to study ionospheric ion upwelling events observed in the vicinity of the dayside cleft. Bulk plasma parameters such as ion-species density and field-aligned bulk velocity and flux were derived at points within several upwelling ion events for the H(+), He(+), O(+), and O(2+), and the ion-species bulk parameters near the source altitude were compared. It was found that O(+) ions comprise about 90 percent of the upwelling particle density, followed by H(+) at less than 10 percent; He(+) and O(2+) contribute about 1 percent each. The upwelling O(+) flux is also dominant, followed by upward H(+) flux, which is relatively more significant than the fractional H(+) density, due to its high upward flow velocity.

  4. Mechanisms for tropical upwelling in the stratosphere

    OpenAIRE

    Semeniuk, Kirill; Shepherd, Theodore G.

    2001-01-01

    The dynamics of the tropical upwelling branch of the stratospheric Brewer–Dobson circulation are examined, with a particular focus on the role of the middle-atmosphere Hadley circulation. Upwelling is examined in terms of both the diabatic circulation and Lagrangian trajectories using a zonally symmetric balance model. The behavior of the wave-driven circulation in the presence of angular momentum redistribution by the Hadley circulation is also considered. The results of the zonally symmetri...

  5. Possible upwelling phenomenon off the Nigerian coast

    OpenAIRE

    Ibe, A.C.; Ajayi, T.O.

    1985-01-01

    Published information favour the occurrence in certain years of wind related upwelling in Nigeria's inshore waters especially between July and September. This is corroborated by the prevalence of petroleum source beds, glauconite, phosphorite and periodic abundance of some fish including Engraulis encrassicolus, Sardinella maderensis and the bonga Ethalmosa fimbriata which are pelagic and are associated with upwelling phenomena. Examination of temperature and salinity data for 1978 - 81 sug...

  6. Effects of Seasonal Upwelling on Inorganic and Organic Matter Dynamics in the Water Column of Eastern Pacific Coral Reefs.

    Science.gov (United States)

    Stuhldreier, Ines; Sánchez-Noguera, Celeste; Rixen, Tim; Cortés, Jorge; Morales, Alvaro; Wild, Christian

    2015-01-01

    The Gulf of Papagayo at the northern Pacific coast of Costa Rica experiences pronounced seasonal changes in water parameters caused by wind-driven coastal upwelling. While remote sensing and open water sampling already described the physical nature of this upwelling, the spatial and temporal effects on key parameters and processes in the water column have not been investigated yet, although being highly relevant for coral reef functioning. The present study investigated a range of water parameters on two coral reefs with different exposure to upwelling (Matapalo and Bajo Rojo) in a weekly to monthly resolution over one year (May 2013 to April 2014). Based on air temperature, wind speed and water temperature, three time clusters were defined: a) May to November 2013 without upwelling, b) December 2013 to April 2014 with moderate upwelling, punctuated by c) extreme upwelling events in February, March and April 2014. During upwelling peaks, water temperatures decreased by 7°C (Matapalo) and 9°C (Bajo Rojo) to minima of 20.1 and 15.3°C respectively, while phosphate, ammonia and nitrate concentrations increased 3 to 15-fold to maxima of 1.3 μmol PO43- L-1, 3.0 μmol NH4+ L-1 and 9.7 μmol NO3- L-1. This increased availability of nutrients triggered several successive phytoplankton blooms as indicated by 3- (Matapalo) and 6-fold (Bajo Rojo) increases in chlorophyll a concentrations. Particulate organic carbon and nitrogen (POC and PON) increased by 40 and 70% respectively from February to April 2014. Dissolved organic carbon (DOC) increased by 70% in December and stayed elevated for at least 4 months, indicating high organic matter release by primary producers. Such strong cascading effects of upwelling on organic matter dynamics on coral reefs have not been reported previously, although likely impacting many reefs in comparable upwelling systems. PMID:26560464

  7. Evolution of a physical and biological front from upwelling to relaxation

    Science.gov (United States)

    Zhang, Yanwu; Bellingham, James G.; Ryan, John P.; Godin, Michael A.

    2015-10-01

    Fronts influence the structure and function of coastal marine ecosystems. Due to the complexity and dynamic nature of coastal environments and the small scales of frontal gradient zones, frontal research is difficult. To advance this challenging research we developed a method enabling an autonomous underwater vehicle (AUV) to detect and track fronts, thereby providing high-resolution observations in the moving reference frame of the front itself. This novel method was applied to studying the evolution of a frontal zone in the coastal upwelling environment of Monterey Bay, California, through a period of variability in upwelling intensity. Through 23 frontal crossings in four days, the AUV detected the front using real-time analysis of vertical thermal stratification to identify water types and the front between them, and the vehicle tracked the front as it moved more than 10 km offshore. The physical front coincided with a biological front between strongly stratified phytoplankton-enriched water inshore of the front, and weakly stratified phytoplankton-poor water offshore of the front. While stratification remained a consistent identifier, conditions on both sides of the front changed rapidly as regional circulation responded to relaxation of upwelling winds. The offshore water type transitioned from relatively cold and saline upwelled water to relatively warm and fresh coastal transition zone water. The inshore water type exhibited an order of magnitude increase in chlorophyll concentrations and an associated increase in oxygen and decrease in nitrate. It also warmed and freshened near the front, consistent with the cross-frontal exchange that was detected in the high-resolution AUV data. AUV-observed cross-frontal exchanges beneath the surface manifestation of the front emphasize the importance of AUV synoptic water column surveys in the frontal zone.

  8. Eastern Boundary Upwelling Ecosystems: Review and Observing Needs

    Science.gov (United States)

    Chavez, F.; Garçon, V. C.; Dewitte, B.; Montes, I.

    2015-12-01

    Eastern Boundary Upwelling Systems (EBUS) cover less than 3% of the world ocean surface but play a significant role in the climate system, and contribute disproportionately to ocean biological productivity with up to 40% of the reported global fish catch. Coupled with the vast coastal human populations, these regions play key socio-economic roles. Human pressure on these productive ecosystems and their services is increasing, requiring new and evolving scientific approaches to collect information and use it in management. Here we review and compare the physical, chemical and biological characteristics of the four major EBUS: Benguela, California, Northwest Africa and Peru/Chile. Long-term trends and climate variability are emphasized. Technologies and systems for observing and understanding the changing marine ecosystems of EBUS are discussed.

  9. Surface circulation and upwelling patterns around Sri Lanka

    Science.gov (United States)

    de Vos, A.; Pattiaratchi, C. B.; Wijeratne, E. M. S.

    2014-10-01

    Sri Lanka occupies a unique location within the equatorial belt in the northern Indian Ocean, with the Arabian Sea on its western side and the Bay of Bengal on its eastern side, and experiences bi-annually reversing monsoon winds. Aggregations of blue whale (Balaenoptera musculus) have been observed along the southern coast of Sri Lanka during the northeast (NE) monsoon, when satellite imagery indicates lower productivity in the surface waters. This study explored elements of the dynamics of the surface circulation and coastal upwelling in the waters around Sri Lanka using satellite imagery and numerical simulations using the Regional Ocean Modelling System (ROMS). The model was run for 3 years to examine the seasonal and shorter-term (~10 days) variability. The results reproduced correctly the reversing current system, between the Equator and Sri Lanka, in response to the changing wind field: the eastward flowing Southwest Monsoon Current (SMC) during the southwest (SW) monsoon transporting 11.5 Sv (mean over 2010-2012) and the westward flowing Northeast Monsoon Current (NMC) transporting 9.6 Sv during the NE monsoon, respectively. A recirculation feature located to the east of Sri Lanka during the SW monsoon, the Sri Lanka Dome, is shown to result from the interaction between the SMC and the island of Sri Lanka. Along the eastern and western coasts, during both monsoon periods, flow is southward converging along the southern coast. During the SW monsoon, the island deflects the eastward flowing SMC southward, whilst along the eastern coast, the southward flow results from the Sri Lanka Dome recirculation. The major upwelling region, during both monsoon periods, is located along the southern coast, resulting from southward flow converging along the southern coast and subsequent divergence associated with the offshore transport of water. Higher surface chlorophyll concentrations were observed during the SW monsoon. The location of the flow convergence and hence the

  10. Benthic primary production in an upwelling-influenced coral reef, Colombian Caribbean

    Science.gov (United States)

    Bayraktarov, Elisa; Hauffe, Torsten; Pizarro, Valeria; Wilke, Thomas; Wild, Christian

    2014-01-01

    In Tayrona National Natural Park (Colombian Caribbean), abiotic factors such as light intensity, water temperature, and nutrient availability are subjected to high temporal variability due to seasonal coastal upwelling. These factors are the major drivers controlling coral reef primary production as one of the key ecosystem services. This offers the opportunity to assess the effects of abiotic factors on reef productivity. We therefore quantified primary net (Pn) and gross production (Pg) of the dominant local primary producers (scleractinian corals, macroalgae, algal turfs, crustose coralline algae, and microphytobenthos) at a water current/wave-exposed and-sheltered site in an exemplary bay of Tayrona National Natural Park. A series of short-term incubations was conducted to quantify O2 fluxes of the different primary producers during non-upwelling and the upwelling event 2011/2012, and generalized linear models were used to analyze group-specific O2 production, their contribution to benthic O2 fluxes, and total daily benthic O2 production. At the organism level, scleractinian corals showed highest Pn and Pg rates during non-upwelling (16 and 19 mmol O2 m−2 specimen area h−1), and corals and algal turfs dominated the primary production during upwelling (12 and 19 mmol O2 m−2 specimen area h−1, respectively). At the ecosystem level, corals contributed most to total Pn and Pg during non-upwelling, while during upwelling, corals contributed most to Pn and Pg only at the exposed site and macroalgae at the sheltered site, respectively. Despite the significant spatial and temporal differences in individual productivity of the investigated groups and their different contribution to reef productivity, differences for daily ecosystem productivity were only present for Pg at exposed with higher O2 fluxes during non-upwelling compared to upwelling. Our findings therefore indicate that total benthic primary productivity of local autotrophic reef communities is

  11. Variabilidad estacional de cadmio en un sistema de surgencia costera del norte de Chile (Bahía Mejillones del Sur, 23° S Seasonal variability of cadmium in a coastal upwelling system off northern Chile (Mejillones bay, 23° S

    Directory of Open Access Journals (Sweden)

    JORGE VALDÉS

    2006-12-01

    observada en esta razón pueden ser explicados ya sea por una mayor eficiencia en la remoción de PO4 que de Cadmio en las aguas superficiales o una mayor remineralización de cadmio en las aguas subsuperficialesTotal and dissolved cadmium were measured from surface to 100 m water depth, between June 2002 and April 2003, in Mejillones bay. Total and dissolved cadmium range concentration was 0.41-10.7 and 0.08-1.61 nM, respectively. Cadmium profiles and water structure were used to study seasonal variability patterns of this metal in this upwelling system. Oceanographic conditions during this period correspond to a normal (non-El Niño year. Water masses present in this bay correspond to subantartic superficial water, subtropical superficial water and Equatorial subsuperficial water with different degree of mixture and stratification during sampling period. Cadmium profiles showed a classic nutrient-type distribution. Whereas some differences in this profiles could be attributed to a water masses mixing condition into the bay. Multivariate analysis indicates that temporal cadmium variations were associated with chlorophyll-a concentration and temperature fluctuation, indicating that, at this temporal resolution, phytoplanktonic biomass production is the principal factor controlling cadmium concentration in surface waters of Mejillones bay. By other hand, in spite of cadmium being a redox-sensitive metal, any significant influence of dissolved oxygen on this metal were founded, thus microxic condition of bottom water of Mejillones bay is not the principal factor that promotes cadmium flux to the sediments. Cd/PO4 ratio is in agreement with normal values reported for the Chilean coast, and its low values, compared with the northeast Pacific coast, can be explained either by the fact that PO4 is more efficiently removed than cadmium from the surface layer, or that cadmium remineralization is occurring much faster than in the case of PO4

  12. Distribution of 226Ra Radionuclide in Upwelling Event Off Ulsan, Gampo and Pohang, Korea

    Directory of Open Access Journals (Sweden)

    Muslim

    2009-07-01

    Full Text Available Upwelling is an important event in the sea for it makes the area to become more productive. The objective of this study is to determine the distribution of radium-226 as radiotoxic in the upwelling area in the summer season. Measurements of the horizontal and vertical activities of 226Ra in the Ulsan, Gampo and Pohang waters were conducted in June, August 1999 and June 2000 when the upwelling event was expected to occur. Water temperature, salinity and dissolved oxygen (DO were also measured concurrently. The thermocline layer or the layer where the temperature decreased drastically occurred at a depth between 30 m to 100 m for samples dated June 1999 and 30 m to more than 100 m for samples dated August 1999 and June 2000. The salinity decreased with depth but the DO concentration increased in this layer. The condition affected the vertical distribution of 226Ra in the study area, where the 226Ra activities showed to be relatively homogeneous vertically in each station. This indicates that the upwelling which occurred in the study area was capable to distribute the 226Ra activities from the bottom to the surface. Thus, the 226Ra distribution at that time did not increase with depth, opposite to what usually occurs in the ocean at normal condition. The 226Ra activities also did not decrease after elapsed time of one year, in fact, it increased. However, horizontally the 226Ra activities decreased with increasing distance from the coastal zone. Based on these results, it can be concluded that the upwelling event in the Ulsan, Gampo and Pohang was effective for increasing the 226Ra activities and was capable to create homogeneous 226Ra activities from the bottom to the surface in the water column, and the source of 226Ra was likely to originate from outside area (i.e. coastal zone and bottom area.

  13. Role of Ekman Transport Versus Ekman Pumping in Driving Summer Upwelling in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    WANG Dakui; WANG Hui; LI Ming; LIU Guimei; WU Xiangyu

    2013-01-01

    Relative roles of Ekman transport and Ekman pumping in driving summer upwelling in the South China Sea (SCS) are examined using QuikSCAT scatterometer wind data.The major upwelling regions in the SCS are the coastal regions east and southeast of Vietnam (UESEV),east and southeast of Hainan Island (UESEH),and southeast of Guangdong province (USEG).It is shown that the Ekman transport due to alongshore winds and Ekman pumping due to offshore wind stress curl play different roles in the three upwelling systems.In UESEV,Ekman pumping and Ekman transport are equally important in generating upwelling.The Ekman transport increases linearly from 0.49 Sv in May to 1.23 Sv in August,while the Ekman pumping increases from 0.36 to 1.22 Sv during the same period.In UESEH,the mean estimates of Ekman transport and Ekman pumping are 0.14 and 0.07 Sv,respectively,indicating that 33% of the total wind-driven upwelling is due to Ekman pumping.In USEG,the mean Ekman transport is 0.041 Sv with the peak occurring in July,while Ekman pumping is much smaller (0.003 on average),indicating that the upwelling in this area is primarily driven by Ekman transport.In the summers of 2003 and 2007 following E1 Ni(n)o-Southem Oscillation (ENSO) events,both Ekman transport and Ekman pumping decrease in UESEV due to the abnormally weak southwest monsoon.During the same events,however,Ekman transport is slightly enhanced and Ekman pumping is weakened in UESEH and USEG.

  14. Comparative study of potential transfer of natural and anthropogenic cadmium to plankton communities in the North-West African upwelling

    Energy Technology Data Exchange (ETDEWEB)

    Auger, P.A., E-mail: pierreamael.auger@gmail.com [Laboratoire de Physique des Océans (LPO), UMR-CNRS 6523/IFREMER/IRD/UBO, BP70, 29280 Plouzané (France); Machu, E.; Gorgues, T.; Grima, N. [Laboratoire de Physique des Océans (LPO), UMR-CNRS 6523/IFREMER/IRD/UBO, BP70, 29280 Plouzané (France); Waeles, M. [Université de Bretagne Occidentale (UBO), Laboratoire de l' Environnement Marin (LEMAR), UMR-CNRS 6539/IRD/UBO, place N. Copernic, 29280 Plouzané (France)

    2015-02-01

    A Lagrangian approach based on a physical–biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the North-West African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is provided by phosphate industry. In our model experiment, Cd-uptake (natural or anthropogenic) in the North-West African upwelling is the result of an interplay between the Cd dispersion (by advection processes) and the simulated biological productivity. In the Moroccan waters, advection processes limit the residence time of water masses resulting in a low natural Cd-uptake by plankton communities while anthropogenic Cd-uptake is high. As expected, the situation is reversed in the Senegalo-Mauritanian upwelling where natural Cd-uptake is higher than anthropogenic Cd-uptake. Based upon an estimate of Cd sources, our modeling study shows, unexpectedly, that the anthropogenic signal of potential Cd-bioaccumulation in the Moroccan upwelling is of the same order of magnitude as the natural signal mainly present in the Senegalo-Mauritanian upwelling region. A comparison with observed Cd levels in mollusk and fishes, which shows overall agreement with our simulations, is confirming our estimates. - Highlights: • We model the physical–biogeochemical dynamics in the North-West African upwelling. • We model the transport of cadmium from natural and anthropogenic sources. • We derive proxies of potential cadmium absorption and bioaccumulation in the plankton food chain. • The anthropogenic signal off Morocco at least equals the natural upwelling signal off Mauritania. • We compare our results with observed cadmium levels in mollusks and fishes.

  15. Diel variation in the vertical distribution of fish larvae forced by upwelling filaments off Punta Angamos (northern Chile)

    OpenAIRE

    Pablo M Rojas

    2014-01-01

    The role of daily vertical migration (DVM) of ichthyoplanktonic associations off Punta Angamos, in northern Chile, was examined. In September 1998 and January 1999, two oceanographic surveys were conducted during coastal upwelling events. Fish larvae were collected during the day/night in three depth strata (0-20, 20-80 and 80-200 m) and inside/outside of upwelling filaments. The study area was dominated by a southward flow along 200 m depth; meanwhile, the Ekman layer did not exceed 20 m dep...

  16. Influences of upwelling and downwelling winds on red tide bloom dynamics in Monterey Bay, California

    Science.gov (United States)

    Ryan, John P.; Fischer, Andrew M.; Kudela, Raphael M.; Gower, James F. R.; King, Stephanie A.; Marin, Roman, III; Chavez, Francisco P.

    2009-03-01

    dinoflagellates and decreased abundance of diatoms. Similar dinoflagellate bloom incubation sites are indicated in other areas of the California Current system and other coastal upwelling systems. Through frequent bloom development and along-coast transports, relatively small incubation sites may significantly influence larger regions of the coastal marine ecosystems in which they reside.

  17. Dynamics of plankton populations in upwelling areas

    Science.gov (United States)

    Szekielda, K. H. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. Spectral properties of the upwelled waters off the NW coast of Africa were studied with observations derived from aircraft and Skylab. Results indicate that the two-channel, ratio approach is ineffective in determining surface chlorophyll concentrations. Ocean color boundaries and temperature gradients were found to be directly correlated with each other and also with fishing effort in the upwelling region. Photographic and scanner data derived from Skylab were effective in locating ocean boundaries and mapping temperature distributions.

  18. Synoptic conditions governing upwelling along the Polish Baltic coast

    OpenAIRE

    Bartosz Czernecki; Ewa Bednorz; Marek Półrolniczak

    2013-01-01

    The study analyses atmospheric feedback to the occurrence of upwelling along the Polish Baltic coast. Upwelling events were identified on the basis of daily mean sea surface temperature (SST) maps from the period 1982-2010 derived from the NOAA OI SST V2 High Resolution Dataset. Synoptic conditions favourable to the occurrence of upwelling were determined on the basis of the NCEP/NCAR reanalysis data. On average, there are approximately 23 days with upwelling each year along the Polish Baltic...

  19. Paleomagnetism of Permian and Triassic rock, central Chilean Andes

    Science.gov (United States)

    Forsythe, Randall D.; Kent, Dennis V.; Mpodozis, Constantino; Davidson, John

    The first paleomagnetic data from Permian and Triassic formations west of the Andean divide are presented. Four formations of Permian or Triassic age in the central Chilean Andes have been investigated: two are located in the coastal ranges, and two are in the main cordillera. Of the formations in the main cordillera (Pastos Blancos and Matahuaico formations), only the Pastos Blancos Formation has yielded characteristic directions. While a fold test is absent, magnetizations are most likely secondary and yield pre-tilt corrected concordant inclinations, but yield declinations discordant 30° clockwise in comparison to the South American apparent polar wander path. Both formations from the coastal ranges (Cifuncho and Pichidangui formations) yielded stable directions. Postfolding magnetizations in the Cifuncho Formation also show declinations discordant 30° clockwise and concordant inclinations. The Pichidangui Formation has two stable components: one of postfolding age is concordant to apparent polar wander path data, and one of probable prefolding (Late Triassic) age is concordant in declination, but discordant in inclination. Further work is needed to better define the prefolding magnetizations in the Pichidangui Formation, but at present these preliminary results are the first paleomagnetic signs of displaced terranes along the Pacific margin of Chile. If correct, the results suggest that the Pichidangui Formation was some 15° of latitude farther south during the Late Triassic and had likely moved northward to its present latitudinal position with respect to cratonic South America by Middle to Late Jurassic.

  20. Low-frequency variations in primary production in the Oman upwelling zone associated with monsoon winds

    Institute of Scientific and Technical Information of China (English)

    LIAO Xiaomei; ZHAN Haigang; WEI Xing

    2012-01-01

    Thirteen-year satellite-derived data are used to investigate the temporal variability of net primaryproduction (NPP) in the Oman upwelling zone and its potential forcing mechanisms.The NPP in the Oman upwelling zone is characterized by an abnormal decrease during El Ni(n)o events.Such an NPP decrease may be related to El Ni(n)o-driven anomalous summertime weak wind.During the summer following El Ni(n)o,the anomalous northeasterly wind forced by southwest Indian Ocean warming weakens the southwest monsoon and warms the Arabian Sea.The abnormal wind weakens the coastal Ekman transport,offshore Ekman pumping and horizontal advection,resulting in reduced upward nutrient supply to the euphotic zone.A slightly declining trend in NPP after 2000 associated with a gradual decrease in surface monsoon winds is discussed.

  1. Coastal processes at the southern tip of India during summer monsoon 2005

    Digital Repository Service at National Institute of Oceanography (India)

    Smitha, B.R.; VimalKumar, K.G.; Sanjeevan, V.N.

    /sec during July) further offshore and carried away by the equator ward flowing west India Coastal Current (WICC). This leads to the mixing of the nutrient rich upwelled waters with the less productive off shore waters, reducing the expected enhanced...

  2. Distribution and respiration of the high-latitude pelagic amphipod Themisto gaudichaudi in the Benguela Current in relation to upwelling intensity

    Science.gov (United States)

    Auel, Holger; Ekau, Werner

    2009-12-01

    The cold and highly productive waters of coastal upwelling areas provide habitats for marine species usually occurring at higher latitudes and allow those species to extend their distribution ranges towards the equator into regions otherwise characterised by warm and oligotrophic sub-tropical waters. The pelagic hyperiid amphipod Themisto gaudichaudi has a circum-Antarctic epipelagic distribution pattern generally south of 35°S and plays an important role in Antarctic food webs as effective link from zooplankton secondary production to higher trophic levels including seabirds and marine mammals. In the cold and productive waters of the Benguela Current coastal upwelling system, the distribution range of the species extents far northward into the subtropics. The present study focuses on the distribution of T. gaudichaudi at the northernmost limit of its range in the Benguela upwelling system in relation to upwelling intensity and hydrographic conditions (sea surface temperature) based on time-series data from 2002 to 2008. Moreover, field data on life-history traits and respiration rates in relation to water temperature are combined to elucidate the environmental and physiological factors limiting the distribution range. Compared to Themisto populations from higher latitudes, the relatively higher water temperatures in the coastal upwelling region lead to higher respiration rates, faster growth, earlier sexual maturity and smaller body size.

  3. Phosphorus cycling in the red tide incubator region of Monterey Bay in response to upwelling

    Directory of Open Access Journals (Sweden)

    Katherine Rose Marie Mackey

    2012-02-01

    Full Text Available This study explores the cycling of phosphorus (P in the euphotic zone following upwelling in northeastern Monterey Bay (the Red Tide Incubator region of coastal California, with particular emphasis on how phytoplankton and bacteria mediate and respond to changes in P availability. In situ measurements of nutrient concentrations, phytoplankton community composition, and cell-specific alkaline phosphatase (AP activity (determined via enzyme labeled fluorescence assay were measured during 3 cruises. Upwelling led to a 10-fold increase in dissolved inorganic (DIP in surface waters, reaching ~0.5 mol L-1. This DIP was drawn down rapidly as upwelling relaxed over a period of 1 week. Relatively low ratios of nitrate to DIP uptake (~5:1 suggest that luxury P uptake was occurring as phytoplankton bloomed. Dissolved organic (DOP remained relatively constant (~0.3mol L-1 before and immediately following upwelling, but doubled as upwelling relaxed, likely due to phytoplankton excretion and release during grazing. This transition from a relatively high DIP:DOP ratio to lower DIP:DOP ratio was accompanied by a decline in the abundance of diatoms, which had low AP activity, toward localized, spatially-heterogeneous blooms of dinoflagellates in the genera Prorocentrum, Ceratium, Dinophysis, Alexandrium, and Scrippsiella that showed high AP activity regardless of ambient DIP levels. A nutrient addition incubation experiment showed that phytoplankton growth was primarily limited by nitrate, followed by DIP and then DOP, suggesting that P is a regulating, rather than limiting, nutrient in this region. AP activity was observed in bacteria associated with lysed cell debris and aggregates of particulate organic material, where it may serve to facilitate P regeneration, as well as affixed to the surfaces of intact phytoplankton cells, possibly indicative of close, beneficial phytoplankton-bacteria interactions.

  4. A modeling study of the effects of river runoff, tides, and surface wind-wave mixing on the Eastern and Western Hainan upwelling systems of the South China Sea, China

    Science.gov (United States)

    Wang, Daoru; Yang, Yi; Wang, Jia; Bai, Xuezhi

    2015-08-01

    This study investigates the variation of eastern Hainan (or Qiongdong) and western Hainan upwelling systems during the East Asia summer monsoon (EASM) season using a state-of-the-art finite-volume coastal model and reveals the impacts of tidal mixing, surface wind-wave mixing, and river runoff on the Hainan upwellings in terms of the spatial and temporal variations, intensification, and vertical structure. It is found that (1) river runoff, a stabilizer of the water column, suppresses the upwelling beneath it from reaching the surface, although strong upwelling still occurs in the lower layer of the water column; (2) tidal mixing, a mechanism of forming bottom mixed layer, promotes upwelling, leading to strengthening of the upwelling; (3) surface wind-wave mixing, a major mechanism for formation of the upper mixed layer and a sharp thermocline, inhibits the upwelling from crossing the thermocline to reach the surface; and (4) unlike the east coast upwelling, the upwelling on the west coast is tidally induced.

  5. Initial observation of upwelling along east coast of Peninsular Malaysia musica-gratis.softonic.it/ >musica gratis

    Science.gov (United States)

    Akhir, M.; Tanggang, F.

    2013-12-01

    There is no published evidence of upwelling in coastal area along the east coast of Peninsular Malaysia. However numbers of recent cruise data collected during the southwest monsoon found features of thermocline lifting and isolated cooler temperature water along the coast, These sign was observed along the 104°E from numbers of parallel transects. To confirm the presence of upwelling, satellite remote sensing data was used, and numerical model experiments were conducted. Cooler sea-surface temperature along the coast was observed from both in-situ and satellite data, while upward movement in the vertical profiles agreed with the location of upwelling from both in-situ and satellite data. Moreover, these data also show that the upwelled water band along the 104°E longitude stretch approximately 650 km long. Initially, southwesterly wind during this season is believed to be the important mechanism that contributed to this wind-induced Ekman upwelling. musica-gratis.softonic.it/ >musica gratis

  6. A physical view of La Guajira Upwelling System, Colombian Basin, Caribbean Sea

    Science.gov (United States)

    Bernal, G.; Beier, E.; Barton, E. D.; Ruiz-Ochoa, M.; Correa, J. G.

    2013-05-01

    La Guajira Peninsula lies within a large upwelling system along the South Caribbean Coast, created by the NE trade winds. In this location, sea surface temperature (SST) exhibits the lowest mean value and the highest variability in the whole Colombian Basin. The seasonal variation of SST explains up to 75 % of the total variability. La Guajira coastal zone also experiences the highest values of wind stress and wind stress curl, with the greatest annual and semiannual variability in the Colombian Basin. It has been shown that wind stress curl enhances the upwelling over the region. Near 90% of the variability of SST in La Guajira can be explained by the seasonality plus the first three EOFs interannual modes: the first, synchronous throughout the Basin, is dominant, and consists of a uniform interannual variation in phase with the North Tropical Atlantic Index; the second co-varies strongly with the second mode of wind stress curl; and the third reflects the role of the vertical atmospheric circulation cell associated with the Caribbean Low Level Jet off Central America. The inclusion of wind stress curl with its maximum offshore of La Guajira explains in part the extension of cool coastal water into the Colombian Basin, with advection in filaments, eddies and meanders. In order to complement the physical knowledge of La Guajira upwelling system, an analysis of water masses, sea surface height, Ekman suction, Ekman transport and coastal upwelling index (CUI) was performed. Hydrographic data was obtained from gridded climatologies from the National Oceanographic Data Center (WOD01); sea surface height anomalies from the Archiving, Validation, and Interpretation of Satellite Oceanography (AVISO) data; and wind data from the Cross-Calibrated Multi-Platform Ocean Surface Wind Velocity Product for Meteorological and Oceanographic Applications (CCMP). The upwelling forms a local water mass, La Guajira surface water (LGSW), with the mixing of subtropical underwater and

  7. Fostering Teaching Quality in Chilean Universities

    Science.gov (United States)

    Guzman Cruzat, Jose Antonio

    2013-01-01

    This study aims to explain the strategies that have been carried out by three Chilean universities in order to advance the quality of their teaching. The studied institutions are the Universidad de los Andes, the Universidad de Talca and the Universidad Catolica de Chile. In each of these three cases the analysis included, both the policies…

  8. The CHilean Automatic Supernova sEarch

    DEFF Research Database (Denmark)

    Hamuy, M.; Pignata, G.; Maza, J.;

    2012-01-01

    The CHilean Automatic Supernova sEarch (CHASE) project began in 2007 with the goal to discover young, nearby southern supernovae in order to (1) better understand the physics of exploding stars and their progenitors, and (2) refine the methods to derive extragalactic distances. During the first...

  9. Examining Text Environments in Elementary Chilean Classrooms

    Science.gov (United States)

    Orellana-Garcia, Pelusa; Sailors, Misty

    2016-01-01

    In this study, we examine the social practices related to literacy in classrooms in Chile in order to examine school-based literacy practices. We also examined the constraints and affordances literacy learning offered Chilean students. Through our case study and cross-case analysis, we discovered that although the classrooms contained an…

  10. Science of Tsunami Forecasting: 2010 Chilean Tsunami Challenge

    Science.gov (United States)

    Titov, Vasily; Bernard, Eddie; Tang, Rachel; Wei, Yong; Uslu, Burak; Eble, Marie

    2010-05-01

    Tsunami forecasting with real-time models and real-time data has always been one of the main goals of tsunami research. The February 27th, 2010 Chile tsunami provided the challenge and the opportunity to test the modern state of the science in tsunami forecasting. By contrast with the previous basin-wide tsunami generated by the third largest 2004 Sumatra earthquake, the fifth largest Chilean earthquake occurred at the time and in the area where a variety of real-time measurements and model forecast models have been available to assess the generated tsunami in real-time. The Chile tsunami was generated by a Mw 8.8 earthquake (35.846S, 72.719W ), at 06:34 UTC, 115 km (60 miles) NNE of Concepcion, Chile (according to the USGS). It has been recorded at coastal sea level gages around the Pacific Ocean, staring from the near-field record that caught the wave half an hour after generation at Valparaiso, to the coastal recordings of the wave arrived at Japan and Russian Far East almost a day later. In approximately 3 hours after the earthquake, the tsunami was first recorded at DART buoy 32412, providing real-time deep ocean signature of the propagating tsunami. All that measurements provided ample data for the real-time forecast analysis and for the model performance and forecast skills assessment throughout the Pacific basin. We present results of the performance of the NOAA forecast. The forecast method uses MOST model with the data assimilated from the earthquake and deep-ocean tsunami DART measurement. The comparison with tide gages and coastal impacts provide opportunity to assess the accuracy and efficiency of the forecast. The successes, lessons learned and future challengers for the tsunami forecast science are discussed.

  11. Behaviorally Mediated Larval Transport in Upwelling Systems

    OpenAIRE

    Morgan, Steven G.

    2014-01-01

    Highly advective upwelling systems along the western margins of continents are widely believed to transport larvae far offshore in surface currents resulting in larval wastage, limited recruitment, and increased population connectivity. However, suites of larval behaviors effectively mediate interspecific differences in the extent of cross-shelf migrations between nearshore adult habitats and offshore larval habitats. Interspecific differences in behavior determining whether larvae complete d...

  12. Biophysical interactions in the Cabo Frio upwelling system, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Sergio Augusto Coelho-Souza

    2012-09-01

    Full Text Available The rising of cold water from deeper levels characterizes coastal upwelling systems. This flow makes nutrients available in the euphotic layer, which enhances phytoplankton production and growth. On the Brazilian coast, upwelling is most intense in the Cabo Frio region (RJ. The basic knowledge of this system was reviewed in accordance with concepts of biophysical interactions. The high frequency and amplitude of the prevailing winds are the main factor promoting the rise of South Atlantic Central Water, but meanders and eddies in the Brazil Current as well as local topography and coast line are also important. Upwelling events are common during spring/summer seasons. Primary biomass is exported by virtue of the water circulation and is also controlled by rapid zooplankton predation. Small pelagic fish regulate plankton growth and in their turn are preyed on by predatory fish. Sardine furnishes an important regional fish stock. Shoreline irregularities define the embayment formation of the Marine Extractive Reserve of Arraial do Cabo making it an area with evident different intensities of upwelled water that harbors high species diversity. Consequently, on a small spatial scale there are environments with tropical and subtropical features, a point to be explored as a particularity of this ecosystem.Os sistemas costeiros de ressurgência são caracterizados pela ascensão de águas frias que tornam os nutrientes disponíveis na camada eufótica para o crescimento e aumento da produção fitoplanctônica. No Brasil, a região do Cabo Frio (RJ é o principal sistema de ressurgência costeira. O objetivo desse artigo foi revisar o atual conhecimento desse sistema através dos conceitos sobre interações biofísicas. A ascensão da Água Central do Atlântico Sul ocorre devido à alta frequência e amplitude dos ventos, à presença de meandros e vórtices na Corrente do Brasil, além da topografia local e da linha de costa. Os eventos de ressurg

  13. Fungal parasites infect marine diatoms in the upwelling ecosystem of the Humboldt current system off central Chile.

    Science.gov (United States)

    Gutiérrez, Marcelo H; Jara, Ana M; Pantoja, Silvio

    2016-05-01

    This is the first report of fungal parasitism of diatoms in a highly productive coastal upwelling ecosystem, based on a year-round time series of diatom and parasitic Chytridiomycota abundance in the Humboldt Current System off Chile (36°30.80'S-73°07.70'W). Our results show co-variation in the presence of Skeletonema, Thalassiosira and Chaetoceros diatoms with attached and detached chytrid sporangia. High abundance of attached sporangia was observed during the austral spring, coinciding with a predominance of Thalassiosira and Skeletonema under active upwelling conditions. Towards the end of austral spring, a decreasing proportion of attached sporangia was accompanied by a decline in abundance of Skeletonema and Thalassiosira and the predominance of Chaetoceros, suggesting specificity and host density dependence of chytrid infection. The new findings on fungal parasitism of diatoms provide further support for the inclusion of Fungi in the current model of the role played by the marine microbial community in the coastal ocean. We propose a conceptual model where Fungi contribute to controlling the dynamics of phytoplankton populations, as well as the release of organic matter and the transfer of organic carbon through the pelagic trophic web in coastal upwelling ecosystems. PMID:26914416

  14. Innovation Performance of Chilean SMEs: A Bivariate Probit Analysis

    OpenAIRE

    Rehman, Naqeeb Ur

    2016-01-01

    The purpose of this paper is to investigate the innovation activities of Chilean firms’ by using micro level data. Previous studies showed research gap related to micro level analysis of the Chilean SMEs. For the first time, multiple proxies have been used as dependent variables (product/process innovations and patent application/spending), which is neglected by the past studies. A micro level data has been obtained from the World Bank, Enterprise Survey on 696 Chilean SMEs. Bivariate probit...

  15. Observations of Gulf Stream-induced and wind-driven upwelling in the Georgia Bight using ocean color and infrared imagery

    Science.gov (United States)

    Mcclain, C. R.; Pietrafesa, L. J.; Yoder, J. A.

    1984-01-01

    Ocean color and infrared imagery from U2 aircraft and satellite sensors are used to study upwelling interaction between Gulf Stream and continental shelf waters in the Georgia Bight. The photographic data are combined with in situ measurements of currents, chlorophyll, temperature, salinity, coastal winds, and sea-level in observations of five different upwelling events including a near-short wind-driven upwelling caused by topographic effects, three filament-induced upwellings in the Gulf Stream, and a possible meander-induced upwelling event in the Gulf Stream. Chlorophyll distributions are used to trace the circulation and propagation of filaments along the advective routes by which the water moves offshore. Photographic and mooring array measurements of temperature time series are found to provide nearly identical results for the phase speeds of each event. Field measurements of surface pigments, and Nimbus/7 coastal zone color scanner (CZCS) estimates are found to agree well over the range of concentrations 0.1 to 0.7 mg/m to the third. Examples of U2/Ocean Color Scanner and Nimbus 7 CZCS photographs are provided.

  16. Ocean-Atmosphere-Land interactions and their consequences on the biogeochemical variability in Eastern Boundary Upwelling System

    Science.gov (United States)

    Renault, L.; McWilliams, J. C.; Deutsch, C.; Molemaker, M. J.

    2015-12-01

    Coastal winds and upwelling of deep water along Eastern Boundary Upwelling System (EBUS) yield some of the ocean's most productive ecosystems, but the effect of coastal wind shape and ocean-atmosphere interactions on regional Net Primary Production (NPP) is not well known. Here, we first show how the spatial and temporal variability of nearshore winds in EBUS is affected by orography, coastline shape, and air-sea interaction. Using regional atmospheric simulations over the US West Coast, we determine monthly characteristics of the wind drop-off, and show that when the mountain orography is combined with the coastline shape of a cape, it has the biggest influence on wind drop-off. Then, using a realistic ocean model of the California Current System, we show that the slackening of the winds near the coast has little effect on near-shore phytoplankton productivity, despite a large reduction in upwelling velocity. On a regional scale, the wind drop-off leads to a substantially higher NPP, especially when it occurs over a broad swath, even when the total upwelling rate remains the same. This partial decoupling of NPP from upwelling is effected by alongshore currents and the eddies they generate. When peak winds extend all the way to the coast, alongshore current shear is stronger, and a more energetic eddy field subducts nutrients offshore and out of the photic zone, reducing overall productivity. This causal sequence is supported by satellite remote sensing. Finally, using a interanual coupled simulation over the US West Coast, we show the ocean-atmosphere interactions can also reduce the eddy activity by pumping energy out from the eddies, reducing their amplitude and rotation speed, and leading to more realistic eddies characteristics. This may also reduce the eddy quenching and therefore increase the NPP. This complex ocean-atmosphere-land interactions imply that simple wind indices are incomplete predictors of productivity in EBUS.

  17. Constructing Realities: Bullying Usages in Chilean Discourses

    Directory of Open Access Journals (Sweden)

    Rodrigo Bassaletti-Contreras

    2013-07-01

    Full Text Available The article reports an exploratory research on the uses given in Chile to the Anglicism bullying. In order to do so, its evolution is reviewed from the early studies in the Nordic countries, to the treatment of the topic in the Chilean context. The focus of this work is based on socioconstructionism and in turn promotes the consideration of the characteristics of the socio-cultural and historical context of knowledge production with a postcolonial intention. To review the constructions on the subject, we selected Chilean videos at the YouTube virtual platform, using as methodology discourse analysis and dense description. In results can be observed two meanings of bullying: (i to refer to any kind of aggression and (ii as a homologous of abuse among schoolchildren. In response, it is realized the discrepancy with the proposed definitions from general academia and those used in the local environment in investigations, interventions, public policy and mass media in Chile.

  18. Organizational and territorial cultures in Chilean journalism

    OpenAIRE

    Claudia Mellado; Claudia Lagos

    2011-01-01

    On the basis of survey responses of 570 journalists from 114 newspapers, radio, newswires, television, and internet news organizations, this paper describes the role conceptions, epistemological underpinning, and ethical values of the Chilean news media workers, comparing the differences that exist among media types and between the capital and the rest of the country. The findings show territorial cultures of journalism, with differences between the capital and provincial regions, mostly clas...

  19. Memorial 1997 - ENDESA (Chilean Electricity Company)

    International Nuclear Information System (INIS)

    This report provides a comprehensive survey, in depth assessment of the activities overview of ENDESA, Chilean Electricity Company, highlighting economical information and including historical and technical aspects. Economics is its focal point, but other relevant data are shown, like technical data on hydroelectric and thermoelectric power plants. Main activities developed by ENDESA are described, such in Chile as in the foreign. Data on power generation, transmission and transport are also presented and an economical balance of each colligated company are done and analysed

  20. Monsoonal variability in abiotic parameters in coastal waters off Trivandrum evokes press and pulse response in biotic variables

    Digital Repository Service at National Institute of Oceanography (India)

    Subina, N.S.; Bhosle, S.; Nair, S.; Lokabharathi, P.A.

    Trivandrum Coast experiences coastal upwelling during south west monsoon, which is accompanied by abiotic changes in physio-chemical parameters. The resultant biotic responses could range from an instantaneous pulse to a sustained press reaction...

  1. A BVAR Forecasting Model for the Chilean Economy A BVAR Forecasting Model for the Chilean Economy

    Directory of Open Access Journals (Sweden)

    Felipe Morandé

    1988-03-01

    Full Text Available A BVAR Forecasting Model for the Chilean Economy Doan, Litterman, and Sims have described a method for estimaling Bayesian vector autoregressive (BVAR forecasting models. The method has been successfully applied to the U.S. macroeconomic dataset, which is relatively long and stable. Despite the brevity and volatily of the post-1976 Chilean macroeconomic dataset, this paper shows that a straightforward application of the DLS method to this datasef, with simple modification to allow for delays in the release of data, also appears to satisfy at least one criterion of relative forecasting accuracy suggested by Doan, Litterman, and Sims. However, the forecast errors of the Chilean BVARs are stil large in absolute term. Also, the model's coefficients change sharply in periods marked by policy shifts, such as the floating of the peso in 1982.

  2. Methane production induced by dimethylsulfide in surface water of an upwelling ecosystem

    Science.gov (United States)

    Florez-Leiva, Lennin; Damm, Ellen; Farías, Laura

    2013-05-01

    Coastal upwelling ecosystems are areas of high productivity and strong outgassing, where most gases, such as N2O and CH4, are produced in subsurface waters by anaerobic metabolisms. We describe seasonal CH4 variation as well as potential mechanisms producing CH4 in surface waters of the central Chile upwelling ecosystem (36°S). Surface waters were always supersaturated in CH4 (from 125% up to 550%), showing a clear seasonal signal triggered by wind driven upwelling processes (austral spring-summer period), that matched with the periods of high chlorophyll-a and dimethylsulfoniopropionate (DMSP) levels. Methane cycling experiments, with/without the addition of dimethylsulfide (including 13C-DMS) and acetylene (a nonspecific inhibitor of CH4 oxidation) along with monthly measurements of CH4, DMSP and other oceanographic variables revealed that DMS can be a CH4 precursor. Net CH4 cycling rates (control) fluctuated between -0.64 and 1.44 nmol L-1 d-1. After the addition of acetylene, CH4 cycling rates almost duplicated relative to the control, suggesting a strong methanotrophic activity. With a spike of DMS, the net CH4 cycling rate significantly increased relative to the acetylene and control treatment. Additionally, the δ13C values of CH4 at the end of the incubations (after addition of 13C enriched-DMS) were changed, reaching -32‰ PDB compared to natural values between -44‰ and -46‰ PDB. These findings indicate that, in spite of the strong CH4 consumption by methanotrophs, this upwelling area is an important source of CH4 to the atmosphere. The effluxes are derived partially from in situ surface production and seem to be related to DMSP/DMS metabolism.

  3. Spatio-temporal variation of microphytoplankton in the upwelling system of the south-eastern Arabian Sea during the summer monsoon of 2009

    Directory of Open Access Journals (Sweden)

    Lathika Cicily Thomas

    2013-02-01

    Full Text Available The phytoplankton standing crop was assessed in detail along the South Eastern Arabian Sea (SEAS during the different phases of coastal upwelling in 2009. During phase 1 intense upwelling was observed along the southern transects(8°N and 8.5°N. The maximum chlorophyll a concentration (22.7 mg m-3 was observedin the coastal waters off Thiruvananthapuram (8.5°N. Further north there was no signature of upwelling, with extensive Trichodesmium erythraeum blooms. Diatoms dominated in these upwelling regions with thecentric diatom Chaetoceros curvisetus being the dominant species along the 8°N transect. Along the 8.5°N transect pennate diatoms like Nitzschia seriata and Pseudo-nitzschia sp. dominated. Duringphase 2, upwelling of varying intensity was observed throughout the study area with maximum chlorophyll a concentrations along the 9°N transect (25 mg m-3 with Chaetoceros curvisetus as the dominantphytoplankton. Along the 8.5°N transect pennate diatoms during phase 1 were replaced by centric diatoms like Chaetoceros sp. The presence of solitary pennate diatoms Amphora sp. and Navicula sp.were significant in the waters off Kochi. Upwelling was waning during phase 3 and was confined to the coastal waters of the southern transects with the highest chlorophyll a concentration of 11.2 mg m-3. Along withdiatoms, dinoflagellate cell densities increased in phases 2 and 3. In the northern transects (9°N and 10°N the proportion of dinoflagellates was comparatively higher and was represented mainly by Protoperidinium spp.

  4. Relation between Upwelling Intensity and the Variability of Physical and Chemical Parameters in the Southern Benguela Upwelling System

    OpenAIRE

    Hassan Ebrahiem Ismail; Johannes Jacobus Agenbag; Stephanie de Villiers; Bhekumusa Jabulani Ximba

    2015-01-01

    The extent to which wind-driven seasonal upwelling cycles manifest in surface ocean temperature and nutrient variability along a monitoring line in the Southern Benguela upwelling system was investigated. Monitoring conducted monthly over a six-year period shows that surface temperature and nutrient concentrations exhibit very poor seasonality and weak correlation with the upwelling index. This is, despite clear evidence for spatial inshore-offshore gradients in temperature, nutrients, and ch...

  5. Spatio-Temporal Variation in Effects of Upwelling on the Fatty Acid Composition of Benthic Filter Feeders in the Southern Benguela Ecosystem: Not All Upwelling Is Equal.

    Science.gov (United States)

    Puccinelli, Eleonora; McQuaid, Christopher David; Noyon, Margaux

    2016-01-01

    Variability in mesoscale nearshore oceanographic conditions plays an important role in the distribution of primary production and food availability for intertidal consumers. Advection of nutrient rich waters by upwelling usually allows the proliferation of diatoms, later replaced by dinoflagellates. We examined upwelling effects on the fatty acid (FA) signature of a benthic intertidal filter feeder to identify its response to pulsed variability in food availability. The study took place in two contrasting seasons and at two upwelling and two non-upwelling sites interspersed within the southern Benguela upwelling system of South Africa. We investigated the FA composition of the adductor muscles and gonads of the mussel Mytilus galloprovincialis to assess how FA are apportioned to the different tissues and whether this changes between upwelling and non-upwelling conditions. In situ temperature loggers used to identify upwelling conditions at the four sites indicated that such events occurred only at the upwelling centres and only in summer. Tissues differed strongly, with gonads presenting a higher proportion of essential FAs. This could reflect the faster turnover rate of gonad tissue or preferential retention of specific FA for reproductive purposes. FA composition did not vary as a direct function of upwelling, but there were strong dissimilarities among sites. Upwelling influenced mussel diets at one upwelling site while at the other, the expected signature of upwelling was displaced downstream of the core of upwelling. Condition Index (CI) and Gonad Index (GI) differed among sites and were not influenced by upwelling, with GI being comparable among sites. In addition, FA proportions were consistent among sites, indicating similar food quality and quantity over time and under upwelling and non-upwelling conditions. This suggests that the influence of upwelling on the west coast of South Africa is pervasive and diffuse, rather than discrete; while nearshore

  6. Spatio-Temporal Variation in Effects of Upwelling on the Fatty Acid Composition of Benthic Filter Feeders in the Southern Benguela Ecosystem: Not All Upwelling Is Equal

    Science.gov (United States)

    McQuaid, Christopher David; Noyon, Margaux

    2016-01-01

    Variability in mesoscale nearshore oceanographic conditions plays an important role in the distribution of primary production and food availability for intertidal consumers. Advection of nutrient rich waters by upwelling usually allows the proliferation of diatoms, later replaced by dinoflagellates. We examined upwelling effects on the fatty acid (FA) signature of a benthic intertidal filter feeder to identify its response to pulsed variability in food availability. The study took place in two contrasting seasons and at two upwelling and two non-upwelling sites interspersed within the southern Benguela upwelling system of South Africa. We investigated the FA composition of the adductor muscles and gonads of the mussel Mytilus galloprovincialis to assess how FA are apportioned to the different tissues and whether this changes between upwelling and non-upwelling conditions. In situ temperature loggers used to identify upwelling conditions at the four sites indicated that such events occurred only at the upwelling centres and only in summer. Tissues differed strongly, with gonads presenting a higher proportion of essential FAs. This could reflect the faster turnover rate of gonad tissue or preferential retention of specific FA for reproductive purposes. FA composition did not vary as a direct function of upwelling, but there were strong dissimilarities among sites. Upwelling influenced mussel diets at one upwelling site while at the other, the expected signature of upwelling was displaced downstream of the core of upwelling. Condition Index (CI) and Gonad Index (GI) differed among sites and were not influenced by upwelling, with GI being comparable among sites. In addition, FA proportions were consistent among sites, indicating similar food quality and quantity over time and under upwelling and non-upwelling conditions. This suggests that the influence of upwelling on the west coast of South Africa is pervasive and diffuse, rather than discrete; while nearshore

  7. Some Thoughts on the Evaluation of the Chilean Voucher System

    Science.gov (United States)

    Sapelli, Claudio

    2010-01-01

    Many papers describe the Chilean voucher system as the "textbook" voucher case. But this is mistaken and has prevented research to undertake the key question of how the particular design of the Chilean voucher system determines the results obtained in Chile. This also prevents discussion of how a voucher system with a different design could lead…

  8. Evidence of Upwelling along Peninsular Malaysia during Southwest Monsoon

    DEFF Research Database (Denmark)

    Daryabor, Farshid

    2015-01-01

    Upwelling off the east coast of Peninsular Malaysia (PM) was detected from recent cruise data collected during the southwest monsoon. Thermocline lifting was observed at 104˚E from a number of parallel transects. To confirm the presence of upwelling, satellite remote sensing data were used...

  9. Isotopic and enzymatic analyses of planktonic nitrogen utilisation in the vicinity of Cape Sines (Portugal) during weak upwelling activity

    Science.gov (United States)

    Slawyk, Gerd; Coste, Bernard; Collos, Yves; Rodier, Martine

    1997-01-01

    Using measurements of 15N uptake and activities of nitrate reductase and glutamine synthetase, the utilization of nitrogenous nutrients by microplankton in the Portuguese upwelling area was investigated. During this cruise the euphotic zone of coastal waters was in most cases bisected by a nitracline forming two layers. Total inorganic nitrogen uptake rates (NH 4+ + NO 3-) in the upper mixed and nitrate-impoverished layer ranged from 0.1 to 0.8 nM h -1 and were primarily supported by regenerated (ammonium) nitrogen (62-97%), whereas they varied between 0.9 and 10.4 nM h -1 in the deep nitrate-rich layer and were mainly driven by new (nitrate) nitrogen (52-82%). Depth profiles of Chl a-specific uptake rates for ammonium and nitrate paralleled those of absolute uptake rates, i.e. values of VNH 4+Chl were highest (up to 16.1 nmol μg -1 h -1) in nitrate-poor surface waters while values of VNO 3-Chl were maximum (up to 8.4 nmol μg -1 h -1)within the nitracline. This latter vertical ordering of planktonic nitrogen nutrition was consistent with an aged upwelling situation. However, applying several indices of cell metabolism and nutritional status, such as 15N uptake/enzyme activity, surge uptake internally controlled uptake, and V maxChl/K t ratios, we were able to demonstrate that the phytoplankton assemblages inhabiting the nutrient-impoverished upper layer still bore the signature of physically mediated nitrogen (nitrate) supply generated by active upwelling that had occurred during the week before our visit to the area. This signature was the most evident in samples from the station furthest inshore and faded with distance from shore as a result of the deepening of the nitrate isopleths (weakening of upwelling activity), which showed the same offshore trend. The appearance of nitrate-rich waters at the surface, after a strong pulse of upwelling favourable winds just before the end of the cruise, led to a five-fold increase in average (over the euphotic zone

  10. Coastal Morphology and Coastal Protection

    OpenAIRE

    de Graaff, J

    2009-01-01

    Lecture notes ct5309. Tides, currents and water; coastal problems; sediment transport processes; coastal transport modes; longshore transport; cross-shore transport; fundamentals of mud; channels and trenches; coastal protection; application of structures; application of nourishments.

  11. Are Chileans exposed to dietary furan?

    Science.gov (United States)

    Mariotti, María S; Toledo, Carla; Hevia, Karen; Gomez, J Pablo; Fromberg, Arvid; Granby, Kit; Rosowski, Jaime; Castillo, Oscar; Pedreschi, Franco

    2013-01-01

    Chilean consumer preferences include foods that may contain considerable amounts of furan, a potential human carcinogen. However, there is no information regarding dietary exposure to furan in Chile. Thus, the objective of this work was to determine the Chilean exposure to dietary furan. To accomplish this objective, the furan concentration of 14 types of commercial foods processed at high temperature were analysed based on a modified headspace-GC/MS (HS-GC/MS) method in which the limits of detection for different food matrices ranged from 0.01 to 0.6 ng g(-1). In addition, a risk assessment was made with exposure estimates based on dietary data from national studies on different age groups (9-month-old babies, school children, adults and elderly people). Of the food items surveyed "American"-type coffee (espresso coffee plus hot water) obtained from automatic coffee machine (936 ng g(-1)) and low moisture starchy products like crisps and "soda"-type crackers showed the highest furan concentrations (259 and 91 ng g(-1), respectively). Furthermore, furan was also found in samples of breakfast cereals (approximately 20 ng g(-1)), jarred fruit baby foods (8.5 ng g(-1)) and orange juice (7.0 ng g(-1)). School children (aged 9-13 years) represented the highest intake of furan (about 500 ng kg(-1)(bw) day(-1)), with margins of exposure of 2479 and 2411, respectively, which points to a possible public health risk. PMID:23875686

  12. A Management Tool for Assessing Aquaculture Environmental Impacts in Chilean Patagonian Fjords: Integrating Hydrodynamic and Pellets Dispersion Models

    Science.gov (United States)

    Tironi, Antonio; Marin, Víctor H.; Campuzano, Francisco J.

    2010-05-01

    This article introduces a management tool for salmon farming, with a scope in the local sustainability of salmon aquaculture of the Aysen Fjord, Chilean Patagonia. Based on Integrated Coastal Zone Management (ICZM) principles, the tool combines a large 3-level nested hydrodynamic model, a particle tracking module and a GIS application into an assessment tool for particulate waste dispersal of salmon farming activities. The model offers an open source alternative to particulate waste modeling and evaluation, contributing with valuable information for local decision makers in the process of locating new facilities and monitoring stations.

  13. Upwelling Index, 60N 149W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  14. Upwelling Index, 51N 131W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  15. Upwelling Index, 21N 107W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  16. Upwelling Index, 42N 125W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  17. Upwelling Index, 30N 119W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  18. Upwelling Index, 36N 122W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  19. Upwelling Index, 27N 116W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  20. Upwelling Index, 57N 137W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  1. Upwelling Index, 54N 134W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  2. Upwelling Index, 48N 125W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  3. Upwelling Index, 39N 125W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  4. Upwelling Index, 24N 113W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  5. Upwelling Index, 33N 119W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  6. Upwelling Index, 45N 125W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  7. Upwelling Index, 60N 146W, 6-hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Upwelling index computed from 1-degree FNMOC sea level pressure for 15 locations off the North American West Coast at each 3 degrees of latitude from 21N to 60N....

  8. Pliocene Warm Period Upwelling in the Southern Benguela Region

    Science.gov (United States)

    Petrick, B. F.; McClymont, E.; Felder, S.; Leng, M. J.; Rosell Mele, A.; Rueda, G.

    2014-12-01

    The mid-Pliocene has been proposed as a possible analogue for understanding future climate change and testing climate models. Previous work has shown that during the Pliocene the major upwelling systems were relatively warm, and thus either inactive, contracted, or upwelling warmer waters than present. Here we examine evidence from a core site located on the margins of the modern Benguela upwelling system, to test whether the upwelling cells had migrated or contracted relative to present during the Pliocene. We applied several organic geochemistry proxies and foraminiferal analyses to reconstruct the Pliocene history of ODP site 1087 (31º28'S, 15º19'E, 1374m water depth), including the UK37' index and TEX86 index (for reconstructing sea surface temperatures), chlorins (for estimating primary productivity) and planktonic foraminifera assemblages (for inferring water mass changes). These proxies show that between 3.5 and 3.0 Ma the southern Benguela region was significantly cooler than the northern Benguela region, the latter where the main upwelling cells are found today. Coupled with higher primary production, a shift in planktonic foraminifera assemblage, and an offset between the UK37' index and TEX86 index, we infer that more extensive upwelling was present in the southern Benguela region during the Pliocene. We infer that the main Benguela upwelling cells had shifted southward relative to today, as a result of changes in the local wind field. We find evidence for pronounced cooling and a shift in the planktonic foraminifera assemblage during the M2 and KM2 glacial stages, showing a sensitivity of Benguela upwelling to these short-lived climate events.

  9. The relationship between Arabian Sea upwelling and Indian monsoon revisited

    OpenAIRE

    Yi, X; B. Hünicke; N. Tim; E. Zorita

    2015-01-01

    Studies based on upwelling indices (sediment records, sea-surface temperature and wind) suggest that upwelling along the western coast of Arabian Sea is strongly affected by the Indian summer monsoon (ISM). In order to examine this relationship directly, we employ the vertical water mass transport produced by the eddy-resolving global ocean simulation STORM driven by meteorological reanalysis over the last 61 years. With its very high spatial resolution (10 ...

  10. Simplicity of the Tax Systems: The Chilean Case. (in Spanish)

    OpenAIRE

    Barra, Patricio

    2006-01-01

    The objective of this paper is to evaluate the concept of the simplicity in a tax system. The analysis approaches the different scopes in which the tax simplicity is observed. For this purpose, the main aspects of the Chilean tax system are analyzed, by using indicators that try to define the concept in a quantitative frame. The analysis of the Chilean case is used to infer some implications that could also be valid in other Latin American tax systems.

  11. Nutrition education in Chilean primary schools.

    Science.gov (United States)

    Olivares, Sonia; Zacarías, Isabel; Andrade, Margarita; Kain, Juliana; Lera, Lydia; Vio, Fernando; Morón, Cecilio

    2005-06-01

    The purpose of this study was to incorporate nutrition education in Chilean primary schools. The baseline information included nutritional status, food consumption and physical activity of 1701 children from 3rd to 7th grade in ten urban and rural schools. Main results showed a high prevalence of obesity (15.4%) and overweight (19.6%), low consumption of vegetables, fruits, and dairy products, high intake of snacks and a low level of physical activity, especially in girls. Because the Ministry of Education does not allow the incorporation of new programs into the curriculum, the educational strategy was based on the development of a text book, a teacher's guide, five practical guides for students from third to eighth grade and a CD-Rom. These materials were validated by 36 teachers in six schools through an educational intervention. Teachers and students considered the educational materials useful, motivational and easy to understand. This program is being implemented in 57 schools.

  12. Outside the paradigm of upwelling rias in NW Iberian Peninsula: Biogeochemical and phytoplankton patterns of a non-upwelling ria

    OpenAIRE

    Ospina-Álvarez, Natalia; Varela, Manuel; Doval, M. Dolores; Gómez-Gesteira, M.; Cervantes-Duarte, Rafael; Prego, R

    2014-01-01

    The Atlantic Galician rias show the effect of natural eutrophication during ENACW upwelling episodes when large amounts of nutrients are injected. However, the Cantabrian Galician rias do not appear to be disturbed by upwelling events and it can be hypothesized that eutrophy is not inherent to the Galician rias. This question was tackled regarding the biogeochemical and phytoplankton characteristic in the Ria of Barqueiro, located on the western boundary of the Cantabrian Sea, from January 20...

  13. Wind influence on a coastal buoyant outflow

    Science.gov (United States)

    Whitney, Michael M.; Garvine, Richard W.

    2005-03-01

    This paper investigates the interplay between river discharge and winds in forcing coastal buoyant outflows. During light winds a plume influenced by the Earth's rotation will flow down shelf (in the direction of Kelvin wave propagation) as a slender buoyancy-driven coastal current. Downwelling favorable winds augment this down-shelf flow, narrow the plume, and mix the water column. Upwelling favorable winds drive currents that counter the buoyancy-driven flow, spread plume waters offshore, and rapidly mix buoyant waters. Two criteria are developed to assess the wind influence on a buoyant outflow. The wind strength index (Ws) determines whether a plume's along-shelf flow is in a wind-driven or buoyancy-driven state. Ws is the ratio of the wind-driven and buoyancy-driven along-shelf velocities. Wind influence on across-shelf plume structure is rated with a timescale (ttilt) for the isopycnal tilting caused by wind-driven Ekman circulation. These criteria are used to characterize wind influence on the Delaware Coastal Current and can be applied to other coastal buoyant outflows. The Delaware buoyant outflow is simulated for springtime high-river discharge conditions. Simulation results and Ws values reveal that the coastal current is buoyancy-driven most of the time (∣Ws∣ 1) several times during the high-discharge period. Strong upwelling events reverse the buoyant outflow; they constitute an important mechanism for transporting fresh water up shelf. Across-shelf plume structure is more sensitive to wind influence than the along-shelf flow. Values of ttilt indicate that moderate or strong winds persisting throughout a day can modify plume width significantly. Plume widening during upwelling events is accompanied by mixing that can erase the buoyant outflow.

  14. Are large macroalgal blooms necessarily bad? Nutrient impacts on seagrass in upwelling-influenced estuaries.

    Science.gov (United States)

    Hessing-Lewis, Margot L; Hacker, Sally D; Menge, Bruce A; McConville, Sea-oh; Henderson, Jeremy

    2015-07-01

    Knowledge of nutrient pathways and their resulting ecological interactions can alleviate numerous environmental problems associated with nutrient increases in both natural and managed systems. Although not unique, coastal systems are particularly prone to complex ecological interactions resulting from nutrient inputs from both the land and sea. Nutrient inputs to coastal systems often spur ulvoid macroalgal blooms, with negative consequences for seagrasses, primarily through shading, as well as through changes in local biogeochemistry. We conducted complementary field and mesocosm experiments in an upwelling-influenced estuary, where marine-derived nutrients dominate, to understand the direct and indirect effects of nutrients on the macroalgal-eelgrass (Zostera marina L.) interaction. In the field experiment, we found weak evidence that nutrients and/or macroalgal treatments had a negative effect on eelgrass. However, in the mesocosm experiment, we found that a combination of nutrient and macroalgal treatments led to strongly negative eelgrass responses, primarily via indirect effects associated with macroalgal additions. Together, increased total light attenuation and decreased sediment oxygen levels were associated with larger effects on eelgrass than shading alone, which was evaluated using mimic algae treatments that did not alter sediment redox potential. Nutrient addition in the mesocosms directly affected seagrass density; biomass, and morphology, but not as strongly as macroalgae. We hypothesize that the contrary results from these parallel experiments are a consequence of differences in the hydrodynamics between field and mesocosm settings. We suggest that the high rates of water movement and tidal submersion of our intertidal field experiments alleviated the light reduction and negative biogeochemical changes in the sediment associated with macroalgal canopies, as well as the nutrient effects observed in the mesocosm experiments. Furthermore, adaptation

  15. Methane in coastal and offshore waters of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Jayakumar, D.A.; Naqvi, S.W.A.; Narvekar, P.V.; George, M.D.

    capped Ž. by a thin 5–10 m lens of fresher water which originates in part from local precipitation and in part from runoff from the narrow coastal plain that re- ceives heavy SWM rainfall. The combination of upwelling and precipitation plus land runoff... to the develop- ment of suboxic conditions at shallow depths off the central and southwest coasts of India. Maximal CH 4 concentrations are frequently seen either at the sur- face, associated with the low salinity water mass which caps the upwelled water...

  16. Coastal Engineering

    NARCIS (Netherlands)

    Van der Velden, E.T.J.M.

    1989-01-01

    Introduction, waves, sediment transport, littoral transport, lonshore sediment transport, onshore-offshore sediment transport, coastal changes, dune erosion and storm surges, sedimentation in channels and trenches, coastal engineering in practice.

  17. Minimun Pension Insurance in the Chilean Pension System Minimun Pension Insurance in the Chilean Pension System

    Directory of Open Access Journals (Sweden)

    Salvador Zurita

    1994-03-01

    Full Text Available One of the "social" features of the Chilean individual capitalization pension system is the minimum pension scheme. which guarantees its members a minimum pension irrespective of the funds they accumulate, with the only requirement of twenty years of social security tax payments. The purpose of this paper is to estimate the implicit fiscal subsidy, using an option-based approach. We capture the risk associated to the returns on the pension fund account of a worker by modeling its value as a diffusion process and show the correspondence between the minimum pension insurance and a financial put option. Our results are the present value of the minimum pension benefit, equivalent to 3 percent of Chilean GDP for current active and non-active affiliated workers. These estimates are notoriously higher than previous results based on deterministic models, and strongly suggest the importance of explicitly considering the risk associated to pension assets when estimating the cost to the government of the insurance implied by the minimum pension benefit. One of the "social" features of the Chilean individual capitalization pension system is the minimum pension scheme. which guarantees its members a minimum pension irrespective of the funds they accumulate, with the only requirement of twenty years of social security tax payments. The purpose of this paper is to estimate the implicit fiscal subsidy, using an option-based approach. We capture the risk associated to the returns on the pension fund account of a worker by modeling its value as a diffusion process and show the correspondence between the minimum pension insurance and a financial put option. Our results are the present value of the minimum pension benefit, equivalent to 3 percent of Chilean GDP for current active and non-active affiliated workers. These estimates are notoriously higher than previous results based on deterministic models, and strongly suggest the importance of explicitly considering

  18. Physical trajectory profile data from glider ru22 deployed by Rutgers, the State University of New Jersey in the Coastal Waters of California from 2014-08-04 to 2014-08-22 (NCEI Accession 0138014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project is a comprehensive observational and analytical program to examine the dynamics and source waters of the relaxation flows in a coastal upwelling system...

  19. Physical trajectory profile data from glider ru22 deployed by Rutgers, the State University of New Jersey in the Coastal Waters of California from 2014-08-25 to 2014-09-23 (NCEI Accession 0138015)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The project is a comprehensive observational and analytical program to examine the dynamics and source waters of the relaxation flows in a coastal upwelling system...

  20. Zooplankton diel vertical migration and influence of upwelling on the biomass in the Chukchi Sea during summer

    Institute of Scientific and Technical Information of China (English)

    WANG Huiwu; CHEN Hongxia; XUE Liang; LIU Na; LIU Yanliang

    2015-01-01

    The diel vertical migration (DVM) of zooplankton and the influence of upwelling on zooplankton biomass were examined using water column data of current velocity and mean volume backscattering strength (MVBS) collected by moored acoustic Doppler current profilers (ADCPs) deployed in the southeastern Chukchi Sea during the 5th Chinese National Arctic Research Expedition (CHINARE) in summer 2012, combined with the satellite observational data such as sea surface temperature (SST), wind, and chlorophylla (Chla). Hourly acoustic data were continuously collected for 49-d in the mooring site. Spectral analysis indicated that there were different migrating patterns of zooplankton, even though precisely classifying the zooplankton taxa was not available. The prevailing 24-h cycle corresponded to the normal DVM with zooplankton swimming upwards at sunrise and returning to deep waters at sunset. There was a clear DVM in the upper 17 m of the water column during the period with distinct day-night cycles, and no active DVM throughout the water column when the sun above the horizon (polar day), suggesting that light intensity was the trigger for DVM. Also there was a second migrating pattern with 12-h cycle. The upwelling event occurring in the northwest of Alaskan coastal area had important influence on zooplankton biomass at the mooring site. During the upwelling, the SST close to the mooring site dropped significantly from maximal 6.35℃ to minimal 1.31℃ within five days. Simultaneously, there was a rapid increase in the MVBS and Chla level, suggesting the aggregation of zooplankton related to upwelling.

  1. Non-limiting food conditions for growth and production of the copepod community in a highly productive upwelling zone

    Science.gov (United States)

    Escribano, Rubén; Bustos-Ríos, Evelyn; Hidalgo, Pamela; Morales, Carmen E.

    2016-09-01

    Zooplankton production is critical for understanding marine ecosystem dynamics. This work estimates copepod growth and production in the coastal upwelling and coastal transition zones off central-southern Chile (~35 to 37°S) during a 3-year time series (2004, 2005, and 2006) at a fixed shelf station, and from spring-summer spatial surveys during the same period. To estimate copepod production (CP), we used species-biomasses and associated C-specific growth rates from temperature dependent equations (food-saturated) for the dominant species, which we assumed were maximal growth rates (gmax). Using chlorophyll-a concentrations as a proxy for food conditions, we determined a size-dependent half-saturation constant with the Michaelis-Menten equation to derive growth rates (g) under the effect of food limitation. These food-dependent C-specific growth rates were much lower (food resources.

  2. Independence and regulatory effectiveness: The Chilean experience

    International Nuclear Information System (INIS)

    International binding documents state that Member States should provide an effectively independent Regulatory Body. There are no recommendations on how independent a Regulatory Body must be. As a result, many different regulatory structures are found worldwide. Economical development status of Member States can be easily correlated to their regulatory organizations; nuclear power programs are also decisory. Along the last fifty years, regulatory activities in Chile have gone through several changes: before 1974 radioactive facilities were controlled by the Ministry of Health. A Supreme Decree issued on June 1974, approved the 'Regulations on Licensing (of radioactive facilities)', conferring this faculty to the Chilean Nuclear Energy Commission. The CNEC had, de facto, the same faculties regarding nuclear facilities. The Nuclear Safety Law, published in 1984 stated that the Chilean Nuclear Energy Commission (CNEC) was the competent authority regarding nuclear facilities, while Regional Health Services belonging to the Ministry of Health, were competent over all radioactive facilities. In 1987 the Law No. 18.730 amended the Nuclear Safety Law, transferring the competence over 1st category radioactive facilities and associated matters to the CNEC. In 2004 the Ministry of Health went under a great reorganization: the Law No. 19.937 defined new competent authorities, providing an effective independence of the regulatory functions. In 2001, the Board of Directors of the CNEC delegated the faculty of granting authorizations to the Head of the Nuclear and Radiological Safety Department. In 2005, the Board also delegated the faculties of proposing regulations and standards and prosecuting regulation violators on the person of the Head of the Nuclear and Radiological Safety Department. Both, the Ministry of Health and the CNEC, have given decisory steps towards fulfilling the principle of regulatory independence: the first one by separating functions at the level of

  3. Why productive upwelling areas are often sources rather than sinks of CO2? – a comparative study on eddy upwellings in the South China Sea

    Directory of Open Access Journals (Sweden)

    N. Jiao

    2013-08-01

    Full Text Available Marine upwelling regions are known to be productive in carbon fixation and thus thought to be sinks of CO2, whereas many upwelling areas in the ocean are actually sources rather than sinks of CO2. To address this paradox, multiple biogeochemical parameters were investigated at two cyclonic-eddy-induced upwelling sites CE1 and CE2 in the western South China Sea. The results showed that upwelling can exert significant influences on biological activities in the euphotic zone and can either increase or decrease particulate organic carbon (POC export flux depending on upwelling conditions such as the magnitude, timing, and duration of nutrient input and consequent microbial activities. At CE2 the increase of phytoplankton biomass caused by the upwelled nutrients resulted in increase of POC export flux compared to non-eddy reference sites, while at CE1 the microbial respiration of organic carbon stimulated by the upwelled nutrients significantly contributed to the attenuation of POC export flux, aggravating outgassing of CO2. These results suggest that on top of upwelled dissolved inorganic carbon release, microbial activities stimulated by upwelled nutrients and phytoplankton labile organic carbon can play a critical role for a marine upwelling area to be a source rather than a sink of CO2. Meanwhile, we point out that even though an upwelling region is outgassing, carbon sequestration still takes place through the POC-based biological pump as well as the refractory dissolved organic carbon (RDOC-based microbial carbon pump.

  4. Modelling Upwelling Irradiance using Secchi disk depth in lake ecosystems

    Directory of Open Access Journals (Sweden)

    Claudio ROSSI

    2009-02-01

    Full Text Available A simple model for upwelling irradiance has been developed. The model represents the relationship between Photosynthetically Active Radiation diffuse attenuation coefficients and Secchi disk depth described with a physical-mathematical expression. This physical mathematical expression allows the evaluation of the sub surface upwelling irradiance that was generated by the interaction between downwelling irradiance and the water column. The validation of the relation was performed using experimental data collected from five different aquatic ecosystems at different latitudes, solar elevations and irradiance levels. We found a good linear, positive correlation between the theoretical and measured upwelling irradiance (R2 = 0.96. The residues were well distributed, around the null value, according a Gaussian curve (R2 = 0.92. The results confirm the importance and the versatility of the Secchi disk measurements for aquatic optics.

  5. Evaluation of upwelling infrared radiance in a nonequilibrium nonhomogeneous atmosphere

    Science.gov (United States)

    Tiwari, S. N.; Subramanian, S. V.

    1982-01-01

    The influence of vibrational nonequilibrium upon upwelling infrared radiance from the earth's atmosphere is investigated. By employing the line-by-line model for spectral absorption, heating rates and upwelling radiances are calculated for equilibrium and nonequilibrium conditions in the spectral range of 4.7 micron CO and 3.3 micron CH4 bands. Heating rates are calculated also for the 15 micron CO2 band and are compared with other available results in the literature. For the spectral range of the CO fundamental band, the influence of different parameters on the upwelling radiance is investigated. It is found that for CO the assumption of local thermodynamic equilibrium (LTE) is not justified at tropospheric temperatures and pressures. If the resonance effects of CO-N2 collisions are considered, then the assumption of LTE is justified up to 60 kilometers. This information is very useful for measurement of atmospheric pollutants, earth radiation budget studies and climate modeling, and infrared signature works.

  6. Evaluation of upwelling infrared radiance from earth's atmosphere

    Science.gov (United States)

    Gupta, S. K.; Tiwari, S. N.

    1975-01-01

    Basic equations for calculating the upwelling atmospheric radiation are presented which account for various sources of radiation coming out at the top of the atmosphere. The theoretical formulation of the transmittance models (line-by-line and quasi-random band model) and the computational procedures used for the evaluation of the transmittance and radiance are discussed in detail. By employing the Lorentz line-by-line and quasi-random computer programs, model calculations were made to determine the upwelling radiance and signal change in the wave number interval of CO fundamental band. These results are useful in determining the effects of different interfering molecules, water vapor profiles, ground temperatures, and ground emittances on the upwelling radiance and signal change. This information is of vital importance in establishing the feasibility of measuring the concentrations of pollutants in the atmosphere from a gas filter correlation instrument flown on an aircraft or mounted on a satellite.

  7. Dynamics of transient upwelling across the tropical tropopause

    Science.gov (United States)

    Randel, W. J.; Abalos, M.

    2013-12-01

    Tropical upwelling is a fundamental component of the stratospheric Brewer Dobson circulation (BDC), influencing temperatures, water vapor and chemical constituents throughout the global stratosphere. There is a substantial component of sub-seasonal variability in upwelling, with strong effects on temperatures and tracers in the tropical lower stratosphere. Upwelling diagnosed using momentum balance calculations from ERAinterim data demonstrate that transience is linked to the effects of extratropical wave forcing, with centers of action in the high latitude winter stratosphere and in the subtropical upper troposphere of both hemispheres. Zonal mean wind tendencies are an important part of communicating the remote wave forcing to the deep tropics. Dynamical patterns reflect clear differences in forcing the shallow vs. deep branches of the BDC; the shallow branch is most correlated with wave forcing in the subtropical upper troposphere, while the deep branch is mainly influenced by high latitude planetary waves.

  8. Results of Chilean water markets: Empirical research since 1990

    Science.gov (United States)

    Bauer, Carl J.

    2004-09-01

    Chile's free-market Water Code turned 20 years old in October 2001. This anniversary was an important milestone for both Chilean and international debates about water policy because Chile has become the world's leading example of the free-market approach to water law and water resources management, the textbook case of treating water rights not merely as private property but also as a fully marketable commodity. The predominant view outside of Chile is that Chilean water markets and the Chilean model of water management have been a success, and this perception has encouraged other countries to follow Chile's lead in water law reform. Much of the debate about Chilean water markets, however, has been based more on theoretical or political beliefs than on empirical study. This paper reverses that emphasis by reviewing the evolution of empirical research about these markets since 1990, when Chile returned to democratic government after 16 years of military rule. During the period since 1990, understanding of how Chilean water markets have worked in practice has gradually improved. There have been two major trends in this research: first, a gradual shift from exaggerated claims of the markets' success toward more balanced assessments of mixed results and, second, a heavy emphasis on the economics of water rights trading with very little attention given to the Water Code's impacts on social equity, river basin management, environmental protection, or resolution of water conflicts. The analysis in this study is qualitative and interdisciplinary, combining law, economics, and institutions.

  9. Wind-driven upwelling effects on cephalopod paralarvae: Octopus vulgaris and Loliginidae off the Galician coast (NE Atlantic)

    Science.gov (United States)

    Otero, Jaime; Álvarez-Salgado, X. Antón; González, Ángel F.; Souto, Carlos; Gilcoto, Miguel; Guerra, Ángel

    2016-02-01

    Circulation patterns of coastal upwelling areas may have central consequences for the abundance and cross-shelf transport of the larval stages of many species. Previous studies have provided evidences that larvae distribution results from a combination of subtidal circulation, species-specific behaviour and larval sources. However, most of these works were conducted on organisms characterised by small-sized and abundant early life phases. Here, we studied the influence of the hydrography and circulation of the Ría de Vigo and adjacent shelf (NW Iberian upwelling system) on the paralarval abundance of two contrasting cephalopods, the benthic common octopus (Octopus vulgaris) and the pelagic squids (Loliginidae). We sampled repeatedly a cross-shore transect during the years 2003-2005 and used zero inflated models to accommodate the scarcity and patchy distribution of cephalopod paralarvae. The probability of catching early stages of both cephalopods was higher at night. Octopus paralarvae were more abundant in the surface layer at night whereas loliginids preferred the bottom layer regardless of the sampling time. Abundance of both cephalopods increased when shelf currents flowed polewards, water temperature was high and water column stability was low. The probability of observing an excess of zero catches decreased during the year for octopus and at high current speed for loliginids. In addition, the circulation pattern conditioned the body size distribution of both paralarvae; while the average size of the captured octopuses increased (decreased) with poleward currents at daylight (nighttime), squids were smaller with poleward currents regardless of the sampling time. These results contribute to the understanding of the effects that the hydrography and subtidal circulation of a coastal upwelling have on the fate of cephalopod early life stages.

  10. Development of Phaeocystis globosa blooms in the upwelling waters of the South Central coast of Viet Nam

    Science.gov (United States)

    Hai, Doan-Nhu; Lam, Nguyen-Ngoc; Dippner, Joachim W.

    2010-11-01

    Blooms of haptophyte algae in the south central coastal waters of Viet Nam often occur in association with upwelling phenomenon during the southwest (SW) monsoon. Depending on the magnitude of the blooms, damage to aquaculture farms may occur. Based on two years of data on biology, oceanography, and marine chemistry, the present study suggests a conceptual model of the growth of the haptophyte Phaeocystis globosa. At the beginning of the bloom, low temperature and abundant nutrient supply, especially nitrate from rain and upwelling, favour bloom development. Diatoms utilize available nitrate and phosphate; subsequently, higher ammonium concentration allows P. globosa to grow faster than the diatoms. At the end of the Phaeocystis bloom, free cells may become available as food for a heterotrophic dinoflagellate species, Noctiluca scintillans. During and after the phytoplankton bloom, remineralization by bacteria reduces dissolved oxygen to a very low concentration at depth, and favors growth of nitrate-reducing bacteria.A Lagrangian Harmful Algal Bloom (HAB) model, driven by a circulation model of the area, realistically simulates the transport of microalgae in surface waters during strong and weak SW monsoon periods, suggesting that it may be a good tool for early warning of HABs in Vietnamese coastal waters.

  11. Paleoproductivity of the Southern Chilean Margin Over the Past 30,000 Years

    Science.gov (United States)

    Colin, E. D.; Chase, Z.; Muratli, J.; McManus, J.; Mix, A.

    2008-12-01

    Productivity on ocean margins is highly sensitive to climate change, including changes in macro-and micro nutrient inputs from land, upwelling intensity, and nutrient content of upwelled waters. Coastal productivity may also contribute to climate change, through impacts on carbon sequestration, sediment and water-column redox state (and hence rates of denitrification), and production of dimethyl sulfide. Reconstructing margin productivity can thus provide insight into the nature and causes of past climate change. We examined productivity off southern Chile at ODP Site 1233. At 41°S, 838 m depth, the site is at the core of Antarctic Intermediate Water (AAIW). It is at the southern limit of the Peru-Chile upwelling system, where the northern extent of the Antarctic Circumpolar Current (ACC) impinges on the South American continent. Paleoproductivity was reconstructed by normalizing biogenic fluxes to the flux of 230Th. Over the last 30ky, maximum organic carbon, opal and carbonate fluxes occurred during the last glacial interval (26-20 ky BP). A steady decline is seen in carbonate flux from the middle Holocene (~8 ky BP) to present, organic carbon flux increases from the late Holocene (~5 ky BP) to present while opal flux is essentially unchanged from 20 ky BP to present. The pattern of reconstructed productivity is consistent with a more northerly position of the ACC during the last glacial interval, bringing the core of high-nutrient waters to 41°S. However, maximum prodctivity is observed well prior (~5 ky) to the deglacial increase in alkenone- reconstructed SST at this site. The productivity maximum is coincident with a maximum in glacier extent, and in the flux of terriginous material to the site. High glacial productivity may therefore have been supported by enhanced macro or micro-nutrient delivery from land. The pattern of reconstructed productivity implies that the less reducing conditions during the glacial interval, inferred from authigenic metal

  12. Chilean Nuclear Energy Commission dosimetric information system

    International Nuclear Information System (INIS)

    This thesis discusses the nuclear radiation that people who work with radioactive material is exposed to and its control by the Chilean Nuclear Energy Commission. A full analysis of the System is presented with information about the Commission and the Department of Nuclear and Radiological Safety which runs the System. Ana analysis of the System is presented in order to obtain requirements. Management flow diagrams, the processes involved and current problems experienced by the users are described. A design logic is modeled producing Data Flow Diagrams (DFD). based on this physical design, or, Model of Physical Data, is prepared including tables, attributes, types of data, primary and foreign keys. A description is presented of how the System is implemented, the tools that are used and how the testing phase is carried out. The Dosimetry System meets the criteria for a Software Engineering project, where the basic cycle was used as a working methodology. The System developed supports the dosimetric control of people exposed to radioactive material. (author)

  13. Bacterial and Archaeal Communities Variability Associated with Upwelling and Anthropogenic Pressures in the Protection Area of Arraial do Cabo (Cabo Frio region - RJ).

    Science.gov (United States)

    Coelho-Souza, Sergio A; Araújo, Fábio V; Cury, Juliano C; Jesus, Hugo E; Pereira, Gilberto C; Guimarães, Jean R D; Peixoto, Raquel S; Dávila, Alberto M R; Rosado, Alexandre S

    2015-09-01

    Upwelling systems contain a high diversity of pelagic microorganisms and their composition and activity are defined by factors like temperature and nutrient concentration. Denaturing gradient gel electrophoresis (DGGE) technique was used to verify the spatial and temporal genetic variability of Bacteria and Archaea in two stations of the Arraial do Cabo coastal region, one under upwelling pressure and another under anthropogenic pressure. In addition, biotic and abiotic variables were measured in surface and deep waters from three other stations between these stations. Six samplings were done during a year and adequately represented the degrees of upwelling and anthropogenic pressures to the system. Principal Component Analysis (PCA) showed negative correlations between the concentrations of ammonia and phosphorous with prokaryotic secondary production and the total heterotrophic bacteria. PCA also showed negative correlation between temperature and the abundance of prokaryotic cells. Bacterial and archaeal compositions were changeable as were the oceanographic conditions, and upwelling had a regional pressure while anthropogenic pressure was punctual. We suggest that the measurement of prokaryotic secondary production was associated with both Bacteria and Archaea activities, and that substrate availability and temperature determine nutrients cycling. PMID:26375020

  14. Anthropogenic nutrient sources rival natural sources on small scales in the coastal waters of the Southern California Bight

    KAUST Repository

    Howard, Meredith D. A.

    2014-01-26

    Anthropogenic nutrients have been shown to provide significant sources of nitrogen (N) that have been linked to increased primary production and harmful algal blooms worldwide. There is a general perception that in upwelling regions, the flux of anthropogenic nutrient inputs is small relative to upwelling flux, and therefore anthropogenic inputs have relatively little effect on the productivity of coastal waters. To test the hypothesis that natural sources (e.g., upwelling) greatly exceed anthropogenic nutrient sources to the Southern California Bight (SCB), this study compared the source contributions of N from four major nutrient sources: (1) upwelling, (2) treated wastewater effluent discharged to ocean outfalls, (3) riverine runoff, and (4) atmospheric deposition. This comparison was made using large regional data sets combined with modeling on both regional and local scales. At the regional bight-wide spatial scale, upwelling was the largest source of N by an order of magnitude to effluent and two orders of magnitude to riverine runoff. However, at smaller spatial scales, more relevant to algal bloom development, natural and anthropogenic contributions were equivalent. In particular, wastewater effluent and upwelling contributed the same quantity of N in several subregions of the SCB. These findings contradict the currently held perception that in upwelling-dominated regions anthropogenic nutrient inputs are negligible, and suggest that anthropogenic nutrients, mainly wastewater effluent, can provide a significant source of nitrogen for nearshore productivity in Southern California coastal waters.

  15. First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae in the coastal valleys of northern Chile

    Directory of Open Access Journals (Sweden)

    Héctor A. Vargas

    2014-03-01

    Full Text Available First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae in the coastal valleys of northern Chile. The trees Haplorhus peruviana Engl. and Schinus molle L. (Anacardiaceae are mentioned as the first host plant records for the little known native moth Iridopsis hausmanni Vargas, 2007 (Lepidoptera, Geometridae, Ennominae in the coastal valleys of the northern Chilean Atacama Desert. This is also the first record of Anacardiaceae as host plant for a Neotropical species of Iridopsis Warren, 1894.

  16. First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae) in the coastal valleys of northern Chile

    OpenAIRE

    2014-01-01

    First host plant records for Iridopsis hausmanni Vargas (Lepidoptera, Geometridae) in the coastal valleys of northern Chile. The trees Haplorhus peruviana Engl. and Schinus molle L. (Anacardiaceae) are mentioned as the first host plant records for the little known native moth Iridopsis hausmanni Vargas, 2007 (Lepidoptera, Geometridae, Ennominae) in the coastal valleys of the northern Chilean Atacama Desert. This is also the first record of Anacardiaceae as host plant for a Neotropical species...

  17. UPWELLING AND SEDIMENTATION DYNAMICS Ⅲ: COINCIDENCE OF UPWELLING AREAS WITH MUD PATCHES IN NORTH HEMISPHERE SHELF SEAS

    Institute of Scientific and Technical Information of China (English)

    庞重光; 胡敦欣

    2002-01-01

    The determinant role of upwelling in fine sediment patches is examined from the viewpoints of physical process and biological process respectively. It is pointed out that physical and biological processes are usually coexistent and interact with each other during the sedimentation of suspended matters. This study used available figures showing the circulation pattern and surface sediment distribution in the whole China Seas, the Gulf of Maine, the Irish Sea and the North Sea, and additional data to verify that wherever upwelling exists on the continental shelf, mud must occur; and that wherever downwelling occurs, coarse sediment substitutes for mud.

  18. Influence of monsoon upwelling on the planktonic foraminifera off Oman during Late Quaternary

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.

    Planktonic foraminifer abundances, fluxes, test sizes, and coiling properties are influenced in various ways by the southwest monsoon winds and associated upwelling in the western Arabian Sea. The influence of monsoon driven upwelling...

  19. Estimates of potential new production in the Java-Sumatra upwelling system

    Institute of Scientific and Technical Information of China (English)

    WEI Xing; LIAO Xiaomei; ZHAN Haigang; LIU Hailong

    2012-01-01

    The Java-Sumatra upwelling is one of the most important upwelling systems in the Indian Ocean,with maximum upwelling intensity in July through August.To estimate the nitrate supplied by upwelling,we developed a three-dimensional hydrodynamic model to calculate the mean vertical speed and determine the depth of upwelling.We used in-situ vertical nitrate profiles to assess nitrate concentration in the upwelled waters,and calculated the nitrate supply as the product of nitrate concentration and vertical transport obtained from the numerical model.The calculated result represents potential new production generated in the upwelling region.We found that on the event time scale (monthly) of Java-Sumatra upwelling,water brought to the surface originated from locations 100-m deep,giving a nitrate supply of 93.77× 103 mol/s and potential new production of 1.02× 1014 gC/a.

  20. Nitrogen transfers off Walvis Bay: a 3-D coupled physical/biogeochemical modeling approach in the Namibian upwelling system

    Directory of Open Access Journals (Sweden)

    E. Gutknecht

    2013-06-01

    Full Text Available Eastern boundary upwelling systems (EBUS are regions of high primary production often associated with oxygen minimum zones (OMZs. They represent key regions for the oceanic nitrogen (N cycle. By exporting organic matter (OM and nutrients produced in the coastal region to the open ocean, EBUS can play an important role in sustaining primary production in subtropical gyres. However, losses of fixed inorganic N through denitrification and anammox processes take place in oxygen depleted environments such as EBUS, and can potentially mitigate the role of these regions as a source of N to the open ocean. EBUS can also represent a considerable source of nitrous oxide (N2O to the atmosphere, affecting the atmospheric budget of N2O. In this paper a 3-D coupled physical/biogeochemical model (ROMS/BioEBUS is used to investigate the N budget in the Namibian upwelling system. The main processes linked to EBUS and associated OMZs are taken into account. The study focuses on the northern part of the Benguela upwelling system (BUS, especially the Walvis Bay area (between 22° S and 24° S where the OMZ is well developed. Fluxes of N off the Walvis Bay area are estimated in order to understand and quantify (1 the total N offshore export from the upwelling area, representing a possible N source that sustains primary production in the South Atlantic subtropical gyre; (2 export production and subsequent losses of fixed N via denitrification and anammox under suboxic conditions (O2 2 m−3; and (3 the N2O emission to the atmosphere in the upwelling area. In the mixed layer, the total N offshore export is estimated as 8.5 ± 3.9 × 1010 mol N yr−1 at 10° E off the Walvis Bay area, with a mesoscale contribution of 20%. Extrapolated to the whole BUS, the coastal N source for the subtropical gyre corresponds to 0.1 ± 0.04 mol N m−2 yr−1. This N flux represents a major source of N for the gyre compared with other N sources, and contributes 28% of the new primary

  1. Nutrients, Recycling, and Biological Populations in Upwelling Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Whitledge, T. E.

    1980-01-01

    Nutrient recycling has been studied in the upwelling areas of Baja California, Northwest Africa, and Peru. Regeneration by biological populations in these areas contributes significant quantities of recycled nitrogen which is utilized in productivity processes. Each area has a different combination of organisms which leads to differences in the relative contributions of zooplankton, nekton, or benthos to the nutrient cycles. Comparisons of ammonium regeneration rates of zooplankton and nekton-micronekton populations in the three upwelling areas show that zooplankton recycle relatively less nitrogen in the Baja California and Peru systems than nekton. In the Northwest Africa upwelling region, however, zooplankton, fish, and benthic inputs are all substantial. In recent years the Peruvian upwelling system has been altered with the decline of the anchoveta population and an increase in the importance of zooplankton in nutrient recycling. The distribution of recycled nitrogen (ammonium and urea) in transects across the shelf at 10°S and 15°S indicates that regeneration is relatively more important at 10°S in the region of the wide shelf. In both areas the distribution of ammonium and urea are not entirely coincident thereby indicating differences in their production and/or utilization.

  2. Upwelling O(+) ion source characteristics. [in polar magnetosphere

    Science.gov (United States)

    Moore, T. E.; Lockwood, M.; Chandler, M. O.; Waite, J. H., Jr.; Chappell, C. R.; Persoon, A.; Sugiura, M.

    1986-01-01

    The characteristics of an upwelling ion source are discussed. A typical upwelling event is analyzed using Dynamic Explorer 1 satellite retarding ion mass spectrometer (RIMS) observations of the low-energy plasma, and energetic ion and local electromagnetic field observations. The RIMS spectrograms of the O(+) ion species, radial and axial head data for O(+), and spin plan O(+) distribution functions are examined. The features of the upwelling observed include: (1) transverse ion heating to temperature of 100,000 K, (2) large outward flows of O(+), (3) enhanced flow of H(+) and He (+), (4) moderately strong field-aligned current sheets, (5) an associated intense eastward convection channel, and (6) strong wave emissions in the range near and below the proton gyrofrequency. The association between the upwelling O(+) signature and auroral current is investigated. Plasma wave and electric field environments are studied and plasma flows and densities are derived. It is noted that the mechanism for ion heating which defines the source region for these polar ion outflows is related to field-aligned currents and an associated auroral convection channel or jet.

  3. Evaluation of upwelling infrared radiance from the earth's troposphere

    Science.gov (United States)

    Tiwari, S. N.; Gupta, S. K.

    1976-01-01

    Basic equations for calculating the upwelling atmospheric radiance are presented. Theoretical formulation of the transmittance models (line-by-line and quasi-random band) and computational procedures for the evaluation of transmittance and radiance are discussed. This information is useful in the interpretation of the data obtained from measuring gaseous pollutants in the troposphere.

  4. Variability in upwelling across the tropical tropopause and correlations with tracers in the lower stratosphere

    OpenAIRE

    M. Abalos; W. J. Randel; E. Serrano

    2012-01-01

    Temporal variability of the upwelling near the tropical tropopause on daily to annual timescales is investigated using three different estimates computed from the ERA-Interim reanalysis. These include upwelling archived by the reanalysis, plus estimates derived from thermodynamic and momentum balance calculations. Substantial variability in upwelling is observed on both seasonal and sub-seasonal timescales, and the three estimates show reasonably good agreement. Tropical upwelling should exer...

  5. Mechanisms of near-surface current and upwelling variability in the tropical Atlantic

    OpenAIRE

    Hüttl, Sabine

    2006-01-01

    The upwelling regions of the eastern equatorial oceans provide not only sources of cold water in a relatively warm environment but also influence the atmospheric circulation and the biological productivity in the tropics. However, the sources of the upwelling waters are well known only for the equatorial upwelling but remained unclear for the off-equatorial upwelling in the Guinea and Angola Dome. A main aspect of this work is to contribute to the understanding of the mean pathways into these...

  6. Variability in upwelling across the tropical tropopause and correlations with tracers in the lower stratosphere

    OpenAIRE

    M. Abalos; W. J. Randel; E. Serrano

    2012-01-01

    Temporal variability of the upwelling near the tropical tropopause on daily to annual timescales is investigated using three different estimates computed from the ERA-Interim reanalysis. These include upwelling archived by the reanalysis, plus estimates derived from thermodynamic and momentum balance calculations. Substantial variability in upwelling is observed on both seasonal and sub-seasonal time scales, and the three estimates show reasonably good agreement. Tropical upwelling sho...

  7. Locking, mass flux and topographic response at convergent plate boundaries - the Chilean case

    Science.gov (United States)

    Oncken, Onno

    2016-04-01

    On the long term, convergent plate boundaries have been shown to be controlled by either accretion/underplating or by subduction erosion. Vertical surface motion is coupled to convergence rate - typically with an uplift rate of the coastal area ranging from 0 to +50% of convergence rate in accretive systems, and -20 to +30% in erosive systems. Vertical kinematics, however, are not necessarily linked to horizontal strain mode, i.e. upper plate shortening or extension, in a simple way. This range of kinematic behaviors - as well as their acceleration where forearcs collide with oceanic ridges/plateau - is well expressed along the Chilean plate margin. Towards the short end of the time scale, deformation appears to exhibit a close correlation with the frictional properties and geodetic locking at the plate interface. Corroborating analogue experiments of strain accumulation during multiple earthquake cycles, forearc deformation and uplift focus above the downdip and updip end of seismic coupling and slip and are each related to a particular stage of the seismic cycle, but with opposite trends for both domains. Similarly, barriers separating locked domains along strike appear to accumulate most upper plate faulting interseismically. Hence, locking patters are reflected in topography. From the long-term memory contained in the forearc topography the relief of the Chilean forearc seems to reflect long term stability of the observed heterogeneity of locking at the plate interface. This has fundamental implications for spatial and temporal distribution of seismic hazard. Finally, the nature of locking at the plate interface controlling the above kinematic behavior appears to be strongly controlled by the degree of fluid overpressuring at the plate interface suggesting that the hydraulic system at the interface takes a key role for the forearc response.

  8. Surface mixing and biological activity in the four Eastern Boundary Upwelling Systems

    Directory of Open Access Journals (Sweden)

    V. Rossi

    2009-08-01

    Full Text Available Eastern Boundary Upwelling Systems (EBUS are characterized by a high productivity of plankton associated with large commercial fisheries, thus playing key biological and socio-economical roles. Since they are populated by several physical oceanic structures such as filaments and eddies, which interact with the biological processes, it is a major challenge to study this sub- and mesoscale activity in connection with the chlorophyll distribution. The aim of this work is to make a comparative study of these four upwelling systems focussing on their surface stirring, using the Finite Size Lyapunov Exponents (FSLEs, and their biological activity, based on satellite data. First, the spatial distribution of horizontal mixing is analysed from time averages and from probability density functions of FSLEs, which allow us to divide each areas in two different subsystems. Then we studied the temporal variability of surface stirring focussing on the annual and seasonal cycle. We also proposed a ranking of the four EBUS based on the averaged mixing intensity. When investigating the links with chlorophyll concentration, the previous subsystems reveal distinct biological signatures. There is a global negative correlation between surface horizontal mixing and chlorophyll standing stocks over the four areas. To try to better understand this inverse relationship, we consider the vertical dimension by looking at the Ekman-transport and vertical velocities. We suggest the possibility of a changing response of the phytoplankton to sub/mesoscale turbulence, from a negative effect in the very productive coastal areas to a positive one in the open ocean. This study provides new insights for the understanding of the variable biological productivity in the ocean, which results from both dynamics of the marine ecosystem and of the 3-D turbulent medium.

  9. Teleconnections between upwelling along the Pacific coast of Baja California and marine and terrestrial gross primary production

    Science.gov (United States)

    Reimer, J. J.; Vargas, R.; Gaxiola-Castro, G.; Hernandez-Ayon, M.; Lara-Lara, R.

    2012-12-01

    Terrestrial processes are closely connected to the oceans through teleconnections in the atmosphere. The global terrestrial carbon cycle is known to be affected by a teleconnection to large scale atmospheric events such as El Niño/Southern Oscillation (ENSO; 2 to 7 year cycles), Pacific Decadal Oscillation (PDO), and North Atlantic Oscillation (NAO; decadal cycles). ENSO and PDO are the predominate atmospheric patterns which impact the Pacific coast of North America. Correlations between ENSO indices and gross primary production have shown that ENSO may partially explain the variability in the global terrestrial carbon cycle. We hypothesize that the remaining variability (for those ecosystems along eastern basin margins) may be explained by the teleconnection between terrestrial primary production and upwelling along continental margins. The study sites were selected along the Baja California peninsula due to the fact that each one is characterized by year round coastal upwelling (though stronger during the boreal spinr/summer months) and their respective terrestrial climate characteristics: 1. Punta Colonet/Sierra San Pedro Martir is located in a mediterranean climate with conifer forest; 2. Punta Abre Ojos (just south of Guerrero Negro) is located in the central desert region; 3. at approximate 29°00' N (west of Bahía de los Angeles) is in the central desert region but is also characterized by fog; and 4. Magdalena Bay is located in a subtropical desert region with sporadic rain events (here the marine portion of the transect will extend out from the mouth of the bay). Using ten years of MODIS Terra and Aqua (terrestrial gross primary production [TGPP]) and SeaWif's (chlorophyll a [chl. a] as a proxy for biomass) data for four transects along the Baja California peninsula (extending from approximately 300 km off the coast to up to 50 km inland depending on the transect) the gross primary production will be analyzed in relation to upwelling (represented by sea

  10. Association between eating behavior scores and obesity in Chilean children

    Directory of Open Access Journals (Sweden)

    Amador Paola

    2011-10-01

    Full Text Available Abstract Background Inadequate eating behavior and physical inactivity contribute to the current epidemic of childhood obesity. The aim of this study was to assess the association between eating behavior scores and childhood obesity in Chilean children. Design and methods We recruited 126 obese, 44 overweight and 124 normal-weight Chilean children (6-12 years-old; both genders according to the International Obesity Task Force (IOTF criteria. Eating behavior scores were calculated using the Child Eating Behavior Questionnaire (CEBQ. Factorial analysis in the culturally-adapted questionnaire for Chilean population was used to confirm the original eight-factor structure of CEBQ. The Cronbach's alpha statistic (>0.7 in most subscales was used to assess internal consistency. Non-parametric methods were used to assess case-control associations. Results Eating behavior scores were strongly associated with childhood obesity in Chilean children. Childhood obesity was directly associated with high scores in the subscales "enjoyment of food" (P Conclusion Our study shows a strong and graded association between specific eating behavior scores and childhood obesity in Chile.

  11. Prevalence and risk factors for bruises in Chilean bovine carcasses

    NARCIS (Netherlands)

    Strappini, A.C.; Frankena, K.; Metz, J.H.M.; Kemp, B.

    2010-01-01

    Records of cattle slaughtered at two Chilean slaughterhouses (SLH1 and SLH2) were used to determine prevalence and risk factors for carcasses with bruises. Bruise prevalence amounted to 12.3% but differed between slaughterhouses (20.8% for SLH1 and 8.6% for SLH2 respectively). Bruise severity grade

  12. Matanchen complex: new radiocarbon dates on early coastal adaptation in west Mexico.

    Science.gov (United States)

    Mountjoy, J B; Taylor, R E; Feldman, L H

    1972-03-17

    Samples of marine shell from archeological context on the coast of Nayarit, Mexico, have given radiocarbon determinations of 1810 +/- 80 B.C., 2000 +/- 100 B.C., and 2100 +/- 100 B.C. Even with maximum correction for upwelling these are the earliest dates for coastal occupation in West Mexico north of Acapulco, Guerrero. Analysis of the midden contents has provided new insights regarding early coastal adaptation.

  13. Origins of the Chilean Binominal Election System

    Directory of Open Access Journals (Sweden)

    Daniel Pastor

    2004-01-01

    Full Text Available strategic reaction by the military regime to the defeat of General Augusto Pinochet in the 1988 Plebiscite since the system was formally established during the period between the plebiscite and the first postauthoritarian elections in 1989. This theory, however, offers a mistaken account of the history and evolution of the binominal election system whose origins are considerably more complex than the conventional wisdom suggests. This article explores the internal political processes and the ideology that led the military government to adopt the binominal system. It argues that the election system was the capstone of the authoritarian institutional framework designed by the military government to protect the 1980 Constitution from efforts by the Concertación to reform it. Contrary to popular belief, the binominal system was proposed long before the 1988 Plebiscite by Arturo Marín Vicuña, then secretary of a government commission studying a new electoral law. This article maintains that, more than any other factor, the binominal system reflects and responds to an interpretation of Chilean political history between 1960 and 1973 that was widely shared among the Pinochet government's legal advisorsSe ha asumido que el presente sistema electoral chileno -el "binominal mayoritario"- fue una reacción ante la derrota del General Augusto Pinochet en el plebiscito de 1988, ya que fue lanzado en el intermedio después del plebiscito, pero antes que el régimen militar abandonara el poder. No obstante, esta hipótesis se equivoca en la historia de la evolución del sistema binominal que es más complejo. Este artículo explora la historia de los procesos políticos dentro del régimen militar y la ideología que llevó al sistema binominal. Argumenta que el sistema binominal fue la piedra arquitectónica de la institucionalidad autoritaria del régimen militar que protegía su Constitución de 1980 contra los esfuerzos de la Concertación para

  14. Main musculoskeletal injuries associated with lameness in Chilean Rodeo horses

    Directory of Open Access Journals (Sweden)

    M Mora-Carreño

    2014-01-01

    Full Text Available Chilean Rodeo is the most popular equestrian discipline in Chile and it is estimated that musculoskeletal diseases of the equine participants are the leading cause of illness and poor performance, however no related reports have been published. The aim of this study was to identify and characterize the main diseases associated with lameness in Chilean Rodeo horses. A retrospective study was performed considering the clinical attention records of horses participating in Chilean Rodeo which presented lameness. Information was collected regarding 114 cases, including identification (name, age and gender and the clinical characteristics of each episode. The average age of the horses was 8 ± 3.4 years. Among the subjects, 98.3% of the episodes corresponded to spontaneous lameness, with 2/4 being the most frequent degree of lameness. Unilateral episodes corresponded to 72.8% (83/114 of the cases, affecting primarily the front limbs (51/83. The most frequent diagnoses were: suspensory ligament desmitis (14%, tarsal osteoarthritis (13.2%, navicular syndrome (8.8%, laminitis (7.9%, deep digital flexor tendonitis (7% and metacarpophalangeal osteoarthritis (6.1%. The high frequency of grade 2 lameness suggests that the majority of veterinary attentions seem to be mostly at obvious conditions. Joint, foot and soft tissue conditions seem to be the main cause of lameness in equines participating in Chilean Rodeo. These results suggest that education regarding the importance of early diagnosis and greater hoof care are primary measures that may favor the prevention of lameness in Chilean Rodeo horses.

  15. The role of Equatorial Undercurrent in sustaining the Eastern Indian Ocean upwelling

    Science.gov (United States)

    Chen, Gengxin; Han, Weiqing; Shu, Yeqiang; Li, Yuanlong; Wang, Dongxiao; Xie, Qiang

    2016-06-01

    By combining volume transport and salinity analysis from 1958 to 2014, this paper investigates how the transient Equatorial Undercurrent (EUC) sustains the summer-fall equatorial eastern Indian Ocean (EIO) upwelling. On seasonal time scales, the EIO upwelling is mainly supplied by the salty water from the western basin through a buffering process: The winter-spring EUC carries the salty water from the western basin eastward, induces downwelling in the EIO, and pushes portion of the salty water below the central thermocline, which subsequently upwells to the central thermocline during summer-fall and sustains the EIO upwelling. On interannual time scales, enhanced upwelling occurs during positive Indian Ocean Dipole (+IOD) years. The strong summer-fall EUC associated with the +IOD supplies water for the intensified upwelling. This research provides new knowledge for basin-scale mass and property exchanges associated with the EIO upwelling, contributing to our understanding of three-dimensional ocean circulation and climate variability.

  16. A permanent record of subduction zone earthquake cycle deformation in the northern Chilean forearc

    Science.gov (United States)

    Loveless, J. P.; Allmendinger, R. W.; Pritchard, M. E.; González, G.

    2006-12-01

    Patterns of faulting in the northern Chilean forearc are consistent with modeled stress fields resulting from the subduction zone earthquake cycle. We define positive Coulomb stress change as encouraging normal faulting motion on steeply-dipping planes striking approximately parallel to the plate boundary, as shown by fault kinematic data collected in the field. Simulations show that coastal regions experience positive Coulomb stress changes due to interseismic strain accumulation on the subduction interface. This is compatible with the structural character of the forearc, typified by 100 m-scale scarps constructed by normal faulting. Conversely, the best-constrained models of interplate slip associated with the 1995 Mw 8.0 Antofagasta earthquake indicate that near-surface coastal areas experienced either zero or negative coseismic stress change, implying that subduction zone earthquakes may be capable of driving reverse motion on these structures if the absolute stress level is sufficiently low. Field exposures show minor amounts of reverse reactivation of some normal faults, expressed both through bedrock exposure and scarp morphology. The consistency between deformation fields related to the seismic cycle and permanent strain demonstrated by observable structures argues for the long-term influence of the earthquake cycle on the structural evolution of the forearc. The distribution of normal and reverse faulting as well as open cracks can thus be used to gain insight into the plate boundary processes that drive the evolution of structures. The change in strike and eastward step of the Atacama Fault System around the latitude of the Mejillones Peninsula (23°S) coincides with a change in subduction zone locking depth from ~35 km south of the peninsula to ~50 km to the north as determined through analyses of teleseismic, local seismic, and GPS data. Dense arrays of open cracks in several forearc localities show mean strikes consistent with static extension axes

  17. February 27, 2010 Chilean Tsunami in Pacific and its Arrival to North East Asia

    Science.gov (United States)

    Zaytsev, Andrey; Pelinovsky, EfiM.; Yalciner, Ahmet C.; Ozer, Ceren; Chernov, Anton; Kostenko, Irina; Shevchenko, Georgy

    2010-05-01

    The outskirts of the fault plane broken by the strong earthquake on February 27, 2010 in Chili with a magnitude 8.8 at the 35km depth of 35.909°S, 72.733°W coordinates generated a moderate size tsunami. The initial amplitude of the tsunami source is not so high because of the major area of the plane was at land. The tsunami waves propagated far distances in South and North directions to East Asia and Wet America coasts. The waves are also recorded by several gauges in Pacific during its propagation and arrival to coastal areas. The recorded and observed amplitudes of tsunami waves are important for the potential effects with the threatening amplitudes. The event also showed that a moderate size tsunami can be effective even if it propagates far distances in any ocean or a marginal sea. The far east coasts of Russia at North East Asia (Sakhalin, Kuriles, Kamchatka) are one of the important source (i.e. November 15, 2006, Kuril Island Tsunami) and target (i.e. February, 27, 2010 Chilean tsunami) areas of the Pacific tsunamis. Many efforts have been spent for establishment of the monitoring system and assessment of tsunamis and development of the mitigation strategies against tsunamis and other hazards in the region. Development of the computer technologies provided the advances in data collection, transfer, and processing. Furthermore it also contributed new developments in computational tools and made the computer modeling to be an efficient tool in tsunami warning systems. In this study the tsunami numerical model NAMI DANCE Nested version is used. NAMI-DANCE solves Nonlinear form of Long Wave (Shallow water) equations (with or without dispersion) using finite difference model in nested grid domains from the source to target areas in multiprocessor hardware environment. It is applied to 2010 Chilean tsunami and its propagation and coastal behavior at far distances near Sakhalin, Kuril and Kamchatka coasts. The main tide gauge records used in this study are from

  18. Meteorological constraints on oceanic halocarbons above the Peruvian Upwelling

    Directory of Open Access Journals (Sweden)

    S. Fuhlbrügge

    2015-07-01

    Full Text Available Halogenated very short lived substances (VSLS are naturally produced in the ocean and emitted to the atmosphere. Recently, oceanic upwelling regions in the tropical East Atlantic were identified as strong sources of brominated halocarbons to the atmosphere. During a cruise of R/V METEOR in December 2012 the oceanic sources and emissions of various halogenated trace gases and their mixing ratios in the marine atmospheric boundary layer (MABL were investigated above the Peruvian Upwelling for the first time. This study presents novel observations of the three VSLS bromoform, dibromomethane and methyl iodide together with high resolution meteorological measurements and Lagrangian transport modelling. Although relatively low oceanic emissions were observed, except for methyl iodide, surface atmospheric abundances were elevated. Radiosonde launches during the cruise revealed a low, stable MABL and a distinct trade inversion above acting both as strong barriers for convection and trace gas transport in this region. Significant correlations between observed atmospheric VSLS abundances, sea surface temperature, relative humidity and MABL height were found. We used a simple source-loss estimate to identify the contribution of oceanic emissions to observed atmospheric concentrations which revealed that the observed marine VSLS abundances were dominated by horizontal advection below the trade inversion. The observed VSLS variations can be explained by the low emissions and their accumulation under different MABL and trade inversion conditions. This study confirms the importance of oceanic upwelling and trade wind systems on creating effective transport barriers in the lower atmosphere controlling the distribution of VSLS abundances above ocean upwelling regions.

  19. Convective upwelling in the mantle beneath the Gulf of California.

    Science.gov (United States)

    Wang, Yun; Forsyth, Donald W; Savage, Brian

    2009-11-26

    In the past six million years, Baja California has rifted obliquely apart from North America, opening up the Gulf of California. Between transform faults, seafloor spreading and rifting is well established in several basins. Other than hotspot-dominated Iceland, the Gulf of California is the only part of the world's seafloor-spreading system that has been surrounded by enough seismometers to provide horizontal resolution of upper-mantle structure at a scale of 100 kilometres over a distance great enough to include several spreading segments. Such resolution is needed to address the long-standing debate about the relative importance of dynamic and passive upwelling in the shallow mantle beneath spreading centres. Here we use Rayleigh-wave tomography to image the shear velocity in the upper 200 kilometres or so of the mantle. Low shear velocities similar to those beneath the East Pacific Rise oceanic spreading centre underlie the entire length of the Gulf, but there are three concentrated locations of anomalously low velocities spaced about 250 kilometres apart. These anomalies are 40 to 90 kilometres beneath the surface, at which depths petrological studies indicate that extensive melting of passively upwelling mantle should begin. We interpret these seismic velocity anomalies as indicating that partial melting triggers dynamic upwelling driven by either the buoyancy of retained melt or by the reduced density of depleted mantle. PMID:19940924

  20. Large Topographic Rises on Venus: Implications for Mantle Upwelling

    Science.gov (United States)

    Stofan, Ellen R.; Smrekar, Suzanne E.; Bindschandler, Duane L.; Senske, David A.

    1995-01-01

    Topographic rises on Venus have been identified that are interpreted to be the surface manifestation of mantle upwellings. These features are classified into groups based on their dominant morphology. Atla and Beta Regiones are classified as rift-dominated, Dione, western Eistla, Bell, and Imdr Regiones as volcano-dominated, and Themis, eastern Eistla, and central Eistla Regiones as corona-dominated. At several topographic rises, geologic indicators were identified that may provide evidence of uplifted topography (e.g., volcanic flow features trending upslope). We assessed the minimum contribution of volcanic construction to the topography of each rise, which in general represents less than 5% of the volume of the rise, similar to the volumes of edifices at terrestrial hotspot swells. The total melt volume at each rise is approximated to be 10(exp 4) - 10(exp 6) cu km. The variations in morphology, topography, and gravity signatures at topographic rises are not interpreted to indicate variations in stage of evolution of a mantle upwelling. Instead, the morphologic variations between the three classes of topographic rises are interpreted to indicate the varying influences of lithospheric structure, plume characteristics, and regional tectonic environment. Within each class, variations in topography, gravity, and amount of volcanism may be indicative of differing stages of evolution. The similarity between swell and volcanic volumes for terrestrial and Venusian hotspots implies comparable time-integrated plume strengths for individual upwellings on the two planets.

  1. Synergistic effects of hypoxia and increasing CO2 on benthic invertebrates of the central Chilean coast

    KAUST Repository

    Steckbauer, Alexandra

    2015-07-10

    Ocean acidification (OA) and hypoxic events are an increasing worldwide problem, but the synergetic effects of these factors are seldom explored. However, this synergetic occurrence of stressors is prevalent. The coastline of Chile not only suffers from coastal hypoxia but the cold, oxygen-poor waters in upwelling events are also supersaturated in CO2, a study site to explore the combined effect of OA and hypoxia. We experimentally evaluated the metabolic response of different invertebrate species (2 anthozoans, 9 molluscs, 4 crustaceans, 2 echinoderms) of the coastline of central Chile (33°30′S, 71°37′W) to hypoxia and OA within predicted levels and in a full factorial design. Organisms were exposed to 4 different treatments (ambient, low oxygen, high CO2, and the combination of low oxygen and high CO2) and metabolism was measured after 3 and 6 days. We show that the combination of hypoxia and increased pCO2 reduces the respiration significantly, compared to a single stressor. The evaluation of synergistic pressures, a more realistic scenario than single stressors, is crucial to evaluate the effect of future changes for coastal species and our results provide the first insight on what might happen in the next 100 years.

  2. Stable nitrogen isotopes in coastal macroalgae: Geographic and anthropogenic variability

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Inés G., E-mail: ines.gonzalez@co.ieo.es; Bode, Antonio

    2013-01-15

    Growing human population adds to the natural nitrogen loads to coastal waters. Both anthropogenic and natural nitrogen is readily incorporated in new biomass, and these different nitrogen sources may be traced by the measurement of the ratio of stable nitrogen isotopes (δ{sup 15}N). In this study δ{sup 15}N was determined in two species of macroalgae (Ascophyllum nodosum and Fucus vesiculosus), and in nitrate and ammonium to determine the relative importance of anthropogenic versus natural sources of nitrogen along the coast of NW Spain. Both algal species and nitrogen sources showed similar isotopic enrichment for a given site, but algal δ{sup 15}N was not related to either inorganic nitrogen concentrations or δ{sup 15}N in the water samples. The latter suggests that inorganic nitrogen inputs are variable and do not always leave an isotopic trace in macroalgae. However, a significant linear decrease in macroalgal δ{sup 15}N along the coast is consistent with the differential effect of upwelling. Besides this geographic variability, the influence of anthropogenic nitrogen sources is evidenced by higher δ{sup 15}N in macroalgae from rias and estuaries compared to those from open coastal areas and in areas with more than 15 × 10{sup 3} inhabitants in the watershed. These results indicate that, in contrast with other studies, macroalgal δ{sup 15}N is not simply related to either inorganic nitrogen concentrations or human population size but depends on other factors as the upwelling or the efficiency of local waste treatment systems. - Highlights: ► Anthropogenic versus upwelling nitrogen effect on macroalgal δ{sup 15}N was studied. ► The influence of populations and upwelling has not been made before on macroalgal δ{sup 15}N. ► Natural variability has not been taken into account in most biomonitoring studies. ► Upwelling explains most of the variability in δ{sup 15}N in macroalgae.

  3. Zooplankton Responses to Low-Oxygen Condition upon a Shallow Oxygen Minimum Zone in the Upwelling Region off Chile

    Science.gov (United States)

    Hidalgo, P.; Escribano, R.

    2015-12-01

    A shallow oxygen minimum zone (OMZ) is a critical component in the coastal upwelling ecosystem off Chile. This OMZ causes oxygen-deficient water entering the photic layer and affecting plankton communities having low tolerance to hypoxia. Variable, and usually species-dependent, responses of zooplankton to hypoxia condition can be found. Most dominant species avoid hypoxia by restricting their vertical distribution, while others can temporarily enter and even spent part of their life cycle within the OMZ. Whatever the case, low-oxygen conditions appear to affect virtually all vital rates of zooplankton, such as mortality, fecundity, development and growth and metabolism, and early developmental stages seem more sensitive, with significant consequences for population and community dynamics. For most study cases, these effects are negative at individual and population levels. Observations and predictions upon increasing upwelling intensity over the last 20-30 years indicate a gradual shoaling of the OMZ, and so that an expected enhancement of these negative effects of hypoxia on the zooplankton community. Unknown processes of adaptation and community-structure adjustments are expected to take place with uncertain consequences for the food web of this highly productive eastern boundary current ecosystem.

  4. Holocene variability in the intensity of wind-gap upwelling in the tropical eastern Pacific

    Science.gov (United States)

    Toth, Lauren T.; Aronson, Richard B.; Cheng, Hai; Edwards, R. Lawrence

    2015-01-01

    Wind-driven upwelling in Pacific Panamá is a significant source of oceanographic variability in the tropical eastern Pacific. This upwelling system provides a critical teleconnection between the Atlantic and tropical Pacific that may impact climate variability on a global scale. Despite its importance to oceanographic circulation, ecology, and climate, little is known about the long-term stability of the Panamanian upwelling system or its interaction with climatic forcing on millennial time scales. Using a combination of radiocarbon and U-series dating of fossil corals collected in cores from five sites across Pacific Panamá, we reconstructed the local radiocarbon reservoir correction, ΔR, from ~6750 cal B.P. to present. Because the ΔR of shallow-water environments is elevated by upwelling, our data set represents a millennial-scale record of spatial and temporal variability of the Panamanian upwelling system. The general oceanographic gradient from relatively strong upwelling in the Gulf of Panamá to weak-to-absent upwelling in the Gulf of Chiriquí was present throughout our record; however, the intensity of upwelling in the Gulf of Panamá varied significantly through time. Our reconstructions suggest that upwelling in the Gulf of Panamá is weak at present; however, the middle Holocene was characterized by periods of enhanced upwelling, with the most intense upwelling occurring just after of a regional shutdown in the development of reefs at ~4100 cal B.P. Comparisons with regional climate proxies suggest that, whereas the Intertropical Convergence Zone is the primary control on modern upwelling in Pacific Panamá, the El Niño–Southern Oscillation drove the millennial-scale variability of upwelling during the Holocene.

  5. The Upper Mixed Layer during Coastal Upwelling Events on the Northern Portugal Shelf

    Institute of Scientific and Technical Information of China (English)

    ZUO Juncheng; SHENG Hong; Alvaro Peliz; Santos A. Miguel

    2003-01-01

    The upper mixed layer (UML) depth obtained from temperature is very close to that from density:thc maximum is about 15 m. This indicates that temperature is a good indicator of mixed layer during measurements. When the surface heat flux is balanced by a cross-shore heat flux, the surface mixed layer depth obtained from the WM model (Weatherly and Martin, 1978), hpRT, is roughly the same as observed. The mixed layer depth calculated from the PWP model (Price, Wellcr and Pinkel, 1986) is close to the depth obtained from thermistor chain temperature data. The results show that both thc WM model and PWP model can provide a good estimate of stratification in the study area during the cruise. The value of log (h/u3)is about 9.5 in the study area, which shows that the study area is strongly stratified in summer. Observations on the northern Portugal shelf reveal high variability in stability, giving rise to semi-diurnal, semi-monthly and diurnal oscillations, and long term variations. The fortnightly oscillations are highlighted by post-springs and post-neaps. The stirring of spring tide is reinforced by strong wind mixing which brings about complete vertical homogeneity everywhere. The semi-diurnal periodic stratification is very pronounced because the major axis of the tidal ellipse is orientated acrossshorc, even though thc tidal current is weak in this area, the maximum stratification is observed around the middle of ebb, and, the water at this time is much warmer. The diurnal oscillation results from the upper ocean response to heating and wind mixing when solar heating warms and stabilizes the upper ocean. There is a clear relationship between upper mixed layer depth and wind-stress magnitude at subtidal frequencies. Stronger winds result in a dccper surface mixed layer. Typically, the surface mixed layer depth lags the wind stress by 6-12h.

  6. Comparative roles of upwelling and glacial iron sources in Ryder Bay, coastal western Antarctic Peninsula

    OpenAIRE

    Annett, Amber; Skiba, Marta; Henley, Sian; Venables, Hugh J.; Meredith, Michael P.; Statham, Peter; Ganeshram, Raja

    2015-01-01

    Iron (Fe) is an essential micronutrient for phytoplankton, and is scarce in many regions including the open Southern Ocean. The western Antarctic Peninsula (WAP), an important source region of Fe to the wider Southern Ocean, is also the fastest warming region of the Southern Hemisphere. The relative importance of glacial versus marine Fe sources is currently poorly constrained, hindering projections of how changing oceanic circulation, productivity, and glacial dynamics may affect the balance...

  7. Wind-driven currents in the coastal and equatorial upwelling regions

    OpenAIRE

    Castellanos, Paola

    2012-01-01

    Durante las últimas dos décadas la comunidad científica internacional ha pasado a reconocer la importancia del Océano Atlántico tropical y las regiones de afloramiento en el clima terrestre. Este reconocimiento ha abierto nuevos interrogantes, tales como: ¿Cuáles son los mecanismos de ajuste del océano a las variaciones en el forzamiento atmosférico?, ¿Existe algún tipo de relación indirecta entre el ciclo estacional atmosférico y la respuesta del océano superficial?, ¿Cómo se conectan los fl...

  8. Sedimentation across the central California oxygen minimum zone: an alternative coastal upwelling sequence.

    Science.gov (United States)

    Vercoutere, T.L.; Mullins, H.T.; McDougall, K.; Thompson, J.B.

    1987-01-01

    Distribution, abundance, and diversity of terrigenous, authigenous, and biogenous material provide evidence of the effect of bottom currents and oxygen minimum zone (OMZ) on continental slope sedimentation offshore central California. Three major OMZ facies are identified, along the upper and lower edges of OMZ and one at its core.-from Authors

  9. Environmental proteomics of microbial plankton in a highly productive coastal upwelling system

    OpenAIRE

    Sowell, Sarah M; Abraham, Paul E; Shah, Manesh; VerBerkmoes, Nathan C.; Smith, Daniel P.; Barofsky, Douglas F.; Giovannoni, Stephen J

    2010-01-01

    Metaproteomics is one of a suite of new approaches providing insights into the activities of microorganisms in natural environments. Proteins, the final products of gene expression, indicate cellular priorities, taking into account both transcriptional and posttranscriptional control mechanisms that control adaptive responses. Here, we report the proteomic composition of the < 1.2 μm fraction of a microbial community from Oregon coast summer surface waters, detected with two-dimensional liqui...

  10. Orographic shaping of US West Coast wind profiles during the upwelling season

    Science.gov (United States)

    Renault, Lionel; Hall, Alex; McWilliams, James C.

    2016-01-01

    Spatial and temporal variability of nearshore winds in eastern boundary current systems is affected by orography, coastline shape, and air-sea interaction. These lead to a weakening of the wind close to the coast: the so-called wind drop-off. In this study, regional atmospheric simulations over the US West Coast are used to demonstrate monthly characteristics of the wind drop-off and assess the mechanisms controlling it. Using a long-term simulation, we show the wind drop-off has spatial and seasonal variability in both its offshore extent and intensity. The offshore extent varies from around 10 to 80 km from the coast and the wind reduction from 10 to 80 %. We show that when the mountain orography is combined with the coastline shape of a cape, it has the biggest influence on wind drop-off. The primary associated processes are the orographically-induced vortex stretching and the surface drag related to turbulent momentum flux divergence that has an enhanced drag coefficient over land. Orographically-induced tilting/twisting can also be locally significant in the vicinity of capes. The land-sea drag difference acts as a barrier to encroachment of the wind onto the land through turbulent momentum flux divergence. It turns the wind parallel to the shore and slightly reduces it close to the coast. Another minor factor is the sharp coastal sea surface temperature front associated with upwelling. This can weaken the surface wind in the coastal strip by shallowing the marine boundary layer and decoupling it from the overlying troposphere.

  11. Complex trophic interactions of calanoid copepods in the Benguela upwelling system

    Science.gov (United States)

    Schukat, Anna; Auel, Holger; Teuber, Lena; Lahajnar, Niko; Hagen, Wilhelm

    2014-01-01

    Life-cycle adaptations, dietary preferences and trophic levels of calanoid copepods from the northern Benguela Current off Namibia were determined via lipid classes, marker fatty acids and stable isotope analyses, respectively. Trophic levels of copepod species were compared to other zooplankton and top consumers. Lipid class analyses revealed that three of the dominant calanoid copepod species stored wax esters, four accumulated triacylglycerols and another three species were characterised by high phospholipid levels. The two biomarker approaches (via fatty acids and stable isotopes) revealed a complex pattern of trophic positions for the various copepod species, but also highlighted the dietary importance of diatoms and dinoflagellates. Calanoides carinatus and Nannocalanus minor occupied the lowest trophic level (predominantly herbivorous) corresponding to high amounts of fatty acid markers for diatoms (e.g. 16:1(n - 7)) and dinoflagellates (e.g. 18:4(n - 3)). These two copepod species represent the classical link between primary production and higher trophic levels. All other copepods belonged to secondary or even tertiary (some deep-sea copepods) consumers. The calanoid copepod species cover the entire range of δ15N ratios, as compared to δ15N ratios of all non-calanoid taxa investigated, from salps to adult fish. These data emphasise that the trophic roles of calanoid copepods are far more complex than just interlinking primary producers with pelagic fish, which should also be considered in the process of developing realistic food-web models of coastal upwelling systems.

  12. Modelling an alkenone-like proxy record in the NW African upwelling

    Directory of Open Access Journals (Sweden)

    X. Giraud

    2006-01-01

    Full Text Available A regional biogeochemical model is applied to the NW African coastal upwelling between 19° N and 27° N to investigate how a water temperature proxy is produced at the sea surface and recorded in the slope sediments. The biological model has two phytoplankton groups, to distinguish an alkenone producer group (considered as coccolithophores from other phytoplankton. The Regional Ocean Modelling System (ROMS is used to simulate the ocean circulation, and takes advantage of the Adaptive Grid Refinement in Fortran (AGRIF package to set up an embedded griding system. The results show that the alkenone-like temperature records in the sediments are between 1.1 and 2.1°C colder compared to the annual mean SSTs. Despite the seasonality of the coccolithophorid production, this temperature difference is not mainly due to a seasonal bias, nor to the lateral advection of phytoplankton and phytodetritus from the cold water domain to most offshore locations, but to the production depth of the coccolithophores. If core-top sediment alkenone-derived temperatures are effectively recording the annual mean SSTs, the quantitative alkenone production in the water column must be inhomogeneous among the coccolithophore population and depend on physiological factors (growth rate, nutrient stress.

  13. Modelling an alkenone-like proxy record in the NW African upwelling

    Directory of Open Access Journals (Sweden)

    X. Giraud

    2006-01-01

    Full Text Available A regional biogeochemical model is applied to the NW African coastal upwelling between 19° N and 27° N to investigate how a water temperature proxy, alkenones, are produced at the sea surface and recorded in the slope sediments. The biogeochemical model has two phytoplankton groups: an alkenone producer group, considered to be coccolithophores, and a group comprising other phytoplankton. The Regional Ocean Modelling System (ROMS is used to simulate the ocean circulation and takes advantage of the Adaptive Grid Refinement in Fortran (AGRIF package to set up an embedded griding system. In the simulations the alkenone temperature records in the sediments are between 1.1 and 2.3°C colder than the annual mean SSTs. Despite the seasonality of the coccolithophore production, this temperature difference is not mainly due to a seasonal bias, nor to the lateral advection of phytoplankton and phytodetritus seaward from the cold near-shore waters, but to the production depth of the coccolithophores. If coretop alkenone temperatures are effectively recording the annual mean SSTs, the amount of alkenone produced must vary among the coccolithophores in the water column and depend on physiological factors (e.g. growth rate, nutrient stress.

  14. The Chilean Health System: 20 Years of Reforms

    Directory of Open Access Journals (Sweden)

    Manuel Annick

    2002-01-01

    Full Text Available The Chilean health care system has been intensively reformed in the past 20 years. Reforms under the Pinochet government (1973-1990 aimed mainly at the decentralization of the system and the development of a private sector. Decentralization involved both a deconcentration process and the devolution of primary health care to municipalities. The democratic governments after 1990 chose to preserve the core organization but introduced reforms intended to correct the system's failures and to increase both efficiency and equity. The present article briefly explains the current organization of the Chilean health care system. It also reviews the different reforms introduced in the past 20 years, from the Pinochet regime to the democratic governments. Finally, a brief discussion describes the strengths and weaknesses of the system, as well as the challenges it currently faces.

  15. Women and changes in the Chilean economy: some questions.

    Science.gov (United States)

    Smiaroski, M S

    1996-10-01

    The author argues that a new development model that encourages greater participation of women in the work force in domestic piecework, temporary work, and subcontracting may further lead to the exploitation of women in Chile. The importance of women in economic development in Chile should be based on building skills, providing support child care services, reorienting women's education, and tax incentives. Chile over the past decade has achieved relatively stable economic growth and increased employment of women. During 1990-93 the growth of women in the work force increased at a rate of 16.8%, while men's presence increased by only 9.8%. The Chilean economy is based on a sophisticated modern sector and a labor-intensive informal sector. The Chilean model of development relies on cheap, flexible labor and a government approval of this model. Increased participation of women in the labor force is usually perceived as increased economic empowerment. A 1994 Oxfam study found that women were being forced into the labor market due to declines in family income and low wages. 46% of men and women received wages that did not cover basic necessities. The Chilean labor market is gender-stratified. Men are paid better than women for the same work. Men are in more permanent positions. Labor laws are either inadequate or violated, particularly for hours of work and overtime pay and conditions of employment and benefits. Traditional female jobs are those that rely on women's natural attributes. These unskilled attributes are rewarded with low wages. Little opportunity is provided for upgrading skills or acquiring new skills. Some women turn down advancement because of a lack of role models. Women have little opportunity to develop their self-image as workers. Poor self-images affect women's work attitudes and motivation. Some firms use competition between women to boost production. Chilean women remain in subordinate roles.

  16. [Minimum legal drinking age in the Chilean context].

    Science.gov (United States)

    Ramírez, Jorge; Heller, Nereida

    2016-01-01

    Alcohol consumption is harmful to minors. One of the most wide ly accepted measures for the prevention of harm associated with alcohol consumption for young people is to establish a minimum legal drinking age. This document presents the evidence available on this policy, offers a condensed analysis of its characteristics in the United States of America, describes current consumption patterns of Chilean youth, and proposes concrete solutions to be implemented. PMID:26998989

  17. EMPIRICAL REGULARITIES OF THE CHILEAN ECONOMY: 1986-2005

    OpenAIRE

    Jorge Enrique Restrepo L.; Claudio Soto G.

    2006-01-01

    This paper documents the main empirical regularities of the Chilean economy over the past twenty years, characterizing it in two dimensions. First, it describes the economy’s structure in terms of the sectors’ relative sizes in the long term and the importance of the various components of aggregate demand. Second, it documents the main features of business cycles in Chile. The volatility and persistence of several variables across the cycles is described, together with the correlations within...

  18. A New Liquidity Risk Measure for the Chilean Banking Sector

    OpenAIRE

    Sebastián Becerra; Gregory Claeys; Juan Francisco Martínez

    2015-01-01

    The objective of this work is to construct an appropriate measure of liquidity risk for Chilean banks. There are already several measures of liquidity risk in the literature. Most of these metrics are based on specific assumptions and expert opinion. In order to overcome the potential problems associated with discretionary assumptions, and to exploit the information available, similar to the work of Drehman and Nikolaou (2012), we propose a metric based on the behavior of banks in the procure...

  19. Bank Lending and Relationship Banking: Evidence from Chilean Firms

    OpenAIRE

    Andrea Repetto; Sergio Rodríguez; Valdés, Rodrigo O.

    2002-01-01

    In this paper we empirically study bank-client relationships using a sample of manufacturing Chilean firms. We examine whether concentration and the duration of bank-firm relationships affect the terms of bank financing, evaluating both the volume of bank lending and bank loan costs. Our results indicate that lower concentration, measured by the number of banks a firm borrows from, is associated with lower costs of loans and with a large and positive non-lincar effect on borrowing. The length...

  20. The social and cultural impact of advertising among chilean youths

    OpenAIRE

    Vergara-Leyton, Enrique; Rodríguez-Salineros, Maite

    2010-01-01

    This work analyzes the impact of advertising among Chilean youngsters of different socioeconomic background. We aim to identify the relationship that this group establishes with advertising and, in particular, the way they incorporate it in their socialization strategies. We do not address what advertising does to youngsters, but instead what youngsters do with advertising in their practices of appropriation and reception of it. The research design included focus groups of male and female you...

  1. Phylogeography in Galaxias maculatus (Jenyns, 1848 along Two Biogeographical Provinces in the Chilean Coast.

    Directory of Open Access Journals (Sweden)

    Claudio A González-Wevar

    Full Text Available Major geologic and climatic changes during the Quaternary exerted a major role in shaping past and contemporary distribution of genetic diversity and structure of aquatic organisms in southern South America. In fact, the northern glacial limit along the Pacific coast, an area of major environmental changes in terms of topography, currents, and water salinity, represents a major biogeographic transition for marine and freshwater species. We used mitochondrial DNA sequences (D-loop to investigate the consequences of Quaternary glacial cycles over the pattern of genetic diversity and structure of G. maculatus (Pisces: Galaxiidae along two biogeographical provinces in the Chilean coast. Extreme levels of genetic diversity and strong phylogeographic structure characterize the species suggesting a low amount of influence of the last glacial cycle over its demography. However, we recognized contrasting patterns of genetic diversity and structure between main biogeographical areas here analyzed. Along the Intermediate Area (38°-41° S each estuarine population constitutes a different unit. In contrast, Magellanic populations (43°-53° S exhibited low levels of genetic differentiation. Contrasting patterns of genetic diversity and structure recorded in the species between the analyzed biogeographic areas are consistent with the marked differences in abiotic factors (i.e., different coastal configurations, Quaternary glacial histories, and oceanographic regimes and to inherent characteristics of the species (i.e., salt-tolerance, physiology, and reproductive behavior.

  2. Phylogeography in Galaxias maculatus (Jenyns, 1848) along Two Biogeographical Provinces in the Chilean Coast.

    Science.gov (United States)

    González-Wevar, Claudio A; Salinas, Pilar; Hüne, Mathias; Segovia, Nicolás I; Vargas-Chacoff, Luis; Astorga, Marcela; Cañete, Juan I; Poulin, Elie

    2015-01-01

    Major geologic and climatic changes during the Quaternary exerted a major role in shaping past and contemporary distribution of genetic diversity and structure of aquatic organisms in southern South America. In fact, the northern glacial limit along the Pacific coast, an area of major environmental changes in terms of topography, currents, and water salinity, represents a major biogeographic transition for marine and freshwater species. We used mitochondrial DNA sequences (D-loop) to investigate the consequences of Quaternary glacial cycles over the pattern of genetic diversity and structure of G. maculatus (Pisces: Galaxiidae) along two biogeographical provinces in the Chilean coast. Extreme levels of genetic diversity and strong phylogeographic structure characterize the species suggesting a low amount of influence of the last glacial cycle over its demography. However, we recognized contrasting patterns of genetic diversity and structure between main biogeographical areas here analyzed. Along the Intermediate Area (38°-41° S) each estuarine population constitutes a different unit. In contrast, Magellanic populations (43°-53° S) exhibited low levels of genetic differentiation. Contrasting patterns of genetic diversity and structure recorded in the species between the analyzed biogeographic areas are consistent with the marked differences in abiotic factors (i.e., different coastal configurations, Quaternary glacial histories, and oceanographic regimes) and to inherent characteristics of the species (i.e., salt-tolerance, physiology, and reproductive behavior). PMID:26161896

  3. The study on aging index of upwelling by the contents of several species phosphorus%以各形态磷存量研究上升流水体老化变性指标

    Institute of Scientific and Technical Information of China (English)

    葛菁萍; 杨志伟; 林鹏

    2000-01-01

    The results from the Minnan- Taiwan Bank fishing ground upwelling ecosystem study during the period from December 1987 through November 1988 and from the upwelling study of the central and northern Taiwan Strait in July 1987 to July 1988 show that the changes of contents of dissolved inorganic phosphorus( DIP ), dissolved organic phosphorus (DOP), particulate phosphorus (PP) and total phosphorus ( TP ) were of an importance to the upwelling ecosystem study. Therefore, it is proposed that the aging status of a given upwelled water mass can be expressed as relative percentages of organic and patieulate species phosphorus and dissolved inorganic phosphorus, and the aging index of upwelling ( AIU ) is indicated by ratio of ( DOP + PP ) to ( DIP + DOP + PP ) ( μmoi/ dm3 ). The oceanographic survey data show this expression of AlU was fit for the two upwelling regions mentioned. The seaonai changes of AIU in the regions correlated closely with predominating alternatively in different periods of time for the coastal upwelling. There are young upwelled waters in the areas where their value of AIU is relatively small, and it is fit for the location of the upwelling centre mentioned.%闽南—台湾浅滩渔场上升流区研究(1987年12月至1988年11月)及台湾海峡上升流区研究(1987年7月至1988年7月)结果表明,各种形态磷含量变化对上升流生态系具有重要作用.因此,提出以涌升水体中有机、颗粒形态磷和溶解无机态磷的相对比率来表示上升流水体的老化程度,即上升流水体老化指标(AIU)为(DOP+PP)与(DIP+DOP+PP)之比值.研究资料表明AIU这一表达式对于上述两上升流区是合适的,海域AIU的季节性变化与其近岸上升流的消长变化规律相一致.AIU较小的区域,其水体为新涌升水,与上升流中心位置相吻合.

  4. The response of inorganic carbon distributions and dynamics to upwelling-favorable winds on the northern Gulf of Mexico during summer

    Science.gov (United States)

    Huang, W.-J.; Cai, W.-J.; Wang, Y.; Hu, X.; Chen, B.; Lohrenz, S. E.; Chakraborty, S.; He, R.; Brandes, J.; Hopkinson, C. S.

    2015-12-01

    Upwelling-favorable winds and an offshore-distributed Mississippi and Atchafalaya River plume trajectory were observed in summer 2009 in contrast to the mean conditions from 2002 to 2010 (upwelling-unfavorable winds and an alongshore river plume trajectory), a set of conditions which was also observed in summer 2007. The responses of dissolved inorganic carbon (DIC) distributions and dynamics to upwelling-favorable winds are studied by comparing the contrasting conditions between summer 2009 and summer 2007 on the northern Gulf of Mexico. Patterns of surface water partial pressure of CO2 (pCO2), DIC, δ13C in DIC, and total alkalinity (TA) determined in July 2009 and August 2007 were strongly related to river plume trajectories, and differed between the two summers. The slope of the relationship between dissolved oxygen (DO) and DIC in summer 2007 was comparable to the Redfield O/C ratio of 1.3, which was attributed to respiration of organic matter in the bottom water. The slope of the DO and DIC relationship and δ13CDIC values in bottom waters during July 2009 were clearly affected by mixing since their salinities were influence on the distribution of coastal currents and plume trajectories and their subsequent impact on biogeochemical processes.

  5. Streamflow responses to Chilean Megathrust earthquakes during the 20th and 21st centuries

    Science.gov (United States)

    Mohr, C.; Manga, M.; Wang, C. Y.; Korup, O.

    2015-12-01

    Coseismic static stress and dynamic stresses generated by propagating seismic waves cause responses in hydrological systems. Such responses include changes in the water level, hydrochemistry and streamflow discharge. Earthquake effects on hydrological systems provide a means to study the interaction between stress changes and regional hydrology, which is otherwise rarely possible. Chile is a country of frequent and large earthquakes and thus provides abundant opportunities to study such interactions and processes. Here we present streamflow responses to several Chilean Megathrust earthquakes, including the 1943 Mw 8.1 Coquimbo, 1950 Mw 8.2 Antofagasta, 1960 Mw 9.5 Valdivia, 1985 Mw 8.0 Valparaiso, 1995 Mw 8.0 Antofagasta, 2010 Mw 8.8 Maule, and the 2014 Mw 8.2 Iquique earthquakes. The stream gauges (n=716) are scattered across Chile, from the Altiplano in the North to Tierra del Fuego in the South. The network thus covers the Andes mountain ranges, the central valley, the Coastal Mountain ranges and (mainly in the more southern parts) the Coastal flats. We combine empirical magnitude-distance relationships, tree-based machine learning tools, and process-based modeling to characterize responses. We first assess the streamflow anomalies and relate these to environmental factors including geology, topography, altitude, soil and vegetation. We then apply 1D-groundwater flow modeling to selected catchments in order to test competing hypotheses for the origin of streamflow changes. We show that the responses of streamflow were heterogeneous, both in sign (decreases and increases in discharge) and in magnitude.

  6. Bayesian exploration of recent Chilean earthquakes

    Science.gov (United States)

    Duputel, Zacharie; Jiang, Junle; Jolivet, Romain; Simons, Mark; Rivera, Luis; Ampuero, Jean-Paul; Liang, Cunren; Agram, Piyush; Owen, Susan; Ortega, Francisco; Minson, Sarah

    2016-04-01

    The South-American subduction zone is an exceptional natural laboratory for investigating the behavior of large faults over the earthquake cycle. It is also a playground to develop novel modeling techniques combining different datasets. Coastal Chile was impacted by two major earthquakes in the last two years: the 2015 M 8.3 Illapel earthquake in central Chile and the 2014 M 8.1 Iquique earthquake that ruptured the central portion of the 1877 seismic gap in northern Chile. To gain better understanding of the distribution of co-seismic slip for those two earthquakes, we derive joint kinematic finite fault models using a combination of static GPS offsets, radar interferograms, tsunami measurements, high-rate GPS waveforms and strong motion data. Our modeling approach follows a Bayesian formulation devoid of a priori smoothing thereby allowing us to maximize spatial resolution of the inferred family of models. The adopted approach also attempts to account for major sources of uncertainty in the Green's functions. The results reveal different rupture behaviors for the 2014 Iquique and 2015 Illapel earthquakes. The 2014 Iquique earthquake involved a sharp slip zone and did not rupture to the trench. The 2015 Illapel earthquake nucleated close to the coast and propagated toward the trench with significant slip apparently reaching the trench or at least very close to the trench. At the inherent resolution of our models, we also present the relationship of co-seismic models to the spatial distribution of foreshocks, aftershocks and fault coupling models.

  7. Simulation of nutrient transport from different depths during an upwelling event in the Gulf of Finland

    OpenAIRE

    Germo Väli; Victor Zhurbas; Jaan Laanemets; Jüri Elken

    2011-01-01

    Numerical simulation experiments with a high-resolution circulation model were carried out to study nutrient transport from different depths to the surface 10-m layer during an upwelling event along the northern coast of the Gulf of Finland in July 1999. The initial nutrient distribution is based on field measurements performed in the north-western part of the Gulf. Wind forcing covering the period of the upwelling along the northern coast was turned through 180° to simulate an upwelling alon...

  8. Nitrate reducing activity pervades surface waters during upwelling.

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, S.O.; Halarnekar, R.; Malik, A.; Vijayan, V.; Varik, S.; RituKumari; Jineesh V.K.; Gauns, M.U.; Nair, S.; LokaBharathi, P.A.

    of the main limiting nutrients in the oceans (Dufour et al., 1999). Increased concentration of NO3- from upwelled waters in the euphotic zone supports higher primary production which in turn could cascade to the tertiary trophic level. Moreover, low... using 10 nM thymidine. TdR incorporation was terminated by addition of 5% TCA (Trichloroacetic acid). The samples were kept at 4 °C for 30 min prior to centrifugation. The tubes were centrifuged for 10 min at 16000 xg after which the supernatant...

  9. Characterisation of coastal counter-currents on the inner shelf of the Gulf of Cadiz

    Science.gov (United States)

    Garel, E.; Laiz, I.; Drago, T.; Relvas, P.

    2016-03-01

    At the Gulf of Cadiz (GoC), poleward currents leaning along the coast alternate with coastal upwelling jets of opposite direction. Here the patterns of these coastal countercurrents (CCCs) are derived from ADCP data collected during 7 deployments at a single location on the inner shelf. The multiyear (2008-2014) time-series, constituting ~ 18 months of hourly records, are further analysed together with wind data from several sources representing local and basin-scale conditions. During one deployment, temperature sensors were also installed near the mooring site to examine the vertical thermal stratification associated with periods of poleward flow. These observations indicate that the coastal circulation is mainly alongshore and barotropic. However, a baroclinic flow is often observed shortly at the time of flow inversion to poleward. CCCs develop all year-round and exclusively control the occurrence of warm coastal water during the upwelling season. On average, one poleward flow lasting 3 days was observed every week, corresponding to CCCs during ~ 40% of the time without seasonal variability. Thus, the studied region is distinct from typical upwelling systems where equatorward coastal upwelling jets largely predominate. CCCs often start to develop near the bed and are frequently associated with 2-layer cross-shore flows characteristic of downwelling conditions (offshore near the bed). In general, the action of alongshore wind stress alone does not justify the development of CCCs. The coastal circulation is best correlated and shows the highest coherence with south-eastward wind in the basin that proceeds from the rotation of southward wind at the West coast of Portugal, hence suggesting a dominant control of large-scale wind conditions. In agreement, wavelet analyses indicate that CCCs are best correlated with alongshore wind occurring in a band period characteristic of the upwelling system (8-32 days). Furthermore, in the absence of wind coastal currents tend

  10. Intensive aggregate formation with low vertical flux during an upwelling-induced diatom bloom

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Tiselius, P.; Mitchell-Innes, B.;

    1998-01-01

    The surfaces of most pelagic diatoms are sticky at times and may therefore form rapidly settling aggregates by physical coagulation. Stickiness and aggregate formation may be particularly adaptive in upwelling systems by allowing the retention of diatom populations in the vicinity of the upwelling...... center. We therefore hypothesized that upwelling diatom blooms are terminated by aggregate formation and rapid sedimentation. We monitored the development of a maturing diatom (mainly Chaetoceros spp.) bloom in the Benguela upwelling current during 7 d in February. Chlorophyll concentrations remained...

  11. Spatio-temporal patterns of C : N : P ratios in the northern Benguela upwelling regime

    Directory of Open Access Journals (Sweden)

    A. Flohr

    2013-06-01

    Full Text Available Dissolved carbon to nutrient ratios in the oceans' interior are remarkably consistent with the classical C : N : P : O2 Redfield ratio of 106 : 16 : 1 : 138 reflecting the mean composition of organic matter photosynthesized in the sunlit surface ocean. Deviations from the Redfield ratio indicate changes in the functioning of the biological carbon pump, which is driven and limited by the availability of nutrients. The northern Benguela coastal upwelling system (NBUS is known for losses of fixed nitrogen (N = NO3–, NO2– and NH4+ and the accumulation of phosphate (P in sub- and anoxic bottom waters and sediments of the Namibian shelf. To study the impact on the regional carbon cycle and consequences for the nutrient export from the BUS into the oligotrophic subtropical gyre of the South Atlantic Ocean we measured dissolved inorganic carbon (CT, oxygen (O2, and nutrient concentrations as well as the total alkalinity (AT in February 2011. Our results indicate that over the Namibian shelf the C : N : P : O2 ratio decreases to 106 : 16 : 1.6 : 138 because of phosphate efflux from sediments. N reduction further increase C : N and reduce N : P ratios in those regions where O2 concentrations in bottom waters are –1. However, off the shelf along the continental margin the mean C : N : P : O2 ratio is again close to the Redfield stoichiometry. Comparing the situation of 2011 with nutrient concentration data measured during 2 cruises in 2008 and 2009 implies that the amount of excess P that is created in the bottom waters on the shelf and its export into the subtropical gyre after upwelling varies through time. The magnitude of excess P formation and export is governed by inputs of excess N along with the South Atlantic Central Water (SACW flowing into the NBUS from the north as a poleward compensation current. Since excess N is produced by the remineralization of N-enriched biomass built up by N2-fixing organisms, factors controlling N2 fixation north

  12. Coastal Structures

    DEFF Research Database (Denmark)

    Oumeraci, H.; Burcharth, H. F.; Rouck, J. De;

    1995-01-01

    The paper attempts to present an overview of five research projects supported by the Commission of the European Communities, Directorate General XII, under the MAST 2- Programme (Marine Sciences and Technology), with the overall objective of contributing to the development of improved rational me...... methods for the design of coastal structures....

  13. Artificial ocean upwelling utilizing the energy of surface waves

    Science.gov (United States)

    Soloviev, Alexander

    2016-04-01

    Artificial upwelling can bring cold water from below the thermocline to the sea surface. Vershinsky, Pshenichnyy, and Soloviev (1987) developed a prototype device, utilizing the energy of surface waves to create an upward flow of water in the tube. This is a wave-inertia pump consisting of a vertical tube, a valve, and a buoy to keep the device afloat. An outlet valve at the top of the unit synchronizes the operation of the device with surface waves and prevents back-splashing. A single device with a 100 m long and 1.2 m diameter tube is able to produce up to 1 m3s-1 flow of deep water to the surface. With a 10 oC temperature difference over 100 m depth, the negative heat supply rate to the sea surface is 42 MW, which is equivalent to a 42 Wm-2 heat flux, if distributed over 1 km2 area. Such flux is comparable to the average net air-sea flux. A system of artificial upwelling devices can cool down the sea surface, modify climate on a regional scale and possibly help mitigate hurricanes. The cold water brought from a deeper layer, however, has a larger density than the surface water and therefore has a tendency to sink back down. In this work, the efficiency of wave-inertia pumps and climatic consequences are estimated for different environmental conditions using a computational fluid dynamics model.

  14. Southern Ocean warming delayed by circumpolar upwelling and equatorward transport

    Science.gov (United States)

    Armour, Kyle C.; Marshall, John; Scott, Jeffery R.; Donohoe, Aaron; Newsom, Emily R.

    2016-07-01

    The Southern Ocean has shown little warming over recent decades, in stark contrast to the rapid warming observed in the Arctic. Along the northern flank of the Antarctic Circumpolar Current, however, the upper ocean has warmed substantially. Here we present analyses of oceanographic observations and general circulation model simulations showing that these patterns--of delayed warming south of the Antarctic Circumpolar Current and enhanced warming to the north--are fundamentally shaped by the Southern Ocean's meridional overturning circulation: wind-driven upwelling of unmodified water from depth damps warming around Antarctica; greenhouse gas-induced surface heat uptake is largely balanced by anomalous northward heat transport associated with the equatorward flow of surface waters; and heat is preferentially stored where surface waters are subducted to the north. Further, these processes are primarily due to passive advection of the anomalous warming signal by climatological ocean currents; changes in ocean circulation are secondary. These findings suggest the Southern Ocean responds to greenhouse gas forcing on the centennial, or longer, timescale over which the deep ocean waters that are upwelled to the surface are warmed themselves. It is against this background of gradual warming that multidecadal Southern Ocean temperature trends must be understood.

  15. Seismic Moment and Slip Distribution of the 1960 and 2010 Chilean Earthquakes as Inferred from Tsunami Waveforms

    Science.gov (United States)

    Satake, K.; Fujii, Y.

    2010-12-01

    The 27 February 2010 Chilean earthquake generated tsunami and caused significant damage on the Chilean coast. The tsunami was recorded at many tide gauge stations around the Pacific Ocean, as well as bottom ocean bottom pressure gauges of DART system. We inverted tsunami waveform data, recorded at 11 tide gauges in Chile and Peru and 4 nearby DART stations, to estimate the slip distribution on the fault. When we assume 36 subfaults (12 along strike by 3 downdip, size of each subfault is 50 km × 50 km), very large slip is located at the most downdip subfaults beneath coast and land. Tsunami waveforms recorded other DART stations also require such deep slips. However, other geodetic and seismic data do not show such deep slips, and tsunami data have limited resolution for such a deep onshore slip. We therefore used coastal uplift and subsidence data at 36 locations reported by Farias et al. (2010). The joint inversion indicates two asperities, one to the north around Constitucion and the other to the south around Arauco peninsula. While the largest slip is still located beneath the coast, the offshore slips generally become larger than the tsunami inversion. The total seismic moment is about 1.8 × 1022 Nm (Mw 8.8), similar to the value estimated from tsunami waveforms only, and the fault length is 450 km. For the 22 May 1960 Chilean earthquake, we first made an inversion of tsunami data, recorded at 12 tide gauge stations mostly in South America. When we assume 27 subfaults (9 along strike by 3 downdip, size of each subfault is 100 km × 50 km), the total seismic moment is 4.6 × 1022 Nm (Mw 9.0). Again, the largest slip is estimated at the deepest subfault beneath land near the epicenter, which would produce large coastal uplift where the coastal subsidence was reported by Plafker and Savage (1970). Poor station coverage of tide gauges may limit the resolution of slip distribution particularly at the southern part of the source area. We therefore made a joint

  16. The Ghost in the Shell : Local and Remote Forcing of a Coastal Bivalve Inhabiting the Humboldt Current System

    Science.gov (United States)

    Gosselin, M.

    2014-12-01

    The external skeleton of mollusc bivalves, the shell, can furnish a recording of the environmental changes to which the organisms and population are exposed during their lives. The bivalve's growth is subjected to the thermocline variability; which itself is affected by environmental and climatic events. A highly variable environment such as the Humboldt current system (HCS) requires tools capable of recording its variations over a wide range of periodicities. Upwelling, Coastal trapped waves (CTWs), El Niño Southern Oscillation, and Pacific decadal oscillation events contribute to this environmental and climatic variability. The thermocline depth is modified by these different events at their own time-scales (respectively, daily to weekly, intraseasonally, interseasonally to interannually, and on a decadal scale). The thermocline variation translates into changes in Sea surface temperature (SST) and in the qualitative and quantitative productivity of phytoplankton. These two environmental factors are critical to bivalve growth.The sclerochronological (increment width) and sclerochemical (δ18O and δ13C) study consisted on the analysis of the Chilean bivalve Eurhomalea rufa, collected in 2005, as a recorder of the environmental HCS variability. The calibration step identified daily, monthly, and annual marks in the growth patterns of E. rufa. The results confirmed that the thermocline variability mainly drives the bivalve's activity and led to the establishment of a paleotemperature equation. Moreover, periodogram and wavelet analyses exposed the respective impacts of each environmental event from daily to interannual periodicities. In particular, the growth pattern of E. rufa follows SST variability at an intraseasonal periodicity (~ 60 days) which is remotely induced by CTWs. CTWs are generated by Kelvin oceanic waves, which are formed primarily by eastward equatorial Pacific winds (e.g. Shaffer et al. 1997; Montecino and Lange 2009).Sclerochronological studies

  17. How marine upwelling influences the distribution of Artemesia longinaris (Decapoda: Penaeoidea?

    Directory of Open Access Journals (Sweden)

    Gustavo S Sancinetti

    2014-05-01

    Full Text Available Upwelling events can occur in most of the oceans altering the water physical, chemical and sediment conditions and consequently the species communities dwelling the areas. For better understanding the behavior of populations inhabiting upwelling regions, the spatial and temporal distribution of a Penaeoidea shrimp was studied correlating it with the abiotic factors that vary during upwelling and non-upwelling periods in an area under influence of Cabo Frio upwelling. Bottom salinity and temperature, organic matter and sediment type from each station were sampled from March 2008 to February 2010, in six stations located between 5 and 45 m depth. The lowest temperatures were recorded during spring and summer for both years with temperature values lower than 19ºC. A total of 26,466 Artemesia longinaris shrimps were captured mainly in 10-35 m depth. Upwelling periods showed significant differences in abundance in relation to non-upwelling periods. The spatial distribution among stations varied according to the temperature with higher abundance in stations with values between 19 and 21ºC. The highest abundance of A. longinaris was recorded in spring and summer when intrusions of the cold waters of South Atlantic Central Waters (SACW were frequent. Thus, the effect of cold water of SACW boosted by the upwelling was a determinant factor in the spatial and temporal distribution of A. longinaris in the studied region.

  18. Non-limiting food conditions for growth and production of the copepod community in a highly productive upwelling zone

    Science.gov (United States)

    Escribano, Rubén; Bustos-Ríos, Evelyn; Hidalgo, Pamela; Morales, Carmen E.

    2016-09-01

    Zooplankton production is critical for understanding marine ecosystem dynamics. This work estimates copepod growth and production in the coastal upwelling and coastal transition zones off central-southern Chile (~35 to 37°S) during a 3-year time series (2004, 2005, and 2006) at a fixed shelf station, and from spring-summer spatial surveys during the same period. To estimate copepod production (CP), we used species-biomasses and associated C-specific growth rates from temperature dependent equations (food-saturated) for the dominant species, which we assumed were maximal growth rates (gmax). Using chlorophyll-a concentrations as a proxy for food conditions, we determined a size-dependent half-saturation constant with the Michaelis-Menten equation to derive growth rates (g) under the effect of food limitation. These food-dependent C-specific growth rates were much lower (ratio of 7.3. We concluded that interannual variation in copepod production resulted from factors and processes regulating copepod abundance and biomass in the absence of bottom-up control, allowing copepods to grow without limitation due to food resources.

  19. Plant Level Evidence on Product Mix Changes in Chilean Manufacturing

    OpenAIRE

    Lucas Navarro

    2008-01-01

    This paper analyzes changes in the product mix by Chilean manufacturing plants in the period 1996-2003. Three-quarters of the surviving plants changed the set of products produced and more than three-quarters of the exporting plants changed the mix of products they exported during the sample period. Plants that changed their product mix contributed 85% of the aggregate growth in real sales of surviving plants between 1996 and 2003. Finally and in contrast to the US evidence, there is a negati...

  20. THE RESPONSE OF MONTEREY BAY TO THE 2010 CHILEAN EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    Laurence C. Breaker

    2011-01-01

    Full Text Available The primary frequencies contained in the arrival sequence produced by the tsunami from the Chilean earthquake of 2010 in Monterey Bay were extracted to determine the seiche modes that were produced. Singular Spectrum Analysis (SSA and Ensemble Empirical Mode Decomposition (EEMD were employed to extract the primary frequencies of interest. The wave train from the Chilean tsunami lasted for at least four days due to multipath arrivals that may not have included reflections from outside the bay but most likely did include secondary undulations, and energy trapping in the form of edge waves, inside the bay. The SSA decomposition resolved oscillations with periods of 52-57, 34-35, 26-27, and 21-22 minutes, all frequencies that have been predicted and/or observed in previous studies. The EEMD decomposition detected oscillations with periods of 50-55 and 21-22 minutes. Periods in the range of 50-57 minutes varied due to measurement uncertainties but almost certainly correspond to the first longitudinal mode of oscillation for Monterey Bay, periods of 34-35 minutes correspond to the first transverse mode of oscillation that assumes a nodal line across the entrance of the bay, a period of 26- 27 minutes, although previously observed, may not represent a fundamental oscillation, and a period of 21-22 minutes has been predicted and observed previously. A period of ~37 minutes, close to the period of 34-35 minutes, was generated by the Great Alaskan Earthquake of 1964 in Monterey Bay and most likely represents the same mode of oscillation. The tsunamis associated with the Great Alaskan Earthquake and the Chilean Earthquake both entered Monterey Bay but initially arrived outside the bay from opposite directions. Unlike the Great Alaskan Earthquake, however, which excited only one resonant mode inside the bay, the Chilean Earthquake excited several modes suggesting that the asymmetric shape of the entrance to Monterey Bay was an important factor and that the

  1. Misconception p value among Chilean and Italian academic psychologists

    Directory of Open Access Journals (Sweden)

    Laura Badenes-Ribera

    2016-08-01

    Full Text Available The p value misconceptions are based on certain beliefs and attributions about the significance of the results. Thus, they affect the professionals’ decisions and jeopardize the quality of interventions and the accumulation of valid scientific knowledge. We conducted a survey on 164 academic psychologists (134 Italians, 30 Chileans, questioned on this topic. Our findings are consistent with original research and suggest that some participants do not know how to correctly interpret p values. The inverse probability fallacy presents the greatest comprehension problems, followed by the replication fallacy. These results highlight the importance of the statistical re-education of researchers. Recommendations for improving statistical cognition are proposed.

  2. Chilean Prosopis Mesocarp Flour: Phenolic Profiling and Antioxidant Activity

    OpenAIRE

    Guillermo Schmeda-Hirschmann; Cristina Quispe; Maria del Pilar C. Soriano; Cristina Theoduloz; Felipe Jiménez-Aspée; Maria Jorgelina Pérez; Ana Soledad Cuello; Maria Inés Isla

    2015-01-01

    In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82–2.57 g gallic acid equivalents/100 g fresh flour weight. The highest ant...

  3. Pervasive cracking of the northern Chilean Coastal Cordillera: New evidence for forearc extension

    Science.gov (United States)

    Loveless, John P.; Hoke, Gregory D.; Allmendinger, Richard W.; González, Gabriel; Isacks, Bryan L.; Carrizo, Daniel A.

    2005-12-01

    Despite convergence across the strongly coupled seismogenic interface between the South American and Nazca plates, the dominant neotectonic signature in the forearc of northern Chile is arc-normal extension. We have used 1 m resolution IKONOS satellite imagery to map nearly 37,000 cracks over an area of 500 km2 near the Salar Grande (21°S). These features, which are best preserved in a ubiquitous gypcrete surface layer, have both nontectonic and tectonic origins. However, their strong preferred orientation perpendicular to the plate convergence vector suggests that the majority owe their formation to approximate east-west extension associated with plate boundary processes such as interseismic loading, coseismic and postseismic strain, and long-term instability resulting from subduction erosion. Similar structures were formed during or shortly after the 1995 Mw = 8.0 earthquake near the city of Antofagasta, south of Salar Grande, and in conjunction with the 2001 Mw = 8.2 8.4 Arequipa, Peru, event. Cracks such as these may form in other forearcs but remain largely unexposed because of vegetative cover or marked fluvial erosion—factors that are absent in northern Chile as a result of its hyperarid climate.

  4. Contrasting Genetic Structure and Diversity of Galaxias maculatus (Jenyns, 1848) Along the Chilean Coast: Stock Identification for Fishery Management.

    Science.gov (United States)

    González-Wevar, Claudio; Salinas, Pilar; Hüne, Mathias; Segovia, Nicolás; Vargas-Chacoff, Luis; Oda, Esteban; Poulin, Elie

    2015-01-01

    Galaxias maculatus (Pisces: Galaxiidae) commonly known as "puye" has a disjunct distribution along the Southern Hemisphere including landlocked and migratory populations at latitudes over 30°S in South America, Australia, Tasmania, and New Zealand. Chilean artisanal fishery of G. maculatus has become less important as a resource due to multiple factors including overexploitation, pollution, introduction of predators, and competitors. At the same time, the current conservation status of the species in Chile is still uncertain. Here, we used mtDNA control region sequences (925bp) to investigate main patterns of genetic diversity and structure in populations from 2 biogeographic areas along the Chilean coast. Extremely high levels of genetic diversity characterize the species, suggesting a low amount of influence of the last glacial cycle over its demography compared with other studies in freshwater and marine South American fishes. However, we recognized contrasting genetic patterns between the Intermediate Area (between 30°S and 42°S) and the Magellanic Province (between 42°S and 56°S). On the one hand, over a narrow geographical range (<200 km) each Intermediate Area estuarine population constitutes a different genetic unit. On the other hand, the Magellanic populations of the species exhibited low levels of differentiation in an area extending for more than 500 km. Such differences may be a consequence of different coastal configurations, oceanographic regimes, and Quaternary glacial histories. Finally, our results support the existence of different stock units for G. maculatus and this information should be integrated in future management strategies and aquaculture programs for this species. PMID:26245779

  5. Hot mantle upwelling across the 660 beneath Yellowstone

    Science.gov (United States)

    Schmandt, Brandon; Dueker, Kenneth; Humphreys, Eugene; Hansen, Steven

    2012-05-01

    P-to-s receiver functions mapped to depth through P and S body-wave tomography models image continuous 410 and 660 km discontinuities beneath the area covered by USArray prior to the year 2011. Mean depths to the 410 and 660 km discontinuities of 410 and 656 km imply a mantle transition zone that is about 4 km thicker than the global average and hence has a slightly cooler mean temperature and/or enhanced water content. Compared to the mean 660 depth beneath this ~ 2000 km wide area, the 660 beneath the Yellowstone hotspot is deflected upward by 12-18 km over an area about 200 km wide. This is the most anomalous shallowing of the 660 imaged and its horizontal extent is similar to the area where P and S tomography image low-velocity mantle extending from the top of the transition zone to about 900 km depth. Together, these results indicate a high-temperature, plume-like upwelling extending across the 660. The depth of 410 km discontinuity beneath the Yellowstone region is within 5 km of the mean depth implying that the plume is vertically heterogeneous and possibly discontinuous. Tomography indicates a similar vertically heterogeneous thermal plume. The irregular plume structure may be intrinsic to the dynamics of upwelling through the transition zone, or distortion may be caused by subduction-induced mantle flow. Topography of the 410 and 660 confirms that subducted slabs beneath the western U.S. are highly segmented, as inferred from recent tomography studies. We find no evidence of regionally pervasive velocity discontinuities between 750 and 1400 km depth. The plume's depth of origin within the lower mantle remains uncertain.

  6. Scales and sources of pH and dissolved oxygen variability in a shallow, upwelling-driven ecosystem

    Science.gov (United States)

    Tanner, C. A.; Martz, T.; Levin, L. A.

    2011-12-01

    In the coastal zone extreme variability in carbonate chemistry and oxygen is driven by fluctuations in temperature, salinity, air-sea gas exchange, mixing processes, and biology. This variability appears to be magnified in upwelling-driven ecosystems where low oxygen and low pH waters intrude into shallow depths. The oxygen and carbon chemistry signal can be further confounded by highly productive ecosystems such as kelp beds where photosynthesis and respiration consume and release significant amounts of dissolved inorganic carbon and oxygen. This variability poses a challenge for scientists assessing the impacts of climate change on nearshore ecosystems. We deployed physical & biogeochemical sensors in order to observe these processes in situ. The "SeapHOx" instruments used in this study consist of a modified Honeywell Durafet° ISFET pH sensor, an Aanderra Optode Oxygen sensor, and a SBE-37 conductivity, temperature, pressure sensor. The instruments were deployed on and around the La Jolla Kelp Forest at a variety of depths. Our goals were to (a) characterize the link between pH and oxygen and identify the magnitude of pH and oxygen variability over a range of intra-annual time scales and (b) investigate spatial patterns of pH and oxygen variability associated with depth, proximity to shore, and presence of kelp. Results thus far reveal a strong relationship between oxygen and pH. Temporal variability is greatest at the semidiurnal frequency where pH (at 7 m) can range up to 0.3 units and oxygen can change 50% over 6 h. Diurnal variability is a combination of the diurnal tidal component and diel cycles of production and respiration. Event-scale dynamics associated with upwelling can maintain pH and oxygen below 7.8 units and 200 μmol kg-1, respectively, for multiple days. Frequent current reversals drive changes in the observed oxygen and pH variability. When alongshore currents are flowing southward, driven by upwelling-favorable winds, the magnitude of

  7. [The and beginnings of Chilean endocrinology in the 1920s].

    Science.gov (United States)

    Sánchez Delgado, Marcelo

    2016-01-01

    Rejuvenation was a chapter of critical importance for the worldwide development of endocrinology in the 1920s. This work explores the acceptance of these techniques in Chile. Starting in the late 19th century, the Chilean Medical Journal (Revista Médica de Chile) incorporated references to experiments with endocrine gland preparations that were being conducted in Europe at the time. An appropriation of the experiments by the Austrian Eugen Steinach began in 1920, with prominent figures such as the Italian professor Juan Noe Crevani and the young Chilean student Ottmar Wilhelm. Between 1922 and 1924, Wilhelm developed a series of experiments on dogs, bulls, pigs, rats and Welfare Board patients through the so-called Steinach operation, which consisted of the sectioning of the efferent channel in one of the testicles. Professor Noe's scientific patronage policy and Wilhelm's strategy of succession in the field led the latter to hold a chair in the new School of Medicine of Universidad de Concepci6n at the age of 25. From this position, the. figure of Wilhelm was fundamental for the development of a line of endocrinological research that was able to position Universidad de Concepci6n as a scientific development centre, which was strengthened by the arrival of another disciple of Steinach in Chile, the Latvian professor Alejandro Lipschütz. PMID:27363250

  8. Positive discrimination in education: Its justification and a Chilean example

    Science.gov (United States)

    Garcia-Huidobro, Juan Eduardo S.

    1994-05-01

    Educational policies in Latin America have centred on two main issues: raising the quality of education, and improving the equity of its distribution. Access to schooling was until recently at the heart of the debate, the degree of justice of the educational systems being measured by their capacity to enrol and retain the population. Attention is now concentrated on the strength of the cultural resources offered by schools and the effectiveness of provision. Learning is the priority of education policy. This article develops the theme of equity, examining the concept and describing a programme which focuses on improving the equity of the Chilean educational system. It is suggested that educational equity should no longer mean equality of access but equality of results. A just system therefore needs to concentrate on raising the quality of schools serving the poorest sectors of society. The Chilean "900 Schools Programme" is an example. Its aim was to raise levels of achievement by improving the learning of poor children from 1st to 4th grade in reading, writing and mathematics. To do so, it improved the school environment, textbooks and methodologies, and offered support to children outside school hours by the work of community monitors.

  9. Report on the 2010 Chilean earthquake and tsunami response

    Science.gov (United States)

    ,

    2011-01-01

    In July 2010, in an effort to reduce future catastrophic natural disaster losses for California, the American Red Cross coordinated and sent a delegation of 20 multidisciplinary experts on earthquake response and recovery to Chile. The primary goal was to understand how the Chilean society and relevant organizations responded to the magnitude 8.8 Maule earthquake that struck the region on February 27, 2010, as well as how an application of these lessons could better prepare California communities, response partners and state emergency partners for a comparable situation. Similarities in building codes, socioeconomic conditions, and broad extent of the strong shaking make the Chilean earthquake a very close analog to the impact of future great earthquakes on California. To withstand and recover from natural and human-caused disasters, it is essential for citizens and communities to work together to anticipate threats, limit effects, and rapidly restore functionality after a crisis. The delegation was hosted by the Chilean Red Cross and received extensive briefings from both national and local Red Cross officials. During nine days in Chile, the delegation also met with officials at the national, regional, and local government levels. Technical briefings were received from the President’s Emergency Committee, emergency managers from ONEMI (comparable to FEMA), structural engineers, a seismologist, hospital administrators, firefighters, and the United Nations team in Chile. Cities visited include Santiago, Talca, Constitución, Concepción, Talcahuano, Tumbes, and Cauquenes. The American Red Cross Multidisciplinary Team consisted of subject matter experts, who carried out special investigations in five Teams on the (1) science and engineering findings, (2) medical services, (3) emergency services, (4) volunteer management, and (5) executive and management issues (see appendix A for a full list of participants and their titles and teams). While developing this

  10. COASTAL, Pacific, Washington

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study data as defined in FEMA Guidelines and Specifications, Appendix D: Guidance for Coastal Flooding Analyses and Mapping, submitted as a coastal study.

  11. COASTAL, Homer, Alaska

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study data as defined in FEMA Guidelines and Specifications, Appendix D: Guidance for Coastal Flooding Analyses and Mapping, submitted as a coastal study.

  12. Coastal Inlet Model Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Coastal Inlet Model Facility, as part of the Coastal Inlets Research Program (CIRP), is an idealized inlet dedicated to the study of coastal inlets and equipped...

  13. Coastal Analysis, Northampton, VA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  14. Coastal Analysis, Accomack, VA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  15. Linking the kinematics of the interplate and the offshore morphology along the Chilean subduction margin

    Science.gov (United States)

    Urrutia, Isabel; Moreno, Marcos; Oncken, Onno

    2016-04-01

    Morphological features at subduction zones are undoubtedly influenced by the complex interplay between the subducting slab and the overriding plate. Several studies suggest that the subduction dynamics is strongly dependent on the geometry and rheology of the margin (including gravity/density anomalies, viscous mantle flow and roughness of the slab, among others). However, it is not clear how the geomorphological variation of the forearc along strike can be used as a proxy for better understanding the mechanics on the interface and seismotectonic segmentation. Here we investigate the links between the kinematics of the plate interface and the morphology of the overriding plate along the Chilean margin by combining morphometrical and statistical analysis. We constructed swath profiles subtracting the averaged topography and performed gradient analysis to characterize variations of morphological features, and we compared these results with the locking degree distribution derived from the inversion of GPS data. On the coastal area the bathymetry and topography analysis shows a planar feature, gently dipping ocean-wards and backed by a cliff, which exhibits spatial variations in its width, height and extension along-strike. This morphology suggests a quiescence process or a "stable tectonic condition", at least since the late Quaternary (over multiple seismic cycles). The results indicate that this planar feature spatially correlates with the rupture size of recent great earthquakes and locking degree areas, suggesting that earthquake cycle deformation has an imprint on the offshore morphology, which can be used to study the transfer of stresses among adjacent seismotectonic segments and the periodicity and location of large earthquakes. In addition, the longevity of this correlation between topography, earthquake rupture and geodetic locking that likely integrates over a time window of several 103 to several 105 years indicates that the instrumentally inferred locking

  16. The biology and ecology of the jumbo squid Dosidicus gigas (Cephalopoda in Chilean waters: a review

    Directory of Open Access Journals (Sweden)

    Christian M Ibáñez

    2015-07-01

    Full Text Available ABSTRACT. The jumbo squid Dosidicus gigas is the most abundant cephalopod species in the southeastern Pacific Ocean, which supports the biggest cephalopod fishery in the world. Due to its growing economic importance, the population growth and distributional expansion of this squid is being increasingly studied. Nevertheless, some basic features of the biology of D. gigas are still unknown or have been poorly investigated. In this review we summarize the known information regarding the biology and ecology of this species in the southeastern Pacific Ocean; we focus on the Chilean region in order to propose hypotheses and research lines for a better understanding the life history of this organism. Available data on the size structure, reproduction and genetics of D. gigas allows us to propose hypotheses related to the squid's life history traits. Based on the current literature and publications of colleagues, we propose two hypotheses regarding the effect of spatial variation on the life history of D. gigas. Hypothesis 1: Squids mature at large sizes and spawn in oceanic waters with warm temperatures where paralarvae and juveniles develop. Immature squids migrate near shore to feed, grow and mature, and then return to the offshore sites to spawn. Hypothesis 2: Alternatively, juvenile D. gigas in the oceanic zone do not migrate to coastal waters and mature at small sizes compared to individuals living near the coast that mature at larger size and migrate to oceanic waters to spawn. We provide background information about the feeding behavior and parasitism of this species, suggesting that D. gigas is an important trophic link in the southeastern Pacific marine ecosystem. However, more studies on the feeding habits, reproduction and parasite load are needed not only to test hypotheses proposed in this study, but also to advance the overall knowledge of this species.

  17. Introduction to coastal engineering

    NARCIS (Netherlands)

    D' Angremond, K.; Pluim-van der Velden, E.T.J.M.

    2001-01-01

    Lecture notes on genesis of the coastline, climatology, oceanography, coastal morphology, coastal formations, coastalzonde management, tidal inlets and estuaries, pollution and density problems, practical problems and common solutions.

  18. Long-term trends of upwelling and impacts on primary productivity in the Alaskan Beaufort Sea

    Science.gov (United States)

    Pickart, Robert S.; Schulze, Lena M.; Moore, G. W. K.; Charette, Matthew A.; Arrigo, Kevin R.; van Dijken, Gert; Danielson, Seth L.

    2013-09-01

    Using a previously established wind proxy for upwelling along the North Slope of Alaska, we examine the interannual to decadal variability in upwelling as well as the climatological monthly trends. The ability of the upwelling to trigger phytoplankton blooms via upward nitrate flux from the halocline is then investigated using data from a moored array together with the proxy. The 70-year record of wind speed from the Barrow, Alaska meteorological station (1941-2010) reveals that strong upwelling events - lasting at least 4 days and exceeding 10 m/s during the storm - occur throughout the year. On average there are 9-10 upwelling events per year, and the number and strength of events has increased over the last 25 years. The low-frequency variability in the upwelling co-varies with previously documented Arctic climate trends, but there is no significant correlation with various high latitude atmospheric indices. There are two seasonal peaks in the occurrence of upwelling, in May and November. The role of the Beaufort High and Aleutian Low in driving the upwelling is investigated using NCEP reanalysis fields. Fluctuations in both of these centers of action contribute to the enhanced winds, and the location of the Aleutian Low storm track plays a key role in the seasonal variability of the upwelling. The upward nitrate flux due to storms in the open water period can account for new primary production that is on par with carbon fixed during the summer growing season in the absence of storms. Evidence from satellite ocean color data of such wind-induced phytoplankton blooms is presented.

  19. Properties of Red Sea coastal currents

    KAUST Repository

    Churchill, J.H.

    2014-02-14

    Properties of coastal flows of the central Red Sea are examined using 2 years of velocity data acquired off the coast of Saudi Arabia near 22 °N. The tidal flow is found to be very weak. The strongest tidal constituent, the M2 tide, has a magnitude of order 4 cm s−1. Energetic near-inertial and diurnal period motions are observed. These are surface-intensified currents, reaching magnitudes of >10 cm s−1. Although the diurnal currents appear to be principally wind-driven, their relationship with the surface wind stress record is complex. Less than 50% of the diurnal current variance is related to the diurnal wind stress through linear correlation. Correlation analysis reveals a classical upwelling/downwelling response to the alongshore wind stress. However, less than 30% of the overall sub-inertial variance can be accounted for by this response. The action of basin-scale eddies, impinging on the coastal zone, is implicated as a primary mechanism for driving coastal flows.

  20. Biological and oceanographic upwelling indicators at Cabo Frio (RJ

    Directory of Open Access Journals (Sweden)

    Gleyci A. O. Moser

    1997-01-01

    Full Text Available Phytoplankton biomass, chemical parameters and hydrology were studied in a transect 101.6 km long off Cabo Frio (RJ, Southeast Brazil, during summer (December 29 to 31, 1991 and winter (June 27 to 30, 1992. Wind induced upwelling events are frequently observed in the area during summer, becoming rare during winter. By the summer cruise a bloom of phytoplankton was observed in surface, close to the coast, with chlorophyll concentrations reaching 25.55 mg Chl-a m-3, uncoupled from the cold, nutrient rich waters of South Atlantic Central Water (SACW, found below 40 m depth. During the winter cruise, the SACW raised at the surface waters in front of Cabo Frio depicting an upwelling event. However, in spite of high surface nitrate concentrations (up to 7.7 f.1M chlorophyll-a were lower than 2 mg Chl-a m-3. The phytoplankton biomass, meteorological and hydrological data suggest a probable upwelling event immediately before the summer cruise, and an ongoing one during winter time. Cluster analyses and principal component analyses (PCA were applied to summer and winter data, pointing out multidimensional fronts in the area during both seasons.A biomassa fitoplanctônica, parâmetros químicos e hidrologia foram estudadas em um transecto de 101,6 Km ao largo de Cabo Frio, (RJ Brasil, durante o verão (Dezembro 29 a 31, 1991 e inverno (Junho 27 a 30, 1992. Nesta área, eventos de ressurgência induzidos pelo vento são comuns durante o verão, tornando-se mais raros durante o inverno. Durante o período de verão uma floração de fitoplâncton foi observada na superfície próximo ao continente, apresentando um máximo de clorofila-a igual a 25,55 mg Cl-a m'3 desacoplado das águas frias e ricas em nutrientes da Água Central do Atlântico Sul (ACAS, presente abaixo de 40 m. Durante o inverno, a ACAS alcançou a superflcie em frente a Cabo Frio, caracterizando um evento de ressurgência. Entretanto, apesar das altas concentrações de nitrato na superf

  1. Understanding the nature of mantle upwelling beneath East-Africa

    Science.gov (United States)

    Civiero, Chiara; Hammond, James; Goes, Saskia; Ahmed, Abdulhakim; Ayele, Atalay; Doubre, Cecile; Goitom, Berhe; Keir, Derek; Kendall, Mike; Leroy, Sylvie; Ogubazghi, Ghebrebrhan; Rumpker, Georg; Stuart, Graham

    2014-05-01

    The concept of hot upwelling material - otherwise known as mantle plumes - has long been accepted as a possible mechanism to explain hotspots occurring at Earth's surface and it is recognized as a way of removing heat from the deep Earth. Nevertheless, this theory remains controversial since no one has definitively imaged a plume and over the last decades several other potential mechanisms that do not require a deep mantle source have been invoked to explain this phenomenon, for example small-scale convection at rifted margins, meteorite impacts or lithospheric delamination. One of the best locations to study the potential connection between hotspot volcanism at the surface and deep mantle plumes on land is the East African Rift (EAR). We image seismic velocity structure of the mantle below EAR with higher resolution than has been available to date by including seismic data recorded by stations from many regional networks ranging from Saudi Arabia to Tanzania. We use relative travel-time tomography to produce P- velocity models from the surface down into the lower mantle incorporating 9250 ray-paths in our model from 495 events and 402 stations. We add smaller earthquakes (4.5 poorly sampled regions in order to have a more uniform data coverage. The tomographic results allow us to image structures of ~ 100-km length scales to ~ 1000 km depth beneath the northern East-Africa rift (Ethiopia, Eritrea, Djibouti, Yemen) with good resolution also in the transition zone and uppermost lower mantle. Our observations provide evidence that the shallow mantle slow seismic velocities continue trough the transition zone and into the lower mantle. In particular, the relatively slow velocity anomaly beneath the Afar Depression extends up to depths of at least 1000 km depth while another low-velocity anomaly beneath the Main Ethiopian Rift seems to be present in the upper mantle only. These features in the lower mantle are isolated with a diameter of about 400 km indicating deep

  2. Effects of suspended mussel culture on benthic-pelagic coupling in a coastal upwrelling system (Ria de Vigo, NW Iberian Peninsula)

    NARCIS (Netherlands)

    Alonso-Perez, F.; Ysebaert, T.; Castro, C.G.

    2010-01-01

    The influence of suspended mussel culture on the benthic-pelagic coupling was evaluated in the Ria de Vigo, in the coastal upwelling system of the NW Iberian Peninsula, during the month of July 2004. Measurements of water column properties were carried out at three stations in the Ria de Vigo: under

  3. The Light-Field of Microbenthic Communities - Radiance Distribution and Microscale Optics of Sandy Coastal Sediments Rid A-1977-2009

    DEFF Research Database (Denmark)

    KUHL, M.; JØRGENSEN, BB

    1994-01-01

    relative to vertically incident collimated light in rinsed quartz sand and in a coastal sandy sediment colonized by microalgae. Upwelling and downwelling components of irradiance and scalar irradiance were calculated from the radiance distributions. Calculated total scalar irradiance agreed well with the...

  4. Creating stability in constant uncertainty : dealing with crisis in the Chilean aquaculture industry

    OpenAIRE

    Amundsen, Vilde Steiro

    2015-01-01

    This thesis is the result of a fieldwork conducted in Fish Inc., a Chilean branch of a Norwegian-owned company dealing with equipment for fish farming. The Chilean aquaculture industry has since the sanitary and financial crisis of 2007 experienced a constant unpredictability, with extreme fluctuation between incredible upswings and crashing downturns. The instability and uncertainty of the industry has generated the necessity of creating a sense of continuity for employees in dealing with th...

  5. BTX abatement using Chilean natural zeolite: the role of Brønsted acid sites

    OpenAIRE

    Alejandro, S.; Valdés, Héctor; Manero, Marie-Hélène; Zaror, Claudio A.

    2012-01-01

    In wastewater treatment facilities, air quality is not only affected by conventional unpleasant odour compounds; toxic volatile organic compounds (VOCs) are also found. In this study, the adsorptive capacity of Chilean natural zeolite toward VOC removal was evaluated. Moreover, the influence of zeolite chemical surface properties on VOC elimination was also investigated. Three modified zeolite samples were prepared from a natural Chilean zeolite (53% clinoptilolite, 40% mordenite and 7% quart...

  6. Strengthening early math skills in preschoolers, a Chilean study

    Directory of Open Access Journals (Sweden)

    Rosario Ortega

    2011-05-01

    Full Text Available The article describes the positive effect in an intervention programbased on number comprehension in early math skill levels that Chileanpreschoolers present in the relational and numerical skill areas evaluated with the Test of Early Mathematics Assessment Utrecht (TEMT-U, the Spanish version of the Utrecht Early Numeracy Test. The study reveals that there are significant differences in the early math skills levels among those groups subjected to thistype of program and those that in the same period of time were only influenced by the content and activities of the traditional curriculum sequence in the Chilean school population. There are positive effects in the program regardless of the educational level that children attend. There are also relational or skillsPiagetian that show higher achievement levels. The results prove that there are no differences in mathematical literacy levels between boys and girls, contrary to what is observed in later years.

  7. Chilean prosopis mesocarp flour: phenolic profiling and antioxidant activity.

    Science.gov (United States)

    Schmeda-Hirschmann, Guillermo; Quispe, Cristina; Soriano, Maria Del Pilar C; Theoduloz, Cristina; Jiménez-Aspée, Felipe; Pérez, Maria Jorgelina; Cuello, Ana Soledad; Isla, Maria Inés

    2015-04-17

    In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82-2.57 g gallic acid equivalents/100 g fresh flour weight. The highest antioxidant activity, measured by the DPPH assay, was observed for samples from the Huasco valley. HPLC-MS/MS analysis allowed the tentative identification of eight anthocyanins and 13 phenolic compounds including flavonol glycosides, C-glycosyl flavones and ellagic acid derivatives. The antioxidant activity and the phenolic composition in the flour suggest that this ancient South American resource may have potential as a functional food.

  8. Chilean Prosopis Mesocarp Flour: Phenolic Profiling and Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Guillermo Schmeda-Hirschmann

    2015-04-01

    Full Text Available In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82–2.57 g gallic acid equivalents/100 g fresh flour weight. The highest antioxidant activity, measured by the DPPH assay, was observed for samples from the Huasco valley. HPLC-MS/MS analysis allowed the tentative identification of eight anthocyanins and 13 phenolic compounds including flavonol glycosides, C-glycosyl flavones and ellagic acid derivatives. The antioxidant activity and the phenolic composition in the flour suggest that this ancient South American resource may have potential as a functional food.

  9. Justified Ilegality?: Controlled clientelism by the Chilean administration

    Directory of Open Access Journals (Sweden)

    Marcelo Moriconi Bezerra

    2011-07-01

    Full Text Available The Chilean civil service is considered one of the most efficient in Latin America. However, different studies describe the informal institutions that operate between the Legislative Power and the bureaucracy to fill positions in the public administration. Although some of these clientelistic practices are against the law, they have been accepted and defended in both the political and scientific spheres. Legality is not considered an important value if certain indexes have a positive development. In this context, it is important to study how corruption and clientelism have been ignored, or hidden, through political discourses and technical reports about the situation of bureaucracy. All of this allows a better understanding of why after 20 years of administrative reforms there are damaging practices which negatively affect democracy that have not been eradicated.

  10. Chilean prosopis mesocarp flour: phenolic profiling and antioxidant activity.

    Science.gov (United States)

    Schmeda-Hirschmann, Guillermo; Quispe, Cristina; Soriano, Maria Del Pilar C; Theoduloz, Cristina; Jiménez-Aspée, Felipe; Pérez, Maria Jorgelina; Cuello, Ana Soledad; Isla, Maria Inés

    2015-01-01

    In South America, the mesocarp flour of Prosopis species plays a prominent role as a food resource in arid areas. The aim of this work was the characterization of the phenolic antioxidants occurring in the pod mesocarp flour of Chilean Prosopis. Samples were collected in the Copiapo, Huasco and Elqui valleys from the north of Chile. The samples of P. chilensis flour exhibited a total phenolic content ranging between 0.82-2.57 g gallic acid equivalents/100 g fresh flour weight. The highest antioxidant activity, measured by the DPPH assay, was observed for samples from the Huasco valley. HPLC-MS/MS analysis allowed the tentative identification of eight anthocyanins and 13 phenolic compounds including flavonol glycosides, C-glycosyl flavones and ellagic acid derivatives. The antioxidant activity and the phenolic composition in the flour suggest that this ancient South American resource may have potential as a functional food. PMID:25898415

  11. Ekman Upwelling, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes science quality Ekman current (in zonal, meridional, and modulus sets) and Ekman upwelling data. This data begins with wind velocity...

  12. Ekman Upwelling, METOP ASCAT, 0.25 degrees, Global, Near Real Time

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes near real time Ekman current (in zonal, meridional, and modulus sets) and Ekman upwelling data. This data begins with wind velocity...

  13. Upwelling at the ice edge - A mechanism for deep water formation?

    Science.gov (United States)

    Hakkinen, Sirpa

    1987-01-01

    This study sets forward a hypothesis which anticipates deep water formation due to ice edge upwelling. The upwelling can raise thermocline waters (the lower Arctic Intermediate Water) to the surface or near it, where the water is exposed to cooling, evaporation, mixing, and oxygenation. Thus, upwelling can act as a preconditioning mechanism for deep convection. The conjecture would also explain the salinity range of the Greenland Sea Deep Water if the upper and lower Arctic Intermediate Water masses are mixed so that the latter has at least an 80-percent contribution. It is also anticipated that the convection events induced by ice edge upwelling during winter season could give rise to a new deep water annual production rate consistent with observations.

  14. Observational evidence of upwelling off the southwest coast of India during June-July 2006

    Digital Repository Service at National Institute of Oceanography (India)

    Lekshmi, S.; Smitha, B.R.; Revichandran, C.

    transects off Thiruvananthapuram (8.5 degrees N) and off Koilam (9 degrees N), during June 25th-6th July 2006. Observed upwelling parameters (local temperature anomalies, salinity, isothermal layer depth (ILD), Mixed Layer Depth (MLD), isotherm slope...

  15. Helicobacter pylori infection and gastrointestinal symptoms on Chilean pregnant women

    Directory of Open Access Journals (Sweden)

    Gina Ferrer Poveda

    2014-07-01

    Full Text Available Objective: the aim of this research was to determine the prevalence of Helicobacter pylori infection on Chilean pregnant women and its relationship with the appearance and severity of hyperemesis and dyspepsia. Methods: quantitative study of prevalence in a transversal cut with variable analysis. The sample was taken from 274 Chilean pregnant women from the Bío Bío province through vein puncture between June and December, 2005. Pregnant women were informed of this study, interviewed and signed an informed consent. The samples were processed using ImmunoComb II Helicobacter pylori IgG kit. Statistical analysis was performed by means of the Statistical Package for Social Sciences (SPSS Program. Results: out of the total number of pregnant women, 68.6% showed infection by Helicobacter pylori. 79.6% of the total sample had symptoms of dyspepsia, and 72.5% of this group presented Helicobacter pylori infection. 12.4% showed pregnancy hyperemesis; among them, 79.4% were infected with Helicobacter pylori. 73.4% of the pregnant women that showed gastric discomfort during the first three months had Helicobacter pylori infection. 53.7% of them continued with gastric discomfort after the first three months; of those, 95.8% were infected. Helicobacter pylori infection was present only in 1.5% of pregnant women without gastric discomfort. Conclusion: both, gastric discomfort of pregnant women and the continuity of severe symptoms of dyspepsia and hyperemesis after the first three months of gestation are significantly correlated with Helicobacter pylori infection.

  16. Indo-European and Asian origins for Chilean and Pacific chickens revealed by mtDNA.

    Science.gov (United States)

    Gongora, Jaime; Rawlence, Nicolas J; Mobegi, Victor A; Jianlin, Han; Alcalde, Jose A; Matus, Jose T; Hanotte, Olivier; Moran, Chris; Austin, Jeremy J; Ulm, Sean; Anderson, Atholl J; Larson, Greger; Cooper, Alan

    2008-07-29

    European chickens were introduced into the American continents by the Spanish after their arrival in the 15th century. However, there is ongoing debate as to the presence of pre-Columbian chickens among Amerindians in South America, particularly in relation to Chilean breeds such as the Araucana and Passion Fowl. To understand the origin of these populations, we have generated partial mitochondrial DNA control region sequences from 41 native Chilean specimens and compared them with a previously generated database of approximately 1,000 domestic chicken sequences from across the world as well as published Chilean and Polynesian ancient DNA sequences. The modern Chilean sequences cluster closely with haplotypes predominantly distributed among European, Indian subcontinental, and Southeast Asian chickens, consistent with a European genetic origin. A published, apparently pre-Columbian, Chilean specimen and six pre-European Polynesian specimens also cluster with the same European/Indian subcontinental/Southeast Asian sequences, providing no support for a Polynesian introduction of chickens to South America. In contrast, sequences from two archaeological sites on Easter Island group with an uncommon haplogroup from Indonesia, Japan, and the Philippines [corrected] and may represent a genetic signature of an early Polynesian dispersal. Modeling of the potential marine carbon contribution to the Chilean archaeological specimen casts further doubt on claims for pre-Columbian chickens, and definitive proof will require further analyses of ancient DNA sequences and radiocarbon and stable isotope data from archaeological excavations within both Chile and Polynesia. PMID:18663216

  17. Practical limitations on the use of diurnal temperature signals to quantify groundwater upwelling

    Science.gov (United States)

    Briggs, Martin; Lautz, Laura K.; Buckley, Sean F.; Lane, Jr., John W.

    2014-01-01

    Groundwater upwelling to streams creates unique habitat by influencing stream water quality and temperature; upwelling zones also serve as vectors for contamination when groundwater is degraded. Temperature time series data acquired along vertical profiles in the streambed have been applied to simple analytical models to determine rates of vertical fluid flux. These models are based on the downward propagation characteristics (amplitude attenuation and phase-lag) of the surface diurnal signal. Despite the popularity of these models, there are few published characterizations of moderate-to-strong upwelling. We attribute this limitation to the thermodynamics of upwelling, under which the downward conductive signal transport from the streambed interface occurs opposite the upward advective fluid flux. Governing equations describing the advection–diffusion of heat within the streambed predict that under upwelling conditions, signal amplitude attenuation will increase, but, counterintuitively, phase-lag will decrease. Therefore the extinction (measurable) depth of the diurnal signal is very shallow, but phase lag is also short, yielding low signal to noise ratio and poor model sensitivity. Conversely, amplitude attenuation over similar sensor spacing is strong, yielding greater potential model sensitivity. Here we present streambed thermal time series over a range of moderate to strong upwelling sites in the Quashnet River, Cape Cod, Massachusetts. The predicted inverse relationship between phase-lag and rate of upwelling was observed in the field data over a range of conditions, but the observed phase-lags were consistently shorter than predicted. Analytical solutions for fluid flux based on signal amplitude attenuation return results consistent with numerical models and physical seepage meters, but the phase-lag analytical model results are generally unreasonable. Through numerical modeling we explore reasons why phase-lag may have been over-predicted by the

  18. The influence of summer upwelling at the western boundary of the Cantabrian coast

    OpenAIRE

    Prego, R; Varela, Manuel; De Castro, M.; Ospina-Álvarez, Natalia; García-Soto, Carlos; Gómez-Gesteira, M.

    2012-01-01

    Recent characterizations of atmospheric conditions favorable to upwelling events in the Western Cantabrian Sea have stressed the need to analyze the significance of the orientation of the coast on the phenomenon of upwelling. Surface-wind fields for the northwestern Galician marine area were provided by the QuikSCAT satellite and an SST map was elaborated using the NASA GHRSST satellite data. A cruise was conducted aboard the RV Lura in June 2009 during northern prevailing winds. Data of ther...

  19. Hydrous upwelling across the mantle transition zone beneath the Afar Triple Junction

    OpenAIRE

    Thompson, D A; Hammond, J.O.S.; Kendall, J-M; Stuart, G.W.; Helffrich, G.R.; Keir, D.; Ayele, A.; Goitom, B.

    2015-01-01

    The mechanisms that drive the upwelling of chemical heterogeneity from the lower to upper mantle (e.g., thermal versus compositional buoyancy) are key to our understanding of whole mantle con- vective processes. We address these issues through a receiver function study on new seismic data from recent deployments located on the Afar Triple Junction, a location associated with deep mantle upwelling. The detailed images of upper mantle and mantle transition zone structure illuminate features tha...

  20. Extensive summer upwelling on Lake Michigan during 1973 observed by NOAA-2 and ERTS-1 satellites

    Science.gov (United States)

    Strong, A. E.; Stumpf, H. G.; Hart, J. L.; Pritchard, J. A.

    1974-01-01

    Two studies are presented that utilize data from the NOAA-2 and ERTS-1 satellites. The studies are concentrated on two summer upwelling episodes in Lake Michigan when considerable contrast was observed in both surface water temperature as observed by NOAA-2 and surface water color as observed by ERTS-1. Physical, biological and chemical processes support the hypothesis that much of the observed 'whitening' is calcium carbonate precipitating as an immediate result of the upwelling.

  1. Numerical simulation of upwelling currents in pockmarks, and data from the Inner Oslofjord, Norway

    OpenAIRE

    Hammer, Ø; Webb, K. E.; Depreiter, D.

    2009-01-01

    The deflection of oceanic or tidal currents into pockmarks has been studied by both general three-dimensional computational fluid dynamics simulations and acoustic measurements in a number of pockmarks in the Inner Oslofjord, Norway. The modeling demonstrates upstream convergence of flow lines, followed by upwelling over the pockmark. This upwelling is an effect of deflected regional currents, not of expulsion of fluids or gas from the seafloor, and is sufficiently strong to prevent the settl...

  2. Dynamics of wind-driven upwelling off the northeastern coast of Hainan Island

    Science.gov (United States)

    Lin, Peigen; Cheng, Peng; Gan, Jianping; Hu, Jianyu

    2016-02-01

    Both observational and reanalysis sea surface temperature data reveal that upwelling occurs frequently off the northeastern coast of Hainan Island (downstream of the change in topography off Tongluo Cape), which cannot be attributed to the along-shelf wind alone. To identify dynamics of the upwelling, we conduct a numerical experiment using an idealized topography that is simplified from the actual topography off the eastern and northeastern coasts of Hainan Island. The result indicates that the upwelling downstream of the change in topography is associated with onshore cross-isobath transport. Analysis of the vertically integrated momentum balance shows that the upwelling-linked onshore transport is primarily intensified by the along-isobath barotropic pressure gradient force (PGT), but is weakened by the along-isobath baroclinic pressure gradient force (PGC). The along-isobath PGT is linked to the advection of relative vorticity, the bottom stress curl and the gradient of momentum flux in vorticity equation. On the other hand, the PGC-related process is diagnosed by potential vorticity (PV) balance. Similar to the negative PV term from wind stress, the negative PV terms of the joint effect of baroclinicity and relief and the baroclinic bottom pressure torque weaken the upwelling-linked onshore transport downstream of the change in topography. The onshore transport is enhanced by the positive PV from bottom stress. In addition, the cross-isobath forces play an important role in upwelling intensification in the shallow nearshore region.

  3. Implications of Upwells as Hydrodynamic Jets in a Pulse Jet Mixed System

    Energy Technology Data Exchange (ETDEWEB)

    Pease, Leonard F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bamberger, Judith A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Minette, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-08-01

    This report evaluates the physics of the upwell flow in pulse jet mixed systems in the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Although the initial downward flow and radial flow from pulse jet mixers (PJMs) has been analyzed in some detail, the upwells have received considerably less attention despite having significant implications for vessel mixing. Do the upwells behave like jets? How do the upwells scale? When will the central upwell breakthrough? What proportion of the vessel is blended by the upwells themselves? Indeed, how the physics of the central upwell is affected by multiple PJMs (e.g., six in the proposed mixing vessels), non-Newtonian rheology, and significant multicomponent solids loadings remain unexplored. The central upwell must satisfy several criteria to be considered a free jet. First, it must travel for several diameters in a nearly constant direction. Second, its velocity must decay with the inverse of elevation. Third, it should have an approximately Gaussian profile. Fourth, the influence of surface or body forces must be negligible. A combination of historical data in a 12.75 ft test vessel, newly analyzed data from the 8 ft test vessel, and conservation of momentum arguments derived specifically for PJM operating conditions demonstrate that the central upwell satisfies these criteria where vigorous breakthrough is achieved. An essential feature of scaling from one vessel to the next is the requirement that the underlying physics does not change adversely. One may have confidence in scaling if (1) correlations and formulas capture the relevant physics; (2) the underlying physics does not change from the conditions under which it was developed to the conditions of interest; (3) all factors relevant to scaling have been incorporated, including flow, material, and geometric considerations; and (4) the uncertainty in the relationships is sufficiently narrow to meet required specifications. Although the central upwell

  4. Trace metal variability in coastal waters of San Jorge Bay, Antofagasta, Chile: An environmental evaluation and statistical approach to propose local background levels.

    Science.gov (United States)

    Valdés, J; Román, D; Guiñez, M; Rivera, L; Ávila, J; Cortés, P; Castillo, A

    2015-11-15

    Between 2008 and 2011, twelve metals from 384 coastal waters samples from San Jorge Bay (Antofagasta, northern Chile) were collected and analyzed. The goal was to evaluate the quality of the bay's water bodies according to the current Chilean Quality Guideline and to establish background levels for these metals. The result suggests that the coastal waters of San Jorge Bay are of very good quality suitable for recreational activities involving human body contact. The natural background thresholds established for this bay were significantly lower than primary and secondary water quality guidelines. The distribution of Cu, Zn and Pb, along the bay's coastline provides evidence of the effects of industrial activity. Both situations suggest that the threshold indicated in the environmental guidelines of the Chilean legislation may be overestimated and do not represent pollution-free environments. PMID:26365501

  5. Trace metal variability in coastal waters of San Jorge Bay, Antofagasta, Chile: An environmental evaluation and statistical approach to propose local background levels.

    Science.gov (United States)

    Valdés, J; Román, D; Guiñez, M; Rivera, L; Ávila, J; Cortés, P; Castillo, A

    2015-11-15

    Between 2008 and 2011, twelve metals from 384 coastal waters samples from San Jorge Bay (Antofagasta, northern Chile) were collected and analyzed. The goal was to evaluate the quality of the bay's water bodies according to the current Chilean Quality Guideline and to establish background levels for these metals. The result suggests that the coastal waters of San Jorge Bay are of very good quality suitable for recreational activities involving human body contact. The natural background thresholds established for this bay were significantly lower than primary and secondary water quality guidelines. The distribution of Cu, Zn and Pb, along the bay's coastline provides evidence of the effects of industrial activity. Both situations suggest that the threshold indicated in the environmental guidelines of the Chilean legislation may be overestimated and do not represent pollution-free environments.

  6. Report on the 2010 Chilean earthquake and tsunami response

    Science.gov (United States)

    ,

    2011-01-01

    In July 2010, in an effort to reduce future catastrophic natural disaster losses for California, the American Red Cross coordinated and sent a delegation of 20 multidisciplinary experts on earthquake response and recovery to Chile. The primary goal was to understand how the Chilean society and relevant organizations responded to the magnitude 8.8 Maule earthquake that struck the region on February 27, 2010, as well as how an application of these lessons could better prepare California communities, response partners and state emergency partners for a comparable situation. Similarities in building codes, socioeconomic conditions, and broad extent of the strong shaking make the Chilean earthquake a very close analog to the impact of future great earthquakes on California. To withstand and recover from natural and human-caused disasters, it is essential for citizens and communities to work together to anticipate threats, limit effects, and rapidly restore functionality after a crisis. The delegation was hosted by the Chilean Red Cross and received extensive briefings from both national and local Red Cross officials. During nine days in Chile, the delegation also met with officials at the national, regional, and local government levels. Technical briefings were received from the President’s Emergency Committee, emergency managers from ONEMI (comparable to FEMA), structural engineers, a seismologist, hospital administrators, firefighters, and the United Nations team in Chile. Cities visited include Santiago, Talca, Constitución, Concepción, Talcahuano, Tumbes, and Cauquenes. The American Red Cross Multidisciplinary Team consisted of subject matter experts, who carried out special investigations in five Teams on the (1) science and engineering findings, (2) medical services, (3) emergency services, (4) volunteer management, and (5) executive and management issues (see appendix A for a full list of participants and their titles and teams). While developing this

  7. The seasonal upwellings in the Gulf of Guinea

    Science.gov (United States)

    Verstraete, Jean-Marc

    Observational as well as numerical experiments show that Ekman divergence neither at the equator nor at the coast can explain a significant part of the annual upwelling in the Gulf of Guinea. The remote forcing theory is tested by analyzing both historical data and the FOCAL hydrographic stations (1982-1984). The meteorological data base is analysed as well. Analyses of the thermostad show that waters with the same characteristics as those of the South Atlantic Central Water (SACW) are carried by the equatorial under current (EUC) and the South Equatorial Undercurrent (SEUC) from the western-central equatorial Atlantic at 35° - 29°W towards the thermostad regions in the Gulf of Guinea. The thermostad water is then carried back westward in the two geostrophic compensation flows flanking the EUC at 2° - 3°N and 2° - 3°S. The cooling of the subthermoclinal waters off Abidjan (5°N) and Pointe-Noire (5°S) is related to the advection and vertical spreading of SACW between 500m and 50m in May-June-July. An exceptional warm event occurred in early 1984 in the Gulf of Guinea. The winds collapsed nearly completely all along the equator in January-April 1984. The onset of the African monsoon was late (in July-August 1984), then the monsoon was weaker than climatology in August-October 1984. The equatorial thermocline was observed 50m deeper than climatology in February 1984, then near the surface in July 1984. Sea levels rose over the equatorial Atlantic, the surge reaching about 13cm at 6°E in February 1984, when the western-central equatorial Atlantic was nearly flat. Minimum sea levels occurred in June-July 1984 at 6°E, before the African monsoon. During this event, the maximum speed in the shallow core of the equatorial undercurrent at 4°W and 6°E was nearly insensitive to large changes in the thermal structure (downwelling or upwelling situations). In February-May 1984, we have observed distinct increasing eastward flows at the equator below 250m and minimum

  8. Observation of internal tide-induced nutrient upwelling in Hungtsai Trough, a submarine canyon in the northern South China Sea

    Science.gov (United States)

    Pai, Su-Cheng; Wei, Ching-Ling; Lin, Saulwood; Wen, Liang-Saw; Tseng, Chun-Mao

    2016-06-01

    Temporal variations in hydrographic parameters and nutrients were observed in a 300 m deep submarine canyon (Hungtsai Trough) near the southern tip of Taiwan. A vigorous oscillation below the surface layer has been observed which relates closely to an internal tidal wave generated from the nearby Luzon Strait. The vertical movement can be measured by monitoring an 18 °C isothermal depth which shows an up-and-down oscillation between 90 and 240 m with an average displacement of 110 m within a tidal cycle, a scale significantly larger than has been reported elsewhere. The frequency of this oscillation coincides with the surface tide but in an almost opposite phase. All hydrographic and chemical parameters (oxygen, density, fluorescence, transmittance and nutrients including nitrate, phosphate and silicate) synchronize with the tidal movement, as judged by normalized plots against temperature. When the nutrient-rich deep water upwells and becomes an outcrop over the trough rim at 100 m deep, it is swept horizontally by the strong alongshore tidal current. Consequently, the trough acts as a source point to supply extra nutrients to the coastal ecosystem.

  9. The organic sea surface microlayer in the upwelling region off Peru and implications for air–sea exchange processes

    Directory of Open Access Journals (Sweden)

    A. Engel

    2015-07-01

    Full Text Available The sea surface microlayer (SML is at the very surface of the ocean, linking the hydrosphere with the atmosphere, and central to a range of global biogeochemical and climate-related processes. The presence and enrichment of organic compounds in the SML have been suggested to influence air–sea gas exchange processes as well as the emission of primary organic aerosols. Among these organic compounds, primarily of plankton origin, are dissolved exopolymers, specifically polysaccharides and proteins, and gel particles, such as Transparent Exopolymer Particles (TEP and Coomassie Stainable Particles (CSP. These organic substances often accumulate in the surface ocean when plankton productivity is high. Here, we report results obtained in December 2012 during the SOPRAN Meteor 91 cruise to the highly productive, coastal upwelling regime off Peru. Samples were collected from the SML and from ~ 20 cm below, and were analyzed for polysaccharidic and proteinaceous compounds, gel particles, total and dissolved organic carbon, bacterial and phytoplankton abundance. Our study provides insight to the physical and biological control of organic matter enrichment in the SML, and discusses the potential role of organic matter in the SML for air–sea exchange processes.

  10. The organic sea-surface microlayer in the upwelling region off the coast of Peru and potential implications for air-sea exchange processes

    Science.gov (United States)

    Engel, Anja; Galgani, Luisa

    2016-02-01

    The sea-surface microlayer (SML) is at the uppermost surface of the ocean, linking the hydrosphere with the atmosphere. The presence and enrichment of organic compounds in the SML have been suggested to influence air-sea gas exchange processes as well as the emission of primary organic aerosols. Here, we report on organic matter components collected from an approximately 50 µm thick SML and from the underlying water (ULW), ˜ 20 cm below the SML, in December 2012 during the SOPRAN METEOR 91 cruise to the highly productive, coastal upwelling regime off the coast of Peru. Samples were collected at 37 stations including coastal upwelling sites and off-shore stations with less organic matter and were analyzed for total and dissolved high molecular weight (> 1 kDa) combined carbohydrates (TCCHO, DCCHO), free amino acids (FAA), total and dissolved hydrolyzable amino acids (THAA, DHAA), transparent exopolymer particles (TEP), Coomassie stainable particles (CSPs), total and dissolved organic carbon (TOC, DOC), total and dissolved nitrogen (TN, TDN), as well as bacterial and phytoplankton abundance. Our results showed a close coupling between organic matter concentrations in the water column and in the SML for almost all components except for FAA and DHAA that showed highest enrichment in the SML on average. Accumulation of gel particles (i.e., TEP and CSP) in the SML differed spatially. While CSP abundance in the SML was not related to wind speed, TEP abundance decreased with wind speed, leading to a depletion of TEP in the SML at about 5 m s-1. Our study provides insight to the physical and biological control of organic matter enrichment in the SML, and discusses the potential role of organic matter in the SML for air-sea exchange processes.

  11. Holocene Paleoceanographic Conditions of Cabo Frio Upwelling System (Rio de Janeiro / Brazil). As Inferred by Bulk and Molecular Geochemical Approach From Sedimentary Organic Matter.

    Science.gov (United States)

    Gurgel, M. H.; Sifeddine, A.; Lallier-Vergès, E.; Boussafir, M.; Jacob, J.

    2005-12-01

    The main upwelling areas in Brazil are along its central coast. Among these, the Cabo Frio (23 deg S x 42 deg W) zone has the strongest signal of low sea surface temperature. The Cabo Frio coastal upwelling cell is controlled by three factors: the topography and orientation of the coastline; the position of the Brazilian Current axes, and the wind pattern, the last being the determining factor. Upwelling events in this region are concentrated in the austral spring and summer (September to April). Their occurrence is associated with NE-ENE winds, and they are inhibited when the wind blows from the southern quadrant (atmospheric frontal passages linked to polar advection). This pattern is associated with the seasonal displacements of the South Atlantic Convergence Zone (SACZ) over this region. Better knowledge of the SACZ behaviour over the time is very important to understanding the climatic variability over the South America in the Holocene. A high resolution sampling study is being done on two Kullenberg piston cores collected from the Brazilian continental shelf, 30-35 km southwest from the Cabo Frio island (115 m and 124 m water depth). AMS radiocarbon dating of organic matter from the core bases gives ages of 3,300 BP and 12,600 BP, respectively. We present the results of elemental analysis (TC and TN), Rock-Eval analysis (TOC, HI and OI), sedimentary organic matter petrographic analysis and alkenone sea surface paleo temperatures. Despite coming from an upwelling area, sediments have very low TOC content and show an increase from around 8,000 year with variations modulated by millennial and secular cycles. Sedimentary organic matter is marine type II that, associated with optical analysis, indicates a high-degraded state and a little continental contribution. The range of paleo temperature values are similar to results of other studies carried out in the same system and are coherent with regional Brazilian Current dynamics. These first results identify two

  12. Chilean Teachers Begin Exchange Program Visit in Magdalena

    Science.gov (United States)

    2007-01-01

    . Kelly. The Chilean teachers are visiting Magdalena while they are on their Southern Hemisphere summer vacation, and Magdalena's schools are in session. Two Magdalena teachers, Joleen Welborn and Sandra Montoya, will visit San Pedro in June, while they are on summer vacation and the Chilean schools will be in session. Dr. Eduardo Hardy, the AUI/NRAO representative in Chile, will accompany the Chilean teachers on their visit, which has been coordinated by Harrison. "ALMA is a groundbreaking example of the type of international cooperation that marks the future of astronomy. We are especially pleased to sponsor a program that brings together two communities that both enjoy proximity to world-class astronomical research facilities," said Dr. Fred K.Y. Lo, NRAO Director. "While separated by many miles, San Pedro de Atacama and Magdalena have much in common. Both are small communities in high desert environments, and both are next to telescopes where the world's astronomers will be making many exciting discoveries in the coming decades. Bringing these two communities together will advance education and international understanding," Harrison said. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  13. Miocene–Pliocene stepwise intensification of the Benguela upwelling over the Walvis Ridge off Namibia

    Directory of Open Access Journals (Sweden)

    S. Hoetzel

    2015-05-01

    Full Text Available Upwelling is a significant part of the ocean circulation controlling largely the transport of cold waters to the surface and therefore influences ocean productivity and global climate. The Benguela Upwelling System (BUS is one of the major upwelling areas in the world. Previous reconstructions of the BUS mainly focused on the onset and intensification in southern and central parts, but changes of the northern part have been rarely investigated in detail. Using the organic-walled dinoflagellate cyst record of ODP Site 1081 from the Late Miocene to the Pliocene we reconstruct and discuss the upwelling history on the Walvis Ridge with a special focus on the movement of the Angola–Benguela Front (ABF. We show that during the Late Miocene the Angola Current flowed southwards over the Walvis Ridge more frequently than today because the ABF was probably located further south as a result of a weaker meridional temperature gradient. A possible strengthening of the meridional gradient during the latest Miocene to early Pliocene in combination with uplift of south-western Africa intensified the upwelling along the coast and increased the upwelling's filaments over the Walvis Ridge. An intermediate period from 6.2 to 5.5 Ma is shown by the dominance of Habibacysta tectata, cysts of a cool-tolerant dinoflagellate known from the northern Atlantic, indicating changing oceanic conditions contemporaneous with the Messinian Salinity Crisis. From 4.4 Ma on, the upwelling signal got stronger again and waters were well-mixed and nutrient-rich. Also effects of Cunene River discharge into the South Atlantic are recorded since 4.4 Ma. Our results show a northward migration of the ABF and the initial stepwise intensification of the BUS.

  14. Steps in the intensification of Benguela upwelling over the Walvis Ridge during Miocene and Pliocene

    Science.gov (United States)

    Hoetzel, Sebastian; Dupont, Lydie M.; Marret, Fabienne; Jung, Gerlinde; Wefer, Gerold

    2016-03-01

    Upwelling is a significant part of the ocean circulation controlling largely the transport of nutrient-rich cold waters to the surface and therefore influencing ocean productivity and global climate. The Benguela upwelling system (BUS) is one of the major upwelling areas in the world. Previous reconstructions of the BUS mainly focused on the onset and intensification in southern and central parts, but changes of the northern part have been rarely investigated in detail. Using the Late Miocene to Pliocene organic-walled dinoflagellate cyst record of ODP Site 1081, we reconstruct and discuss the early upwelling history over the Walvis Ridge with a special focus on the movement of the Angola-Benguela Front (ABF). We suggest that during the Late Miocene the Angola Current flowed southwards over the Walvis Ridge more frequently than today because the ABF was probably located further south as a result of a weaker meridional temperature gradient. A possible strengthening of the meridional gradient during the latest Miocene to early Pliocene in combination with uplift of south-western Africa intensified the upwelling along the coast and increased the upwelling's filaments over the Walvis Ridge. An intermediate period from 6.2 to 5.5 Ma is shown by the dominance of Habibacysta tectata, cysts of a cool-tolerant dinoflagellate known from the northern Atlantic, indicating changing oceanic conditions contemporaneous with the Messinian Salinity Crisis. From 4.3 Ma on, the upwelling signal got stronger again and waters were well-mixed and nutrient-rich. Our results indicate a northward migration of the ABF as early as 7 Ma and the initial stepwise intensification of the BUS.

  15. Stable nitrogen isotopes in coastal macroalgae: geographic and anthropogenic variability.

    Science.gov (United States)

    Viana, Inés G; Bode, Antonio

    2013-01-15

    Growing human population adds to the natural nitrogen loads to coastal waters. Both anthropogenic and natural nitrogen is readily incorporated in new biomass, and these different nitrogen sources may be traced by the measurement of the ratio of stable nitrogen isotopes (δ(15)N). In this study δ(15)N was determined in two species of macroalgae (Ascophyllum nodosum and Fucus vesiculosus), and in nitrate and ammonium to determine the relative importance of anthropogenic versus natural sources of nitrogen along the coast of NW Spain. Both algal species and nitrogen sources showed similar isotopic enrichment for a given site, but algal δ(15)N was not related to either inorganic nitrogen concentrations or δ(15)N in the water samples. The latter suggests that inorganic nitrogen inputs are variable and do not always leave an isotopic trace in macroalgae. However, a significant linear decrease in macroalgal δ(15)N along the coast is consistent with the differential effect of upwelling. Besides this geographic variability, the influence of anthropogenic nitrogen sources is evidenced by higher δ(15)N in macroalgae from rias and estuaries compared to those from open coastal areas and in areas with more than 15×10(3) inhabitants in the watershed. These results indicate that, in contrast with other studies, macroalgal δ(15)N is not simply related to either inorganic nitrogen concentrations or human population size but depends on other factors as the upwelling or the efficiency of local waste treatment systems. PMID:23247291

  16. Public coastal access in Nova Scotia's coastal strategy

    OpenAIRE

    Joshua Kelly Mackintosh

    2011-01-01

    Public coastal access is an issue that affects coastal communities and coastal populations worldwide. One such place where public coastal access is of particular relevance is the Province of Nova Scotia, Canada where the government is developing a provincial Coastal Strategy to address priority coastal management issues, one of which is public coastal access. This study examines best practices in public coastal access in selected US States and their potential application in study areas in Nov...

  17. Chemical metrology, strategic job for the Chilean Nuclear Energy Commission

    International Nuclear Information System (INIS)

    The National Standardization Institute's (INN) Metrology unit prepared a study in 1996 to evaluate the impact of metrological activity in Chile. This study was based on a survey of the supply and demand of metrological services and on studies of the behavior of the production system and technological services in Chile during the period 1990-1996. With the information obtained in this study the economic impact resulting from the lack of a national metrology system could be evaluated. This impact was estimated to be a 5% loss in gross national product equal to 125-500 million dollars because of direct product rejection in the mining, fisheries, agricultural and manufacturing sectors. Chemical measurements are responsible for 50% of these losses. In response to this need and coordinated by the INN, a metrological network of reference laboratories began to operate in 1997 for the principal physical magnitudes (mass, temperature, longitude and force) and a CORFO-FDI project began in 2001 that includes the chemical magnitudes. The Chilean Nuclear Energy Commission, aware of the problem's importance and the amount of economic damage that the country may suffer, as a result of these deficiencies, has formed a Chemical Metrology Unit to provide technical support. It aims to raise the standards of local analytical laboratories by providing international recognition to the export sector. Nuclear analytical techniques are used as reference methods. This work describes the laboratories that are included in this Chemical Metrology Unit and the historical contribution to the development of local analytical chemistry. The national and international projects are described together with the publications they have generated. The quality assurance program applied to the laboratories is described as well, which has led to the accreditation of the analytical chemical assays. The procedures used for validation and calculation of uncertain nuclear methodologies are described together with

  18. Dental fluorosis in Chilean children: evaluation of risk factors.

    Science.gov (United States)

    Villa, A E; Guerrero, S; Icaza, G; Villalobos, J; Anabalón, M

    1998-10-01

    The purpose of this case-control study was to determine the association between very-mild-to-moderate enamel fluorosis and exposure during early childhood to fluoridated water, mainly through ingestion of powdered milk. Analysis was performed on 136 residents of the optimally fluoridated community of San Felipe in the Chilean Fifth Region, who were categorised into one of three groups according to their age when water fluoridation was introduced in 1986: Group I was born after 1986; Group II was 16-24 months old in 1986; and Group III was >24 months of age. The case and control subjects were selected on the basis of a clinical examination given in July 1996. Dean's scoring system was used to determine fluorosis status. Risk factor exposure was ascertained by a questionnaire used in interviews with mothers of participating children. Logistic regression analysis, after adjustment for confounding variables, revealed that very-mild-to-moderate enamel fluorosis of permanent central maxillary incisors (CMI) was strongly associated both with the age of the subjects when water fluoridation began and with breast-feeding duration for children belonging to Group I. Subjects in Group I were 20.44 times more likely (95% CI: 5.00-93.48) to develop CMI fluorosis than children who were older than 24 months (Group III) when fluoridation began. Subjects who were between 16 and 24 months old when water fluoridation began were 4.15 times more likely (95% CI: 1.05-16.43) to have CMI fluorosis than children older than 24 months. An inverse association was found with breastfeeding duration (OR=0.86, 95% CI: 0.75-0.98) among Group I subjects but not in Groups II and III. Results obtained suggest that the current fluoride concentration in drinking water may be contributing to fluorosis. Further studies will be necessary to determine the relative competing risks of dental fluorosis and dental caries in Chilean children in order to establish the most appropriate water fluoridation level in

  19. Struktur vertikal upwelling – downwelling di Samudera Hindia Selatan Jawa hingga Selatan Bali berdasarkan salinitas musiman periode 2004 – 2010

    OpenAIRE

    Restu Wardani; Widodo S. Pranowo; Elis Indrayanti

    2013-01-01

    Salinitas berperan penting untuk mengidentifikasi fenomena upwelling dan downwelling. Upwelling yang terjadi di samudera Hindia Selatan Jawa hingga Selatan Bali dipengaruhi oleh angin musim, ENSO (El Nino Southern Oscillation) dan IOD (Indian Oscillation Dipole Mode). Dalam peneletian ini dikaji pola upwelling dan downwelling berdasarkan distribusi salinitas secara vertikal dan vaeriabilitas musiman dikaji dalam waktu tujuh tahun (2004 – 2010). Data hasil akuisisi argo float digunakan dalam p...

  20. Decadal variability and trends of the Benguela upwelling system as simulated in a high-resolution ocean simulation

    OpenAIRE

    N. Tim; E. Zorita; B. Hünicke

    2015-01-01

    Detecting the atmospheric drivers of the Benguela upwelling systems is essential to understand its present variability and its past and future changes. We present a statistical analysis of a high-resolution (0.1°) ocean-only simulation driven by observed atmospheric fields over the last 60 years with the aim of identifying the large-scale atmospheric drivers of upwelling variability and trends. The simulation is found to reproduce well the seasonal cycle of upwelling intens...

  1. Decadal variability and trends of the Benguela Upwelling System as simulated in a high-resolution ocean simulation

    OpenAIRE

    N. Tim; E. Zorita; B. Hünicke

    2015-01-01

    Detecting the atmospheric drivers of the Benguela Upwelling Systems is essential to understand its present variability and its past and future changes. We present a statistical analysis of an ocean-only simulation driven by observed atmospheric fields over the last decades with the aim of identifying the large-scale atmospheric drivers of upwelling variability and trends. The simulation is found to reproduce well the seasonal cycle of upwelling intensity, with a maximum in t...

  2. Contradictory Evidence on Wave Forcing of Tropical Upwelling in the Brewer-Dobson Circulation - A Suggested Resolution

    Science.gov (United States)

    Zhou, Tiehan; Geller, Marvin A.; Lin, Wuyin

    2011-01-01

    ERA-40 data are analyzed to demonstrate that wave forcing at lower latitudes plays a crucial role in driving the tropical upwelling portion of the Brewer-Dobson circulation. It is shown that subtropical wave forcing is correlated with tropical upwelling on both intraseasonal and interannual time scales when transient waves are taken into account, and that tropical wave forcing exerts its influence on tropical upwelling via its body force on the zonal mean flow.

  3. An annually-resolved palaeoenvironmental archive for the Eastern Boundary North Atlantic upwelling system: Sclerochronology of Glycymeris glycymeris (Bivalvia) shells from the Iberian shelf

    Science.gov (United States)

    Freitas, Pedro; Monteiro, Carlos; Butler, Paul; Reynolds, David; Richardson, Christopher; Gaspar, Miguel; Scourse, James

    2015-04-01

    The seasonally variable western Iberia upwelling system, albeit placed at a crucial climatic boundary position to record high frequency climate events, lacks well-dated high-resolution records of environmental variability. Bivalve shells provide robust high-resolution archives of oceanographic and climatic variability on timescales of decades to millennia. In particular, the North Atlantic Ocean region has recently seen several noteworthy sclerochronological and geochemical reconstructions based on bivalve shells (mainly Arctica islandica) of high frequency oceanographic and climatic conditions during the last millennium. However, due to the absence of Arctica islandica and similarly long-lived bivalves, sclerochronological palaeoenvironmental studies of southern European coastal shelf seas are scarce. In particular, none of these studies focus on reconstructing the variability of an eastern boundary upwelling system. The relatively long-lived bivalve (>100 years) Glycymeris glycymeris occurs in European and North West African coastal shelf seas and provides a valid annually resolved archive of environmental conditions during growth. Annual growth increment width series from living G. glycymeris shells, collected in 2014 on the western Iberian continental shelf (ca. 35 m water depth), were used to construct a statistically robust, ca. 70-year long absolutely-dated chronology. Sub-annually resolved (11 to 22 samples per year) oxygen stable isotope (δ18Oshell) data covering three years of shell growth, together with the direct evaluation of the time of growth mark deposition in shells collected during the autumn and winter months, were used to constrain the season of growth and to evaluate the seasonal bias of the sea-surface temperature signal preserved in the δ18Oshelldata. The growth increment width and δ18Oshell series, once robustly calibrated against modelled and instrumental oceanographic and climatic series, potentially provide novel insights into the

  4. Glacial discharge, upwelling and productivity off the Adélie coast, Antarctica: results from a 171 m Holocene sediment core from IODP Expedition 318

    Science.gov (United States)

    Newton, Kate; Bendle, James; McKay, Robert; Albot, Anya; Moossen, Heiko; Seki, Osamu; Willmott, Veronica; Schouten, Stefan; Riesselman, Christina; Dunbar, Robert

    2016-04-01

    Antarctica's coastal oceans play a vital role in controlling both the global carbon cycle and climate change, through variations in primary production, ocean stratification and ice melt. Yet, the Southern Ocean remains the least studied region on Earth with respect to Holocene climate variability. The few Antarctic proximal marine sedimentary records available tend to be short, low resolution, and discontinuous. However, sediments recovered from the Adélie drift during IODP Expedition 318 present a new opportunity to study East Antarctic Holocene climatic evolution, at a resolution that facilitates direct comparison with ice-cores. A 171m core of Holocene laminated diatom ooze was recovered from site U1357, representing continuous Holocene accumulation in a climatically-sensitive coastal polynya. We present results of biomarker analyses (TEX86-L and compound specific fatty acid delta-D and delta-13C, and sterol delta-D) and grain size from throughout the Holocene, revealing the complexities of this climatically sensitive environment. Carbon isotopes are interpreted predominantly as a productivity signal via CO2 drawdown, whilst hydrogen isotopes reflect inputs of isotopically-depleted glacial meltwater from the large Mertz glacier tongue and other proximal glaciers. Both upwelling, as shown by TEX86-L and grain size, and glacial meltwater inputs, indicated by biomarker delta-D, appear to have an important control on productivity on various time scales. The latter may be forced by warm subsurface temperatures through basal melting of the Mertz glacier tongue, indicating both direct and indirect effects of upwelling on productivity. The post-glacial, Early Holocene appears to be characterized by a highly variable system, due to both strong upwelling and meltwater inputs, followed by a more stable and highly productive Middle Holocene under a warmer climate. During the Late Holocene, characterized by a sea-ice expansion, temperature-induced sea-ice melt may have

  5. Waist Circumferences of Chilean Students: Comparison of the CDC-2012 Standard and Proposed Percentile Curves

    Directory of Open Access Journals (Sweden)

    Rossana Gómez-Campos

    2015-07-01

    Full Text Available The measurement of waist circumference (WC is considered to be an important means to control overweight and obesity in children and adolescents. The objectives of the study were to (a compare the WC measurements of Chilean students with the international CDC-2012 standard and other international standards, and (b propose a specific measurement value for the WC of Chilean students based on age and sex. A total of 3892 students (6 to 18 years old were assessed. Weight, height, body mass index (BMI, and WC were measured. WC was compared with the CDC-2012 international standard. Percentiles were constructed based on the LMS method. Chilean males had a greater WC during infancy. Subsequently, in late adolescence, males showed values lower than those of the international standards. Chilean females demonstrated values similar to the standards until the age of 12. Subsequently, females showed lower values. The 85th and 95th percentiles were adopted as cutoff points for evaluating overweight and obesity based on age and sex. The WC of Chilean students differs from the CDC-2012 curves. The regional norms proposed are a means to identify children and adolescents with a high risk of suffering from overweight and obesity disorders.

  6. Coastal Erosion Armoring 2005

    Data.gov (United States)

    California Department of Resources — Coastal armoring along the coast of California, created to provide a database of all existing coastal armoring based on data available at the time of creation....

  7. Octopus vulgaris paralarvae vertical distribution in a fluctuating upwelling-downwelling system

    Directory of Open Access Journals (Sweden)

    Lorena Olmos Pérez

    2014-06-01

    - Upwelling situation: superficial waters (0-20m enter through the northern mouth of the Ría and are washed through the southern mouth. This water movement promotes the entrance of cold, bottom upwelled water through the southern mouth of the Ría. Under this scenario, Octopus paralarvae are concentrated at the surface (10-0m, thus leaving the Ría. This difference is bigger after strong upwelling during the previous days. Abundances inside the Ría are the highest, maybe because it acts as a temporal retention area, or because cold upwelled waters might stimulate hatching inside the Ría. Day/night changes under strong upwelling conditions: paralarvae abundance in both mouths was quite similar, except that during the day they were in sub-surficial waters (10-5 m, while at night paralarvae were mainly found close to the surface (0-5 m. This vertical distribution during the day is remarkable because paralarvae may select offward surface waters.

  8. Synchronisation of the equatorial QBO by the annual cycle in tropical upwelling in a warming climate

    Science.gov (United States)

    Rajendran, Kylash; Moroz, Irene; Read, Peter; Osprey, Scott

    2016-04-01

    The response of the period of the quasi-biennial oscillation (QBO) to increases in tropical upwelling is considered using a one-dimensional model. We find that the imposition of the annual cycle in tropical upwelling creates substantial variability in the period of the QBO. The annual cycle creates synchronisation regions in the wave forcing space, within which the QBO period locks onto an integer multiple of the annual forcing period. Outside of these regions, the QBO period undergoes discrete jumps as it attempts to find a stable relationship with the oscillator forcing. The resulting set of QBO periods can be either discrete or broad-banded, depending on the intrinsic period of the QBO. We use the same model to study the evolution of the QBO period as the strength of tropical upwelling increases as would be expected in a warmer climate. The QBO period lengthens and migrates closer towards 36 and 48 month locking regions as upwelling increases. The QBO period does not vary continuously with increased upwelling, however, but instead transitions through a series of 2- and 3-cycles before becoming locked to the annual cycle. Some evidence for the cyclical behaviour of the QBO periods in the real atmosphere is presented.

  9. Aragonite saturation state in a monsoonal upwelling system off Java, Indonesia

    Science.gov (United States)

    Xue, Liang; Wang, Huiwu; Jiang, Li-Qing; Cai, Wei-Jun; Wei, Qinsheng; Song, Hongjun; Kuswardani, Rita Tisiana Dwi; Pranowo, Widodo S.; Beck, Brian; Liu, Lin; Yu, Weidong

    2016-01-01

    Aragonite saturation state (Ωarag) and its influence from upwelling along the southern coast of Java, Indonesia were examined using carbonate and hydrographic data collected from 22 September to 2 October 2013. Results showed that sea surface Ωarag was lower in the upwelling area (2.97-3.44) than in the nonupwelling area (3.45-3.57), with the lowest value in the eastern part of the study area. We used a two end-member mixing model to separate contributions on Ωarag from two processes associated with upwelling: physical transport vs. biological production. Results indicated that physical transport induced at least a Ωarag decrease of 0.8, whereas biological production caused Ωarag to increase by up to 0.6. Additionally, the influence on Ωarag of interannual upwelling variability modulated by the Indian Ocean Dipole (IOD), a unique climate phenomenon in the Indian Ocean, was roughly estimated. We argue that the effect of interannual upwelling variability modulated by IOD events was possibly larger than what was imposed on Ωarag by increasing atmospheric CO2 levels over the past decade.

  10. Peer victimization: Intimidation and victmization in Chilean students

    Directory of Open Access Journals (Sweden)

    Verónica López

    2009-12-01

    Full Text Available This paper presents the results of a study about peer intimidation and victimization with 1167 school students from 6th, 7th, and 8th grade from the Valparaiso Region of Valparaíso, Chile. The instrument used was the Insebull Battery (Avilés & Elices, 2007. Results show that approximately 9% of students have been victim of peer victimization many times or almost every day during the school year. Psychological victimization was more frequent thanphysical aggression, particularly through virtual communication such as cell-phone messages and e-mails. Participants tend to be groups of male students. Although male students participate more in physical aggression, they also receive more physical and psychological aggression. The most frequent places were inside the classroom and the school yard, when the teacher is not present. Most students inform not knowing, or vaguely knowing, thereasons underlying these aggressions, and do not do anything to deal with them. These results coincide with international studies and allow a better understanding of the characteristics of peer victimization in specific educational contexts within the Chilean school system.

  11. Banking reform and the financing of firm investment : An empirical analysis of the Chilean experience, 1983-92

    NARCIS (Netherlands)

    Hermes, N; Lensink, R

    1998-01-01

    This article investigates whether the Chilean banking reforms of the 1980s have contributed to reducing market imperfections in Chilean financial markets in the late 1980 and early 1990s. To analyse this issue, patterns of investment and its finance for different types of firms are studied, based on

  12. Warm Bias and Parameterization of Boundary Upwelling in Ocean Models

    Energy Technology Data Exchange (ETDEWEB)

    Cessi, Paola; Wolfe, Christopher

    2012-11-06

    It has been demonstrated that Eastern Boundary Currents (EBC) are a baroclinic intensification of the interior circulation of the ocean due to the emergence of mesoscale eddies in response to the sharp buoyancy gradients driven by the wind-stress and the thermal surface forcing. The eddies accomplish the heat and salt transport necessary to insure that the subsurface flow is adiabatic, compensating for the heat and salt transport effected by the mean currents. The EBC thus generated occurs on a cross-shore scale of order 20-100 km, and thus this scale needs to be resolved in climate models in order to capture the meridional transport by the EBC. Our result indicate that changes in the near shore currents on the oceanic eastern boundaries are linked not just to local forcing, such as coastal changes in the winds, but depend on the basin-wide circulation as well.

  13. A new species of Eccopsis Zeller (Lepidoptera, Tortricidae from the coastal valleys of northern Chile, with the first continental record of E. galapagana Razowski & Landry

    Directory of Open Access Journals (Sweden)

    Héctor A. Vargas

    2011-06-01

    Full Text Available A new species of Eccopsis Zeller (Lepidoptera, Tortricidae from the coastal valleys of northern Chile, with the first continental record of E. galapagana Razowski & Landry. Eccopsis Zeller, 1852 is reported for the first time from Chile. Eccopsis razowskii Vargas, n. sp. is described and illustrated based on specimens reared from larvae collected on native Acacia macracantha Willd. (Fabaceae in the coastal valleys of the northern Chilean desert. Eccopsis galapagana Razowski & Landry, 2008, previously known only from the Galapagos Islands, Ecuador, is recorded for the first time from continental South America. Larvae of the latter were collected in northern Chile feeding on Prosopis alba Griseb (Fabaceae.

  14. Linking mantle upwelling with the lithosphere descent [corrected] and the Japan Sea evolution: a hypothesis.

    Science.gov (United States)

    Ismail-Zadeh, Alik; Honda, Satoru; Tsepelev, Igor

    2013-01-01

    Recent seismic tomography studies image a low velocity zone (interpreted as a high temperature anomaly) in the mantle beneath the subducting Pacific plate near the Japanese islands at the depth of about 400 km. This thermal feature is rather peculiar in terms of the conventional view of mantle convection and subduction zones. Here we present a dynamic restoration of the thermal state of the mantle beneath this region assimilating geophysical, geodetic, and geological data up to 40 million years. We hypothesise that the hot mantle upwelling beneath the Pacific plate partly penetrated through the subducting plate into the mantle wedge and generated two smaller hot upwellings, which contributed to the rapid subsidence in the basins of the Japan Sea and to back-arc spreading. Another part of the hot mantle migrated upward beneath the Pacific lithosphere, and the presently observed hot anomaly is a remnant part of this mantle upwelling. PMID:23355951

  15. Linking mantle upwelling with the lithosphere descent [corrected] and the Japan Sea evolution: a hypothesis.

    Science.gov (United States)

    Ismail-Zadeh, Alik; Honda, Satoru; Tsepelev, Igor

    2013-01-01

    Recent seismic tomography studies image a low velocity zone (interpreted as a high temperature anomaly) in the mantle beneath the subducting Pacific plate near the Japanese islands at the depth of about 400 km. This thermal feature is rather peculiar in terms of the conventional view of mantle convection and subduction zones. Here we present a dynamic restoration of the thermal state of the mantle beneath this region assimilating geophysical, geodetic, and geological data up to 40 million years. We hypothesise that the hot mantle upwelling beneath the Pacific plate partly penetrated through the subducting plate into the mantle wedge and generated two smaller hot upwellings, which contributed to the rapid subsidence in the basins of the Japan Sea and to back-arc spreading. Another part of the hot mantle migrated upward beneath the Pacific lithosphere, and the presently observed hot anomaly is a remnant part of this mantle upwelling.

  16. TRADE POLICY AND MAJOR TRENDS IN CHILEAN EXPORTS UNDER DEMOCRACY, 1990-2012

    Directory of Open Access Journals (Sweden)

    Manuel Llorca-Jaña

    2015-06-01

    Full Text Available This paper deals with trade policy and the principal trends in Chilean exports after the return to democracy in 1990. During this period, both exports and imports expanded significantly in Chile. As far as exports are concerned, this boom is mainly due to an effective trade policy of additive regionalism, booming copper prices, export diversification and the economic dynamism of China, the principal beneficiary of Chilean exports. On the negative side, the country is still too dependant on copper and a few other primary products. In addition, nowadays, in relative terms Chile is exporting more copper minerals and less refined copper than it used to do in the 1990s, while Chilean exports remained highly concentrated in a few companies only, many of which belong to foreign nationals.

  17. HIV prevention and low-income Chilean women: machismo, marianismo and HIV misconceptions.

    Science.gov (United States)

    Cianelli, Rosina; Ferrer, Lilian; McElmurry, Beverly J

    2008-04-01

    Socio-cultural factors and HIV-related misinformation contribute to the increasing number of Chilean women living with HIV. In spite of this, and to date, few culturally specific prevention activities have been developed for this population. The goal of the present study was to elicit the perspectives of low-income Chilean women regarding HIV and relevant socio-cultural factors, as a forerunner to the development of a culturally appropriate intervention. As part of a mixed-methods study, fifty low-income Chilean women participated in a survey and twenty were selected to participate in prevention, in-depth interviews. Results show evidence of widespread misinformation and misconceptions related to HIV/AIDS. Machismo and marianismo offer major barriers to prevention programme development. Future HIV prevention should stress partner communication, empowerment and improving the education of women vulnerable to HIV.

  18. Reporting quality of papers published in Chilean dental journals. Evaluation period: 2002-2012.

    Directory of Open Access Journals (Sweden)

    Sergio E Uribe

    2015-08-01

    Full Text Available Aim: To assess the reporting quality of papers published between 2002-2012 in Chilean dental journals. Methods: Bibliometric analysis of research papers published in indexed Chilean dental journals between 2002-2012. Three calibrated examinators (interoperator- Kappa=.83 assessed 205 papers: 150 case-reports, 37 observational studies and 18 clinical trials. Reporting quality was evaluated using CARE for case reports, STROBE for observational studies and CONSORT for clinical trials. Descriptive statistics were conducted. Results: Case-reports reported 35% of the required methodological items; epidemiological research reported 16% of required items for Materials and Methods and 10% for Results. Clinical research reported 29% of required Materials and Methods items and 20% of Results items. Conclusion: Case-report, epidemiological and clinician research papers in Chilean dental journals published during the 2002-2012 period are lacking explicit key methodological items, preventing a proper research replication or clinical application of the results.

  19. Privatizing Water in the Chilean Andes: The Case of Las Vegas de Chiu-Chiu

    Directory of Open Access Journals (Sweden)

    Manuel Prieto

    2015-08-01

    Full Text Available The Chilean water model has been described as a textbook example of a free-market water system. This article contributes to the critiques of this model by showing the effect of its implementation in the Atacameño community of Chiu-Chiu, located in the Atacama Desert in the south-central Andes. In this community, the privatization of water rights ignored local water management practices that had produced a high-altitude wetland (known as a vega. This led to the inhabitants’ dispossession of crucial water rights and to wetland degradation. This process belies statements that the Chilean model relies on an unregulated market and instead highlights the state’s role in marginalizing local irrigation practices by reducing the water consumption of the indigenous population while keeping the copper mining industry (the main source of Chilean income and related growing urban populations supplied with water.

  20. La familia Hemiaulaceae (Bacillariophyceae de las aguas marinas chilenas The family Hemiaulaceae (Bacillariophyceae from marine Chilean waters

    Directory of Open Access Journals (Sweden)

    PATRICIO RIVERA

    2003-12-01

    Full Text Available La familia Hemiaulaceae comprende cuatro géneros, señalados previamente para las aguas chilenas con las siguientes especies: Cerataulina pelagica (Cleve Hendey, Hemiaulus sinensis Greville, H. membranaceus Cleve, Climacodium biconcavum Cleve, Eucampia antarctica (Castracane Mangin, E. cornuta (Cleve Grunow y E. zodiacus Ehrenberg. Sin embargo, el análisis con microscopía fotónica y electrónica de muestras recolectadas en aguas marinas chilenas que contenían representantes de esta familia (incluyendo la mayoría de aquellas estudiadas anteriormente por otros investigadores nacionales reveló que (1 el género Cerataulina está representado por C. pelagica, distribuida a lo largo de la costa chilena entre Arica por el norte y el Estrecho de Magallanes por el sur, (2 el género Eucampia está representado por cuatro taxa: E. zodiacus f. cylindrocornis Syvertsen (señalada en trabajos anteriores como E. zodiacus f. zodiacus, E. zodiacus f. recta Rivera. Avaria & Cruces f. nov. (descrita aquí, E. cornuta y E. antarctica. Los primeros tres taxa se distribuyen en la zona central y norte de Chile, mientras que E. antarctica es propia de las aguas antárticas desde el Estrecho de Magallanes al sur, (3 las citas anteriores de Hemiaulus sinensis, H. membranaceus y Climacodium biconcavum para las aguas chilenas corresponden a determinaciones erróneas de Eucampia zodiacus f. recta, f. nov. Se entregan descripciones de los taxa encontrados y fotografías obtenidas con los microscopios fotónico y electrónicos que ilustran sus principales características morfológicasThe Family Hemiaulaceae comprises four genera, all of which have been previously reported for coastal waters off Chile, and represented by the following taxa: Cerataulina pelagica (Cleve Hendey, Hemiaulus sinensis Greville, H. membranaceus Cleve, Climacodium biconcavum Cleve, Eucampia antarctica (Castracane Mangin, E. cornuta (Cleve Grunow and E. zodiacus Ehrenberg. However, examination

  1. The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking

    Institute of Scientific and Technical Information of China (English)

    YAN BangLiang

    2007-01-01

    The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking is examined by using a mixed-mode model. The results show that the positive feedback process of the effects of the seasonal variation of the upwelling mean on the Kelvin wave is the mechanism of the locking of the event mature phase to the end of the calendar year. The memory of the Rossby waves for the sign-shifting of the sea surface temperature anomaly from positive to negative 6 months before the cold peak time is the other mechanism of the locking of the La Ni(n)a event mature phase to the end of the calendar year. The results here are different from previous ones which suggest that the balance between cold and warm trends of sea surface temperature anomaly is the mechanism involved. The cold trend is caused by the upwelling Kelvin wave from upwelling Rossby wave reflected at the western boundary, excited by the westerly anomaly stress over the central Pacific and amplified by the seasonal variation of the coupled strength in its way propagating westward. The warm trend is caused by the Kelvin wave forced by the western wind stress over the middle and eastern equatorial Pacific. The cause of the differences is due to the opposite phase of the seasonal variation of the upwelling mean to that in the observation and an improper parameterization scheme for the effects of the seasonal variation of the upwelling mean on the ENSO cycle in previous studies.

  2. The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The mechanism of the effects of the upwelling mean on the ENSO event mature phase locking is ex-amined by using a mixed-mode model. The results show that the positive feedback process of the ef-fects of the seasonal variation of the upwelling mean on the Kelvin wave is the mechanism of the locking of the event mature phase to the end of the calendar year. The memory of the Rossby waves for the sign-shifting of the sea surface temperature anomaly from positive to negative 6 months before the cold peak time is the other mechanism of the locking of the La Nia event mature phase to the end of the calendar year. The results here are different from previous ones which suggest that the balance between cold and warm trends of sea surface temperature anomaly is the mechanism involved. The cold trend is caused by the upwelling Kelvin wave from upwelling Rossby wave reflected at the western boundary, excited by the westerly anomaly stress over the central Pacific and amplified by the seasonal variation of the coupled strength in its way propagating westward. The warm trend is caused by the Kelvin wave forced by the western wind stress over the middle and eastern equatorial Pacific. The cause of the differences is due to the opposite phase of the seasonal variation of the upwelling mean to that in the observation and an improper parameterization scheme for the effects of the seasonal varia-tion of the upwelling mean on the ENSO cycle in previous studies.

  3. Mantle Plume Upwelling Rates: Evidence from U-Series in Young Ocean Island Basalts

    Science.gov (United States)

    Bourdon, B.; Turner, S. P.; Stracke, A.; Saal, A. E.

    2004-12-01

    U-series disequilibria measured in recent lavas at intraplate volcanoes provide a powerful probe to examine the validity of the plume model. U-Th and U-Pa fractionation produced during melting is a function of the melting rate. In turn, this parameter should scale with mantle upwelling velocities. Simply stated, a larger melting rate (larger mantle upwelling velocity) yields smaller Th and Pa excess relative to their parent nuclides. A number of observations supports this approach: (1) there is a negative correlation between 230Th excess and buoyancy fluxes (2) based on new measurements of 231Pa in the Azores, Iceland and the Galapagos and literature data, we show here that there is also a well defined correlation between 231Pa excess and buoyancy flux (3) For Hawaii, Iceland and the Azores, 230Th excess (or 231Pa excess) increases as a function of the distance from the centre of the `hotspot'. These observations suggests that `hotspot' buoyancy fluxes are associated with a greater melt production per unit of time and that the centre of `hotspot' corresponds to a faster mantle upwelling velocity than its periphery. This is therefore in strong support of a model where ocean islands are associated with faster upwelling at depth. However, there is in fact not a simple relationship between melt productivity and upwelling velocities. Notably, the presence of volatiles, of mafic lithologies or of variably enriched peridotitic source could all affect melting rate and hence U-Th-Pa fractionation. We have considered these issues in great detail using a large data base for the Azores islands. While there are clear variations in mantle source composition, they cannot explain the observations of increasing 231Pa/235U ratio with distance from the centre of the Azores hotspot . If we take into account the effect of water in the source of the Azores, it clearly affects the scaling between U-series fractionation and upwelling velocity but not the overall conclusions.

  4. Enhanced upwelling in the eastern equatorial Pacific at the last five glacial terminations

    OpenAIRE

    bin Shaari, Hasrizal; Yamamoto, Masanobu; Irino, Tomohisa

    2013-01-01

    TEX86H- and UK37′-derived paleotemperatures, and isoprenoid glycerol dialkyl glycerol tetraether (GDGT), and alkenone concentrations were examined for ODP Site 1239 in the eastern equatorial Pacific (EEP) for the last 430 kyr. We propose that the difference between TEX86H- and UK37′-derived temperatures (∆T) and the abundance ratio of GDGTs to alkenones (GDGT/alkenone ratio) are potential upwelling indices which show consistent results with other upwelling indices. The ∆T and GDGT/alkenone ra...

  5. Evaluation of ERTS data for certain oceanographic uses. [upwelling, water circulation, and pollution in Great Lakes

    Science.gov (United States)

    Strong, A. E. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Upwelling along the eastern shore of Lake Michigan was occurring during the 3 and 21 August 1973 visits by ERTS-1. The NOAA-2 VHRR thermal-IR data are being digitized for comparison. Early indications are that these upwellings induced a calcium carbonate precipitate to form in the surface waters. It is most pronounced in the MSS-4 channel. On the lake bottom this jell-like sediment is known as marl and adds to the eutrophication of the lake. This phenomenon may help to explain the varve-like nature of bottom cores that have been observed in the Great Lakes.

  6. Laboratory Experiments Concerning Upwellings From the Slab-Graveyard: Implications For Geochemical and Seismic Models

    Science.gov (United States)

    Harris, A. C.; Kincaid, C.; Hall, P.

    2005-12-01

    The ongoing plume debate appears to focus on upwellings characterized by large heads and smaller tails, that form from a deep or basal thermal boundary layer (BTBL), which are driven by temperature excesses in the range of 200° C. We use 3-D laboratory experiments to explore how upwellings might differ from this common plume description when BTBLs are influenced by subducted plates. An important aspect of the models is the representation of ridge chemical differentiation processes resulting in slabs with two distinct layers; a lighter, depleted upper mantle component (Harzburgite:H) and a heavier, iron-rich crustal component (Basalt/Eclogite:B/E). Laboratory experiments utilize a working fluid of glucose syrup with temperature dependent density and viscosity. Compositionally distinct mantle reservoirs are represented through isothermal density/viscosity contrasts controlled by water content. The ambient fluid (AF) is contained within a rectangular tank that is heated from below and cooled from above to produce background convection with a Rayleigh number of 10-5-10-6. Highly viscous, tabular slabs are produced by pouring compositionally distinct syrup from two slab reservoirs (B/E and H) into a mold which is chilled to -5° C. The viscous layered slab is emplaced at the fluid surface and subsequently sinks through, stalls and spreads within a BTBL roughly twice the slab thickness (1 cm). Results show that a wide variety in upwelling morphologies form when layered slabs reside within the BTBL and that plume heads/tails are largely dissimilar to those of the standard plume model. The manner in which the slab laminae vs. AF in the BTBL combine (or segregate) within upwellings depends on viscosity/density contrasts, how slabs collapse in the BTBL, and time. End-member regimes include: experiments dominated by a very light H-slab component with early, cold H-plumes and late, hot B/E-AF plumes and experiments where density differences between H, B/E and AF are small and

  7. Upwelling radiance at 976 nm measured from space using the OPALS CCD camera on the ISS

    Science.gov (United States)

    Biswas, Abhijit; Kovalik, Joseph M.; Oaida, Bogdan V.; Abrahamson, Matthew; Wright, Malcolm W.

    2015-03-01

    The Optical Payload for Lasercomm Science (OPALS) Flight System on-board the International Space Station uses a charge coupled device (CCD) camera to detect a beacon laser from Earth. Relative measurements of the background contributed by upwelling radiance under diverse illumination conditions and varying surface terrain is presented. In some cases clouds in the field-of-view allowed a comparison of terrestrial and cloud-top upwelling radiance. In this paper we will report these measurements and examine the extent of agreement with atmospheric model predictions.

  8. The potential role of mass balance models for the management of upwelling ecosystems

    DEFF Research Database (Denmark)

    Jarre, Astrid

    1998-01-01

    Upwelling ecosystems are productive fishing grounds, contributing >30% to the world's catch of marine fish. A set of seven trophic mass balance models of productive subsystems of the four largest upwelling areas is used to demonstrate key features of the modeling process and the analysis...... set of species interactions, and its impact can thus be readily compared to that of other piscivores in the ecosystem. This approach consequently allows us to assess the ecological sustainability of a fishery. It therefore addresses the Code of Conduct for Responsible Fisheries recently published...

  9. Application of Coastal Remote Sensing to Rhincodon Typus Habitat Monitoring Northeast of the Yucatán Peninsula

    Science.gov (United States)

    Leben, R. R.; Shannon, M. R.

    2013-05-01

    Whale sharks, Rhincodon Typus, congregate annually in the coastal waters northeast of the Yucatán Peninsula from May through mid-September, with peak abundance in occurring between late July and the middle of August. This coincides with seasonal upwelling along the northern Yucatán coast and the eastern margin of the Yucatán shelf. Remote sensing data, including ocean color, sea surface temperature, ocean vector winds, and satellite altimetry, are used to characterize the physical environment supporting this unique coastal ecology, which also has important economic ramifications for the region because of increasing ecotourism activities focused on whale shark aggregations.

  10. Organic carbon in glacial fjords of Chilean Patagonia

    Science.gov (United States)

    Pantoja, Silvio; Gutiérrez, Marcelo; Tapia, Fabián; Abarzúa, Leslie; Daneri, Giovanni; Reid, Brian; Díez, Beatriz

    2016-04-01

    The Southern Ice Field in Chilean Patagonia is the largest (13,000 km2) temperate ice mass in the Southern hemisphere, yearly transporting ca. 40 km3 of freshwater to fjords. This volume of fresh and cold water likely affects adjacent marine ecosystems by changing circulation, productivity, food web dynamics, and the abundance and distribution of planktonic and benthic organisms. We hypothesize that freshwater-driven availability of inorganic nutrient and transport of organic and inorganic suspended matter, as well as microbes, become a controlling factor for productivity in the fjord associated with the Baker river and Jorge Montt glacier. Both appear to be sources of silicic acid, but not of nitrate and particulate organic carbon, especially during summer, when surface PAR and glacier thawing are maximal. In contrast to Baker River, the Jorge Montt glacier is also a source of dissolved organic carbon towards a proglacial fjord and the Baker Channel, indicating that a thorough chemical description of sources (tidewater glacier and glacial river) is needed. Nitrate in fiord waters reaches ca. 15 μM at 25 m depth with no evidence of mixing up during summer. Stable isotope composition of particulate organic nitrogen reaches values as low as 3 per mil in low-salinity waters near both glacier and river. Nitrogen fixation could be depleting δ15N in organic matter, as suggested by the detection at surface waters of nif H genes belonging to diazotrophs near the Montt glacier. As diazotrophs have also been detected in other cold marine waters (e.g. Baltic Sea, Arctic Ocean) as well as glaciers and polar terrestrial waters, there is certainly a potential for both marine and freshwater microbes to contribute and have a significant impact on the Patagonian N and C budgets. Assessing the impact of freshwater on C and N fluxes and the microbial community structure in Patagonian waters will allow understanding future scenarios of rapid glacier melting. This research was funded

  11. Dynamics of Black Band Disease in a Diploria strigosa population subjected to annual upwelling on the northeastern coast of Venezuela

    Science.gov (United States)

    Rodríguez, S.; Cróquer, A.

    2008-06-01

    Temporal variability of Black Band Disease (BBD) prevalence, incidence, recurrence, recovery and virulence was estimated in a Diploria strigosa population from an upwelling zone of Venezuela, for 1 year between August 2004 and August 2005. The sampling spanned both upwelling and non-upwelling seasons, and included three samplings, roughly 60 days apart, within each season. The negative effects of BBD epizootiology in the sampling population (El Mercado reef) were positively correlated with sea surface temperature (taken as an upwelling estimator). Disease prevalence, incidence and recurrence decreased significantly during upwelling, and the recovery rate increased. Contrary to expectations, tissue mortality did not decrease significantly during the upwelling season, remaining at 1.2 ± 0.7 mm day-1. BBD prevalence, and the ensuing rates of tissue mortality were higher than values previously reported for other Caribbean reefs, even during upwelling episodes, suggesting that nutrient enrichment of the local waters by upwelling counteracts the expected reductions of the disease prevalence and virulence due to the lower temperature. Colonies which had previously been infected with BBD were up to six times more susceptible to new infections than those which were not infected during the preceding 7 months, suggesting that the infected colonies never healed completely. The high variability between tissue mortality values among coral colonies also suggests that overall host health-status may alter susceptibility to BBD infections.

  12. Coastal Economic Trends for Coastal Geographies

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These market data provide a comprehensive set of measures of changes in economic activity throughout the coastal regions of the United States. In regard to the...

  13. La infografía de 'El Mercurio' de Chile. Chilean El Mercurio's infographics Chilean El Mercurio's infographics

    Directory of Open Access Journals (Sweden)

    Raymond Colle

    Full Text Available Resumen: El diario chileno El Mercurio incluye algunas veces en sus artículos la mención «ver infografía» para invitar a los lectores a completar la lectura con la observación de un cuadro anexo. Este cuadro, sin embargo, no siempre incluye un elemento icónico: como lo demostramos aquí, este diario utiliza una definición extremadamente amplia del concepto de infografía. Además de presentar aquí las características de todos los infográficos publicados en enero y febrero de 2009, mostramos también que los casos en que aparece la mención «ver infografía» no son predecibles a partir de estos cuadros y que éstos no se distinguen, por sus características, del resto de los publicados.Abstract:The chilean newspaper El Mercurio sometimes include in their articles the words «see infographics» inviting readers to complete the reading with the observation of an annexed table. This table, however, does not always include an iconic: as we demonstrated here, this newspaper uses an extremely broad definition of the concept of infographics. Apart from presenting here the characteristics of all infographics published in January and February 2009, we also show that cases in which the words «see infographics» are not predictable from these graphics and they are not distinguished by their characteristics from the rest of them.

  14. Wind-driven coastal upwelling along the western boundary of the Bay of Bengal during the southwest monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Shenoi, S.S.C.; Gouveia, A.D.; Michael, G.S.; Sundar, D.; Nampoothiri, G.

    along the coast oflndia. IOC/Unesco Workshop on Regional Co-operation in Marine Science in the Central Indian Ocean and Adjacent Seas and Gulfs, Colombo, 8--13 July 1985, IOC Workshop Report No. 37 (Supplement), UNESCO, Paris, 366 pp. SHETYE S. R...

  15. The response of microzooplankton (20-200 mu m) to coastal upwelling and summer stratification in the southeastern

    Digital Repository Service at National Institute of Oceanography (India)

    Jyothibabu, R.; Devi, C.R.A.; Madhu, N.V.; Sabu, P.; Jayalakshmy, K.V.; Jacob, J.; Habeebrehman, H.; Prabhakaran, M.P.; Balasubramanian, T.; Nair, K.K.C.

    Sea is important, since smaller individuals are widespread and form the majority of phytoplankton community. The present study points also to the fact that the MZP could play an important role, even in nutrient-enriched environment, if smaller...

  16. [Association of sardine fishery, Sardinella aurita (Teleostei: Clupeidae) and environmental variability of the coastal upwelling ecosystem of Nueva Esparta, Venezuela].

    Science.gov (United States)

    Gonzźlez, Leo W; Euán, Jorge; Eslava, Nora; Suniaga, Jesús

    2007-03-01

    The present research is an analysis of Spanish sardine fishing (Sardinella aurita) associated with some climatic and meteorologic parameters of the ecosystem from El Morro Nueva Esparta, Venezuela. The catch and environmental data from the area were taken in the period 1996-2000. Catch data as a function of wind speed, sea surface temperature, air temperature and rain were analyzed by means of simple lineal regression and multiple models. We found a positive correlation of catch with wind speed, and a negative correlation with sea surface temperature, air temperature, and rain. The multiple regression model with intercept had a poor fit, therefore, we made a model without intercept, which improve greatly the fit. A selection of the variables using the forward procedure verified that the independent variables "wind speed" and "air temperature" have a significant relation with catch (p < 0.001) at real time. This method suggests that sea surface temperature and rain have little influence on the catch, and suggests a major availability of resources in the months with low air temperature and the highest wind speed (January-June). Rev. PMID:18457137

  17. Evaluation of the ecological integrity and ecosystem health of three benthic networks influenced by coastal upwelling in the northern Chile

    Science.gov (United States)

    The ecological health of ecosystems relates to the maintenance or restoration of optimal system function when confronted with a disturbance. A healthy ecosystem is a prerequisite for ecological sustainability. Ecological integrity has been defined as an emergent property of ecosy...

  18. The upwelling record in the sediments of the westen continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.; PrakashBabu, C.; Rao, Ch.M.

    . 39, No. 3/4, pp. 715-723, 1992. 0198-0149/92 $5.(XI + 0.(1~1 Printed in Great Britain. © 1992 Pergamon Press pie NOTE The upwelling record in the sediments of the western continental margin of India P. DIVAKAR NAIDU,* C. PRAKASH BABU* and CH. M...

  19. Foraminiferal production and monsoonal upwelling in the Arabian sea: evidence from sediment traps

    Digital Repository Service at National Institute of Oceanography (India)

    Curry, W.B.; Ostermann, D.R.; Guptha, M.V.S.; Ittekkot, V.

    (18) O values by about 1%, accurately reflecting the average 4 degrees C sea surface temperature decrease associated with the upwelling. The mean value of delta super(18) O for G. ruber was greater in the western Arabian Sea than in the central...

  20. Melt-peridotite reactions in upwelling EM1-type eclogite bodies

    DEFF Research Database (Denmark)

    Søager, Nina; Holm, Paul Martin

    2013-01-01

    The processes of magma generation in upwelling eclogite bodies of recycled lithospheric material are not fully understood but are important for our understanding and modelling of major and trace element variations in many ocean island basalts (OIB). The primitive alkaline intraplate basalts from...

  1. Diagnosing CO2 fluxes in the upwelling system off the Oregon coast

    Directory of Open Access Journals (Sweden)

    Z. Cao

    2014-05-01

    Full Text Available It is generally known that the interplay between the carbon and nutrients supplied from subsurface waters via biological metabolism would determine the CO2 fluxes in upwelling systems. However, quantificational assessment of such interplay is difficult because of the dynamic nature of both upwelling circulation and the associated biogeochemistry. In this study, the diagnosis approach based upon the carbon/nutrient mass balance in the Ocean-dominated Margin (OceMar framework was applied to resolve the CO2 fluxes in the well-known upwelling system in the US west coast off Oregon, using the data collected along two cross-shelf transects from the inner shelf to the open basin in spring/early summer 2007. Through examining the biological consumption on top of the water mass mixing built upon the total alkalinity–salinity relationship, we successfully predicted and semi-analytically resolved the CO2 fluxes showing strong uptakes from the atmosphere beyond the nearshore regions, primarily resulting from the higher utilization of nutrients relative to dissolved inorganic carbon (DIC based on their concurrent inputs from the depth. On the other hand, we showed significant CO2 outgassing in the nearshore regions associated with intensified upwelling and minor biological consumption, where CO2 fluxes could be simplified without considering DIC/nutrient consumption. We reasoned that our approach in conceptualizing OceMar would be in a steady state with balanced DIC and nutrients via both physical transport and biological alterations in comparable timescales.

  2. Climate change in the Iberian Upwelling System: a numerical study using GCM downscaling

    Science.gov (United States)

    Cordeiro Pires, Ana; Nolasco, Rita; Rocha, Alfredo; Ramos, Alexandre M.; Dubert, Jesus

    2016-07-01

    The present work aims at evaluating the impacts of a climate change scenario on the hydrography and dynamics of the Iberian Upwelling System. Using regional ocean model configurations, the study domain is forced with three different sets of surface fields: a climatological dataset to provide the control run; a dataset obtained from averaging several global climate models (GCM) that integrate the Intergovernmental Panel for Climate Change (IPCC) models used in climate scenarios, for the same period as the climatological dataset; and this same dataset but for a future period, retrieved from the IPCC A2 climate scenario. After ascertaining that the ocean run forced with the GCM dataset for the present compared reasonably well with the climatologically forced run, the results for the future run (relative to the respective present run) show a general temperature increase (from +0.5 to +3 °C) and salinity decrease (from -0.1 to -0.3), particularly in the upper 100-200 m, although these differences depend strongly on season and distance to the coast. There is also strengthening of the SST cross-shore gradient associated to upwelling, which causes narrowing and shallowing of the upwelling jet. This effect is contrary to the meridional wind stress intensification that is also observed, which would tend to strengthen the upwelling jet.

  3. Upwelling and associated hydrography along the west coast of india during southwest monsoon, 1999

    Digital Repository Service at National Institute of Oceanography (India)

    Maheswaran, P.A.; Rajesh, G.; Revichandran, C; Nair, K.K.C

    and related hydrography is discussed. Analysis of wind field and hydrography indicated active upwelling along the southwest coast of India. The sea surface temperature near the coast were lower by 1.7 degrees C (off Kanyakumari), 1.4 degrees C (off Cochin...

  4. Observation of summertime upwelling off the eastern and northeastern coasts of Hainan Island, China

    Science.gov (United States)

    Lin, Peigen; Hu, Jianyu; Zheng, Quanan; Sun, Zhenyu; Zhu, Jia

    2016-03-01

    Using cruise observations and reanalysis data, this study analyzes the effects of wind, freshwater, and turbulent mixing on the two upwellings: one is off the eastern coast of Hainan Island (HEU) and the other is off the northeastern coast of Hainan Island (HNEU). During the cruise in 2009, the HNEU occurred with southwesterly to southeasterly wind. The relative large values of turbulent kinetic energy dissipation rate and diffusivity estimated from the Thorpe scale indicate that the upwelling water is further uplifted to the surface by strong turbulent mixing in the HNEU region. But the HEU was not observed under the southeasterly wind. During the cruise in 2012, the HNEU disappeared in the upper layer with freshwater covered and southeasterly wind, while the apparent HEU only accompanied with southwesterly wind. To obtain the general characteristics, we define three types of upwelling patterns, i.e., the intensified HEU, the intensified HNEU, and both HEU and HNEU in one day, using the reanalysis data. The composites of sea surface temperature (SST), wind, and precipitate for each upwelling pattern identify that the HNEU is associated with the prevailing southeasterly wind and can be limited in the lower layer when it is covered by freshwater. But the HEU is mainly driven by southwesterly wind but is not remarkably affected by freshwater.

  5. The significance of nitrogen regeneration for new production within a filament of the Mauritanian upwelling system

    Science.gov (United States)

    Clark, Darren R.; Widdicombe, Claire E.; Rees, Andrew P.; Woodward, E. Malcolm S.

    2016-05-01

    The Lagrangian progression of a biological community was followed in a filament of the Mauritanian upwelling system, north-west Africa, during offshore advection. The inert dual tracers sulfur hexafluoride and helium-3 labelled a freshly upwelled patch of water that was mapped for 8 days. Changes in biological, physical, and chemical characteristics were measured, including phytoplankton productivity, nitrogen assimilation, and regeneration. Freshly upwelled water contained high nutrient concentrations but was depleted in N compared to Redfield stoichiometry. The highest rate of primary productivity was measured on the continental shelf, associated with high rates of nitrogen assimilation and a phytoplankton community dominated by diatoms and flagellates. Indicators of phytoplankton abundance and activity decreased as the labelled water mass transited the continental shelf slope into deeper water, possibly linked to the mixed layer depth exceeding the light penetration depth. By the end of the study, the primary productivity rate decreased and was associated with lower rates of nitrogen assimilation and lower nutrient concentrations. Nitrogen regeneration and assimilation took place simultaneously. Results highlighted the importance of regenerated NH4+ in sustaining phytoplankton productivity and indicate that the upwelled NO3- pool contained an increasing fraction of regenerated NO3- as it advected offshore. By calculating this fraction and incorporating it into an f ratio formulation, we estimated that of the 12.38 Tg C of annual regional production, 4.73 Tg C was exportable.

  6. The lower cretaceous volcanism in the coastal range of Central Chile: Geochronology and isotopic geochemistry

    International Nuclear Information System (INIS)

    Major factors involved in subduction zone magmatism are related to the melting of the underlying mantle, which can contain a component of aqueous fluid and/or melts derived from the subducting plate (e.g. Peate et al., 1997). The Chilean Pacific margin is a subduction zone, active from Early Mesozoic to now, in which the magmatic arc emplaced on the Paleozoic basement progressively migrate to the east. The western part of this arc constitutes the Coastal Range. In this work, isotopic and radiometric data from four E-W profiles along c. 500 km of the Lower Cretaceous volcanic rocks in the Coastal Range of Chile are presented. The aim of this research is to obtain a model for the genesis of this Cretaceous volcanic arc based on their isotopic signature (au)

  7. Characteristics of the Distribution of Upwelling Flow off Guangdong Coast in Summer Based on Remote Sensing Dataset%基于遥感资料的夏季广东沿岸上升流分布特征

    Institute of Scientific and Technical Information of China (English)

    王妍; 胡运; 任慧军

    2015-01-01

    【目的】研究广东沿岸夏季上升流的时空变化规律及其对沿岸区域气候的影响。【方法】采用 Sobel 梯度算法,综合 MODIS 海表温度和 QuikSCAT 海面风场资料对2003年夏季广东沿海上升流的范围、强度、持续时间等时空分布特征进行综合分析。【结果】广东沿岸海域存在明显的上升流现象,整体呈现强弱强的特征,在7月初出现具有明显上升流特征的低温表层水,至7月底低温水活动减弱至最低,于8月初又存在一个增强的过程;同时,上升流并非始终稳定存在。【结论】对比海表温度数据和风场资料可以发现,上升流的强度、持续时间等与风场的变化存在密切联系,风场是上升流的一个重要影响因素,此外,沿岸水团的分布也是影响广东沿岸上升流空间分布的重要因素。%Objective]The upwelling off Guangdong coast was studied in order to understand the characteristics of its spatial and temporal distributions,as well as its influence on the coastal re﹣gional climate.[Methods]Based on the MODIS sea surface temperature(hereafter,SST)data and sea surface wind of QuikSCA,the upwelling off Guangdong coast was surveyed in the sum﹣mer of 2003.The characteristics of spatial and temporal distributions,including the range,the intensity, and the duration, have been comprehensively analyzed using the Sobel gradient algorithm.[Results]The upwelling phe﹣nomena were obvious off Guangdong coast, which changed overall from stronger to weaker and then to stronger again.The low surface wa﹣ters with clear upwelling appeared in early July, decreased to the lowest in late July,and in﹣creased again in early August.Meanwhile the upwelling phenomena did not always stably exist.Conclusion Comparison of SST with wind field suggested that the intensity and duration of upwelling were closely associated with wind variations.The wind field was one of the main factors affecting the

  8. Home and Instruction Effects on Emergent Literacy in a Sample of Chilean Kindergarten Children

    Science.gov (United States)

    Strasser, Katherine; Lissi, Maria Rosa

    2009-01-01

    The study examines the home literacy experiences, emergent literacy skills, and instructional experiences of a sample of Chilean kindergarten children (n = 126) and kindergarten families (n = 188) nested in 12 kindergarten classrooms from different socioeconomic status groups and types of schools. Descriptive information is given showing the level…

  9. The Dad in the Che Guevara T-Shirt: Narratives of Chilean English Teachers

    Science.gov (United States)

    Menard-Warwick, Julia

    2008-01-01

    Building on previous critical research regarding student resistance to English Language Teaching (ELT), this paper illustrates Chilean high-school English teachers' use of narrative to make sense of ideological challenges from students. While the government of Chile is promoting English in connection with the nation's export-oriented economic…

  10. Bruises in Chilean cattle: their characterization, occurrence and relation with pre-slaughter conditions

    NARCIS (Netherlands)

    Strappini, A.C.

    2012-01-01

    Bruises on cattle carcass affect the quality of the meat and are indicators of poor welfare conditions. According to the literature the occurrence of bruises is related to pre- slaughter conditions, however their contribution is not clear for Chilean cattle. The aim of this thesis was to provide a b

  11. Estimating enteric methane emissions from Chilean beef fattening systems using a mechanistic model

    NARCIS (Netherlands)

    Arias, R.A.; Catrileo, A.; Larraín, R.; Vera, R.; Velásquez, A.; Toneatti, M.; France, J.; Dijkstra, J.; Kebreab, E.

    2015-01-01

    A mechanistic model (COWPOLL) was used to estimate enteric methane (CH4) emissions from beef production systems in Chile. The results expressed as a proportion of gross energy intake (GEI) were compared with enteric fermentation data reported in the last Chilean greenhouse gases inventory, which uti

  12. Chilean Adolescents' and Parents' Views on Autonomy Development

    Science.gov (United States)

    Martínez, M. Loreto; Pérez, J. Carola; Cumsille, Patricio

    2014-01-01

    This study aims to understand Chilean parents' and adolescents' conceptions of autonomy and whether they hold different expectations for autonomous behaviors by generation and socioeconomic level. A qualitative approach to data collection was used through separate focus groups of parents and adolescents from different socioeconomic…

  13. New English Cultures and Learner Autonomy for Intrinsic Motivation and Democratic Empowerment in the Chilean Context

    Science.gov (United States)

    Glas, Katharina; Cardenas-Claros, Monica S.

    2013-01-01

    Chilean youth are currently demanding access to better-quality education for all: greater democracy and curricula that respect the country's indigenous cultural roots form part of their petitions. This article puts forward a twofold pedagogical proposal for English Language Teaching intended to foster intrinsic motivation and democratic…

  14. Morphology, anatomy and histology of Doto uva Marcus, 1955 (Opisthobranchia: Nudibranchia) from the Chilean coast

    NARCIS (Netherlands)

    Fischer, M.A.; Velde, van der G.; Roubos, E.W.

    2006-01-01

    Doto uva Marcus, 1955 is a nudibranch species recorded from the Brazilian and Chilean coast. In spite of its wide distribution, D. uva has been described only superficially, mainly as to the pattern of its coloration, external morphology, radular teeth and reproductive system. Here we substantially

  15. [Recommendations for Chilean travelers to the FIFA World Cup 2014 in Brazil].

    Science.gov (United States)

    Perret, Cecilia; Weitzel, Thomas

    2014-04-01

    This article provides a checklist of precautions and vaccines for Chilean travelers attending the FIFA World Cup 2014 in Brazil. It aims to help physicians to prepare visitors of this mass gathering and summarizes useful hints to avoid infectious diseases considering the circumstances and availabilities in Chile.

  16. Eating Disorders among a Community-Based Sample of Chilean Female Adolescents

    Science.gov (United States)

    Granillo, M. Teresa; Grogan-Kaylor, Andrew; Delva, Jorge; Castillo, Marcela

    2011-01-01

    The purpose of this study was to explore the prevalence and correlates of eating disorders among a community-based sample of female Chilean adolescents. Data were collected through structured interviews with 420 female adolescents residing in Santiago, Chile. Approximately 4% of the sample reported ever being diagnosed with an eating disorder.…

  17. Educational Effectiveness in Chilean Secondary Education: Comparing Different "Value Added" Approaches to Evaluate Schools

    Science.gov (United States)

    Muñoz-Chereau, B.; Thomas, S. M.

    2016-01-01

    This article reports an original investigation into school performance measures and the multilevel nature of pupil achievement data in the Chilean school system using a sample of 177,461 students, nested within 7146 classrooms, 2283 secondary schools and 313 municipalities. The data-set comprised Year 10 students' 2006 SIMCE test's results in two…

  18. Bringing the Schools Back in: The Stratification of Educational Achievement in the Chilean Voucher System

    Science.gov (United States)

    Mizala, Alejandra; Torche, Florencia

    2012-01-01

    This paper analyzes the socioeconomic stratification of achievement in the Chilean voucher system using a census of 4th and 8th graders, a multilevel methodology, and accounting for unobserved selectivity into school sector. Findings indicate that the association between the school's aggregate family socioeconomic status (SES) and test scores is…

  19. The Chilean miracle : patrimonialism in a modern free-market democracy

    NARCIS (Netherlands)

    Peppelenbos, L.P.C.

    2005-01-01

    International policy institutions claim that Chile's remarkable economic performance testifies to the merits of a neo-liberal development model. This book argues, however, that 'the Chilean miracle' did not result from the adoption ofneoliberalismitself, but from the persis

  20. Upwelling processes along a western boundary current in the Abrolhos-Campos region of Brazil

    Science.gov (United States)

    Aguiar, A. L.; Cirano, M.; Pereira, J.; Marta-Almeida, M.

    2014-08-01

    Upwelling events observed from the years 2003 to 2011 were analyzed. Our focus was on the Abrolhos-Campos region (ACR, 15°S-23°S), which is located along the Brazilian Margin and influenced by a western boundary current, the Brazil Current (BC). Satellite sea surface temperature, National Centers for Environmental Prediction (NCEP) and Global Forecast System (GFS) wind data were used to complement the results of a high-resolution regional oceanic model to investigate the occurrence of and the mechanisms responsible for intense upwelling events in this region. These events were more frequent from 20°S to 23°S. Over 90% of the identified upwelling events were influenced by favorable wind stress. Surface Ekman transport was found to be more important for the region from Prado (17°S) to Marataízes (21°S), whereas upward Ekman pumping played a more important role from 22°S to 23°S. Current-driven upwelling processes associated with the location of the BC as well as its velocity and meso-scale activity were also analyzed. The results showed that these mechanisms are highly influenced by the local topography. Topographic effects exerted via the acceleration of the BC are more obvious in the southern ACR, while in the Prado region, BC cyclonic meanders tend to be more relevant. Moreover, eddy-driven upwelling increases in the southward direction after the passage of the Vitória-Trindade Ridge (20°S), an important submarine chain, which acts to constrain and modulate the southward flow of the BC.

  1. Coastal & Marine Issues Survey

    OpenAIRE

    Sidman, Charles; Fik, Tim; Havens, Karl

    2008-01-01

    Florida Sea Grant management and extension specialists developed a questionnaire to solicit information regarding the recipient’s county of residence, occupation, and primary coastal activities. Survey recipients were also asked to select from a list the top five marine-related topics that defined prior strategic plan themes (i.e., marine bio-technology, fisheries, aquaculture, seafood safety, coastal communities, ecosystem health, coastal hazards, and marine education). In add...

  2. Coastal Innovation Imperative

    Directory of Open Access Journals (Sweden)

    Bruce C. Glavovic

    2013-03-01

    Full Text Available This is the second of two articles that explores the coastal innovation paradox and imperative. Paradoxically, innovation is necessary to escape the vulnerability trap created by past innovations that have degraded coastal ecosystems and imperil coastal livelihoods. The innovation imperative is to reframe and underpin business and technology with coherent governance innovations that lead to social transformation for coastal sustainability. How might coastal management help to facilitate this transition? It is argued that coastal management needs to be reconceptualised as a transformative practice of deliberative coastal governance. A foundation comprising four deliberative or process outcomes is posited. The point of departure is to build human and social capital through issue learning and improved democratic attitudes and skills. Attention then shifts to facilitating community-oriented action and improving institutional capacity and decision-making. Together, these endeavours enable improved community problem-solving. The ultimate process goal is to build more collaborative communities. Instituting transformative deliberative coastal governance will help to stimulate innovations that chart new sustainability pathways and help to resolve the coastal problems. This framework could be adapted and applied in other geographical settings.

  3. Prevalence rates of mental disorders in Chilean prisons.

    Directory of Open Access Journals (Sweden)

    Adrian P Mundt

    Full Text Available OBJECTIVE: High rates of mental disorders have been reported for prison populations worldwide, particularly in low- and middle-income countries (LMICs. The present study aimed to establish prevalence rates of mental disorders in Chilean prisoners. METHOD: A nationwide random sample of 1008 prisoners was assessed in 7 penal institutions throughout Chile. Twelve-month prevalence rates were established using the Composite International Diagnostic Interview (CIDI and compared to the prevalence rates previously published for the general population. RESULTS: Prevalence rates were 12.2% (95% CI, 10.2-14.1 for any substance use disorder, 8.3% (6.6-10.0 for anxiety disorders, 8.1% (6.5-9.8 for affective disorders, 5.7% (4.4-7.1 for intermittent explosive disorders, 2.2% (1.4-3.2 for ADHD of the adult, and 0.8% (0.3-1.3 for non-affective psychoses. Significantly higher prevalence rates among prisoners as compared to the general population in Chile were seen for major depression (6.1% vs. 3.7% males, Z=2.58, p<0.05 and illicit drug use (3.3% vs. 0.6% males with drug abuse, Z=2.04, p<0.05; 2.6% vs. 0.1% females with drug abuse, Z=5.36, p<0.001; 3.4% vs. 1.1% males with drug dependence, Z=3.70; p<0.001. Dysthymia (6.5% vs. 15.6%, Z=-2.39, p<0.05, simple (3.3% vs. 11.5%, Z=-3.13, p<0.001 and social phobias (3.9% vs. 9.7%, Z=2.38, p<0.05 were significantly less frequent in the female prison population than in the general population. One-year prevalence rates of alcohol abuse (2.3% vs. 3.9%; Z=-2.04; p<0.05 and dependence (2.7% vs. 8.2%; Z=-5.24; p<0.001 were less prevalent in the male prison population than in the general population. CONCLUSIONS: Service provision for prison populations in Chile should acknowledge high rates of depression and illicit drug use. Overall prevalence rates are lower than reported in other LMICs. Previous research in prison populations in LMICs might have overestimated prevalence rates of mental disorders.

  4. Population genetics of the Chilean frog Batrachyla Leptopus (Leptodactylidae

    Directory of Open Access Journals (Sweden)

    J.R. Formas

    2000-03-01

    Full Text Available Electrophoretic variation of proteins encoded by 14 loci was analyzed in eight (five continental and three insular populations of the Chilean leptodactylid frog Batrachyla leptopus. The overall proportion of polymorphic loci was estimated to be 18.7% and the average number of alleles per locus, 1.2, while observed and expected heterozygosities were 1.7 and 5.1%, respectively. The estimated coefficient of genetic identity was 0.940; the corresponding figure for genetic distance was 0.063. F-statistics analysis showed a total inbreeding coefficient (Fit of 0.855 and high levels of genetic subdivision (Fst = 0.596 as well as of inbreeding within populations (Fis = 0.640. However, there was only a moderate level of genetic differentiation (Fst = 0.181 between the insular group of populations and the continental group.A variação eletroforética de proteínas codificadas por 14 loci foi analisada em oito populações (5 continentais e 3 insulares da rã leptodactilídea chilena Batrachyla leptopus. A proporção geral de loci polimórficos foi estimada como sendo de 18,7% e o número médio de alelos por loco, 1,2, enquanto que as heterozigosidades observada e esperada foram 1,7 e 5,1%, respectivamente. O coeficiente esperado de identidade genética foi 0,940; o número correspondente para a distância genética foi 0,063. A análise estatística F mostrou um coeficiente de endogamia total (Fit de 0,855 e altos níveis de subdivisão genética (Fst = 0,596, assim como de endogamia dentro das populações (Fis = 0,640. Contudo, houve apenas um nível moderado de diferenciação genética (Fst = 0,181 entre o grupo insular de populações e o grupo continental.

  5. Last millenium environmental changes in Lake Bertrand sediments, Chilean Patagonia

    Science.gov (United States)

    Sacré, V.; Fagel, N.; Schmidt, S.; Alvarez, D.; Araneda, A.; Urrutia, R.

    2012-04-01

    'W). The identification of the diatom assemblages and its temporal variability in both lake sediments will help to identify the origin of those silica-rich layers. In addition, further sedimentological analyses are in progress to better characterize the sediment deposition models. This research was funded by Chilean Fondecyt project number 1070508 and Belgian projects (FNRS proposal 1360 2007-2010, ULg CFRA 1060 2009-2010).

  6. Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach

    Directory of Open Access Journals (Sweden)

    S. Meisel

    2011-08-01

    Full Text Available The last 5500 years of climate change and environmental response in the northern Benguela Coastal Upwelling are reconstructed by means of three sediment cores from the inner shelf off central Namibia. The study is based on nutrient (δ15N, δ13C and productivity proxies (accumulation rates of total organic carbon; ARTOC. Reconstructed sea surface temperatures (alkenone-derived SST and temperatures at subsurface depths (Tδ18O; based on tests of planktonic foraminifers reflect the physical boundary conditions. The selection of proxy indicators proved a valuable basis for robust palaeo-climatic reconstructions, with the resolution ranging from multi-decadal (NAM1 over centennial (core 178 to millennial scale (core 226620. The northern Benguela experienced pronounced and rapid perturbation during the middle and late Holocene, and apparently, not all are purely local in character. In fact, numerous correlations with records from the adjacent South African subcontinent and the northern hemisphere testify to global climatic teleconnections. The Holocene Hypsithermal, for instance, is just as evident as the Little Ice Age (LIA and the Roman Warm Period. The marked SST-rise associated with the latter is substantiated by other marine and terrestrial data from the South African realm. The LIA (at least its early stages manifests itself in intensified winds and upwelling, which accords with increased rainfall receipts above the continental interior. It appears that climate signals are transferred both via the atmosphere and ocean. The combined analysis of SST and Tδ18O proved a useful tool in order to differentiate between both pathways. SSTs are primarily controlled by the intensity of atmospheric circulation features, reflecting changes of upwelling-favourable winds. Tδ18O records the temperature of the source water and often correlates with global ocean conveyor speed due to varying inputs of warm Agulhas Water. It seems as though conveyor slowdown or

  7. Observations of Upwelling Filaments in the Southern North-West African Upwelling System : a Joint Effect of the Bottom Topography and the Offshore Eddy Field?

    Science.gov (United States)

    Meunier, T.; Barton, E. D.; Torres, R.; Barreiro, B.

    2010-12-01

    The nature and dynamics of the long filaments forming in the southern edge of the West-African upwelling system are investigated using data from the SOLAS-ICON cruise, that took place in April-May 2009 offshore of Cap Blanc, between 19.5 and 22.5 °N and 17 and 19 °W. Two synoptic hydrographic surveys using a Moving Vessel Profiler were performed at a 15 days interval on two distinct upwelling filaments at different stages of development. The first survey showed the presence of a large anticyconic eddy North of the filament, also evident in the satellite imagery. Two transects were performed across the tip of the filament, showing a steep rising of the isohalines and the isotherms, with horizontal gradients of 3.10-2 psu km-1 and 10 -1 °C km-1. The density compensation of temperature and salinity in this part of the North West African upwelling system resulted in a weaker doming of the isopycnals across the filament. The second filament developed during a strong wind episode directly following a 2 days wind relaxation period. 8 cross sections were performed, all showing a steeper doming of the isohalines and isotherms than during the first survey, resulting in horizontal gradients of 8.10-2 psu km-1 and 5.10-1 °C km-1 near the surface. The hydrographic signature of the filament was evident as deep as 300 m. Satellite imagery showed the persistence between the two surveys of a shorter and colder filament West of Cap Blanc , rolling around a small anticyclonic eddy, in spite of the relaxation of the wind. The surveyed filaments both appeared to emerge from this struc ture. A process study using a simple two layer shallow water isopycnic numerical model (MICOM) and an idealized topography was carried out to elucidate the development and stationarity of the anticyclone and cold filament at the root of the longer structures. Potential vorticity anomalies generated by topographic effects were shown to play a major role in the filament formation, when interacting with

  8. Coastal Analysis, Dorchester County, MD

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  9. Coastal Analysis, Charles County, MD

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  10. Coastal Analysis, Essex County, VA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  11. Coastal Analysis, Virginia Beach, VA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  12. Coastal Analysis, Mathews County, VA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  13. Coastal Analysis, Caroline County, MD

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  14. Coastal Analysis, Nassau,NY

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

  15. Summer upwelling at the Boknis Eck time series station (1982 to 2012 – a combined glider and wind data analysis

    Directory of Open Access Journals (Sweden)

    J. Karstensen

    2014-02-01

    Full Text Available Two consecutive summer upwelling events, each lasting for less than 24 h, where surveyed in high temporal and vertical resolution at the Boknis Eck time series station (BE in the western Belt Sea (Baltic Sea in summer 2010 with an autonomous glider. Driven only by moderate offshore winds, both events resulted in strong cooling of surface waters (up to 5 K. Only for the second event, significant irreversible changes in the vertical stratification were observed and the appearance of low oxygen waters at the bottom indicated that the upwelling had an impact on the water column as a whole. A combination of wind and seasurface temperature data revealed that summer (June to September upwelling at BE occurs for wind directions between 190 ° to 260 ° and with hourly averaged wind speed exceeding 4 m s−1. For the period 1982 to 2012 BE experience about 18 days of upwelling favourable wind conditions on average. Large interannual variability exist ranging from only 7.7 days in 2006 to more than 28 days in 1985. Surface (1 m depth and deep water (below 25 m depth anomalies of salinity and oxygen at the BE follow extended periods of strong upwelling favourable winds. Although seasurface temperature is good indicator for the existence of summer upwelling, the upwelling intensity does not correlate with the temperature anomaly.

  16. Shelf/Offshore interactions in the Benguela upwelling system using a 3-D coupled physical/biogeochemical model

    OpenAIRE

    Gutknecht, E.

    2011-01-01

    The main objective of this PhD thesis is the study of the shelf/offshore interactions in the Benguela upwelling system, off South African and Namibian coasts, using a numerical model as well as satellite and in-situ data. A Biogeochemical model adapted for the Benguela Upwelling System (BioBUS), taking into account the main processes linked with eastern boundary upwelling systems and associated oxygen minimum zones, has been developed and coupled with the ROMS hydrodynamical model, in order t...

  17. Resilience from coastal protection.

    Science.gov (United States)

    Ewing, Lesley C

    2015-10-28

    Coastal areas are important residential, commercial and industrial areas; but coastal hazards can pose significant threats to these areas. Shoreline/coastal protection elements, both built structures such as breakwaters, seawalls and revetments, as well as natural features such as beaches, reefs and wetlands, are regular features of a coastal community and are important for community safety and development. These protection structures provide a range of resilience to coastal communities. During and after disasters, they help to minimize damages and support recovery; during non-disaster times, the values from shoreline elements shift from the narrow focus on protection. Most coastal communities have limited land and resources and few can dedicate scarce resources solely for protection. Values from shore protection can and should expand to include environmental, economic and social/cultural values. This paper discusses the key aspects of shoreline protection that influence effective community resilience and protection from disasters. This paper also presents ways that the economic, environmental and social/cultural values of shore protection can be evaluated and quantified. It presents the Coastal Community Hazard Protection Resilience (CCHPR) Index for evaluating the resilience capacity to coastal communities from various protection schemes and demonstrates the use of this Index for an urban beach in San Francisco, CA, USA. PMID:26392613

  18. Coping with coastal change

    NARCIS (Netherlands)

    Nicholls, R.J.; Stive, M.J.F.; Tol, R.S.J.

    2014-01-01

    The coastal zone is one of the most dynamic environments on our planet and is much affected by global change, especially sea-level rise. Coastal environments harbour valuable ecosystems, but they are also hugely important from a societal point of view. This book, which draws on the expertise of 21 l

  19. Comparing Sociodemographic Factors Associated with Disability between Immigrants and the Chilean-Born: Are There Different Stories to Tell?

    OpenAIRE

    Baltica Cabieses; Pickett, Kate E.; Helena Tunstall

    2012-01-01

    This study explored a range of sociodemographic factors associated with disability among international immigrants in Chile, and compared them to the Chilean-born. Secondary data analysis of the Chilean population-based survey CASEN-2006 was conducted (268,873 participants). Main health outcomes: any disability and six different types of disability: visual, hearing, learning, physical, psychiatric and speaking (binary outcomes). Sociodemographic variables: Demographic factors (age, sex, marita...

  20. Fishing the future. A snapshot of the Chilean TURFs through the lens of fishers and key stakeholders‟ perceptions

    OpenAIRE

    Ueyonahara, Jorge

    2012-01-01

    Overfishing is not an exclusive topic of big fishing industry. Overfishing by small-scale fishers is also happening. The Territorial Use of Rights – TURFs was implemented in Chile to protect the Chilean abalone from overfishing. Through the implementation of the TURFs Chilean abalone are no longer threatened by overfishing. The challenge to protect the resource thus seems to be solved. However, while some problems are solved others persist or new ones arise. The thesis explores the discourses...

  1. Cadmium distribution in coastal sediments and mollusks of the US

    International Nuclear Information System (INIS)

    Cadmium (Cd) concentrations in the coastal United States were assessed using the National Status and Trends (NS and T) Mussel Watch dataset, which is based on the analysis of sediments and bivalves collected from 280 sites since 1986. Using the 1997 sediment data, Pearson correlation (r = 0.44, p < 0.0001) suggested that Cd distributions in sediment can, be to some extent, explained by the proximity of sites to population centers. The 2003 tissue data indicated that 'high' Cd concentrations (greater than 5.6 μg/g dry weights [dw] for mussel and 5.4 μg/g dw for oysters) were related to salinity along the East and Gulf coasts. Along the West coast, however, these 'high' sites appeared to be related to upwelling phenomenon. Additionally, sedimentary diagenesis was found to be the most likely explanation of why sediment and mollusk Cd content were not well correlated.

  2. Simulating coastal to offshore interactions around the South Florida coastal seas and implications on management issues

    Science.gov (United States)

    Kang, H.; Kourafalou, V. H.; Hogan, P. J.; Smedstad, O.

    2008-12-01

    The South Florida coastal seas include shelf areas and shallow water bodies around ecologically fragile environments and Marine Protected Areas, such as Florida Bay, the Florida Keys National Marine Sanctuary (around the largest coral reef system of the continental U.S.) and the Dry Tortugas Ecological Reserve. Man- made changes in the hydrology of the Everglades have caused dramatic degradation of the coastal ecosystem through discharge in Florida Bay. New management scenarios are under way to restore historical flows. The environmental impacts of the management propositions are examined with an inter-disciplinary, multi-nested modeling system. The HYbrid Coordinate Ocean Model (HYCOM) has been employed for the Regional Model for South Florida Coastal Seas (SoFLA-HYCOM, 1/25 degree resolution) and for the embedded, high resolution coastal Florida Keys model (FKEYS- HYCOM, 1/100 degree). Boundary conditions are extracted from GODAE products: the large scale North Atlantic model (ATL-HYCOM, 1/12 degree) and the intermediate scale Gulf of Mexico model (GOM-HYCOM, 1/25 degree). The study targets the impacts of large scale oceanic features on the coastal dynamics. Eddies that travel along the Loop Current/Florida Current front are known to be an important mechanism for the interaction of nearshore and offshore flows. The high resolution FKEYS simulations reveal both mescoscale and sub- mesoscale eddy passages during a targeted 2-year simulation period (2004-2005), forced with high resolution/high frequency atmospheric forcing. Eddies influence sea level changes in the vicinity of Florida Bay with possible implications on current and future flushing patterns. They also enable upwelling of cooler, nutrient-rich waters in the vicinity of the Reef Tract and they influence transport and recruitment pathways for coral fish larvae, as they carry waters of different properties (such as river-borne low-salinity/nutrient-rich waters from as far as the Mississippi River) and

  3. Characteristics of the Norwegian Coastal Current during Years with High Recruitment of Norwegian Spring Spawning Herring (Clupea harengus L..

    Directory of Open Access Journals (Sweden)

    Øystein Skagseth

    Full Text Available Norwegian Spring Spawning herring (NSSH Clupea harengus L. spawn on coastal banks along the west coast of Norway. The larvae are generally transported northward in the Norwegian Coastal Current (NCC with many individuals utilizing nursery grounds in the Barents Sea. The recruitment to this stock is highly variable with a few years having exceptionally good recruitment. The principal causes of recruitment variability of this herring population have been elusive. Here we undertake an event analysis using data between 1948 and 2010 to gain insight into the physical conditions in the NCC that coincide with years of high recruitment. In contrast to a typical year when northerly upwelling winds are prominent during spring, the years with high recruitment coincide with predominantly southwesterly winds and weak upwelling in spring and summer, which lead to an enhanced northward coastal current during the larval drift period. Also in most peak recruitment years, low-salinity anomalies are observed to propagate northward during the spring and summer. It is suggested that consistent southwesterly (downwelling winds and propagating low-salinity anomalies, both leading to an enhanced northward transport of larvae, are important factors for elevated recruitment. At the same time, these conditions stabilize the coastal waters, possibly leading to enhanced production and improved feeding potential along the drift route to Barents Sea. Further studies on the drivers of early life history mortality can now be undertaken with a better understanding of the physical conditions that prevail during years when elevated recruitment occurs in this herring stock.

  4. "One of the Most Uniform Races of the Entire World": Creole Eugenics and the Myth of Chilean Racial Homogeneity.

    Science.gov (United States)

    Walsh, Sarah

    2015-11-01

    This article illuminates why Nicolás Palacios's 1904 monograph, Raza chilena: Libro escrito por un Chileno i para los Chilenos [Chilean Race: A Book Written by a Chilean for Chileans], is central to the creation of a myth of Chilean racial homogeneity at the turn of the twentieth century. Placing Palacios in the context of Latin American eugenic discourse, it demonstrates how he selected a specific racial origin story in order to accommodate his belief in racial hierarchy while also depicting race mixing in a positive light. Specifically, the article highlights how the myth of Chilean racial homogeneity elided the difference between the term "mestizo," which was applied to people of mixed racial heritage, and "white." I contend that Palacios sought to differentiate Chileans from other Latin Americans by emphasizing their racial distinctiveness. The article therefore highlights that Latin American eugenics was concerned with the creation of national narratives that historicized particular racial mixtures in order to reify and affirm national differences. As such, it connects to literature regarding the history of eugenics, race, nation, and the creation of whiteness. PMID:25733067

  5. "One of the Most Uniform Races of the Entire World": Creole Eugenics and the Myth of Chilean Racial Homogeneity.

    Science.gov (United States)

    Walsh, Sarah

    2015-11-01

    This article illuminates why Nicolás Palacios's 1904 monograph, Raza chilena: Libro escrito por un Chileno i para los Chilenos [Chilean Race: A Book Written by a Chilean for Chileans], is central to the creation of a myth of Chilean racial homogeneity at the turn of the twentieth century. Placing Palacios in the context of Latin American eugenic discourse, it demonstrates how he selected a specific racial origin story in order to accommodate his belief in racial hierarchy while also depicting race mixing in a positive light. Specifically, the article highlights how the myth of Chilean racial homogeneity elided the difference between the term "mestizo," which was applied to people of mixed racial heritage, and "white." I contend that Palacios sought to differentiate Chileans from other Latin Americans by emphasizing their racial distinctiveness. The article therefore highlights that Latin American eugenics was concerned with the creation of national narratives that historicized particular racial mixtures in order to reify and affirm national differences. As such, it connects to literature regarding the history of eugenics, race, nation, and the creation of whiteness.

  6. Modelling the upwelling offthe east Hainan Island coast in summer 2010

    Science.gov (United States)

    Bai, Peng; Gu, Yanzhen; Li, Peiliang; Wu, Kejian

    2016-03-01

    A synoptic-scale upwelling event that developed offthe east coast of the Hainan Island (EHIU) in the summer of 2010 is defined well via processing the Moderate Resolution Imaging Spectroradiometer (MODIS) sea surface temperature (SST) data. The Regional Ocean Modeling System (ROMS) with high spatial resolution has been used to investigate this upwelling event. By comparing the ROMS results against tide station data, Argo float profiles and MODIS SST, it is confirmed that the ROMS reproduces the EHIU well. The cooler-water core (CWC) distinguished by waters stress curl that dominated the east Qiongzhou Strait mouth area suppressed the intensity of the CWC by 0.2-0.4°C. Further, nonlinear interaction between tidal currents and wind stress enhanced vertical mixing greatly, which would benefit the development of the CWC.

  7. Upwelling of Arctic pycnocline associated with shear motion of sea ice

    Science.gov (United States)

    McPhee, M. G.; Kwok, R.; Robins, R.; Coon, M.

    2006-01-01

    High-resolution radar imagery shows that the dynamic response of winter sea ice to gradients in large-scale surface wind stress is often localized along quasi-linear fractures hundreds of kilometers long. Relative shearing motion across these narrow fractures can exceed 10 cm/s. In one event recorded during the drift of the SHEBA ice camp, we observed an intense zone of pycnocline upwelling (approx.14 m) associated with significant shear motion near the camp, while upward turbulent heat flux in the ocean boundary layer reached nearly 400 W/sq m, an order of magnitude greater than at any other time during the year-long drift. We attribute the upwelling to Ekman pumping associated with concentrated ice shear. Over the entire Arctic Ocean sea ice cover, this process could be responsible for significant heat exchange between the cold surface layer and warmer subsurface water at the ubiquitous fractures resulting from large-scale atmosphere-ice interactions.

  8. Application of the Hyperspectral Imager for the Coastal Ocean to Phytoplankton Ecology Studies in Monterey Bay, CA, USA

    Directory of Open Access Journals (Sweden)

    John P. Ryan

    2014-01-01

    Full Text Available As a demonstrator for technologies for the next generation of ocean color sensors, the Hyperspectral Imager for the Coastal Ocean (HICO provides enhanced spatial and spectral resolution that is required to understand optically complex aquatic environments. In this study we apply HICO, along with satellite remote sensing and in situ observations, to studies of phytoplankton ecology in a dynamic coastal upwelling environment—Monterey Bay, CA, USA. From a spring 2011 study, we examine HICO-detected spatial patterns in phytoplankton optical properties along an environmental gradient defined by upwelling flow patterns and along a temporal gradient of upwelling intensification. From a fall 2011 study, we use HICO’s enhanced spatial and spectral resolution to distinguish a small-scale “red tide” bloom, and we examine bloom expansion and its supporting processes using other remote sensing and in situ data. From a spectacular HICO image of the Monterey Bay region acquired during fall of 2012, we present a suite of algorithm results for characterization of phytoplankton, and we examine the strengths, limitations, and distinctions of each algorithm in the context of the enhanced spatial and spectral resolution.

  9. ADCP application for long-term monitoring of coastal water

    Institute of Scientific and Technical Information of China (English)

    YOSHIOKA Hiroshi; TAKAYAMA Tomotsuka; SERIZAWA Shigeatsu

    2005-01-01

    Three kind of application of ADCP is reported for long-term monitoring in coastal sea.(1)The rourine monitoring of water qualities.The water quality and ADCP echo data (600 kHz) observed in the long-term are analgzed at MT (Marine Tower) Station of Kansai International Airport in the Osaka Bay, Japan. The correlation between the turbidity and echo intensity in the surface layer is not good because air bubbles generated by breaking wave are not detected by the turbidity meter, but detected well by ADCP. When estimating the turbidity consists of plankton population from echo intensity, the effect ofbubbles have to be eliminated. (2) Monitoring stirring up of bottom sediment. The special observation was carded out by using following two ADCP in the Osaka Bay, One ADCP was installed upward on the sea. The other ADCP was hanged downward at the gate type stand about 3 m above from the bottom. At the spring tide, high echo intensities indicating the stirring up of bottom sediment were observed. (3) The monitoring for the boundary condition of water mixing at an estuary. In summer season, the ADCP was set at the mouth of Tanabe Bay in Wakayama Prefecture, Japan.During the observation, water temperature near the bottom showed remarkable falls with interval of about 5~7 d. When the bottom temperature fell, the inflow current with low echo intensity water appears at the bottom layer in the ADCP record. It is concluded that when occasional weak northeast wind makes weak coastal upwelling at the mouth of the bay, the combination of upwelling with internal tidal flow causes remarkable water exchange and dispels the red tide.

  10. Variability in biological responses influenced by upwelling events in the Eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Habeebrehman, H.; Prabhakaran, M.P.; Jacob, J.; Sabu, P.; Jayalakshmi, K.J.; Achuthankutty, C.T.; Revichandran, C.

    in the P. Sabu, K.J. Jayalakshmi, Systems er.com/locate/jmarsys compared to the surrounding area (Mantora et al.,1993). As a consequence of this enrichment, a high productivity occurs in the Arabian Sea during the season. The upwelling phenomenon... (LSM) summer monsoon. , Table 2 Phytoplankton species identified during the different phases of summer monsoon in the southeastern Arabian Sea Class: Bacillariophyceae Order: Dinophysales Family: RhizosoleniaceaeOrder: Biddulphiales Family...

  11. A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network

    OpenAIRE

    Z. Lachkar; Gruber, N.

    2012-01-01

    Eastern Boundary Upwelling Systems (EBUS) are highly productive ocean regions. Yet, substantial differences in net primary production (NPP) exist within and between these systems for reasons that are still not fully understood. Here, we explore the leading physical processes and environmental factors controlling NPP in EBUS through a comparative study of the California, Canary, Benguela, and Humboldt Current systems. The NPP drivers are identified with the aid of an artifici...

  12. A comparative study of biological production in eastern boundary upwelling systems using an artificial neural network

    OpenAIRE

    Z. Lachkar; Gruber, N.

    2011-01-01

    Eastern Boundary Upwelling Systems (EBUS) are highly productive ocean regions. Yet, substantial differences in net primary production (NPP) exist within and between these systems for reasons that are still not fully understood. Here, we explore the leading physical processes and environmental factors controlling NPP in EBUS through a comparative study of the California, Canary, Benguela, and Humboldt Current systems. The identification of NPP drivers is done with the aid of an artificial neur...

  13. Pemodelan Numerik untuk Identifikasi Daerah Upwelling sebagai kriteria Lokasi Penangkapan Ikan di Selat Makassar

    OpenAIRE

    Mahie, Andi Galsan

    2013-01-01

    Abstrak Penelitian ini mengkaji dinamika upwelling di perairan Selat Makassar yang akan dijadikan pedoman dalam menentukan lokasi penangkapan ikan (fishing ground). Kajian ini menggunakan model hidrodinamika tiga-dimensi (3D), dengan gaya pembangkit arus: angin 6 jam-an dari National Center Environmental Prediction (NCEP) tahun 1997. Model hidrodinamika yang akan digunakan adalah model POM (Princeton Ocean Model). Dari penelitian ini diperoleh informasi yang detil tentang kejadian upwelli...

  14. Influence of ocean winds on the pelagic ecosystem in upwelling regions

    OpenAIRE

    Rykaczewski, Ryan R.; Checkley, David M.

    2008-01-01

    Upwelling of nutrient-rich, subsurface water sustains high productivity in the ocean's eastern boundary currents. These ecosystems support a rate of fish harvest nearly 100 times the global mean and account for >20% of the world's marine fish catch. Environmental variability is thought to be the major cause of the decadal-scale biomass fluctuations characteristic of fish populations in these regions, but the mechanisms relating atmospheric physics to fish production remain unexplained. Two at...

  15. Global Climatology of the Coastal Low-Level Wind Jets using different Reanalysis

    Science.gov (United States)

    Lima, Daniela C. A.; Soares, Pedro M. M.; Semedo, Alvaro; Cardoso, Rita M.

    2016-04-01

    Coastal Low-Level Jets (henceforth referred to as "coastal jets" or simply as CLLJ) are low-tropospheric mesoscale wind features, with wind speed maxima confined to the marine atmospheric boundary layer (MABL), typically bellow 1km. Coastal jets occur in the eastern flank of the semi-permanent subtropical mid-latitude high pressure systems, along equatorward eastern boundary currents, due to a large-scale synoptic forcing. The large-scale synoptic forcing behind CLLJ occurrences is a high pressure system over the ocean and a thermal low inland. This results in coastal parallel winds that are the consequence of the geostrophic adjustment. CLLJ are found along the California (California-Oregon) and the Canary (Iberia and Northeastern Africa) currents in the Northern Hemisphere, and along the Peru-Humboldt (Peru-Chile), Benguela (Namibia) and Western Australia (West Australia) currents in the Southern Hemisphere. In the Arabian Sea (Oman CLLJ), the interaction between the high pressure over the Indian Ocean in summer (Summer Indian Monsoon) and the Somali (also known as Findlater) Jet forces a coastal jet wind feature off the southeast coast of Oman. Coastal jets play an important role in the regional climates of the mid-latitude western continental regions. The decrease of the sea surface temperatures (SST) along the coast due to upwelling lowers the evaporation over the ocean and the coast parallel winds prevents the advection of marine air inshore. The feedback processes between the CLLJ and upwelling play a crucial role in the regional climate, namely, promoting aridity since the parallel flow prevents the intrusion of moisture inland, and increasing fish stocks through the transport of rich nutrient cold water from the bottom. In this study, the global coastal low-level wind jets are identified and characterized using an ensemble of three reanalysis, the ECMWF Interim Reanalysis (ERA-Interim), the Japanese 55-year Reanalysis (JRA-55) and the NCEP Climate Forecast

  16. Degree of nutrient consumption as an aging index of upwelling or vertically mixed water in the northern Taiwan Strait

    Institute of Scientific and Technical Information of China (English)

    CHEN Chentung Arthur; HSING Liyu

    2005-01-01

    In order to determine the relative aging status ofupwelled or vertically mixed water in the northern Taiwan Strait, a recently developed method of calcularing the degree of nutrient consumption (DNC) was employed. Upwelling was detected at a water depth of about 75m in summer. Bottom waters in the aphoric zone and newly-upwelled waters in the euphoric zone were found to be low in terms of their DNC. In general, a low DNC was noted alongside the other traditional upwelling indicators, such as lower temperature and degree of oxygen saturation, but higher salinity, apparent oxygen utilization, nutrient contents and chlorophyll-a. Enhanced vertical mixing,but without an apparent upwelling signal, was detected near the same location in winter.

  17. Dynamic mechanism of the upwelling on the west side of the submerged river valley off the Changjiang mouth in summertime

    Institute of Scientific and Technical Information of China (English)

    ZHU Jianrong

    2003-01-01

    Based on the analysis of the field observation data off the Changjiang mouth in August 2000 and satellite image of sea surface temperature (SST) in summer of 1997, it indicates that there exists the upwelling event on the west side of the submerged river valley (SRV) off the Changjiang mouth. The calculated results of the three-dimensional numerical model show that this upwelling is induced by the barotropic effect, baroclinic effect, bottom Ekman effect and their interaction with the slope bottom topography. The baroclinic effect is the main cause producing the upwelling at the northern SRV (on the east side of the South Passage of the Changjiang estuary), while the barotropic effect is the main cause at the southern SRV (on the east side of the center of the Hangzhou Bay mouth). The dynamic mechanism producing the upwelling off the Changjiang mouth is different with the general one along coast and on the continental shelf.

  18. Consequences of winter upwelling events on biogeochemical and phytoplankton patterns in a western Galician ria (NW Iberian peninsula)

    Science.gov (United States)

    Prego, Ricardo; Guzmán-Zuñiga, Dafne; Varela, Manuel; deCastro, Maite; Gómez-Gesteira, Moncho

    2007-07-01

    The consequences of two upwelling events in mid- (MW) and late (LW) winter on biogeochemical and phytoplankton patterns were studied in the Pontevedra Ria and compared with the patterns measured under typical winter conditions and under a summer upwelling event. Thermohaline patterns measured during the mid-winter upwelling event (MW-up) revealed the intrusion of saltier seawater (35.9) into the ria associated with the Iberian Poleward Current (IPC). During the late-winter upwelling event (LW-up), the seawater which had welled up into the ria showed characteristics of the Eastern North Atlantic Central Water mass (ENACW). In both cases the measured water residence time (4 days during MW-up and 10 days during LW-up) was related to both meteorological and fluvial forcing. This residence time contrasts with that of summer upwelling (7 days) and with that estimated under unfavorable upwelling atmospheric conditions (2-4 weeks). During MW-up, the ria became poor in nutrients due to continental freshwater dilution, associated with the shorter residence time of the water, and the intrusion of IPC, which is a water body poor in nutrient salts: 2.9 μM of nitrate, 0.1 μM of phosphate and 1.5 μM of silicate. During this event, the ria exported 3.4 mol DIN s -1, compared with 6.9 mol DIN s -1 in non-upwelling conditions. Phytoplankton showed a uniform distribution throughout the ria, as during unfavorable upwelling conditions, and was characterized by the dominance of diatoms, mainly Nitzschia longissima and Skeletonema costatum. During LW-up, a nutrient depletion in the photic layer also occurred, but as a result of a phytoplankton spring bloom developing at this time. The ria was a nutrient trap where 4.1 mol DIN s -1 were processed by photosynthesis. This budget is three times higher than the one under non-upwelling conditions. In contrast with the MW-up, which had no effect on primary production, during LW-up the ria became more productive, although not as productive as

  19. Physiological acclimation to elevated temperature in a reef-building coral from an upwelling environment

    Science.gov (United States)

    Mayfield, A. B.; Fan, T.-Y.; Chen, C.-S.

    2013-12-01

    Recent work has found that pocilloporid corals from regions characterized by unstable temperatures, such as those exposed to periodic upwelling, display a remarkable degree of phenotypic plasticity. In order to understand whether important reef builders from these upwelling reefs remain physiologically uncompromised at temperatures they will experience in the coming decades as a result of global climate change, a long-term elevated temperature experiment was conducted with Pocillopora damicornis specimens collected from Houbihu, a small embayment within Nanwan Bay, southern Taiwan that is characterized by 8-9 °C temperature changes during upwelling events. Upon nine months of exposure to nearly 30 °C, all colony (mortality and surface area), polyp ( Symbiodinium density and chlorophyll a content), tissue (total thickness), and molecular (gene expression and molecular composition)-level parameters were documented at similar levels between experimental corals and controls incubated at 26.5 °C, suggesting that this species can readily acclimate to elevated temperatures that cause significant degrees of stress, or even bleaching and mortality, in conspecifics of other regions of the Indo-Pacific. However, the gastrodermal tissue layer was relatively thicker in corals of the high temperature treatment sampled after nine months, possibly as an adaptive response to shade Symbiodinium from the higher photosynthetically active radiation levels that they were experiencing at that sampling time. Such shading may have prevented high light and high temperature-induced photoinhibition, and consequent bleaching, in these samples.

  20. Influence of upwelling saline groundwater on iron and manganese cycling in the Rio Grande floodplain aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, Matthew F. [Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131 (United States)], E-mail: matthew.f.kirk@gmail.com; Crossey, Laura J. [Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131 (United States); Takacs-Vesbach, Cristina [Department of Biology, University of New Mexico, Albuquerque, NM 87131 (United States); Newell, Dennis L. [Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131 (United States); Bowman, Robert S. [Department of Earth and Environmental Science, New Mexico Tech, Socorro, NM 87801 (United States)

    2009-03-15

    Salinity contributions from upwelling groundwater significantly degrade water quality in the Rio Grande, a major source of water for the southwestern USA. This study considers the influence of this upwelling water on the geochemistry and microbiology of the Rio Grande floodplain alluvial aquifer. The composition of surface water, groundwater, and floodplain sediment samples collected from three transects in the Socorro Basin was examined. Terminal-restriction fragment length polymorphism (T-RFLP) was also used to examine microbial biomass samples. The distribution of salinity in the floodplain groundwater largely reflects the configuration of local groundwater flow and mixing of two major water sources, deeply-sourced saline groundwater and river water. Microbial populations in the shallow aquifer consume O{sub 2} and NO{sub 3}{sup -} and serve to redistribute metal oxides from the saturated zone to locations of groundwater discharge at the surface and possibly near the water table. The upwelling saline groundwater affects floodplain microbial processes by transporting reduced metals and organic electron donors to the alluvial aquifer system. This enhances metal reduction in the saturated zone and ultimately metal oxidation at or near the surface. Geochemical modeling suggests that mixing of the saline groundwater with more dilute water in the floodplain creates conditions more favorable for metal oxidation to occur and thereby influences the distribution of metal oxides.