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Sample records for primary production sea

  1. Primary production in the Sulu Sea

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    its remotely sensed values from OCTS (Ocean Colour Temperature Scanner) are found to be in ... Although the Sulu Sea is more productive than the adjacent South China Sea, the central area ... surrounding ocean by a chain of islands.

  2. Primary productivity of the Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattathiri, P.M.A.; Devassy, V.P.

    The average surface and column primary productivity, chl a and particulate organic carbon, estimated at 24 stations during Feb. 1979, were respectively 5.3 mg C/m3/d and 273 mg C/m2 /d; 0.03 mg/m3 and 3.64 mg/m2; and 132mg/m3 and 4.59 g/m2...

  3. Primary Productivity, SeaWiFS and Pathfinder, 0.1 degrees, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from SeaWiFS Chl a, Pathfinder SST, and SeaWiFS PAR data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific...

  4. Primary production calculations for sea ice from bio-optical observations in the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Susann Müller

    2016-09-01

    Full Text Available Abstract Bio-optics is a powerful approach for estimating photosynthesis rates, but has seldom been applied to sea ice, where measuring photosynthesis is a challenge. We measured absorption coefficients of chromophoric dissolved organic matter (CDOM, algae, and non-algal particles along with solar radiation, albedo and transmittance at four sea-ice stations in the Gulf of Finland, Baltic Sea. This unique compilation of optical and biological data for Baltic Sea ice was used to build a radiative transfer model describing the light field and the light absorption by algae in 1-cm increments. The maximum quantum yields and photoadaptation of photosynthesis were determined from 14C-incorporation in photosynthetic-irradiance experiments using melted ice. The quantum yields were applied to the radiative transfer model estimating the rate of photosynthesis based on incident solar irradiance measured at 1-min intervals. The calculated depth-integrated mean primary production was 5 mg C m–2 d–1 for the surface layer (0–20 cm ice depth at Station 3 (fast ice and 0.5 mg C m–2 d–1 for the bottom layer (20–57 cm ice depth. Additional calculations were performed for typical sea ice in the area in March using all ice types and a typical light spectrum, resulting in depth-integrated mean primary production rates of 34 and 5.6 mg C m–2 d–1 in surface ice and bottom ice, respectively. These calculated rates were compared to rates determined from 14C incorporation experiments with melted ice incubated in situ. The rate of the calculated photosynthesis and the rates measured in situ at Station 3 were lower than those calculated by the bio-optical algorithm for typical conditions in March in the Gulf of Finland by the bio-optical algorithm. Nevertheless, our study shows the applicability of bio-optics for estimating the photosynthesis of sea-ice algae.

  5. Potential impacts of climate change on the primary production of regional seas: A comparative analysis of five European seas

    Science.gov (United States)

    Holt, Jason; Schrum, Corinna; Cannaby, Heather; Daewel, Ute; Allen, Icarus; Artioli, Yuri; Bopp, Laurent; Butenschon, Momme; Fach, Bettina A.; Harle, James; Pushpadas, Dhanya; Salihoglu, Baris; Wakelin, Sarah

    2016-01-01

    Regional seas are potentially highly vulnerable to climate change, yet are the most directly societally important regions of the marine environment. The combination of widely varying conditions of mixing, forcing, geography (coastline and bathymetry) and exposure to the open-ocean makes these seas subject to a wide range of physical processes that mediates how large scale climate change impacts on these seas' ecosystems. In this paper we explore the response of five regional sea areas to potential future climate change, acting via atmospheric, oceanic and terrestrial vectors. These include the Barents Sea, Black Sea, Baltic Sea, North Sea, Celtic Seas, and are contrasted with a region of the Northeast Atlantic. Our aim is to elucidate the controlling dynamical processes and how these vary between and within these seas. We focus on primary production and consider the potential climatic impacts on: long term changes in elemental budgets, seasonal and mesoscale processes that control phytoplankton's exposure to light and nutrients, and briefly direct temperature response. We draw examples from the MEECE FP7 project and five regional model systems each using a common global Earth System Model as forcing. We consider a common analysis approach, and additional sensitivity experiments. Comparing projections for the end of the 21st century with mean present day conditions, these simulations generally show an increase in seasonal and permanent stratification (where present). However, the first order (low- and mid-latitude) effect in the open ocean projections of increased permanent stratification leading to reduced nutrient levels, and so to reduced primary production, is largely absent, except in the NE Atlantic. Even in the two highly stratified, deep water seas we consider (Black and Baltic Seas) the increase in stratification is not seen as a first order control on primary production. Instead, results show a highly heterogeneous picture of positive and negative change

  6. Patterns of primary production in the Red Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Qurban, M.A.; Wafar, M.; Jyothibabu, R.; Manikandan, K.P.

    for bio- phic stations occupied in e Indian Ocean (source - et al., 1995), remotely-sensed (CZCS) chlorophyll data were used to make deductions on rates of primary production at basin-scale. The conclusion consistently arrived at from all earlier studies... acquired along the axis of the basin in the 2013 cruise, Wafar et al. (2016a) identified alternating zonal currents at six locations – 18–18.5°N, 19–20.5°N, 22°N, 24°N, 24.5°N and 26°N - and concluded that they represent three successive anticyclonic cells...

  7. Recent Primary Production and Small Phytoplankton Contribution in the Yellow Sea during the Summer in 2016

    Science.gov (United States)

    Jang, Hyo Keun; Kang, Jae Jung; Lee, Jae Hyung; Kim, Myungjoon; Ahn, So Hyun; Jeong, Jin-Yong; Yun, Mi Sun; Han, In-Seong; Lee, Sang Heon

    2018-05-01

    The high nutrient concentration associated with the mixing dynamics of two warm and cold water masses supports high primary production in the Yellow Sea. Although various environmental changes have been reported, no recent information on small phytoplankton contribution to the total primary production as an important indicator for marine ecosystem changes is currently available in the Yellow Sea. The major objective of this study is to determine the small (values decades ago. The higher contributions of small phytoplankton to the total chlorophyll a concentration and primary production might be caused by P-limited conditions and this resulted in lower chlorophyll a concentration and total primary production in this study compared to previous studies.

  8. Sea ice and primary production proxies in surface sediments from a High Arctic Greenland fjord

    DEFF Research Database (Denmark)

    Ribeiro, Sofia; Sejr, Mikael K; Limoges, Audrey

    2017-01-01

    Monitoring Programme. Clear spatial gradients in organic carbon and biogenic silica contents reflected marine influence, nutrient availability and river-induced turbidity, in good agreement with in situ measurements. The sea ice proxy IP25 was detected at all sites but at low concentrations, indicating...... that IP25 records from fjords need to be carefully considered and not directly compared to marine settings. The sea ice-associated biomarker HBI III revealed an open-water signature, with highest concentrations near the mid-July ice edge. This proxy evaluation is an important step towards reliable......In order to establish a baseline for proxy-based reconstructions for the Young Sound–Tyrolerfjord system (Northeast Greenland), we analysed the spatial distribution of primary production and sea ice proxies in surface sediments from the fjord, against monitoring data from the Greenland Ecosystem...

  9. On the role of tides and strong wind events in promoting summer primary production in the Barents Sea

    Science.gov (United States)

    Le Fouest, Vincent; Postlethwaite, Clare; Morales Maqueda, Miguel Angel; Bélanger, Simon; Babin, Marcel

    2011-11-01

    Tides and wind-driven mixing play a major role in promoting post-bloom productivity in subarctic shelf seas. Whether this is also true in the high Arctic remains unknown. This question is particularly relevant in a context of increasing Arctic Ocean stratification in response to global climatic change. We have used a three-dimensional ocean-sea ice-plankton ecosystem model to assess the contribution of tides and strong wind events to summer (June-August 2001) primary production in the Barents Sea. Tides are responsible for 20% (60% locally) of the post-bloom primary production above Svalbard Bank and east of the Kola Peninsula. By contrast, more than 9% of the primary production is due to winds faster than 8 m s -1 in the central Barents Sea. Locally, this contribution reaches 25%. In the marginal ice zone, both tides and wind events have only a limited effect on primary production (central Barents Sea), respectively. When integrated over all Barents Sea sub-regions, tides and strong wind events account, respectively, for 6.8% (1.55 Tg C; 1 Tg C=10 12 g C) and 4.1% (0.93 Tg C) of the post-bloom primary production (22.6 Tg C). To put this in context, this contribution to summer primary production is equivalent to the spring bloom integrated over the Svalbard area. Tides and winds are significant drivers of summer plankton productivity in the Barents Sea.

  10. Microalgal composition and primary production in Arctic sea ice: a seasonal study from Kobbeijord (Kangerluarsunnguaq), West Greenland

    DEFF Research Database (Denmark)

    Mikkelsen, Ditte Marie; Rysgaard, Søren; Glud, Ronnie N.

    2008-01-01

    We investigated the microalgal community in sea ice and in the water column of Kobbefjord, west Greenland, through an entire sea ice season, Temporal variation in physical (photosynthetically active radiation [PAR), temperature, brine volume) and chemical (salinity, nutrient concentration......) properties confirmed that sea ice is a very dynamic habitat. Nevertheless, a viable sea ice algal comuunity was present throughout the year, with a species succession from flagellate dominance (dinoflagellates and cryptophytes) in December to February, followed by Chaetoceros simplex (a centric diatom...... (maxima of 1.8 and 2.6 mu g chl](-1) in March and May, respectively). Primary production mirrored biomass dynamic, which had 2 seasonal peaks of ca. 21 and 15 mg Cm-2 d(-1). Integrated primary production over 7 mo was 0.8 g Cm-2 in sea ice and 94.4 g C m(-2) in the water column, with the vast majority...

  11. Microalgal composition and primary production in Arctic sea ice: a seasonal study from Kobbeijord (Kangerluarsunnguaq), West Greenland

    DEFF Research Database (Denmark)

    Mikkelsen, Ditte Marie; Rysgaard, Søren; Glud, Ronnie N.

    2008-01-01

    We investigated the microalgal community in sea ice and in the water column of Kobbefjord, west Greenland, through an entire sea ice season, Temporal variation in physical (photosynthetically active radiation [PAR), temperature, brine volume) and chemical (salinity, nutrient concentration...... (maxima of 1.8 and 2.6 mu g chl](-1) in March and May, respectively). Primary production mirrored biomass dynamic, which had 2 seasonal peaks of ca. 21 and 15 mg Cm-2 d(-1). Integrated primary production over 7 mo was 0.8 g Cm-2 in sea ice and 94.4 g C m(-2) in the water column, with the vast majority......) properties confirmed that sea ice is a very dynamic habitat. Nevertheless, a viable sea ice algal comuunity was present throughout the year, with a species succession from flagellate dominance (dinoflagellates and cryptophytes) in December to February, followed by Chaetoceros simplex (a centric diatom...

  12. Small phytoplankton contribution to the standing stocks and the total primary production in the Amundsen Sea

    Directory of Open Access Journals (Sweden)

    S. H. Lee

    2017-08-01

    Full Text Available Small phytoplankton are anticipated to be more important in a recently warming and freshening ocean condition. However, little information on the contribution of small phytoplankton to overall phytoplankton production is currently available in the Amundsen Sea. To determine the contributions of small phytoplankton to total biomass and primary production, carbon and nitrogen uptake rates of total and small phytoplankton were obtained from 12 productivity stations in the Amundsen Sea. The daily carbon uptake rates of total phytoplankton averaged in this study were 0.42 g C m−2 d−1 (SD  =  ± 0.30 g C m−2 d−1 and 0.84 g C m−2 d−1 (SD  =  ± 0.18 g C m−2 d−1 for non-polynya and polynya regions, respectively, whereas the daily total nitrogen (nitrate and ammonium uptake rates were 0.12 g N m−2 d−1 (SD  =  ± 0.09 g N m−2 d−1 and 0.21 g N m−2 d−1 (SD  =  ± 0.11 g N m−2 d−1, respectively, for non-polynya and polynya regions, all of which were within the ranges reported previously. Small phytoplankton contributed 26.9 and 27.7 % to the total carbon and nitrogen uptake rates of phytoplankton in this study, respectively, which were relatively higher than the chlorophyll a contribution (19.4 % of small phytoplankton. For a comparison of different regions, the contributions for chlorophyll a concentration and primary production of small phytoplankton averaged from all the non-polynya stations were 42.4 and 50.8 %, which were significantly higher than those (7.9 and 14.9 %, respectively in the polynya region. A strong negative correlation (r2 = 0. 790, p<0. 05 was found between the contributions of small phytoplankton and the total daily primary production of phytoplankton in this study. This finding implies that daily primary production decreases as small phytoplankton contribution increases, which is

  13. Late holocene primary productivity and sea surface temperature variations in the northeastern Arabian Sea: Implications for winter monsoon variability.

    Digital Repository Service at National Institute of Oceanography (India)

    Boll, A.; Luckge, A.; Munz, P.; Forke, S.; Schulz, H.; Ramaswamy, V.; Rixen, T.; Gaye, B.; Emeis, K.-C.

    changes in winter monsoon strength with winds from the northeast that drive convective mixing and high surface ocean productivity in the northeastern Arabian Sea. To establish a high-resolution record of winter monsoon variability for the late Holocene, we...

  14. Denali Ice Core Record of North Pacific Sea Surface Temperatures and Marine Primary Productivity

    Science.gov (United States)

    Polashenski, D.; Osterberg, E. C.; Kreutz, K. J.; Winski, D.; Wake, C. P.; Ferris, D. G.; Introne, D.; Campbell, S. W.

    2016-12-01

    Chemical analyses of precipitation preserved in glacial ice cores provide a unique opportunity to study changes in atmospheric circulation patterns and ocean surface conditions through time. In this study, we aim to investigate changes in both the physical and biological parameters of the north-central Pacific Ocean and Bering Sea over the twentieth century using the deuterium excess (d-excess) and methanesulfonic acid (MSA) records from the Mt. Hunter ice cores drilled in Denali National Park, Alaska. These parallel, 208 m-long ice cores were drilled to bedrock during the 2013 field season on the Mt. Hunter plateau (63° N, 151° W, 3,900 m above sea level) by a collaborative research team consisting of members from Dartmouth College and the Universities of Maine and New Hampshire. The cores were sampled on a continuous melter system at Dartmouth College and analyzed for the concentrations major ions (Dionex IC) and trace metals (Element2 ICPMS), and for stable water isotope ratios (Picarro). The depth-age scale has been accurately dated to 400 AD using annual layer counting of several chemical species and further validated using known historical volcanic eruptions and the Cesium-137 spike associated with nuclear weapons testing in 1963. We use HYSPLIT back trajectory modeling to identify likely source areas of moisture and aerosol MSA being transported to the core site. Satellite imagery allows for a direct comparison between chlorophyll a concentrations in these source areas and MSA concentrations in the core record. Preliminary analysis of chlorophyll a and MSA concentrations, both derived almost exclusively from marine biota, suggest that the Mt. Hunter ice cores reflect changes in North Pacific and Bering Sea marine primary productivity. Analysis of the water isotope and MSA data in conjunction with climate reanalysis products shows significant correlations (psea surface temperatures in the Bering Sea and North Central Pacific. These findings, coupled with

  15. Seasonal variability of mixed layer in the central Arabian Sea and its implication on nutrients and primary productivity

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Narvekar, J.

    -1 Seasonal variability of mixed layer in the central Arabian Sea and its implication on nutrients and primary productivity S. Prasanna Kumar and Jayu Narvekar National Institute of Oceanography, Dona Paula, Goa-403 004, India... on a 2? x 4? grids up to a depth of 500m. Monthly mean temperature and salinity data were used to calculate the sigma-t values (UNESCO, 1981). We also used nitrate, chlorophyll a and primary productivity data in the upper 120m water column...

  16. Frontal dynamics boost primary production in the summer stratified Mediterranean sea

    Science.gov (United States)

    Olita, Antonio; Capet, Arthur; Claret, Mariona; Mahadevan, Amala; Poulain, Pierre Marie; Ribotti, Alberto; Ruiz, Simón; Tintoré, Joaquín; Tovar-Sánchez, Antonio; Pascual, Ananda

    2017-06-01

    Bio-physical glider measurements from a unique process-oriented experiment in the Eastern Alboran Sea (AlborEx) allowed us to observe the distribution of the deep chlorophyll maximum (DCM) across an intense density front, with a resolution (˜ 400 m) suitable for investigating sub-mesoscale dynamics. This front, at the interface between Atlantic and Mediterranean waters, had a sharp density gradient (Δ ρ ˜ 1 kg/m3 in ˜ 10 km) and showed imprints of (sub-)mesoscale phenomena on tracer distributions. Specifically, the chlorophyll-a concentration within the DCM showed a disrupted pattern along isopycnal surfaces, with patches bearing a relationship to the stratification (buoyancy frequency) at depths between 30 and 60 m. In order to estimate the primary production (PP) rate within the chlorophyll patches observed at the sub-surface, we applied the Morel and Andrè (J Geophys Res 96:685-698 1991) bio-optical model using the photosynthetic active radiation (PAR) from Argo profiles collected simultaneously with glider data. The highest production was located concurrently with domed isopycnals on the fresh side of the front, suggestive that (sub-)mesoscale upwelling is carrying phytoplankton patches from less to more illuminated levels, with a contemporaneous delivering of nutrients. Integrated estimations of PP (1.3 g C m-2d-1) along the glider path are two to four times larger than the estimations obtained from satellite-based algorithms, i.e., derived from the 8-day composite fields extracted over the glider trip path. Despite the differences in spatial and temporal sampling between instruments, the differences in PP estimations are mainly due to the inability of the satellite to measure DCM patches responsible for the high production. The deepest (depth > 60 m) chlorophyll patches are almost unproductive and probably transported passively (subducted) from upper productive layers. Finally, the relationship between primary production and oxygen is also investigated

  17. Primary productivity

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Parulekar, A.H.

    Photosynthetic production in the oceans in relation to light, nutrients and mixing processes is discussed. Primary productivity in the estuarine region is reported to be high in comparison to coastal and oceanic waters. Upwelling phenomenon...

  18. Effects of ocean acidification on primary production in a coastal North Sea phytoplankton community.

    Directory of Open Access Journals (Sweden)

    Tim Eberlein

    Full Text Available We studied the effect of ocean acidification (OA on a coastal North Sea plankton community in a long-term mesocosm CO2-enrichment experiment (BIOACID II long-term mesocosm study. From March to July 2013, 10 mesocosms of 19 m length with a volume of 47.5 to 55.9 m3 were deployed in the Gullmar Fjord, Sweden. CO2 concentrations were enriched in five mesocosms to reach average CO2 partial pressures (pCO2 of 760 μatm. The remaining five mesocosms were used as control at ambient pCO2 of 380 μatm. Our paper is part of a PLOS collection on this long-term mesocosm experiment. Here, we here tested the effect of OA on total primary production (PPT by performing 14C-based bottle incubations for 24 h. Furthermore, photoacclimation was assessed by conducting 14C-based photosynthesis-irradiance response (P/I curves. Changes in chlorophyll a concentrations over time were reflected in the development of PPT, and showed higher phytoplankton biomass build-up under OA. We observed two subsequent phytoplankton blooms in all mesocosms, with peaks in PPT around day 33 and day 56. OA had no significant effect on PPT, except for a marginal increase during the second phytoplankton bloom when inorganic nutrients were already depleted. Maximum light use efficiencies and light saturation indices calculated from the P/I curves changed simultaneously in all mesocosms, and suggest that OA did not alter phytoplankton photoacclimation. Despite large variability in time-integrated productivity estimates among replicates, our overall results indicate that coastal phytoplankton communities can be affected by OA at certain times of the seasonal succession with potential consequences for ecosystem functioning.

  19. Physical control of primary productivity on a seasonal scale in central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Madhupratap, M.; DileepKumar, M.; Gauns, M.; Muraleedharan, P.M.; Sarma, V.V.S.S.; DeSouza, S.N.

    Using in situ data collected during 1992-1997, under the Indian programme of Joint Global Ocean Flux Study (JGOFS), it is shown that the biological productivity of the Arabian Sea is tightly coupled to the physical forcing mediated through nutrient...

  20. Influence of the Phytoplankton Community Structure on the Spring and Annual Primary Production in the Northwestern Mediterranean Sea

    Science.gov (United States)

    Mayot, Nicolas; D'Ortenzio, Fabrizio; Uitz, Julia; Gentili, Bernard; Ras, Joséphine; Vellucci, Vincenzo; Golbol, Melek; Antoine, David; Claustre, Hervé

    2017-12-01

    Satellite ocean color observations revealed that unusually deep convection events in 2005, 2006, 2010, and 2013 led to an increased phytoplankton biomass during the spring bloom over a large area of the northwestern Mediterranean Sea (NWM). Here we investigate the effects of these events on the seasonal phytoplankton community structure, we quantify their influence on primary production, and we discuss the potential biogeochemical impact. For this purpose, we compiled in situ phytoplankton pigment data from five ship surveys performed in the NWM and from monthly cruises at a fixed station in the Ligurian Sea. We derived primary production rates from a light photosynthesis model applied to these in situ data. Our results confirm that the maximum phytoplankton biomass during the spring bloom is larger in years associated with intense deep convection events (+51%). During these enhanced spring blooms, the contribution of diatoms to total phytoplankton biomass increased (+33%), as well as the primary production rate (+115%). The occurrence of a highly productive bloom is also related to an increase in the phytoplankton bloom area (+155%) and in the relative contribution of diatoms to primary production (+63%). Therefore, assuming that deep convection in the NWM could be significantly weakened by future climate changes, substantial decreases in the spring production of organic carbon and of its export to deep waters can be expected.

  1. Parameterization of surface irradiance and primary production in Århus Bay, SW Kattegat, Baltic Sea

    DEFF Research Database (Denmark)

    Lund-Hansen, Lars Chresten; Sørensen, Helene Munk

    2009-01-01

    . The study is based on a one year long time-series of PAR, CTD-casts (n = 45), and primary production measurements (n = 24) from Århus Bay (56°09′ N; 10°20′ E), south west Kattegat. Results showed a high and positive correlation between observed and calculated primary production in the bay, as based...

  2. Multi-centennial Record of Labrador Sea Primary Productivity and Sea-Ice Variability Archived in Coralline Algal Ba/Ca

    Science.gov (United States)

    Chan, Phoebe; Halfar, Jochen; Adey, Walter; Hetzinger, Steffen; Zack, Thomas; Moore, Kent; Wortmann, Ulrich; Williams, Branwen; Hou, Alicia

    2017-04-01

    Arctic sea-ice thickness and concentration have dropped by approximately 9% per decade since 1978. Concurrent with this sea-ice decline is an increase in rates of phytoplankton productivity, driven by shoaling of the mixed layer and enhanced transmittance of solar radiation into the surface ocean. This has recently been confirmed by phytoplankton studies in Arctic and Subarctic basins that have revealed earlier timing, prolonged duration, and increased primary productivity of the spring phytoplankton bloom. However, difficulties of navigating in remote ice-laden waters and harsh polar climates have often resulted in short and incomplete records of in-situ plankton abundance in the northwestern Labrador Sea. Alternatively, information of past ocean productivity may be gained through the study of trace nutrient distributions in the surface water column. Investigations of dissolved barium (Ba) concentrations in the Arctic reveal significant depletions of Ba in surface seawaters due to biological scavenging during the spring phytoplankton bloom. Here we apply a barium-to-calcium (Ba/Ca) and carbon isotope (δ13C) multiproxy approach to long-lived crustose coralline algae in order to reconstruct an annually-resolved multi-centennial record of Labrador Sea productivity related to sea-ice variability in Labrador, Canada that extends well into the Little Ice Age (LIA; 1646 AD). The crustose coralline alga Clathromorphum compactum is a shallow marine calcareous plant that is abundant along the eastern Canadian coastline, and produces annual growth increments which allow for the precise calendar dating and geochemical sampling of hard tissue. Algal Ba/Ca ratios can serve as a promising new proxy for surface water productivity, demonstrating a close correspondence to δ13C that does not suffer from the anthropogenically-induced carbon isotope decline (ex. Suess Effect) beginning in the 1960s. Coralline algal Ba/Ca demonstrates statistically significant correlations to both

  3. SeaWiFS Technical Report Series. Volume 42; Satellite Primary Productivity Data and Algorithm Development: A Science Plan for Mission to Planet Earth

    Science.gov (United States)

    Falkowski, Paul G.; Behrenfeld, Michael J.; Esaias, Wayne E.; Balch, William; Campbell, Janet W.; Iverson, Richard L.; Kiefer, Dale A.; Morel, Andre; Yoder, James A.; Hooker, Stanford B. (Editor); hide

    1998-01-01

    Two issues regarding primary productivity, as it pertains to the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Program and the National Aeronautics and Space Administration (NASA) Mission to Planet Earth (MTPE) are presented in this volume. Chapter 1 describes the development of a science plan for deriving primary production for the world ocean using satellite measurements, by the Ocean Primary Productivity Working Group (OPPWG). Chapter 2 presents discussions by the same group, of algorithm classification, algorithm parameterization and data availability, algorithm testing and validation, and the benefits of a consensus primary productivity algorithm.

  4. Primary production, nutrients, and size spectra of suspended particles in the southern North Sea

    NARCIS (Netherlands)

    Gieskes, W.W.C.

    1972-01-01

    The effect of nutrient enrichment from the Rhine on some major characteristics of the phytoplankton ecosystem of Dutch coastal waters was studied with 14C, liquid scintillation and Coulter Counter techniques. The magnitude of primary production in the most eutrophic waters closest to

  5. Historical changes of the Mediterranean Sea ecosystem: modelling the role and impact of primary productivity and fisheries changes over time

    Science.gov (United States)

    Piroddi, Chiara; Coll, Marta; Liquete, Camino; Macias, Diego; Greer, Krista; Buszowski, Joe; Steenbeek, Jeroen; Danovaro, Roberto; Christensen, Villy

    2017-03-01

    The Mediterranean Sea has been defined “under siege” because of intense pressures from multiple human activities; yet there is still insufficient information on the cumulative impact of these stressors on the ecosystem and its resources. We evaluate how the historical (1950-2011) trends of various ecosystems groups/species have been impacted by changes in primary productivity (PP) combined with fishing pressure. We investigate the whole Mediterranean Sea using a food web modelling approach. Results indicate that both changes in PP and fishing pressure played an important role in driving species dynamics. Yet, PP was the strongest driver upon the Mediterranean Sea ecosystem. This highlights the importance of bottom-up processes in controlling the biological characteristics of the region. We observe a reduction in abundance of important fish species (~34%, including commercial and non-commercial) and top predators (~41%), and increases of the organisms at the bottom of the food web (~23%). Ecological indicators, such as community biomass, trophic levels, catch and diversity indicators, reflect such changes and show overall ecosystem degradation over time. Since climate change and fishing pressure are expected to intensify in the Mediterranean Sea, this study constitutes a baseline reference for stepping forward in assessing the future management of the basin.

  6. Benthic reef primary production in response to large amplitude internal waves at the Similan Islands (Andaman Sea, Thailand)

    KAUST Repository

    Jantzen, Carin

    2013-11-29

    Coral reefs are facing rapidly changing environments, but implications for reef ecosystem functioning and important services, such as productivity, are difficult to predict. Comparative investigations on coral reefs that are naturally exposed to differing environmental settings can provide essential information in this context. One prevalent phenomenon regularly introducing alterations in water chemistry into coral reefs are internal waves. This study therefore investigates the effect of large amplitude internal waves (LAIW) on primary productivity in coral reefs at the Similan Islands (Andaman Sea, Thailand). The LAIW-exposed west sides of the islands are subjected to sudden drops in water temperature accompanied by enhanced inorganic nutrient concentrations compared to the sheltered east. At the central island, Ko Miang, east and west reefs are only few hundred meters apart, but feature pronounced differences. On the west lower live coral cover (-38%) coincides with higher turf algae cover (+64%) and growth (+54%) compared to the east side. Turf algae and the reef sand-associated microphytobenthos displayed similar chlorophyll a contents on both island sides, but under LAIW exposure, turf algae exhibited higher net photosynthesis (+23%), whereas the microphytobenthos displayed reduced net and gross photosynthesis (-19% and -26%, respectively) accompanied by lower respiration (-42%). In contrast, the predominant coral Porites lutea showed higher chlorophyll a tissues contents (+42%) on the LAIW-exposed west in response to lower light availability and higher inorganic nutrient concentrations, but net photosynthesis was comparable for both sides. Turf algae were the major primary producers on the west side, whereas microphytobenthos dominated on the east. The overall primary production rate (comprising all main benthic primary producers) was similar on both island sides, which indicates high primary production variability under different environmental conditions.

  7. Nutrient flux fuels the summer primary productivity in the oligotrophic waters of the Gulf of Aqaba, Red Sea

    Directory of Open Access Journals (Sweden)

    Tariq Al-Najjar

    2005-03-01

    Full Text Available The thermohaline characteristics of the Gulf of Aqaba, Red Sea,depict a well-defined seasonal pattern of winter mixing from December toApril and summer stratification from May to November. This thermohalinestructure is a major controlling factor of the nutrient, chlorophyll aand primary productivity seasonal cycles. The nitrate and chlorophyll aconcentration records generated down to 200 m at a vertical resolution of25 m - weekly during 1994, 1995 and every two weeks from April 1997 throughto December 2000 - are employed to assess the nitrogen flux across the summerthermocline of the Gulf of Aqaba. The flux calculations are based on a simplediffusion model that incorporates the physical stress eddy diffusivity factorKz and a biological stress factor k. Both Kz and k arecalculated using the Michaelis-Menten equation and the nitrate concentrationgradient. The total nitrate flux of the Gulf of Aqaba during the seven summermonths (May-November is estimated at 0.52 mole N m-2. In relation toestablished primary productivity values (75.5 g C m-2 (MayNovember-1 and the generated chlorophyll a records, thisyields an f fraction of new to total primary production of 0.50. Thisrelatively high f value is discussed with respect to the geophysicalcharacteristics of the Gulf of Aqaba and similar oceanic basins. The remaining50% is accounted for by cross-sectional flow from the relativelynutrient-rich coral reef coastal habitat and rapid recycling, triggered byhigh irradiance and water temperature.

  8. Spatial and seasonal variability of fractionated phytoplankton biomass and primary production in the frontal region of the Northern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    M.R. VADRUCCI

    2005-06-01

    Full Text Available Spatial and seasonal patterns of variation of fractionated phytoplankton biomass and primary production and their relationships with nutrient concentrations were analyzed along an inshore - offshore gradient and in relation to the presence of a frontal system in the Northern Adriatic Sea. Sampling was carried out in winter and summer during four oceanographic cruises (June 1996 and 1997, February 1997 and 1998 as part of the PRISMA II project. Water samples for determining nutrient concentrations, phytoplankton biomass (as Chla and primary production (as 14 C assimilation were collected at five optical depths. Sampling stations were located along 2 or 4 parallel transects arranged perpendicularly to the shoreline and the frontal system. The transects were located at such a distance from the coast that the frontal system crossed them at their halfway point. Total dissolved nitrogen (TDN and total dissolved phosphorus concentrations (TDP were 12.41 ± 3 .95 mM and 0.146 ± 0 .070 mM, respectively. The values in the two seasonal periods were similar, decreasing along the inshore-offshore gradient. Values for phytoplankton biomass and primary productionwere higher in the winter than the summer cruises, and decreased, in both seasonal periods, along the inshore / offshore gradient. Moreover, in both seasonal periods, picophytoplankton dominated both biomass and productivity, (56% and 44%, respectively at stations beyond the frontal system, while microphytoplankton was more important at stations inside it (44% and 44%, respectively. Total phytoplankton biomass and primary production were directly related to nutrient concentrations. Regarding size classes, significant patterns of variation with nutrients were observed particularly for biomass. The results indicate that the size structure and function of phytoplankton guilds seem to be mediated by nutrient inflow, as well as by competitive interaction among size fractions.

  9. Effects of ocean acidification on primary production in a coastal North Sea phytoplankton community

    NARCIS (Netherlands)

    Eberlein, Tim; Wohlrab, Sylke; Rost, Björn; John, Uwe; Bach, Lennart T.; Riebesell, U.; Van de Waal, D.B.

    2017-01-01

    We studied the effect of ocean acidification (OA) on a coastal North Sea plankton community in a long-term mesocosm CO2-enrichment experiment (BIOACID II long-term mesocosm study). From March to July 2013, 10 mesocosms of 19 m length with a volume of 47.5 to 55.9 m3 were deployed in the Gullmar

  10. Long-term changes in primary production and mineralization of organic matter in the Neva Estuary (Baltic Sea)

    Science.gov (United States)

    Golubkov, Sergey; Golubkov, Mikhail; Tiunov, Alexei; Nikulina, Vera

    2017-07-01

    The Neva Estuary situated in the eastern part of the Gulf of Finland is one of the largest estuaries of the Baltic Sea. At present, heavy nutrient and organic matter loading, mainly from the Neva River and point sources in the upper estuary are the most serious environmental problem for the Neva Estuary and adjacent parts of the eastern Gulf of Finland. Long-term studies of mid-summer primary production and mineralization of organic matter were conducted in upper and middle parts of the Neva Estuary. A considerable increase of production and biomass of phytoplankton was observed in the middle part of the estuary during the last decades mainly due to an increase in biomass of cyanobacteria. However, they are mostly concentrated in the upper water layers and only a small part of them reached the near bottom water layers and may be used as a food by zoobenthos. The mineralization of organic matter in the water column was twice higher than primary production that indicates the importance of allochthonous organic matter in the carbon budget of the both parts of the estuary. The carbon isotope signature of seston and most of the zoobenthic species in the upper part of the estuary was close to the signature of allochthonous carbon leaking from watershed (- 27‰). Higher values of δ13C of seston in the upper mix layer of the Middle estuary indicate intensive primary production in mid-summer. The carbon isotopic signature of zoobenthos in this part of the estuary was also in general lower than in the Neva Bay reflected higher importance of autochthonous organic matter in food webs of the estuary.

  11. Enhanced chlorophyll a and primary production in the northern Arabian Sea during the spring intermonsoon due to green Noctiluca scintillans bloom

    Digital Repository Service at National Institute of Oceanography (India)

    Madhu, N.V.; Jyothibabu, R.; Maheswaran, P.A.; Jayaraj, K.A.; Achuthankutty, C.T.

    The surface waters of the northeastern Arabian Sea sustained relatively high chlorophyll a (average 0.81+ or -0.80 mg m sup(-3)) and primary production (average 29.5+ or -23.6 mgC m sup(-3)d sup(-1)) during the early spring intermonsoon 2000...

  12. Exploring the Potential Impact of Greenland Meltwater on Stratification, Photosynthetically Active Radiation, and Primary Production in the Labrador Sea

    Science.gov (United States)

    Oliver, Hilde; Luo, Hao; Castelao, Renato M.; van Dijken, Gert L.; Mattingly, Kyle S.; Rosen, Joshua J.; Mote, Thomas L.; Arrigo, Kevin R.; Rennermalm, Åsa K.; Tedesco, Marco; Yager, Patricia L.

    2018-04-01

    In July 2012, the surface of the Greenland Ice Sheet (GrIS) melted to an extent unprecedented over the last 100 years; we questioned the potential for such an extreme melt event to impact marine phytoplankton offshore. We hypothesized that stratification from meltwater could reduce light limitation for phytoplankton, and used a suite of numerical models to quantify the impact for 2003-2012. Because much of the 2012 meltwater discharged from southern Greenland, our study focused on the southwestern and southeastern coasts of Greenland, and the Labrador Sea. A 1-D phytoplankton model used output from a Regional Ocean Modeling System (ROMS) coupled with a Regional Climate Model and a hydrological model of meltwater from runoff sources on the ice sheet, peripheral glaciers, and tundra. ROMS was run with and without meltwater to test the sensitivity of phytoplankton photosynthetic rates to the meltwater input. With meltwater, the pycnocline was shallower during late summer and early fall and thus light limitation on photosynthesis was reduced. Averaged over all years, added meltwater had the potential to increase gross primary production by 3-12% in the summer (July-August), and 13-60% in the fall (September-October). This meltwater effect was amplified when light was more limiting, and thus was greatest in the fall, under cloudier conditions, with higher self-shading, and with more light-sensitive phytoplankton groups. As the GrIS melt is projected to increase, late summer primary production in this region has the potential to increase as well, which could constitute an important biosphere response to high-latitude climate change.

  13. Comparison of primary productivity estimates in the Baltic Sea based on the DESAMBEM algorithm with estimates based on other similar algorithms

    Directory of Open Access Journals (Sweden)

    Małgorzata Stramska

    2013-02-01

    Full Text Available The quasi-synoptic view available from satellites has been broadly used in recent years to observe in near-real time the large-scale dynamics of marine ecosystems and to estimate primary productivity in the world ocean. However, the standard global NASA ocean colour algorithms generally do not produce good results in the Baltic Sea. In this paper, we compare the ability of seven algorithms to estimate depth-integrated daily primary production (PP, mg C m-2 in the Baltic Sea. All the algorithms use surface chlorophyll concentration, sea surface temperature, photosynthetic available radiation, latitude, longitude and day of the year as input data. Algorithm-derived PP is then compared with PP estimates obtained from 14C uptake measurements. The results indicate that the best agreement between the modelled and measured PP in the Baltic Sea is obtained with the DESAMBEM algorithm. This result supports the notion that a regional approach should be used in the interpretation of ocean colour satellite data in the Baltic Sea.

  14. Contribution of crenarchaeal autotrophic ammonia oxidizers to the dark primary production in Tyrrhenian deep waters (Central Mediterranean Sea).

    Science.gov (United States)

    Yakimov, Michail M; Cono, Violetta La; Smedile, Francesco; DeLuca, Thomas H; Juárez, Silvia; Ciordia, Sergio; Fernández, Marisol; Albar, Juan Pablo; Ferrer, Manuel; Golyshin, Peter N; Giuliano, Laura

    2011-06-01

    Mesophilic Crenarchaeota have recently been thought to be significant contributors to nitrogen (N) and carbon (C) cycling. In this study, we examined the vertical distribution of ammonia-oxidizing Crenarchaeota at offshore site in Southern Tyrrhenian Sea. The median value of the crenachaeal cell to amoA gene ratio was close to one suggesting that virtually all deep-sea Crenarchaeota possess the capacity to oxidize ammonia. Crenarchaea-specific genes, nirK and ureC, for nitrite reductase and urease were identified and their affiliation demonstrated the presence of 'deep-sea' clades distinct from 'shallow' representatives. Measured deep-sea dark CO(2) fixation estimates were comparable to the median value of photosynthetic biomass production calculated for this area of Tyrrhenian Sea, pointing to the significance of this process in the C cycle of aphotic marine ecosystems. To elucidate the pivotal organisms in this process, we targeted known marine crenarchaeal autotrophy-related genes, coding for acetyl-CoA carboxylase (accA) and 4-hydroxybutyryl-CoA dehydratase (4-hbd). As in case of nirK and ureC, these genes are grouped with deep-sea sequences being distantly related to those retrieved from the epipelagic zone. To pair the molecular data with specific functional attributes we performed [(14)C]HCO(3) incorporation experiments followed by analyses of radiolabeled proteins using shotgun proteomics approach. More than 100 oligopeptides were attributed to 40 marine crenarchaeal-specific proteins that are involved in 10 different metabolic processes, including autotrophy. Obtained results provided a clear proof of chemolithoautotrophic physiology of bathypelagic crenarchaeota and indicated that this numerically predominant group of microorganisms facilitate a hitherto unrecognized sink for inorganic C of a global importance.

  15. Microphytobenthic primary production along a non-tidal sandy beach gradient: an annual study from the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Barbara Urban-Malinga

    2003-12-01

    Full Text Available The microphytobenthic primary production and chlorophyll a content were studied over the annual cycle (May 1998 - May 1999 on a non-tidal Baltic sandy beach at three stations along the beach gradient: littoral, waterline and splash zone. The chlorophyll a concentrations varied between 0.88 and 12.18 µg cm-3. Net and gross primary production rates respectively lay within the ranges 0.1-31.4 mgC m-2 h-1 and 0.2-41.8 mgC m-2 h-1. The highest values of both Chl a content and primary production were noted at the littoral station, the lowest ones at the waterline. The mean annual P/B ratio was highest at the waterline. The differences in Chl a content between stations were statistically significant and may be related to water dynamics, resuspension and water content. Production rates were highly variable on monthly time scales, and the highest results at all the study locations were noted in July. The gross photosynthetic rates were significantly correlated with water temperature.

  16. Productivity, chlorophyll a, Photosynthetically Active Radiation (PAR) and other phytoplankton data from the Arctic Ocean, Bering Sea, Chukchi Sea, Beaufort Sea, East Siberian Sea, Kara Sea, Barents Sea, and Arctic Archipelago measured between 17 April, 1954 and 30 May, 2006 compiled as part of the Arctic System Science Primary Production (ARCSS-PP) observational synthesis project (NODC Accession 0063065)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Arctic Ocean primary production data were assembled from original input data archived in various international databases, provided by individual investigators or in...

  17. The distribution feature of size-fractionated chlorophyll a and primary productivity in Prydz Bay and its north sea area during the austral summer

    Institute of Scientific and Technical Information of China (English)

    刘子琳; 陈忠元

    2003-01-01

    The investigation of size-fractionated chlorophyll a and primary productivity were carried out in three longitudinal sections (63°-69°12′S, 70°30′E, 73°E and 75(30′E) at December 18 -26, 1998 and January 12 -18, 1999 in Prydz Bay and its north sea area, Antarctica. The results showed that surface chlorophyll a concentration were 0.16 - 3.99 μg dm -3. The high values of chlorophyll a concentration ( more than 3.5 μg dm -3 ) were in Prydz Bay and in the west Ladies Bank. The average chlorophyll a concentration at sub-surface layer was higher than that at surface layer; its concentration at the deeper layers of 50 m decreased with increasing depth and that at 200 m depth was only 0.01 -0.95 μg dm-3. The results of size-fractionated chlorophyll a showed that the contribution of the netplanktion to total chlorophyll a was 56% , those of the nanoplankton and the picoplankton were 24% and 20% respectively in the surveyed area. The potential primary productivity at the euphotic zone in the surveyed area was 0. 11 - 11.67 mgC m-3 h -1 and average value was 2.00 ±2.80 mgC m-3h-1. The in-situ productivity in the bay and the continental shelf was higher and that in the deep-sea area was lower. The assimilation number of ted primary productivity show that the contribution of the netplanktion to total productivity was 58% , those of the nanoplankton and the picoplankton were 26% and 16% respectively. The cell abundance of phytoplankton was 1. 6 + 103 - 164. 8 + 103 cell dm-3 in the surface water.

  18. The dynamics of nutrient enrichment and primary production related to the recent changes in the ecosystem of the Black Sea

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, A; Yayla, M; Salihoglu, I [Middle East Technical University, Institute of Marine Sciences, Erdemli-Icel (Turkey); Morkoc, E [Turkish Scientific and Technological Research Council (TUBITAK), Marmara Research Center, Gebze-Kocaeli (Turkey)

    1999-07-01

    During the spring period of 1998, light penetrated into the upper 25-35 m, with an attenuation coefficient varying between 0.1 and 0.5 m{sup -1}. The chlorophyll-a (Chl-a) concentrations for the euphotic zone ranged from 0.2 to 1.4 {mu}g l{sup -1}. Coherent sub-surface Chl-a maxima were formed near the base of the euphotic zone and a secondary one was located at very low level of light in the Rim Current region. Production rates varied between 450 and 690 mgC/m{sup 2}/d in this period. The chemocline boundaries and the distinct chemical features of the oxic/anoxic transition layer (the so-called suboxic zone) are all located at specific density surfaces; however, they exhibited remarkable spatial variations both in their position and in their magnitude. Bioassay experiments (using extra NO{sub 3}, NH{sub 4}, PO{sub 4} and Si) performed during Spring 1998 cruise showed that under optimum light conditions the phytoplankton population is nitrate limited in the open waters. Phosphate seems to control the growth in the Rim Current regions of the southern Black Sea. Si concentration also influenced the phytoplankton growth since the majority of the population was determined as diatom. (author) 30 refs, 5 figs

  19. The dynamics of nutrient enrichment and primary production related to the recent changes in the ecosystem of the Black Sea

    International Nuclear Information System (INIS)

    Yilmaz, A.; Yayla, M.; Salihoglu, I.; Morkoc, E.

    1999-01-01

    During the spring period of 1998, light penetrated into the upper 25-35 m, with an attenuation coefficient varying between 0.1 and 0.5 m -1 . The chlorophyll-a (Chl-a) concentrations for the euphotic zone ranged from 0.2 to 1.4 μg l -1 . Coherent sub-surface Chl-a maxima were formed near the base of the euphotic zone and a secondary one was located at very low level of light in the Rim Current region. Production rates varied between 450 and 690 mgC/m 2 /d in this period. The chemocline boundaries and the distinct chemical features of the oxic/anoxic transition layer (the so-called suboxic zone) are all located at specific density surfaces; however, they exhibited remarkable spatial variations both in their position and in their magnitude. Bioassay experiments (using extra NO 3 , NH 4 , PO 4 and Si) performed during Spring 1998 cruise showed that under optimum light conditions the phytoplankton population is nitrate limited in the open waters. Phosphate seems to control the growth in the Rim Current regions of the southern Black Sea. Si concentration also influenced the phytoplankton growth since the majority of the population was determined as diatom. (author)

  20. Contribution of crenarchaeal autotrophic ammonia oxidizers to the dark primary production in Tyrrhenian deep waters (Central Mediterranean Sea)

    OpenAIRE

    Yakimov, Michail M.; La Cono, Violetta; Smedile, Francesco; DeLuca, Thomas H.; Juarez, Silvia; Ciordia, Sergio; Fernandez, Marisol; Albar, Juan Pablo; Ferrer, Manuel; Golyshin, Peter N.; Giuliano, Laura

    2011-01-01

    Mesophilic Crenarchaeota have recently been thought to be significant contributors to nitrogen (N) and carbon (C) cycling. In this study, we examined the vertical distribution of ammonia-oxidizing Crenarchaeota at offshore site in Southern Tyrrhenian Sea. The median value of the crenachaeal cell to amoA gene ratio was close to one suggesting that virtually all deep-sea Crenarchaeota possess the capacity to oxidize ammonia. Crenarchaea-specific genes, nirK and ureC, for nitrite reductase and u...

  1. Benthic reef primary production in response to large amplitude internal waves at the Similan Islands (Andaman Sea, Thailand)

    KAUST Repository

    Jantzen, Carin; Schmidt, Gertraud M.; Wild, Christian; Roder, Cornelia; Khokiattiwong, Somkiat; Richter, Claudio

    2013-01-01

    Coral reefs are facing rapidly changing environments, but implications for reef ecosystem functioning and important services, such as productivity, are difficult to predict. Comparative investigations on coral reefs that are naturally exposed

  2. Variability and Trends in Sea Ice Extent and Ice Production in the Ross Sea

    Science.gov (United States)

    Comiso, Josefino; Kwok, Ronald; Martin, Seelye; Gordon, Arnold L.

    2011-01-01

    Salt release during sea ice formation in the Ross Sea coastal regions is regarded as a primary forcing for the regional generation of Antarctic Bottom Water. Passive microwave data from November 1978 through 2008 are used to examine the detailed seasonal and interannual characteristics of the sea ice cover of the Ross Sea and the adjacent Bellingshausen and Amundsen seas. For this period the sea ice extent in the Ross Sea shows the greatest increase of all the Antarctic seas. Variability in the ice cover in these regions is linked to changes in the Southern Annular Mode and secondarily to the Antarctic Circumpolar Wave. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate of increase in the net ice export of about 30,000 sq km/yr. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 cu km/yr, which is almost identical, within error bars, to our estimate of the trend in ice production. The increase in brine rejection in the Ross Shelf Polynya associated with the estimated increase with the ice production, however, is not consistent with the reported Ross Sea salinity decrease. The locally generated sea ice enhancement of Ross Sea salinity may be offset by an increase of relatively low salinity of the water advected into the region from the Amundsen Sea, a consequence of increased precipitation and regional glacial ice melt.

  3. Primary Productivity (PP_Master)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set included primary production for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came...

  4. MODIS Snow and Sea Ice Products

    Science.gov (United States)

    Hall, Dorothy K.; Riggs, George A.; Salomonson, Vincent V.

    2004-01-01

    In this chapter, we describe the suite of Earth Observing System (EOS) Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra and Aqua snow and sea ice products. Global, daily products, developed at Goddard Space Flight Center, are archived and distributed through the National Snow and Ice Data Center at various resolutions and on different grids useful for different communities Snow products include binary snow cover, snow albedo, and in the near future, fraction of snow in a 5OO-m pixel. Sea ice products include ice extent determined with two different algorithms, and sea ice surface temperature. The algorithms used to develop these products are described. Both the snow and sea ice products, available since February 24,2000, are useful for modelers. Validation of the products is also discussed.

  5. Physical control of primary productivity on a seasonal scale in ...

    Indian Academy of Sciences (India)

    Keywords. Primary production; upwelling; winter cooling; Ekman-pumping, nutrient transport; Arabian Sea ... on the other hand, is driven by advection from the Somalia upwelling. Surface cooling and convection resulting from reduced solar radiation and increased evaporation make the northern region productive in winter.

  6. Nutrients, chlorophyll, fractional primary productivity in water column of the North Arabian Sea in support of the North Arabian Sea Environment and Ecosystem Research from 1992-1994 (NODC Accession 0000778)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Five cruises were carried out under the Pak-US cooperative project 'North Arabian Sea Environment and Ecosystem Research' (NASEER) from 1992-1994. The main objective...

  7. Sea ice production and transport of pollutants in Laptev Sea, 1979 to 1992

    International Nuclear Information System (INIS)

    Rigor, I.; Colony, R.

    1995-01-01

    About 900,000 km 2 of the polar pack ice is transferred annually from the Arctic Basin to the North Atlantic. The largest portion of this exported ice cover is created by the large scale divergence within the ice pack, but a significant portion of the ice cover originates in the marginal seas, either by fall freezing of the seasonally ice free waters or by wintertime advection away from the coast. The main objective of this study was to estimate the annual production of ice in the Laptev Sea and to determine its ultimate fate. The study was motivated by the possibility that ice formed in the Laptev Sea may be an agent for the long range transport of pollutants such as radionuclides. The authors have attempted to characterize the mean and interannual variability of ice production by investigating the winter production and subsequent melt of ice in the Laptev Sea from 1979 through 1992. The general approach was to associate pollution transport with the net exchange of ice area from the Laptev Sea to the perennial ice pack. The primary data sets supporting the study were ice charts, ice motion and geostrophic wind. 3 refs., 4 figs., 1 tab

  8. DUACS: Toward High Resolution Sea Level Products

    Science.gov (United States)

    Faugere, Y.; Gerald, D.; Ubelmann, C.; Claire, D.; Pujol, M. I.; Antoine, D.; Desjonqueres, J. D.; Picot, N.

    2016-12-01

    The DUACS system produces, as part of the CNES/SALP project, and the Copernicus Marine Environment and Monitoring Service, high quality multimission altimetry Sea Level products for oceanographic applications, climate forecasting centers, geophysic and biology communities... These products consist in directly usable and easy to manipulate Level 3 (along-track cross-calibrated SLA) and Level 4 products (multiple sensors merged as maps or time series) and are available in global and regional version (Mediterranean Sea, Arctic, European Shelves …).The quality of the products is today limited by the altimeter technology "Low Resolution Mode" (LRM), and the lack of available observations. The launch of 2 new satellites in 2016, Jason-3 and Sentinel-3A, opens new perspectives. Using the global Synthetic Aperture Radar mode (SARM) coverage of S3A and optimizing the LRM altimeter processing (retracking, editing, ...) will allow us to fully exploit the fine-scale content of the altimetric missions. Thanks to this increase of real time altimetry observations we will also be able to improve Level-4 products by combining these new Level-3 products and new mapping methodology, such as dynamic interpolation. Finally these improvements will benefit to downstream products : geostrophic currents, Lagrangian products, eddy atlas… Overcoming all these challenges will provide major upgrades of Sea Level products to better fulfill user needs.

  9. Primary tasks of environmental improvement of the Aral Sea region

    International Nuclear Information System (INIS)

    Tauipbaev, S.T.; Turebaev, Sh.Kh.; Kusherbaev, A.E.

    1997-01-01

    Main reasons of environmental crisis in Aral Sea region are analyzed. Primary tasks of its environmental improvement are planed: - creation of conditions of guarantee ensuring (by territory and time) for all water consumers of water resources of the Syr-Dariya and Amu Dariya rivers at the expense of increase of water system efficiency and organization of Water Union of Basin Countries; - acceptance of regional measures on good quality water supply for the Aral Sea region population, mainly at expense of underground water use; -fulfillment of primary measures for Aral Sea save, envisaging building of land dam separating the Small Aral: - solution of unemployment problem by capacity of strengthening of farm economy and rebirth of native business

  10. Short-term variability of primary production and inorganic nitrogen uptake related to the environmental conditions in a shallow coastal area (Gulf of Trieste, N Adriatic Sea)

    OpenAIRE

    Cantoni, C; Cozzi, S; Pecchiar, I; Cabrini, M; Mozeti, P; Catalano, G; Umani, Sf

    2003-01-01

    La production primaire et l’assimilation de nitrates et d’ammonium ont été mesurées en même temps que les facteurs du milieu entre octobre 1999 et février 2001 dans le golfe de Trieste. La variabilité est élevée en raison de l’action combinée des conditions météorologiques, de la circulation et des apports des rivières. La production primaire varie entre 0,2 et 15,9 μmol C dm–3 j–1 alors que l’assimilation de nitrates va de 0,8 à 442 nmol N dm–3 j–1, montrant une tendance identique au carbone...

  11. Wintertime Arctic Ocean sea water properties and primary marine aerosol concentrations

    Directory of Open Access Journals (Sweden)

    J. Zábori

    2012-11-01

    Full Text Available Sea spray aerosols are an important part of the climate system through their direct and indirect effects. Due to the diminishing sea ice, the Arctic Ocean is one of the most rapidly changing sea spray aerosol source areas. However, the influence of these changes on primary particle production is not known.

    In laboratory experiments we examined the influence of Arctic Ocean water temperature, salinity, and oxygen saturation on primary particle concentration characteristics. Sea water temperature was identified as the most important of these parameters. A strong decrease in sea spray aerosol production with increasing water temperature was observed for water temperatures between −1°C and 9°C. Aerosol number concentrations decreased from at least 1400 cm−3 to 350 cm−3. In general, the aerosol number size distribution exhibited a robust shape with one mode close to dry diameter Dp 0.2 μm with approximately 45% of particles at smaller sizes. Changes in sea water temperature did not result in pronounced change of the shape of the aerosol size distribution, only in the magnitude of the concentrations. Our experiments indicate that changes in aerosol emissions are most likely linked to changes of the physical properties of sea water at low temperatures. The observed strong dependence of sea spray aerosol concentrations on sea water temperature, with a large fraction of the emitted particles in the typical cloud condensation nuclei size range, provide strong arguments for a more careful consideration of this effect in climate models.

  12. Decadal Changes in Global Ocean Annual Primary Production

    Science.gov (United States)

    Gregg, Watson; Conkright, Margarita E.; Behrenfeld, Michael J.; Ginoux, Paul; Casey, Nancy W.; Koblinsky, Chester J. (Technical Monitor)

    2002-01-01

    The Sea-viewing Wide Field-of-View Sensor (SeaWiFS) has produced the first multi-year time series of global ocean chlorophyll observations since the demise of the Coastal Zone Color Scanner (CZCS) in 1986. Global observations from 1997-present from SeaWiFS combined with observations from 1979-1986 from the CZCS should in principle provide an opportunity to observe decadal changes in global ocean annual primary production, since chlorophyll is the primary driver for estimates of primary production. However, incompatibilities between algorithms have so far precluded quantitative analysis. We have developed and applied compatible processing methods for the CZCS, using modern advances in atmospheric correction and consistent bio-optical algorithms to advance the CZCS archive to comparable quality with SeaWiFS. We applied blending methodologies, where in situ data observations are incorporated into the CZCS and SeaWiFS data records, to provide improvement of the residuals. These re-analyzed, blended data records provide maximum compatibility and permit, for the first time, a quantitative analysis of the changes in global ocean primary production in the early-to-mid 1980's and the present, using synoptic satellite observations. An intercomparison of the global and regional primary production from these blended satellite observations is important to understand global climate change and the effects on ocean biota. Photosynthesis by chlorophyll-containing phytoplankton is responsible for biotic uptake of carbon in the oceans and potentially ultimately from the atmosphere. Global ocean annual primary decreased from the CZCS record to SeaWiFS, by nearly 6% from the early 1980s to the present. Annual primary production in the high latitudes was responsible for most of the decadal change. Conversely, primary production in the low latitudes generally increased, with the exception of the tropical Pacific. The differences and similarities of the two data records provide evidence

  13. Primary productivity of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Pant, A.

    stream_size 13 stream_content_type text/plain stream_name Trop_Ecosyst_Ecol_Manage_1992_255.pdf.txt stream_source_info Trop_Ecosyst_Ecol_Manage_1992_255.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  14. Species sensitivity distribution approach to primary risk analysis of the metal pyrithione photodegradation product, 2,2'-dipyridyldisulfide in the Inland Sea and induction of notochord undulation in fish embryos.

    Science.gov (United States)

    Mochida, Kazuhiko; Amano, Haruna; Ito, Katsutoshi; Ito, Mana; Onduka, Toshimitsu; Ichihashi, Hideki; Kakuno, Akira; Harino, Hiroya; Fujii, Kazunori

    2012-08-15

    To carry out a primary risk assessment in the Inland Sea of Japan for 2,2'-dipyridyldisulfide [(PS)(2)], a metal pyrithione photodegradation product, we used a methodology based on the species sensitivity distribution (SSD) estimated with a Bayesian statistical model. We first conducted growth inhibition tests with three marine phytoplankton species, Tetraselmis tetrathele, Chaetoceros calcitrans, and Dunaliella tertiolecta. We also performed acute and early life stage toxicity (ELS) tests with a teleost fish, the mummichog (Fundulus heteroclitus). The algal growth inhibition tests revealed that the 72-h EC(50) ranged from 62 to 1100 μg/L. Acute toxicity tests with larval mummichogs revealed that the 96-h LC(50) was approximately 500 μg/L based on the actual toxicant concentrations. ELS testing of (PS)(2) under continuous flow-through conditions for 50 days revealed that growth was the most sensitive endpoint, and both total length and body weight were significantly lower in the groups exposed to 27 μg/L (PS)(2) compared to the solvent control group. We determined a lowest observed effect concentration of 17 μg/L and a NOEC of 5.9 μg/L based on the actual toxicant concentrations. By using the ecotoxicity data (LC(50) and EC(50)) from this study and previous work, we calculated a hazardous concentration that should protect 95% and 99% of species (HC(5) and HC(1)) based on the SSD derived with a Bayesian statistical model. The medians with 90% confidence intervals (parentheses) of the HC(5) and HC(1) were 31.0 (3.2, 101.8) μg/L and 10.1 (0.5, 44.2) μg/L, respectively. In the ELS test, about 80% of hatched larvae exposed to 243-μg/L (PS)(2) displayed a notochord undulation. To elucidate the cause of the notochord undulation, we carried out embryo toxicity tests by exposing embryos at various developmental stages to (PS)(2). Exposure to (PS)(2) through the entire gastrulae stage was important to induction of the morphological abnormality. Lysyl oxidase activity

  15. Evaluation of Organic Proxies for Quantifying Past Primary Productivity

    Science.gov (United States)

    Raja, M.; Rosell-Melé, A.; Galbraith, E.

    2017-12-01

    Ocean primary productivity is a key element of the marine carbon cycle. However, its quantitative reconstruction in the past relies on the use of biogeochemical models as the available proxy approaches are qualitative at best. Here, we present an approach that evaluates the use of phytoplanktonic biomarkers (i.e. chlorins and alkenones) as quantitative proxies to reconstruct past changes in marine productivity. We compare biomarkers contents in a global suite of core-top sediments to sea-surface chlorophyll-a abundance estimated by satellites over the last 20 years, and the results are compared to total organic carbon (TOC). We also assess satellite data and detect satellite limitations and biases due to the complexity of optical properties and the actual defined algorithms. Our findings show that sedimentary chlorins can be used to track total sea-surface chlorophyll-a abundance as an indicator for past primary productivity. However, degradation processes restrict the application of this proxy to concentrations below a threshold value (1µg/g). Below this threshold, chlorins are a useful tool to identify reducing conditions when used as part of a multiproxy approach to assess redox sedimentary conditions (e.g. using Re, U). This is based on the link between anoxic/disoxic conditions and the flux of organic matter from the sea-surface to the sediments. We also show that TOC is less accurate than chlorins for estimating sea-surface chlorophyll-a due to the contribution of terrigenous organic matter, and the different degradation pathways of all organic compounds that TOC includes. Alkenones concentration also relates to primary productivity, but they are constrained by different processes in different regions. In conclusion, as lons as specific constraints are taken into account, our study evaluates the use of chlorins and alkenones as quantitative proxies of past primary productivity, with more accuracy than by using TOC.

  16. Ocean primary production and available light: Further algorithms for remote sensing

    Digital Repository Service at National Institute of Oceanography (India)

    Platt, T.; Sathyendranath, S.; Caverhill, C.M.; Lewis, M.R.

    (1986, Deep-Sea Research, 33, 149-163) Further empirical evidence is presented to show the stability of the relationship between surface light and biomass-normalized primary production of the ocean water column A theoretical explanation is given...

  17. Productivity and sea surface temperature are correlated with the pelagic larval duration of damselfishes in the Red Sea.

    Science.gov (United States)

    Robitzch, Vanessa S N; Lozano-Cortés, Diego; Kandler, Nora M; Salas, Eva; Berumen, Michael L

    2016-04-30

    We examined the variation of pelagic larval durations (PLDs) among three damselfishes, Dascyllus aruanus, D. marginatus, and D. trimaculatus, which live under the influence of an environmental gradient in the Red Sea. PLDs were significantly correlated with latitude, sea surface temperature (SST), and primary production (CHLA; chlorophyll a concentrations). We find a consistent decrease in PLDs with increasing SST and primary production (CHLA) towards the southern Red Sea among all species. This trend is likely related to higher food availability and increased metabolic rates in that region. We suggest that food availability is a potentially stronger driver of variation in PLD than temperature, especially in highly oligotrophic regions. Additionally, variations in PLDs were particularly high among specimens of D. marginatus, suggesting a stronger response to local environmental differences for endemic species. We also report the first average PLD for this species over a broad geographic range (19.82 ± 2.92 days). Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Productivity and sea surface temperature are correlated with the pelagic larval duration of damselfishes in the Red Sea

    KAUST Repository

    Robitzch, Vanessa S.N.

    2015-12-01

    We examined the variation of pelagic larval durations (PLDs) among three damselfishes, Dascyllus aruanus, D. marginatus, and D. trimaculatus, which live under the influence of an environmental gradient in the Red Sea. PLDs were significantly correlated with latitude, sea surface temperature (SST), and primary production (CHLA; chlorophyll a concentrations). We find a consistent decrease in PLDs with increasing SST and primary production (CHLA) towards the southern Red Sea among all species. This trend is likely related to higher food availability and increased metabolic rates in that region. We suggest that food availability is a potentially stronger driver of variation in PLD than temperature, especially in highly oligotrophic regions. Additionally, variations in PLDs were particularly high among specimens of D. marginatus, suggesting a stronger response to local environmental differences for endemic species. We also report the first average PLD for this species over a broad geographic range (19.82 ± 2.92 days).

  19. Productivity and sea surface temperature are correlated with the pelagic larval duration of damselfishes in the Red Sea

    KAUST Repository

    Robitzch, Vanessa S.N.; Lozano-Corté s, Diego; Kandler, Nora; Salas, Eva; Berumen, Michael L.

    2015-01-01

    We examined the variation of pelagic larval durations (PLDs) among three damselfishes, Dascyllus aruanus, D. marginatus, and D. trimaculatus, which live under the influence of an environmental gradient in the Red Sea. PLDs were significantly correlated with latitude, sea surface temperature (SST), and primary production (CHLA; chlorophyll a concentrations). We find a consistent decrease in PLDs with increasing SST and primary production (CHLA) towards the southern Red Sea among all species. This trend is likely related to higher food availability and increased metabolic rates in that region. We suggest that food availability is a potentially stronger driver of variation in PLD than temperature, especially in highly oligotrophic regions. Additionally, variations in PLDs were particularly high among specimens of D. marginatus, suggesting a stronger response to local environmental differences for endemic species. We also report the first average PLD for this species over a broad geographic range (19.82 ± 2.92 days).

  20. HANPP Collection: Human Appropriation of Net Primary Productivity as a Percentage of Net Primary Productivity

    Data.gov (United States)

    National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) as a Percentage of Net Primary Product (NPP) portion of the HANPP Collection represents a map identifying...

  1. Method for the production of primary amines

    NARCIS (Netherlands)

    Baldenius, Kai-Uwe; Ditrich, Klaus; Breurer, Michael; Navickas, Vaidotas; Janssen, Dick; Crismaru, Ciprian; Bartsch, Sebastian

    2014-01-01

    The present invention relates to a novel enzymatically catalyzed method for the production of aliphatic primary amines, which method comprises the enzymatic oxidation of a primary aliphatic alcohol catalyzed by an alcohol dehydrogenase, amination of the resulting oxocompound catalyzed by a

  2. Deep primary production in coastal pelagic systems

    DEFF Research Database (Denmark)

    Lyngsgaard, Maren Moltke; Richardson, Katherine; Markager, Stiig

    2014-01-01

    produced. The primary production (PP) occurring below the surface layer, i.e. in the pycnocline-bottom layer (PBL), is shown to contribute significantly to total PP. Oxygen concentrations in the PBL are shown to correlate significantly with the deep primary production (DPP) as well as with salinity...... that eutrophication effects may include changes in the structure of planktonic food webs and element cycling in the water column, both brought about through an altered vertical distribution of PP....

  3. Primary production of tropical marine ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattathiri, P.M.A.

    Among tropical marine ecosystems estuaries are one of the highly productive areas and act as a nursery to large number of organisms. The primary production in most of the estuaries is less during the monsoon period. Post-monsoon period shows...

  4. Cell surface of sea urchin micromeres and primary mesenchyme

    International Nuclear Information System (INIS)

    DeSimone, D.W.

    1985-01-01

    The cell surface and extracellular matrix (ECM) of the sea urchin embryo were studied during the early morphogenetic events involved in the differentiation of the micromere cell lineage. Sixteen-cell and early cleavage stage blastomeres were isolated and the protein composition of their cell surfaces examined by 125 I-labelling followed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Micromere-specific cell surface proteins are reported for Arbacia punctulata, Strongylocentrotus droebachiensis, and Strongylocentrotus purpuratus. Cell surface glycoproteins were characterized on the basis of lectin binding specificity with a novel lectin affinity transfer technique. Using this procedure, cell-type specific surface proteins, which are also lectin-binding specific, can be detected. In addition, fluorescein conjugated lectins were microinjected into the blastocoels of living S. drobachiensis and Lytechinus pictus embryos and the patterns of lectin bindings observed by fluorescence microscopy. The evidence presented in this thesis suggests that the differentiation of the primary mesenchyme cells is correlated with changes in the molecular composition of the cell-surface and the ECM

  5. Physical forcing of biological productivity in the northern Arabian Sea during the northeast monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Ramaiah, N.; Gauns, M.; Sarma, V.V.S.S.; Muraleedharan, P.M.; Raghukumar, S.; DileepKumar, M.; Madhupratap, M.

    that this interannual variation is of basin-wide spatial scale. After the termination of winter cooling and subsequent warming during the Spring Intermonsoon, the Arabian Sea has low primary production. During the latter period, micro-organisms, i.e. heterotrophic...

  6. Enhanced biological production in the southeastern Arabian Sea during spring intermonsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Laluraj, C.M.; Balachandran, K.K.; Sabu, P.

    spring intermonsoon This water mass was relatively low saline (34.2) and nitrate-rich (0.5 mu M), favoring moderate primary production (6.7 mg C m sup(-3) d sup(-1) Since the mixing of the Arabian Sea and the Bay of Bengal waters is an important process...

  7. AKRO/SF: Vessel (at-sea) Production Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Vessel (at-sea) production reports are mandatory reports submitted by catcher/processors and motherships that are issued a Federal Fishing Permit. These reports...

  8. NOAA High-Resolution Sea Surface Temperature (SST) Analysis Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archive covers two high resolution sea surface temperature (SST) analysis products developed using an optimum interpolation (OI) technique. The analyses have a...

  9. Primary Productivity of the Cengklik Dam Boyolali

    Directory of Open Access Journals (Sweden)

    WIRYANTO

    2002-01-01

    Full Text Available Primary productivity dynamic of the water ecosystem was conducted faster in the last decades. This study was intended to find out the primary productivity of Cengklik dam Boyolali, Central Java to explain the ecosystem dynamic and to lead the maintenance of dam. This study used quantitative methods in completely randomized group design (CRD, and the data was analized by Analysis of Variance (ANAVA. Samples were taken horizontally in four sampling point, respectively in the riparian zone, around of the floating net (“karamba”, in the center of dam water and around of the ex-paddy fields. There were taken vertically in three-depth point in each of the sampling point, respectively 0.5 meter, 1.5 meter, and 2.5 meter. The results showed that the gross primary productivity of the dam was 11.122.500-22.545.600 mgC/m3/days, and the primary productivity differences in each of the point sampling caused by light intensity, nutrient supply, and abundance of the chlorophyll organisms.

  10. Assessing concentration uncertainty estimates from passive microwave sea ice products

    Science.gov (United States)

    Meier, W.; Brucker, L.; Miller, J. A.

    2017-12-01

    Sea ice concentration is an essential climate variable and passive microwave derived estimates of concentration are one of the longest satellite-derived climate records. However, until recently uncertainty estimates were not provided. Numerous validation studies provided insight into general error characteristics, but the studies have found that concentration error varied greatly depending on sea ice conditions. Thus, an uncertainty estimate from each observation is desired, particularly for initialization, assimilation, and validation of models. Here we investigate three sea ice products that include an uncertainty for each concentration estimate: the NASA Team 2 algorithm product, the EUMETSAT Ocean and Sea Ice Satellite Application Facility (OSI-SAF) product, and the NOAA/NSIDC Climate Data Record (CDR) product. Each product estimates uncertainty with a completely different approach. The NASA Team 2 product derives uncertainty internally from the algorithm method itself. The OSI-SAF uses atmospheric reanalysis fields and a radiative transfer model. The CDR uses spatial variability from two algorithms. Each approach has merits and limitations. Here we evaluate the uncertainty estimates by comparing the passive microwave concentration products with fields derived from the NOAA VIIRS sensor. The results show that the relationship between the product uncertainty estimates and the concentration error (relative to VIIRS) is complex. This may be due to the sea ice conditions, the uncertainty methods, as well as the spatial and temporal variability of the passive microwave and VIIRS products.

  11. Temporal variatiions of Sea ice cover in the Baltic Sea derived from operational sea ice products used in NWP.

    Science.gov (United States)

    Lange, Martin; Paul, Gerhard; Potthast, Roland

    2014-05-01

    Sea ice cover is a crucial parameter for surface fluxes of heat and moisture over water areas. The isolating effect and the much higher albedo strongly reduces the turbulent exchange of heat and moisture from the surface to the atmosphere and allows for cold and dry air mass flow with strong impact on the stability of the whole boundary layer and consequently cloud formation as well as precipitation in the downstream regions. Numerical weather centers as, ECMWF, MetoFrance or DWD use external products to initialize SST and sea ice cover in their NWP models. To the knowledge of the author there are mainly two global sea ice products well established with operational availability, one from NOAA NCEP that combines measurements with satellite data, and the other from OSI-SAF derived from SSMI/S sensors. The latter one is used in the Ostia product. DWD additionally uses a regional product for the Baltic Sea provided by the national center for shipping and hydrografie which combines observations from ships (and icebreakers) for the German part of the Baltic Sea and model analysis from the hydrodynamic HIROMB model of the Swedish meteorological service for the rest of the domain. The temporal evolution of the three different products are compared for a cold period in Februar 2012. Goods and bads will be presented and suggestions for a harmonization of strong day to day jumps over large areas are suggested.

  12. Fish production and climate: Sprat in the Baltic Sea

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Köster, Fritz

    2004-01-01

    Processes controlling the production of new fish (recruitment) are poorly understood and therefore challenge population ecologists and resource managers. Sprat in the Baltic Sea is no exception: recruitment varies widely between years and is virtually independent of the biomass of mature sprat......-scale climate variability (North Atlantic Oscillation), Baltic Sea ice coverage, and water temperature. These relationships increase our understanding of sprat population dynamics and enable a desirable integration of fisheries ecology and management with climatology and oceanography....

  13. Reconstruction of Redox Conditions and Productivity in Coastal Waters of the Bothnian Sea during the Holocene

    Science.gov (United States)

    Dijkstra, N.; Quintana Krupinski, N. B.; Slomp, C. P.

    2014-12-01

    Hypoxia is a growing problem in coastal waters worldwide, and is a well-known cause of benthic mortality. The semi-enclosed Baltic Sea is currently the world's largest human-induced dead zone. During the early Holocene, it experienced several periods of natural hypoxia following the intrusion of seawater into the previous freshwater lake. Recent studies suggest that at that time, the hypoxia expanded north to include the deep basin of the Bothnian Sea. In this study, we assess whether the coastal zone of the Bothnian Sea was also hypoxic during the early Holocene. We analysed a unique sediment record (0 - 30 mbsf) from the Ångermanälven estuary, which was retrieved during the International Ocean Discovery Programme (IODP) Baltic Sea Paleoenvironment Expedition 347 in 2013. Using geochemical proxies and foraminifera abundances, we reconstruct the changes in redox conditions, salinity and productivity in the estuary. Our preliminary results suggest that bottom waters in this coastal basin became anoxic upon the intrusion of brackish seawater in the early Holocene and that the productivity was elevated. The presence of benthic foraminifera in this estuary during the mid-Holocene suggests more saline conditions in the Bothnian Sea than today. Due to isostatic uplift, the estuary likely gradually became more isolated from the Bothnian Sea, which itself became more isolated from the Baltic Sea. Both factors likely explain the subsequent re-oxygenation of bottom waters and gradual refreshening of the estuary as recorded in the sediments. Interestingly, the upper meters of sediment are enriched in minerals that contain iron, phosphorus and manganese. We postulate that the refreshening of the estuary triggered the formation of these minerals, thereby increasing the phosphorus retention in these sediments and further reducing primary productivity. This enhanced retention linked to refreshening may contribute to the current oligotrophic conditions in the Bothnian Sea.

  14. Planktonic primary production evaluation by means of the 14C method with liquid scintillation counting

    International Nuclear Information System (INIS)

    Frangopol, T.P.; Bologa, S.A.

    1979-05-01

    Preliminary results on the planktonic primary production obtained for the first time with the 14 C method off the Romanian Black Sea coast (1977, 1978) and in the Sinoe, Mamaia and Bicaz lakes (1978) are presented, along with a review of this method with special reference to liquid scintillation counting. 140 Refs. (author)

  15. Mass extinctions: Ecological selectivity and primary production

    Science.gov (United States)

    Rhodes, Melissa Clark; Thayer, Charles W.

    1991-09-01

    If mass extinctions were caused by reduced primary productivity, then extinctions should be concentrated among animals with starvation-susceptible feeding modes, active lifestyles, and high-energy budgets. The stratigraphic ranges (by stage) of 424 genera of bivalves and 309 genera of articulate brachiopods suggest that there was an unusual reduction of primary productivity at the Cretaceous/Tertiary (K/T) boundary extinction. For bivalves at the K/T, there were (1) selective extinction of suspension feeders and other susceptible trophic categories relative to deposit feeders and other resistant categories, and (2) among suspension feed-ers, selective extinction of bivalves with active locomotion. During the Permian-Triassic (P/Tr) extinction and Jurassic background time, extinction rates among suspension feeders were greater for articulate brachiopods than for bivalves. But during the K/T event, extinction rates of articulates and suspension-feeding bivalves equalized, possibly because the low-energy budgets of articulates gave them an advantage when food was scarce.

  16. Multiple stressors for oceanic primary production

    KAUST Repository

    Agusti, Susana

    2015-12-15

    Marine ecosystems are increasingly exposed to stress factors of anthropogenic origin that change their function, structure and services they deliver society. Climate change occurs simultaneously with other changes in the environment acting jointly in a context of global environmental change. For oceanic phytoplankton communities, the research conducted so far has identified stress factors associated with global change and their impact individually (warming, acidification, increased UVB radiation, pollutants). But when several stressors act simultaneously interactions and responses are not equal to the sum of individual impacts, but may have synergistic effects (the effects are multiplied) or antagonistic (cancel out the effects) that hinder predictions of the vulnerability of ecosystems to global change. Here we will examine the vulnerability of oceanic primary producers to the accumulation of different stressors associated with global change. The trend for autotrophic picoplankton to increase with temperature in the ocean has led to predictions that autotrophic picoplankton abundance will increase with warming. However, it is documented a trend towards a decline in productivity, due to declined autotroph biomass and production with warming and the associated stratification in the subtropical ocean. Models predicting an increase in abundance are in contradiction with the reported decrease in productivity in several oceanic areas, and associate oligotrophication. Here we perform a global study to analyze the relationships of autotrophic picoplankton with oceanic temperature, nutrients, underwater light and ultraviolet B (UVB) radiation, and productivity. We built a model to project the future changes of autotrophic picoplankton considering multiple environmental changes in future climate scenarios for the subtropical gyres. We considered increased water temperature, and associated changes in productivity and underwater light and UVB. The model show that warming and

  17. Multiple stressors for oceanic primary production

    KAUST Repository

    Agusti, Susana; Llabré s, Moira; Lubiá n, Luis M.; Moreno-Ostos, Enrique; Estrada, Marta; Duarte, Carlos M.; Cerezo, Maria I.

    2015-01-01

    Marine ecosystems are increasingly exposed to stress factors of anthropogenic origin that change their function, structure and services they deliver society. Climate change occurs simultaneously with other changes in the environment acting jointly in a context of global environmental change. For oceanic phytoplankton communities, the research conducted so far has identified stress factors associated with global change and their impact individually (warming, acidification, increased UVB radiation, pollutants). But when several stressors act simultaneously interactions and responses are not equal to the sum of individual impacts, but may have synergistic effects (the effects are multiplied) or antagonistic (cancel out the effects) that hinder predictions of the vulnerability of ecosystems to global change. Here we will examine the vulnerability of oceanic primary producers to the accumulation of different stressors associated with global change. The trend for autotrophic picoplankton to increase with temperature in the ocean has led to predictions that autotrophic picoplankton abundance will increase with warming. However, it is documented a trend towards a decline in productivity, due to declined autotroph biomass and production with warming and the associated stratification in the subtropical ocean. Models predicting an increase in abundance are in contradiction with the reported decrease in productivity in several oceanic areas, and associate oligotrophication. Here we perform a global study to analyze the relationships of autotrophic picoplankton with oceanic temperature, nutrients, underwater light and ultraviolet B (UVB) radiation, and productivity. We built a model to project the future changes of autotrophic picoplankton considering multiple environmental changes in future climate scenarios for the subtropical gyres. We considered increased water temperature, and associated changes in productivity and underwater light and UVB. The model show that warming and

  18. Shelf erosion and submarine river canyons: implications for deep-sea oxygenation and ocean productivity during glaciation

    Directory of Open Access Journals (Sweden)

    I. Tsandev

    2010-06-01

    Full Text Available The areal exposure of continental shelves during glacial sea level lowering enhanced the transfer of erodible reactive organic matter to the open ocean. Sea level fall also activated submarine canyons thereby allowing large rivers to deposit their particulate load, via gravity flows, directly in the deep-sea. Here, we analyze the effects of shelf erosion and particulate matter re-routing to the open ocean during interglacial to glacial transitions, using a coupled model of the marine phosphorus, organic carbon and oxygen cycles. The results indicate that shelf erosion and submarine canyon formation may significantly lower deep-sea oxygen levels, by up to 25%, during sea level low stands, mainly due to the supply of new material from the shelves, and to a lesser extent due to particulate organic matter bypassing the coastal zone. Our simulations imply that deep-sea oxygen levels can drop significantly if eroded shelf material is deposited to the seafloor. Thus the glacial ocean's oxygen content could have been significantly lower than during interglacial stages. Primary production, organic carbon burial and dissolved phosphorus inventories are all affected by the erosion and rerouting mechanisms. However, re-routing of the continental and eroded shelf material to the deep-sea has the effect of decoupling deep-sea oxygen demand from primary productivity in the open ocean. P burial is also not affected showing a disconnection between the biogeochemical cycles in the water column and the P burial record.

  19. Primary production in the Bay of Bengal during August 1977

    Digital Repository Service at National Institute of Oceanography (India)

    Devassy, V.P.; Bhattathiri, P.M.A.; Radhakrishna, K.

    Primary production, chlorophyll @ia@@, phaeophytin, phytoplankton and particulate organic carbon (POC) were studied at 14 stations in the Bay of Bengal during August 1977. Column primary production, chlorophyll @ia@@, and phaeopigments varied from 0...

  20. Relationship between chlorophyll-a and column primary production

    Digital Repository Service at National Institute of Oceanography (India)

    Dalal, S.G.; Bhargava, R.M.S.

    Relationship between surface chlorophyll a and column primary production has been established to help in estimating the latter more quickly and accurately. The equation derived is Primary Production, y = 0.54 Ln Chl a - 0.6. The relationship...

  1. HANPP Collection: Global Patterns in Net Primary Productivity (NPP)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Net Primary Productivity (NPP) portion of the Human Appropriation of Net Primary Productivity (HANPP) Collection maps the net amount of solar...

  2. Bacterial Standing Stock, Activity, and Carbon Production during Formation and Growth of Sea Ice in the Weddell Sea, Antarctica.

    Science.gov (United States)

    Grossmann, S; Dieckmann, G S

    1994-08-01

    Bacterial response to formation and growth of sea ice was investigated during autumn in the northeastern Weddell Sea. Changes in standing stock, activity, and carbon production of bacteria were determined in successive stages of ice development. During initial ice formation, concentrations of bacterial cells, in the order of 1 x 10 to 3 x 10 liter, were not enhanced within the ice matrix. This suggests that physical enrichment of bacteria by ice crystals is not effective. Due to low concentrations of phytoplankton in the water column during freezing, incorporation of bacteria into newly formed ice via attachment to algal cells or aggregates was not recorded in this study. As soon as the ice had formed, the general metabolic activity of bacterial populations was strongly suppressed. Furthermore, the ratio of [H]leucine incorporation into proteins to [H]thymidine incorporation into DNA changed during ice growth. In thick pack ice, bacterial activity recovered and growth rates up to 0.6 day indicated actively dividing populations. However, biomass-specific utilization of organic compounds remained lower than in open water. Bacterial concentrations of up to 2.8 x 10 cells liter along with considerably enlarged cell volumes accumulated within thick pack ice, suggesting reduced mortality rates of bacteria within the small brine pores. In the course of ice development, bacterial carbon production increased from about 0.01 to 0.4 mug of C liter h. In thick ice, bacterial secondary production exceeded primary production of microalgae.

  3. Emerald oil field on production in North Sea

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that Midland and Scottish Energy Ltd. (MSE) has placed Emerald oil field on stream in the U.K. North Sea with a floating production unit. Initial production, from two satellite wells, will be used to commission facilities. Three water injection wells have been unplugged and are ready for start-up. MSE will place a central cluster of wells-five producers and one water injector-on stream during the next few weeks. Production will build to an expected 25,000 b/d from 35 million bbl of reserves. Field development has undergone an unusually large number of setbacks and changes

  4. Has eutrophication promoted forage fish production in the Baltic Sea?

    DEFF Research Database (Denmark)

    Eero, Margit; Andersson, Helén C; Almroth-Rosell, Elin

    2016-01-01

    Reducing anthropogenic nutrient inputs is a major policy goal for restoring good environmental status of coastal marine ecosystems. However, it is unclear to what extent reducing nutrients would also lower fish production and fisheries yields. Empirical examples of changes in nutrient loads...... and concurrent fish production can provide useful insights to this question. In this paper, we investigate to what extent a multi-fold increase in nutrient loads from the 1950s to 1980s enhanced forage fish production in the Baltic Sea. We use monitoring data on fish stock dynamics covering the period...

  5. Environmental conditions and primary production in a Sahelian ...

    African Journals Online (AJOL)

    Environmental descriptors (nutrient, water transparency, temperature ... Nutrient concentrations were low, with high variability (from 0 to 30 µg.l-1 for DIN and from 0 to 18 µg.l-1 for. PO4). The primary ... and permanent interventions of sea water.

  6. From monsoon to marine productivity in the Arabian Sea: insights from glacial and interglacial climates

    Science.gov (United States)

    Le Mézo, Priscilla; Beaufort, Luc; Bopp, Laurent; Braconnot, Pascale; Kageyama, Masa

    2017-07-01

    The current-climate Indian monsoon is known to boost biological productivity in the Arabian Sea. This paradigm has been extensively used to reconstruct past monsoon variability from palaeo-proxies indicative of changes in surface productivity. Here, we test this paradigm by simulating changes in marine primary productivity for eight contrasted climates from the last glacial-interglacial cycle. We show that there is no straightforward correlation between boreal summer productivity of the Arabian Sea and summer monsoon strength across the different simulated climates. Locally, productivity is fuelled by nutrient supply driven by Ekman dynamics. Upward transport of nutrients is modulated by a combination of alongshore wind stress intensity, which drives coastal upwelling, and by a positive wind stress curl to the west of the jet axis resulting in upward Ekman pumping. To the east of the jet axis there is however a strong downward Ekman pumping due to a negative wind stress curl. Consequently, changes in coastal alongshore stress and/or curl depend on both the jet intensity and position. The jet position is constrained by the Indian summer monsoon pattern, which in turn is influenced by the astronomical parameters and the ice sheet cover. The astronomical parameters are indeed shown to impact wind stress intensity in the Arabian Sea through large-scale changes in the meridional gradient of upper-tropospheric temperature. However, both the astronomical parameters and the ice sheets affect the pattern of wind stress curl through the position of the sea level depression barycentre over the monsoon region (20-150° W, 30° S-60° N). The combined changes in monsoon intensity and pattern lead to some higher glacial productivity during the summer season, in agreement with some palaeo-productivity reconstructions.

  7. Identifying metabolic pathways for production of extracellular polymeric substances by the diatom Fragilariopsis cylindrus inhabiting sea ice.

    Science.gov (United States)

    Aslam, Shazia N; Strauss, Jan; Thomas, David N; Mock, Thomas; Underwood, Graham J C

    2018-05-01

    Diatoms are significant primary producers in sea ice, an ephemeral habitat with steep vertical gradients of temperature and salinity characterizing the ice matrix environment. To cope with the variable and challenging conditions, sea ice diatoms produce polysaccharide-rich extracellular polymeric substances (EPS) that play important roles in adhesion, cell protection, ligand binding and as organic carbon sources. Significant differences in EPS concentrations and chemical composition corresponding to temperature and salinity gradients were present in sea ice from the Weddell Sea and Eastern Antarctic regions of the Southern Ocean. To reconstruct the first metabolic pathway for EPS production in diatoms, we exposed Fragilariopsis cylindrus, a key bi-polar diatom species, to simulated sea ice formation. Transcriptome profiling under varying conditions of EPS production identified a significant number of genes and divergent alleles. Their complex differential expression patterns under simulated sea ice formation was aligned with physiological and biochemical properties of the cells, and with field measurements of sea ice EPS characteristics. Thus, the molecular complexity of the EPS pathway suggests metabolic plasticity in F. cylindrus is required to cope with the challenging conditions of the highly variable and extreme sea ice habitat.

  8. Global patterns in human consumption of net primary production

    Science.gov (United States)

    Imhoff, Marc L.; Bounoua, Lahouari; Ricketts, Taylor; Loucks, Colby; Harriss, Robert; Lawrence, William T.

    2004-06-01

    The human population and its consumption profoundly affect the Earth's ecosystems. A particularly compelling measure of humanity's cumulative impact is the fraction of the planet's net primary production that we appropriate for our own use. Net primary production-the net amount of solar energy converted to plant organic matter through photosynthesis-can be measured in units of elemental carbon and represents the primary food energy source for the world's ecosystems. Human appropriation of net primary production, apart from leaving less for other species to use, alters the composition of the atmosphere, levels of biodiversity, energy flows within food webs and the provision of important ecosystem services. Here we present a global map showing the amount of net primary production required by humans and compare it to the total amount generated on the landscape. We then derive a spatial balance sheet of net primary production `supply' and `demand' for the world. We show that human appropriation of net primary production varies spatially from almost zero to many times the local primary production. These analyses reveal the uneven footprint of human consumption and related environmental impacts, indicate the degree to which human populations depend on net primary production `imports' and suggest policy options for slowing future growth of human appropriation of net primary production.

  9. Valuing ecosystem services. A shadow price for net primary production

    International Nuclear Information System (INIS)

    Richmond, Amy; Kaufmann, Robert K.; Myneni, Ranga B.

    2007-01-01

    We analyze the contribution of ecosystem services to GDP and use this contribution to calculate an empirical price for ecosystem services. Net primary production is used as a proxy for ecosystem services and, along with capital and labor, is used to estimate a Cobb Douglas production function from an international panel. A positive output elasticity for net primary production probably measures both marketed and nonmarketed contributions of ecosystems services. The production function is used to calculate the marginal product of net primary production, which is the shadow price for ecosystem services. The shadow price generally is greatest for developed nations, which have larger technical scalars and use less net primary production per unit output. The rate of technical substitution indicates that the quantity of capital needed to replace a unit of net primary production tends to increase with economic development, and this rate of replacement may ultimately constrain economic growth. (author)

  10. Primary production in the Kattegat - past and present

    DEFF Research Database (Denmark)

    Richardson, K.; Heilmann, Jens

    1995-01-01

    data collected during the period 1984-1993 are calculated using the method employed in the 1950s. It is concluded that primary production in the Kattegat has increased from less than 100 g C m(-2) y(- 1) to about 200 g C m(-2) y(-1) since the 1950s. This increase is not seen during the winter months...... to be responses to increases in primary production. However, for most areas, there are insufficient data to demonstrate whether or not increases in primary production have actually occurred. In this study, the evidence for increased primary production in the Kattegat is examined by comparing primary production...... measurements from the 1950s and measurements made in the period 1984-1993. The methods employed during the two periods differ considerably. These differences and how they may affect the validity of a comparison of the results from the studies carried out in two periods are addressed. The primary production...

  11. Methane Production by Seagrass Ecosystems in the Red Sea

    KAUST Repository

    Garcias Bonet, Neus

    2017-11-07

    Atmospheric methane (CH) is the second strongest greenhouse gas and it is emitted to the atmosphere naturally by different sources. It is crucial to define the dimension of these natural emissions in order to forecast changes in atmospheric CH mixing ratio in future scenarios. However, CH emissions by seagrass ecosystems in shallow marine coastal systems have been neglected although their global extension. Here we quantify the CH production rates of seagrass ecosystems in the Red Sea. We measured changes in CH concentration and its isotopic signature by cavity ring-down spectroscopy on chambers containing sediment and plants. We detected CH production in all the seagrass stations with an average rate of 85.09 ± 27.80 μmol CH m d. Our results show that there is no seasonal or daily pattern in the CH production rates by seagrass ecosystems in the Red Sea. Taking in account the range of global estimates for seagrass coverage and the average seagrass CH production, the global CH production and emission by seagrass ecosystems could range from 0.09 to 2.7 Tg yr. Because CH emission by seagrass ecosystems had not been included in previous global CH budgets, our estimate would increase the contribution of marine global emissions, hitherto estimated at 9.1 Tg yr, by about 30%. Thus, the potential contribution of seagrass ecosystems to marine CH emissions provides sufficient evidence of the relevance of these fluxes as to include seagrass ecosystems in future assessments of the global CH budgets.

  12. Methane Production by Seagrass Ecosystems in the Red Sea

    KAUST Repository

    Garcias Bonet, Neus; Duarte, Carlos M.

    2017-01-01

    Atmospheric methane (CH) is the second strongest greenhouse gas and it is emitted to the atmosphere naturally by different sources. It is crucial to define the dimension of these natural emissions in order to forecast changes in atmospheric CH mixing ratio in future scenarios. However, CH emissions by seagrass ecosystems in shallow marine coastal systems have been neglected although their global extension. Here we quantify the CH production rates of seagrass ecosystems in the Red Sea. We measured changes in CH concentration and its isotopic signature by cavity ring-down spectroscopy on chambers containing sediment and plants. We detected CH production in all the seagrass stations with an average rate of 85.09 ± 27.80 μmol CH m d. Our results show that there is no seasonal or daily pattern in the CH production rates by seagrass ecosystems in the Red Sea. Taking in account the range of global estimates for seagrass coverage and the average seagrass CH production, the global CH production and emission by seagrass ecosystems could range from 0.09 to 2.7 Tg yr. Because CH emission by seagrass ecosystems had not been included in previous global CH budgets, our estimate would increase the contribution of marine global emissions, hitherto estimated at 9.1 Tg yr, by about 30%. Thus, the potential contribution of seagrass ecosystems to marine CH emissions provides sufficient evidence of the relevance of these fluxes as to include seagrass ecosystems in future assessments of the global CH budgets.

  13. Climate change impacts on southern Ross Sea phytoplankton composition, productivity, and export

    Science.gov (United States)

    Kaufman, Daniel E.; Friedrichs, Marjorie A. M.; Smith, Walker O.; Hofmann, Eileen E.; Dinniman, Michael S.; Hemmings, John C. P.

    2017-03-01

    The Ross Sea, a highly productive region of the Southern Ocean, is expected to experience warming during the next century along with reduced summer sea ice concentrations and shallower mixed layers. This study investigates how these climatic changes may alter phytoplankton assemblage composition, primary productivity, and export. Glider measurements are used to force a one-dimensional biogeochemical model, which includes diatoms and both solitary and colonial forms of Phaeocystis antarctica. Model performance is evaluated with glider observations, and experiments are conducted using projections of physical drivers for mid-21st and late-21st century. These scenarios reveal a 5% increase in primary productivity by midcentury and 14% by late-century and a proportional increase in carbon export, which remains approximately 18% of primary production. In addition, scenario results indicate diatom biomass increases while P. antarctica biomass decreases in the first half of the 21st century. In the second half of the century, diatom biomass remains relatively constant and P. antarctica biomass increases. Additional scenarios examining the independent contributions of expected future changes (temperature, mixed layer depth, irradiance, and surface iron inputs from melting ice) demonstrate that earlier availability of low light due to reduction of sea ice early in the growing season is the primary driver of productivity increases over the next century; shallower mixed layer depths additionally contribute to changes of assemblage composition and export. This study further demonstrates how glider data can be effectively used to facilitate model development and simulation, and inform interpretation of biogeochemical observations in the context of climate change.Plain Language SummaryUnderstanding how the global ocean responds to climate change requires knowing the natural behavior of individual regions and anticipating how future changes will affect each region differently. It

  14. Site-level evaluation of satellite-based global terrestrial gross primary production and net primary production monitoring.

    Science.gov (United States)

    David P. Turner; William D. Ritts; Warren B. Cohen; Thomas K. Maeirsperger; Stith T. Gower; Al A. Kirschbaum; Steve W. Runnings; Maosheng Zhaos; Steven C. Wofsy; Allison L. Dunn; Beverly E. Law; John L. Campbell; Walter C. Oechel; Hyo Jung Kwon; Tilden P. Meyers; Eric E. Small; Shirley A. Kurc; John A. Gamon

    2005-01-01

    Operational monitoring of global terrestrial gross primary production (GPP) and net primary production (NPP) is now underway using imagery from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling...

  15. Temperature, salinity, transmissivity, pressure, plankton, oxygen, nutrients, chlorophyll, and primary productivity data collected using CTD, bottle, and plankton net from the R/V Italica in the Ross Sea and Magellan Strait during 10th Italian Antarctic Expedition from 1994-11-13 to 1995-04-02 (NCEI Accession 0068289)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, transmissivity, pressure, plankton, oxygen, nutrients, chlorophyll, and primary productivity data collected using CTD, bottle, and plankton...

  16. Phytoplankton primary production in the world's estuarine-coastal ecosystems

    Science.gov (United States)

    Cloern, James E.; Foster, S.Q.; Kleckner, A.E.

    2014-01-01

    Estuaries are biogeochemical hot spots because they receive large inputs of nutrients and organic carbon from land and oceans to support high rates of metabolism and primary production. We synthesize published rates of annual phytoplankton primary production (APPP) in marine ecosystems influenced by connectivity to land – estuaries, bays, lagoons, fjords and inland seas. Review of the scientific literature produced a compilation of 1148 values of APPP derived from monthly incubation assays to measure carbon assimilation or oxygen production. The median value of median APPP measurements in 131 ecosystems is 185 and the mean is 252 g C m−2 yr−1, but the range is large: from −105 (net pelagic production in the Scheldt Estuary) to 1890 g C m−2 yr−1 (net phytoplankton production in Tamagawa Estuary). APPP varies up to 10-fold within ecosystems and 5-fold from year to year (but we only found eight APPP series longer than a decade so our knowledge of decadal-scale variability is limited). We use studies of individual places to build a conceptual model that integrates the mechanisms generating this large variability: nutrient supply, light limitation by turbidity, grazing by consumers, and physical processes (river inflow, ocean exchange, and inputs of heat, light and wind energy). We consider method as another source of variability because the compilation includes values derived from widely differing protocols. A simulation model shows that different methods reported in the literature can yield up to 3-fold variability depending on incubation protocols and methods for integrating measured rates over time and depth. Although attempts have been made to upscale measures of estuarine-coastal APPP, the empirical record is inadequate for yielding reliable global estimates. The record is deficient in three ways. First, it is highly biased by the large number of measurements made in northern Europe (particularly the Baltic region) and North America. Of the 1148

  17. Subsurface phytoplankton blooms fuel pelagic production in the North Sea

    DEFF Research Database (Denmark)

    Richardson, Kathrine; Visser, Andre; Pedersen, Flemming

    2000-01-01

    The seasonal phytoplankton biomass distribution pattern in stratified temperate marine waters is traditionally depicted as consisting of spring and autumn blooms. The energy source supporting pelagic summer production is believed to be the spring bloom. However, the spring bloom disappears...... relatively quickly from the water column and a large proportion of the material sedimenting to the bottom following the spring bloom is often comprised of intact phytoplankton cells. Thus, it is easy to argue that the spring bloom is fueling the energy demands of the benthos, but more difficult to argue...... convincingly that energy fixed during the spring bloom is fueling the pelagic production occurring during summer months. We argue here that periodic phytoplankton blooms are occurring during the summer in the North Sea at depths of >25 m and that the accumulated new production [sensu (Dugdale and Goering...

  18. Sea Surface Temperature Products and Research Associated with GHRSST

    Science.gov (United States)

    Kaiser-Weiss, Andrea K.; Minnett, Peter J.; Kaplan, Alexey; Wick, Gary A.; Castro, Sandra; Llewellyn-Jones, David; Merchant, Chris; LeBorgne, Pierre; Beggs, Helen; Donlon, Craig J.

    2012-03-01

    GHRSST serves its user community through the specification of operational Sea Surface Temperature (SST) products (Level 2, Level 3 and Level 4) based on international consensus. Providers of SST data from individual satellites create and deliver GHRSST-compliant near-real time products to a global GHRSST data assembly centre and a long-term stewardship facility. The GHRSST-compliant data include error estimates and supporting data for interpretation. Groups organised within GHRSST perform research on issues relevant to applying SST for air-sea exchange, for instance the Diurnal Variability Working Group (DVWG) analyses the evolution of the skin temperature. Other GHRSST groups concentrate on improving the SST estimate (Estimation and Retrievals Working Group EARWiG) and on improving the error characterization, (Satellite SST Validation Group, ST-VAL) and on improving the methods for SST analysis (Inter-Comparison Technical Advisory Group, IC-TAG). In this presentation we cover the data products and the scientific activities associated with GHRSST which might be relevant for investigating ocean-atmosphere interactions.

  19. Estimation of austral summer net community production in the Amundsen Sea: Self-organizing map analysis approach

    Science.gov (United States)

    Park, K.; Hahm, D.; Lee, D. G.; Rhee, T. S.; Kim, H. C.

    2014-12-01

    The Amundsen Sea, Antarctica, has been known for one of the most susceptible region to the current climate change such as sea ice melting and sea surface temperature change. In the Southern Ocean, a predominant amount of primary production is occurring in the continental shelf region. Phytoplankton blooms take place during the austral summer due to the limited sunlit and sea ice cover. Thus, quantifying the variation of summer season net community production (NCP) in the Amundsen Sea is essential to analyze the influence of climate change to the variation of biogeochemical cycle in the Southern Ocean. During the past three years of 2011, 2012 and 2014 in austral summer, we have conducted underway observations of ΔO2/Ar and derived NCP of the Amundsen Sea. Despite the importance of NCP for understanding biological carbon cycle of the ocean, the observations are rather limited to see the spatio-temporal variation in the Amundsen Sea. Therefore, we applied self-organizing map (SOM) analysis to expand our observed data sets and estimate the NCP during the summer season. SOM analysis, a type of artificial neural network, has been proved to be a useful method for extracting and classifying features in geoscience. In oceanography, SOM has applied for the analysis of various properties of the seawater such as sea surface temperature, chlorophyll concentration, pCO2, and NCP. Especially it is useful to expand a spatial coverage of direct measurements or to estimate properties whose satellite observations are technically or spatially limited. In this study, we estimate summer season NCP and find a variables set which optimally delineates the NCP variation in the Amundsen Sea as well. Moreover, we attempt to analyze the interannual variation of the Amundsen Sea NCP by taking climatological factors into account for the SOM analysis.

  20. Towards uncertainty estimation for operational forecast products - a multi-model-ensemble approach for the North Sea and the Baltic Sea

    Science.gov (United States)

    Golbeck, Inga; Li, Xin; Janssen, Frank

    2014-05-01

    Several independent operational ocean models provide forecasts of the ocean state (e.g. sea level, temperature, salinity and ice cover) in the North Sea and the Baltic Sea on a daily basis. These forecasts are the primary source of information for a variety of information and emergency response systems used e.g. to issue sea level warnings or carry out oil drift forecast. The forecasts are of course highly valuable as such, but often suffer from a lack of information on their uncertainty. With the aim of augmenting the existing operational ocean forecasts in the North Sea and the Baltic Sea by a measure of uncertainty a multi-model-ensemble (MME) system for sea surface temperature (SST), sea surface salinity (SSS) and water transports has been set up in the framework of the MyOcean-2 project. Members of MyOcean-2, the NOOS² and HIROMB/BOOS³ communities provide 48h-forecasts serving as inputs. Different variables are processed separately due to their different physical characteristics. Based on the so far collected daily MME products of SST and SSS, a statistical method, Empirical Orthogonal Function (EOF) analysis is applied to assess their spatial and temporal variability. For sea surface currents, progressive vector diagrams at specific points are consulted to estimate the performance of the circulation models especially in hydrodynamic important areas, e.g. inflow/outflow of the Baltic Sea, Norwegian trench and English Channel. For further versions of the MME system, it is planned to extend the MME to other variables like e.g. sea level, ocean currents or ice cover based on the needs of the model providers and their customers. It is also planned to include in-situ data to augment the uncertainty information and for validation purposes. Additionally, weighting methods will be implemented into the MME system to develop more complex uncertainty measures. The methodology used to create the MME will be outlined and different ensemble products will be presented. In

  1. Unintegrated sea quark at small x and vector boson production

    CERN Document Server

    Hautmann, F; Jung, H

    2012-01-01

    Parton-shower event generators that go beyond the collinear-ordering approximation at small x have so far included only gluon and valence quark channels at transverse momentum dependent level. In this contribution we provide a denition of a transverse momentum depend (TMD) sea quark distribution valid in the small x region, which is based on the TMD gluon-to-quark splitting function. As an example process we consider vector boson production in the forward direction of one of the protons. The qq ! Z matrix element (with one o-shell quark) is calculated in an explicit gauge invariant way, making use of high energy factorization.

  2. Fission product release into the primary coolant

    International Nuclear Information System (INIS)

    Apperson, C.E.

    1977-01-01

    The analytic evaluation of steady state primary coolant activity is discussed. The reported calculations account for temperature dependent fuel failure in two particle types and arbitrary radioactive decay chains. A matrix operator technique implemented in the SUVIUS code is used to solve the simultaneous equations. Results are compared with General Atomic Company's published results

  3. A review of ocean chlorophyll algorithms and primary production models

    Science.gov (United States)

    Li, Jingwen; Zhou, Song; Lv, Nan

    2015-12-01

    This paper mainly introduces the five ocean chlorophyll concentration inversion algorithm and 3 main models for computing ocean primary production based on ocean chlorophyll concentration. Through the comparison of five ocean chlorophyll inversion algorithm, sums up the advantages and disadvantages of these algorithm,and briefly analyzes the trend of ocean primary production model.

  4. Chemical phenomena in primary titanium production

    CSIR Research Space (South Africa)

    van Vuuren, DS

    2011-01-01

    Full Text Available TiO2 $ 490m p.a. $ 2500 p.a. Pigment Production ~20 kt TiO2 5100 kt TiO2 $ 37m p.a. $ 10000 m.p.a. Sponge Production Nil 125 kt p.a. Ti $ 1250 m.p.a. Ingot Production Nil 145 kt p.a. Ti $ 2600 m.p.a. Mill Products Nil ~90 kt p.a. Ti $ 4500 m... Museum Photo courtesy of the Kyushu National Museum http://web-japan.org/nipponia/nipponia38/en/travel/travel03.html V AL U E TiCl4 TiO2 Sponge Powder M2TiF6 Ingot INC R EAS ING COS T PRECURSOR REDUCTANT PRODUCT...

  5. Dissolved lipid production in the Northern Adriatic (Mediterranean) in response to sea surface warmin

    Science.gov (United States)

    Gasparovic, Blazenka; Novak, Tihana; Godrijan, Jelena; Mlakar, Marina; MAric, Daniela; Djakovac, Tamara

    2017-04-01

    Marine dissolved organic matter (OM) represents one of the largest active pools of organic carbon in the global carbon cycle. Oceans and seas are responsible for half of global primary production. Ocean warming caused by climate change is already starting to impact the marine life that necessary will have impact on ocean productivity. The partition of OM production by phytoplankton (major OM producer in seas and ocens) in the conditions of rising temperatures may considerably change. This has implications for the export of organic matter from the photic zone. In this study, we set out to see how annual temperature changes between 10 and 30 C in the Northern Adriatic (Mediterranean) affect production of DOM and particularly dissolved lipids and lipid classes. We have sampled at two stations being oligotrophic and mesotrophic where we expected different system reaction to temperature changes. In addition, we performed microcosm incubations covering temperature range of the NA with nutrient amendments to test whether changes in the available nutrients would reflect those of dissolved OM in the NA. We have selected to work with extracellular OM produced during growth of diatom Chaetoceros curvisetus cultures according to the criteria that genera Chaetoceros are important component of the phytoplankton in the NA and are often among bloom-forming taxa. Details on the dissolved lipid and lipid classes production as plankton responce to rising temperature will be discussed.

  6. A consistent high primary production and chlorophyll-a maximum in a narrow strait – effects of hydraulic control

    DEFF Research Database (Denmark)

    Lund-Hansen, Lars Chresten; Nielsen, Morten Holtegaard; Bruhn, Annette

    2008-01-01

    and the North Sea. The time-series were supplemented with Scan Fish transects — a towed CTD, ADCP measurements, and nutrient data. There is a significant maximum in primary production (mg C m− 2 day− 1) in central LB, which is 30% higher than outside the LB region. Chl-a concentrations are 30% higher in central...

  7. Interannual Variation in Phytoplankton Primary Production at a Global Scale

    Science.gov (United States)

    Rousseaux, Cecile Severine; Gregg, Watson W.

    2013-01-01

    We used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of four phytoplankton groups to the total primary production. First, we assessed the contribution of each phytoplankton groups to the total primary production at a global scale for the period 1998-2011. Globally, diatoms contributed the most to the total phytoplankton production ((is)approximately 50%, the equivalent of 20 PgC·y1). Coccolithophores and chlorophytes each contributed approximately 20% ((is) approximately 7 PgC·y1) of the total primary production and cyanobacteria represented about 10% ((is) approximately 4 PgC·y1) of the total primary production. Primary production by diatoms was highest in the high latitudes ((is) greater than 40 deg) and in major upwelling systems (Equatorial Pacific and Benguela system). We then assessed interannual variability of this group-specific primary production over the period 1998-2011. Globally the annual relative contribution of each phytoplankton groups to the total primary production varied by maximum 4% (1-2 PgC·y1). We assessed the effects of climate variability on group-specific primary production using global (i.e., Multivariate El Niño Index, MEI) and "regional" climate indices (e.g., Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability as indicated by significant correlation (p (is) less than 0.05) between the MEI and the group-specific primary production from all groups except coccolithophores. In the Atlantic, climate variability as indicated by NAO was significantly correlated to the primary production of 2 out of the 4 groups in the North Central Atlantic (diatoms/cyanobacteria) and in the North Atlantic (chlorophytes and coccolithophores). We found that climate variability as indicated by SAM had only a limited effect

  8. On Tour... Primary Hardwood Processing, Products and Recycling Unit

    Science.gov (United States)

    Philip A. Araman; Daniel L. Schmoldt

    1995-01-01

    Housed within the Department of Wood Science and Forest Products at Virginia Polytechnic Institute is a three-person USDA Forest Service research work unit (with one vacancy) devoted to hardwood processing and recycling research. Phil Araman is the project leader of this truly unique and productive unit, titled ãPrimary Hardwood Processing, Products and Recycling.ä The...

  9. Seasonal distribution of dissolved inorganic carbon and net community production on the Bering Sea shelf

    Directory of Open Access Journals (Sweden)

    J. T. Mathis

    2010-05-01

    Full Text Available In order to assess the current state of net community production (NCP in the southeastern Bering Sea, we measured the spatio-temporal distribution and controls on dissolved inorganic carbon (DIC concentrations in spring and summer of 2008 across six shelf domains defined by differing biogeochemical characteristics. DIC concentrations were tightly coupled to salinity in spring and ranged from ~1900 μmoles kg−1 over the inner shelf to ~2400 μmoles kg−1 in the deeper waters of the Bering Sea. In summer, DIC concentrations were lower due to dilution from sea ice melt, terrestrial inputs, and primary production. Concentrations were found to be as low ~1800 μmoles kg−1 over the inner shelf. We found that DIC concentrations were drawn down 30–150 μmoles kg−1 in the upper 30 m of the water column due to primary production and calcium carbonate formation between the spring and summer occupations. Using the seasonal drawdown of DIC, estimated rates of NCP on the inner, middle, and outer shelf averaged 28 ± 9 mmoles C m−2 d−1. However, higher rates of NCP (40–47 mmoles C m−2 d−1 were observed in the "Green Belt" where the greatest confluence of nutrient-rich basin water and iron-rich shelf water occurs. We estimated that in 2008, total NCP across the shelf was on the order of ~96 Tg C yr−1. Due to the paucity of consistent, comparable productivity data, it is impossible at this time to quantify whether the system is becoming more or less productive. However, as changing climate continues to modify the character of the Bering Sea, we have shown that NCP can be an important indicator of how the ecosystem is functioning.

  10. Sea Spray Aerosol Production over the North Atlantic

    Science.gov (United States)

    Bates, T. S.; Quinn, P.

    2017-12-01

    Breaking waves on the ocean surface generate air bubbles that scavenge organic matter from the surrounding seawater. When injected into the atmosphere, these bubbles burst, yielding sea spray aerosol (SSA), a mixture of organic and inorganic compounds with the organic matter enriched relative to seawater. SSA mass is well documented as the dominant component of aerosol light scattering over the remote oceans. The importance of SSA number to marine boundary layer cloud condensation nuclei (CCN) is much less certain. During the Western Atlantic Climate Study cruises (WACS-1 - August 2012 and WACS-2 - May-June 2014) and the North Atlantic Aerosols and Marine Ecosystem Study cruises (NAAMES-1 - November 2015, NAAMES-2 - May 2016, and NAAMES-3 - September 2017), we generated and measured freshly emitted SSA using the Sea Sweep SSA generator. During the 2017 cruise we also generated SSA with a Marine Aerosol Reference Tank (MART). Using the data generated on these 5 cruises and a large database of remote marine boundary layer aerosol measurements we will address three questions during this presentation: 1 - Do phytoplankton ecosystems affect the organic enrichment of freshly emitted SSA?, 2 - Do plankton ecosystems affect the number production flux of SSA?, and 3 - Is SSA a significant source of atmospheric CCN?

  11. Hydrate prevention in petroleum production sub sea system

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Paula L.F.; Rocha, Humberto A.R. [Universidade Estacio de Sa (UNESA), Rio de Janeiro, RJ (Brazil); Rodrigues, Antonio P. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-07-01

    In spite of the merits of the several hydrate prevention techniques used nowadays, such as: chemical product injection for inhibition and use of thick thermal insulate lines; hydrates per times happen and they are responsible for considerable production losses. Depressurization techniques can be used so much for prevention as in the remediation. Some hydrate removal techniques need a rig or vessel, resources not readily available and with high cost, reason that limits such techniques just for remediation and not for prevention. In the present work it is proposed and described an innovative depressurization system, remote and resident, for hydrate prevention and removal, applicable as for individual sub sea wells as for grouped wells by manifold. Based on low cost jet pumps, without movable parts and with a high reliability, this technique allows hydrate prevention or remediation in a fast and remote way, operated from the production unit. The power fluid line and fluid return line can be integrated in the same umbilical or annulus line structure, without significant increase in the construction costs and installation. It is not necessary to wait for expensive resource mobilization, sometimes not available quickly, such as: vessels or rigs. It still reduces the chemical product consumption and permits to depressurized stopped lines. Other additional advantage, depressurization procedure can be used in the well starting, removing fluid until riser emptying. (author)

  12. Britain's North Sea oil and gas production: a critical review

    International Nuclear Information System (INIS)

    Odell, P.R.

    1996-01-01

    The size and longevity of Britain's offshore hydrocarbons resources have been underestimated. Gas reserves were seriously under-exploited for almost 20 years from the late 1960s, given a belief that gas should be used only as a premium fuel and in the context of an uncompetitive market. Oil reserves' development and production has suffered from time to time from inappropriate politico-economic conditions. Nevertheless, offshore oil and gas has come to dominate the UK's energy production over the past 20 years and currently accounts for 85% of the country's total energy output. Fears for resources' exhaustion remain unjustified, as the industry continues to replace oil and gas reserves used each year. The North Sea is still not comprehensively explored: the continuation of the process will enable oil production to remain at high levels and that of gas to expand further. Supplementary output from the new west of Shetland province will become progressively more important after 2000. But continued intensive production overall depends on the maintenance of attractive politico-economic conditions and on present oil prices. It also requires the European gas market to remain firm but, ironically, the planned flow of UK gas to the mainland constitutes a threat to this condition. (Author)

  13. Primary energy sources for hydrogen production

    International Nuclear Information System (INIS)

    Hassmann, K.; Kuehne, H.M.

    1993-01-01

    The costs for hydrogen production through water electrolysis are estimated, assuming the electricity is produced from solar, hydro-, fossil, or nuclear power. The costs for hydrogen end-use in the power generation, heat and transportation sectors are also calculated, based on a state of the art technology and a more advanced technology expected to represent the state by the year 2010. The costs for hydrogen utilization (without energy taxes) are shown to be higher than current prices for fossil fuels (including taxes). Without restrictions imposed on fossil fuel consumption, hydrogen shall not gain a significant market share in either of the cases discussed. 2 figs., 3 tabs., 4 refs

  14. Work Environment and Productivity among Primary School Teachers ...

    African Journals Online (AJOL)

    User

    International Multidisciplinary Journal, Ethiopia. Vol. 5 (5), Serial No. ... work environment of Nigeria primary school teachers to greater productivity ... changes on the structure and curriculum, recommend and prescribed teaching methods and ...

  15. UV radiation and primary production in the Antarctic waters

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Krishnakumari, L.; Bhattathiri, P.M.A.; Chandramohan, D.

    at 683 nm), scalar irradiance (photosynthetically active radiation (PAR), computed primary production (pp), diffuse attenuation coefficient, and UVB (308 and 320 nm) and UVA (340 and 380 nm) radiation and ocean temperature all measured as a function...

  16. HANPP Collection: Global Patterns in Net Primary Productivity (NPP)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Net Primary Productivity (NPP) portion of the HANPP Collection maps the net amount of solar energy converted to plant organic matter through...

  17. Bacterial Standing Stock, Activity, and Carbon Production during Formation and Growth of Sea Ice in the Weddell Sea, Antarctica †

    OpenAIRE

    Grossmann, Sönnke; Dieckmann, Gerhard S.

    1994-01-01

    Bacterial response to formation and growth of sea ice was investigated during autumn in the northeastern Weddell Sea. Changes in standing stock, activity, and carbon production of bacteria were determined in successive stages of ice development. During initial ice formation, concentrations of bacterial cells, in the order of 1 × 108 to 3 × 108 liter-1, were not enhanced within the ice matrix. This suggests that physical enrichment of bacteria by ice crystals is not effective. Due to low conce...

  18. Do Offshore Wind Farms Influence Marine Primary Production?

    Science.gov (United States)

    Tweddle, J. F.; Murray, R. B. O.; Gubbins, M.; Scott, B. E.

    2016-02-01

    Primary producers (phytoplankton) form the basis of marine food-webs, supporting production of higher trophic levels, and act as a sink of CO2. We considered the impact of proposed large scale offshore wind farms in moderately deep waters (> 45 m) off the east coast of Scotland on rates of primary production. A 2 stage modelling process was used, employing state-of-the-art 3-D hydrographic models with the ability to capture flow at the spatial resolution of 10 m combined with 1-D vertical modelling using 7 years of local forcing data. Through influencing the strength of stratification via changes in current flow, large (100 m) modelled wind turbine foundations had a significant effect on primary producers, consistently reducing total annual primary production, although within the range of natural interannual variability. The percentage reduction was largest over submarine banks less than 54 m in depth, and was outside the range of natural interannual variability. Smaller (10 m) turbine foundations had no discernible effect on total annual primary production. The results indicate that smaller foundations should be favored as a mitigation measure, in terms of effects on primary production, and this type of analysis should be considered within sectoral planning and licensing processes for future renewable energy developments.

  19. A transnational and holistic breeding approach is needed for sustainable wheat production in the Baltic Sea region.

    Science.gov (United States)

    Chawade, Aakash; Armoniené, Rita; Berg, Gunilla; Brazauskas, Gintaras; Frostgård, Gunilla; Geleta, Mulatu; Gorash, Andrii; Henriksson, Tina; Himanen, Kristiina; Ingver, Anne; Johansson, Eva; Jørgensen, Lise Nistrup; Koppel, Mati; Koppel, Reine; Makela, Pirjo; Ortiz, Rodomiro; Podyma, Wieslaw; Roitsch, Thomas; Ronis, Antanas; Svensson, Jan T; Vallenback, Pernilla; Weih, Martin

    2018-03-14

    The Baltic Sea is one of the largest brackish water bodies in the world. Eutrophication is a major concern in the Baltic Sea due to the leakage of nutrients to the sea with agriculture being the primary source. Wheat (Triticum aestivum L.) is the most widely grown crop in the countries surrounding the Baltic Sea and thus promoting sustainable agriculture practices for wheat cultivation will have a major impact on reducing pollution in the Baltic Sea. This approach requires identifying and addressing key challenges for sustainable wheat production in the region. Implementing new technologies for climate-friendly breeding and digital farming across all surrounding countries should promote sustainable intensification of agriculture in the region. In this review, we highlight major challenges for wheat cultivation in the Baltic Sea region and discuss various solutions integrating transnational collaboration for pre-breeding and technology sharing to accelerate development of low input wheat cultivars with improved host plant resistance to pathogen and enhanced adaptability to the changing climate. © 2018 The Authors. Physiologia Plantarum published by John Wiley & Sons Ltd on behalf of Scandinavian Plant Physiology Society.

  20. Production and Utilization of Core-Textbooks in Primary School ...

    African Journals Online (AJOL)

    Production and Utilization of Core-Textbooks in Primary School System: Impact of Authors and Publishers. ... These stakeholders have specific roles to play and cannot operate in isolation. The study, therefore investigated the influence of authorship and publishers on core textbook production and utilisation in Oyo State ...

  1. MODIS-derived terrestrial primary production [chapter 28

    Science.gov (United States)

    Maosheng Zhao; Steven Running; Faith Ann Heinsch; Ramakrishna Nemani

    2011-01-01

    Temporal and spatial changes in terrestrial biological productivity have a large impact on humankind because terrestrial ecosystems not only create environments suitable for human habitation, but also provide materials essential for survival, such as food, fiber and fuel. A recent study estimated that consumption of terrestrial net primary production (NPP; a list of...

  2. Primary productivity in nearshore waters of Thal, Maharashtra coast

    Digital Repository Service at National Institute of Oceanography (India)

    Varshney, P.K.; Nair, V.R.; Abidi, S.A.H.

    Primary productivity off Thal, Maharashtra, India was evaluated at 3 stations during Feb. 1980 to Jan. 1981. The area was quite turbid and the euphotic zone never exceeded 2.5 m. Column production ranged from 0.69 to 605.21 mg C.m/2.d/2 (av. 78.2 mg...

  3. A Triple P review of the feasibility of sustainable offshore seaweed production in the North Sea

    NARCIS (Netherlands)

    Burg, van den S.W.K.; Stuiver, M.; Veenstra, F.A.; Bikker, P.; Lopez Contreras, A.M.; Palstra, A.P.; Broeze, J.; Jansen, H.M.; Jak, R.G.; Gerritsen, A.L.; Harmsen, P.F.H.; Kals, J.; Blanco Garcia, A.; Brandenburg, W.A.; Krimpen, van M.M.; Duijn, van A.P.; Mulder, W.J.; Raamsdonk, van L.W.D.

    2013-01-01

    This study focused on the potential of seaweed, cultivated in the North Sea, as a sustainable and profitable resource for feed and non-food applications. Seawood production can take place as part of multi-use platforms at sea (MUPS). A review of the state-of-the-art in seaweed production and its

  4. Bose-type distribution and primary cosmic ray nucleon spectrum from sea-level muon spectrum

    CERN Document Server

    Bhattacharya, D P; Roychowdhury, R K

    1976-01-01

    The recent CERN Intersecting Storage Ring cross section data on the p +p to pi /sup +or-/+X inclusive reactions have been analysed using the Bose-type distribution of the form E(d/sup 3/ sigma )/(d/sup 3/p)=(Axs /sup 1/2/)/(exp( epsilon ( lambda )/T)-1) proposed by Hoang (1973). This formula has been used to derive the cosmic ray primary nucleon spectrum from the sea-level muon spectrum. It is found that the primary spectrum obeys the following relation: N(E/sub p/)dE/sub p /=2.06E/sub p//sup -2.64/dE/sub p/. The result has been compared with the recent experimental data and theoretical predictions given by different authors. (11 refs).

  5. Bulk and export production fluxes from sediment traps in the Gulf of Aqaba, north Red Sea

    Science.gov (United States)

    Torfstein, A.; Kienast, S.; Shaked, Y.

    2016-12-01

    Real time observations of the dynamics between dust input, primary production, and export production in deep oligotrophic waters are extremely rare. This is especially true in the context of the direct response and lag time between nutrient supply (e.g., dust), the oceanic biogeochemical response and the signal transfer from the water to sedimentary record. Here, we present the first direct measurments of bulk and export production fluxes in the deep oligotrophic Gulf of Aqaba (GOA), northern Red Sea, located between the hyper-arid Sahara and Arabia Deserts. This study is based on a coupled sediment trap array that provides daily- and monthly- resolution since January 2014. This coupled configuration allows for a unique collection of marine particulates, whereby the annual and seasonal patterns can be evaluated in the context of discrete (daily-timescale) events such as abrupt dust storms, floods and biological blooms. The marine organic C and N fluxes range annually between 0.02-0.25 and 0.001-0.1 g d-1 m-2, respectively. Both show a sharp decay with depth, corresponding to the "Martin curve" (Martin et al., 1987, Deep-Sea Research, 34, 267-285). Importantly, the daily-resolution sampling provides insights to the seasonal increase in export production during the winter and early spring. Rather than a smooth seasonal cycle, this increase is driven by only very few short events, lasting no more than a few days, during which export production increases by an order of magnitude above the baseline. Yet, the nature of these export production "spikes" is non-unique because they reflect different "trigger" events such as dust storms or water column mixing. Accordingly, we present a quantitative evaluation of the observations in the context of coeval dust flux records and the physical and chemical configuration of the GOA over the time of sampling period, and present and quantitative mass balance of particle fluxes in this deep yet land-locked marine setting.

  6. Cdc42 controls primary mesenchyme cell morphogenesis in the sea urchin embryo.

    Science.gov (United States)

    Sepúlveda-Ramírez, Silvia P; Toledo-Jacobo, Leslie; Henson, John H; Shuster, Charles B

    2018-05-15

    In the sea urchin embryo, gastrulation is characterized by the ingression and directed cell migration of primary mesenchyme cells (PMCs), as well as the primary invagination and convergent extension of the endomesoderm. Like all cell shape changes, individual and collective cell motility is orchestrated by Rho family GTPases and their modulation of the actomyosin cytoskeleton. And while endomesoderm specification has been intensively studied in echinoids, much less is known about the proximate regulators driving cell motility. Toward these ends, we employed anti-sense morpholinos, mutant alleles and pharmacological inhibitors to assess the role of Cdc42 during sea urchin gastrulation. While inhibition of Cdc42 expression or activity had only mild effects on PMC ingression, PMC migration, alignment and skeletogenesis were disrupted in the absence of Cdc42, as well as elongation of the archenteron. PMC migration and patterning of the larval skeleton relies on the extension of filopodia, and Cdc42 was required for filopodia in vivo as well as in cultured PMCs. Lastly, filopodial extension required both Arp2/3 and formin actin-nucleating factors, supporting models of filopodial nucleation observed in other systems. Together, these results suggest that Cdc42 plays essential roles during PMC cell motility and organogenesis. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Impact of equatorial and continental airflow on primary greenhouse gases in the northern South China Sea

    International Nuclear Information System (INIS)

    Ou-Yang, Chang-Feng; Yen, Ming-Cheng; Lin, Neng-Huei; Lin, Tang-Huang; Wang, Jia-Lin; Schnell, Russell C; Lang, Patricia M; Chantara, Somporn

    2015-01-01

    Four-year ground-level measurements of the two primary greenhouse gases (carbon dioxide (CO 2 ) and methane (CH 4 )) were conducted at Dongsha Island (DSI), situated in the northern South China Sea (SCS), from March 2010 to February 2014. Their mean mixing ratios are calculated to be 396.3 ± 5.4 ppm and 1863.6 ± 50.5 ppb, with an annual growth rate of +2.19 ± 0.5 ppm yr –1 and +4.70 ± 4.4 ppb yr –1 for CO 2 and CH 4 , respectively, over the study period. Our results suggest that the Asian continental outflow driven by the winter northeast monsoon could have brought air pollutants into the northern SCS, as denoted by significantly elevated levels of 6.5 ppm for CO 2 and 59.6 ppb for CH 4 , which are greater than the marine boundary layer references at Cape Kumukahi (KUM) in the tropical northern Pacific in January. By contrast, the summertime CH 4 at DSI is shown to be lower than that at KUM by 19.7 ppb, whereas CO 2 is shown to have no differences (<0.42 ppm in July) during the same period. Positive biases of the Greenhouse Gases Observing Satellite (GOSAT) L4B data against the surface measurements are estimated to be 2.4 ± 3.4 ppm for CO 2 and 43.2 ± 36.8 ppb for CH 4 . The satellite products retrieved from the GOSAT showed the effects of anthropogenic emissions and vegetative sinks on land on a vertical profiling basis. The prevailing southeasterly winds originating from as far south as the equator or Southern Hemisphere pass through the lower troposphere in the northern SCS, forming a tunnel of relatively clean air masses as indicated by the low CH 4 mixing ratios observed on the DSI in summer. (letter)

  8. HANPP Collection: Human Appropriation of Net Primary Productivity (HANPP) by Country and Product

    Data.gov (United States)

    National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) by Country and Product portion of the HANPP Collection contains tabular data on carbon-equivalents of...

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

    Science.gov (United States)

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

    2017-11-01

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

  10. The 2010 spring drought reduced primary productivity in southwestern China

    International Nuclear Information System (INIS)

    Zhang Li; Li Jing; Xiao Jingfeng; Wang Kun; Lei Liping; Guo Huadong

    2012-01-01

    Many parts of the world experience frequent and severe droughts. Summer drought can significantly reduce primary productivity and carbon sequestration capacity. The impacts of spring droughts, however, have received much less attention. A severe and sustained spring drought occurred in southwestern China in 2010. Here we examine the influence of this spring drought on the primary productivity of terrestrial ecosystems using data on climate, vegetation greenness and productivity. We first assess the spatial extent, duration and severity of the drought using precipitation data and the Palmer drought severity index. We then examine the impacts of the drought on terrestrial ecosystems using satellite data for the period 2000–2010. Our results show that the spring drought substantially reduced the enhanced vegetation index (EVI) and gross primary productivity (GPP) during spring 2010 (March–May). Both EVI and GPP also substantially declined in the summer and did not fully recover from the drought stress until August. The drought reduced regional annual GPP and net primary productivity (NPP) in 2010 by 65 and 46 Tg C yr −1 , respectively. Both annual GPP and NPP in 2010 were the lowest over the period 2000–2010. The negative effects of the drought on annual primary productivity were partly offset by the remarkably high productivity in August and September caused by the exceptionally wet conditions in late summer and early fall and the farming practices adopted to mitigate drought effects. Our results show that, like summer droughts, spring droughts can also have significant impacts on vegetation productivity and terrestrial carbon cycling. (letter)

  11. Secondary production at the Polar Front, Barents Sea, August 2007

    Science.gov (United States)

    Basedow, Sünnje L.; Zhou, Meng; Tande, Kurt S.

    2014-02-01

    To investigate spatial patterns of secondary production we sampled four core hydrographical regions of the Polar Front in the Barents Sea (Arctic Water, ArW; Polar Front Water, PFW; Atlantic Water, AtW; and Melt Water, MW) by towing an undulating instrument platform along a transect crossing the front from August 8-9, 2007. Sensors mounted on the platform provided data on the hydrography (CTD), fluorescence (Fluorometer, F) and zooplankton abundance in the size range between 0.1 and 30 mm (Laser Optical Plankton Counter, LOPC). These continuous, biophysical data with high-spatial resolution were supplemented by discrete water and zooplankton net samples at stations for sensor calibrations. After in depth quality assessments of the biophysical data, estimates were made of the vital rates based on biovolume spectrum theory. Five size groups were distinguished from the LOPC data: small (S), mainly Oithona spp. and the appendicularian Fritillaria sp.; medium (M), mainly Pseudocalanus spp. and Calanus spp. CI-CIII; large (L), mainly Calanus spp. CIV-CV; and extra large (XL and 2XL), juvenile and adult euphausids. Size groups were further divided based on transparency of organisms. Vital rates based on the biophysical in situ data in combination with biovolume spectrum theories agreed generally well with data from empirical and numerical models in the literature. ArW was characterised by subsurface maxima of chlorophyll a (chl a), and an estimated population growth of ca. 13 mg C m- 3 d- 1 for CI-CIII Calanus spp. and some older Pseudocalanus within the chl a maxima. Frontal waters were characterised by low chl a concentrations, but high abundances and production (around 1 g C m- 3 d- 1) of small copepods (Oithona spp.) and appendicularians (Fritillaria sp.). The estimated production of small-size zooplankton was an order of magnitude higher than the production of all other size groups combined, including large copepods. The high loss rates (- 166 to - 271 mg C m- 3 d- 1

  12. Benthic primary production and mineralization in a High Arctic Fjord

    DEFF Research Database (Denmark)

    Attard, Karl M.; Hancke, Kasper; Sejr, Mikael K.

    2016-01-01

    Coastal and shelf systems likely exert major influence on Arctic Ocean functioning, yet key ecosystem processes remain poorly quantified. We employed the aquatic eddy covariance (AEC) oxygen (O2) flux method to estimate benthic primary production and mineralization in a High Arctic Greenland fjord....... Seabed gross primary production (GPP) within the 40 m deep photic zone was highest at 10 m (29 mmol O2 m−2 d−1) and decreased to 5 mmol O2 m−2 d−1 at 40 m, while nighttime community respiration (CR) ranged from 11 to 25 mmol O2m−2 d−1. CR decreased to ~2.5 mmol O2m−2 d−1 at 80 m and remained constant...... with further depth. Fauna activity accounted for ~50% of the CR at depths ≤60 m but was primary production...

  13. Pigment Cell Differentiation in Sea Urchin Blastula-Derived Primary Cell Cultures

    Science.gov (United States)

    Ageenko, Natalya V.; Kiselev, Konstantin V.; Dmitrenok, Pavel S.; Odintsova, Nelly A.

    2014-01-01

    The quinone pigments of sea urchins, specifically echinochrome and spinochromes, are known for their effective antioxidant, antibacterial, antifungal, and antitumor activities. We developed in vitro technology for inducing pigment differentiation in cell culture. The intensification of the pigment differentiation was accompanied by a simultaneous decrease in cell proliferation. The number of pigment cells was two-fold higher in the cells cultivated in the coelomic fluids of injured sea urchins than in those intact. The possible roles of the specific components of the coelomic fluids in the pigment differentiation process and the quantitative measurement of the production of naphthoquinone pigments during cultivation were examined by MALDI and electrospray ionization mass spectrometry. Echinochrome A and spinochrome E were produced by the cultivated cells of the sand dollar Scaphechinus mirabilis in all tested media, while only spinochromes were found in the cultivated cells of another sea urchin, Strongylocentrotus intermedius. The expression of genes associated with the induction of pigment differentiation was increased in cells cultivated in the presence of shikimic acid, a precursor of naphthoquinone pigments. Our results should contribute to the development of new techniques in marine biotechnology, including the generation of cell cultures producing complex bioactive compounds with therapeutic potential. PMID:24979272

  14. Clinical productivity of primary care nurse practitioners in ambulatory settings.

    Science.gov (United States)

    Xue, Ying; Tuttle, Jane

    Nurse practitioners are increasingly being integrated into primary care delivery to help meet the growing demand for primary care. It is therefore important to understand nurse practitioners' productivity in primary care practice. We examined nurse practitioners' clinical productivity in regard to number of patients seen per week, whether they had a patient panel, and patient panel size. We further investigated practice characteristics associated with their clinical productivity. We conducted cross-sectional analysis of the 2012 National Sample Survey of Nurse Practitioners. The sample included full-time primary care nurse practitioners in ambulatory settings. Multivariable survey regression analyses were performed to examine the relationship between practice characteristics and nurse practitioners' clinical productivity. Primary care nurse practitioners in ambulatory settings saw an average of 80 patients per week (95% confidence interval [CI]: 79-82), and 64% of them had their own patient panel. The average patient panel size was 567 (95% CI: 522-612). Nurse practitioners who had their own patient panel spent a similar percent of time on patient care and documentation as those who did not. However, those with a patient panel were more likely to provide a range of clinical services to most patients. Nurse practitioners' clinical productivity was associated with several modifiable practice characteristics such as practice autonomy and billing and payment policies. The estimated number of patients seen in a typical week by nurse practitioners is comparable to that by primary care physicians reported in the literature. However, they had a significantly smaller patient panel. Nurse practitioners' clinical productivity can be further improved. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Sea surface temperature control of taxon specific phytoplankton production along an oligotrophic gradient in the Mediterranean Sea

    NARCIS (Netherlands)

    van de Poll, W.H.V.; Boute, P.G.; Rozema, P.D.; Buma, A.; Kulk, G.; Rijkenberg, M.J.

    2015-01-01

    The current study aimed to assess changes in phytoplankton composition and productivity along an oligotrophic gradient in relation to changes in sea surface temperature (SST). Phytoplankton pigments, nutrients, and physical water column properties were studied along a longitudinal transect in the

  16. Tracing anthropogenic inputs to production in the Seto Inland Sea, Japan - A stable isotope approach

    International Nuclear Information System (INIS)

    Miller, Todd W.; Omori, Koji; Hamaoka, Hideki; Shibata, Jun-ya; Hidejiro, Onishi

    2010-01-01

    The Seto Inland Sea (SIS) receives waste runoff from ∼24% of Japan's total population, yet it is also important in regional fisheries, recreation and commerce. During August 2006 we measured carbon and nitrogen stable isotopes of particulate organic matter (POM) and zooplankton across urban population gradients of the SIS. Results showed a consistent trend of increasing δ 15 N in POM and zooplankton from the western to eastern subsystems of the SIS, corresponding to increasing population load. Principal components analysis of environmental variables indicated high positive loadings of δ 15 N and δ 13 C with high chlorophyll-a and surface water temperatures, and negative loadings of low salinities related to inputs from large rivers and high urban development in the eastern SIS. Anthropogenic nitrogen was therefore readily integrated into the SIS food web from primary production to copepods, which are a critical food source for many commercially important fishes.

  17. Tracing anthropogenic inputs to production in the Seto Inland Sea, Japan--a stable isotope approach.

    Science.gov (United States)

    Miller, Todd W; Omori, Koji; Hamaoka, Hideki; Shibata, Jun-ya; Hidejiro, Onishi

    2010-10-01

    The Seto Inland Sea (SIS) receives waste runoff from ∼24% of Japan's total population, yet it is also important in regional fisheries, recreation and commerce. During August 2006 we measured carbon and nitrogen stable isotopes of particulate organic matter (POM) and zooplankton across urban population gradients of the SIS. Results showed a consistent trend of increasing δ(15)N in POM and zooplankton from the western to eastern subsystems of the SIS, corresponding to increasing population load. Principal components analysis of environmental variables indicated high positive loadings of δ(15)N and δ(13)C with high chlorophyll-a and surface water temperatures, and negative loadings of low salinities related to inputs from large rivers and high urban development in the eastern SIS. Anthropogenic nitrogen was therefore readily integrated into the SIS food web from primary production to copepods, which are a critical food source for many commercially important fishes. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Potential consequences of climate change for primary production and fish production in large marine ecosystems.

    Science.gov (United States)

    Blanchard, Julia L; Jennings, Simon; Holmes, Robert; Harle, James; Merino, Gorka; Allen, J Icarus; Holt, Jason; Dulvy, Nicholas K; Barange, Manuel

    2012-11-05

    Existing methods to predict the effects of climate change on the biomass and production of marine communities are predicated on modelling the interactions and dynamics of individual species, a very challenging approach when interactions and distributions are changing and little is known about the ecological mechanisms driving the responses of many species. An informative parallel approach is to develop size-based methods. These capture the properties of food webs that describe energy flux and production at a particular size, independent of species' ecology. We couple a physical-biogeochemical model with a dynamic, size-based food web model to predict the future effects of climate change on fish biomass and production in 11 large regional shelf seas, with and without fishing effects. Changes in potential fish production are shown to most strongly mirror changes in phytoplankton production. We project declines of 30-60% in potential fish production across some important areas of tropical shelf and upwelling seas, most notably in the eastern Indo-Pacific, the northern Humboldt and the North Canary Current. Conversely, in some areas of the high latitude shelf seas, the production of pelagic predators was projected to increase by 28-89%.

  19. Anthropogenic climate change has altered primary productivity in Lake Superior.

    Science.gov (United States)

    O'Beirne, M D; Werne, J P; Hecky, R E; Johnson, T C; Katsev, S; Reavie, E D

    2017-06-09

    Anthropogenic climate change has the potential to alter many facets of Earth's freshwater resources, especially lacustrine ecosystems. The effects of anthropogenic changes in Lake Superior, which is Earth's largest freshwater lake by area, are not well documented (spatially or temporally) and predicted future states in response to climate change vary. Here we show that Lake Superior experienced a slow, steady increase in production throughout the Holocene using (paleo)productivity proxies in lacustrine sediments to reconstruct past changes in primary production. Furthermore, data from the last century indicate a rapid increase in primary production, which we attribute to increasing surface water temperatures and longer seasonal stratification related to longer ice-free periods in Lake Superior due to anthropogenic climate warming. These observations demonstrate that anthropogenic effects have become a prominent influence on one of Earth's largest, most pristine lacustrine ecosystems.

  20. Seasonality of primary and secondary production in an Arctic river

    Science.gov (United States)

    Kendrick, M.; Huryn, A.; Deegan, L.

    2011-12-01

    Rivers and streams that freeze solid for 8-9 months each year provide excellent examples of the extreme seasonality of arctic habitats. The communities of organisms inhabiting these rivers must complete growth and development during summer, resulting in a rapid ramp-up and down of production over the short ice-free period. The effects of recent shifts in the timing of the spring thaw and autumn freeze-up on the duration and pattern of the period of active production are poorly understood. We are currently investigating: 1) the response of the biotic community of the Kuparuk River (Arctic Alaska) to shifts in the seasonality of the ice-free period, and 2) the community response to increases in phosphorous (P) supply anticipated as the volume of the permafrost active-layer increases in response to climate warming. Here algal production supports a 2-tier web of consumers. We tracked primary and secondary production from the spring thaw through mid-August in a reference reach and one receiving low-level P fertilization. Gross primary production/community respiration (GPP/R) ratios for both reaches were increasing through mid-July, with higher GPP/R in response to the P addition. Understanding the degree of synchrony between primary and secondary production in this Arctic river system will enhance further understanding of how shifts in seasonality affect trophic dynamics.

  1. Hemingway’s Internal Deviation from His Primary Norm in The Old Man and the Sea

    Directory of Open Access Journals (Sweden)

    Trisnowati Tanto

    2009-01-01

    Full Text Available Ernest Hemingway is well known for the use of short and simple sentences when writing his novels since he aims at ‘[getting] the most out of the least’. This sentence-simplicity style is Hemingway’s primary norm. The Old Man and the Sea is the perfect example of this. However, in this novel, he sometimes uses long, complex sentences to describe certain points, and this sentence-complexity style can be said to be Hemingway’s secondary norm. In this case, there is a deviation within Hemingway’s own style of writing – an internal deviation. The deviation is obviously done on purpose as a kind of distraction so as to make the readers aware of the special and important ‘message’ that Hemingway wants to convey. In this novel, the deviation is used to build the elements of suspense and foreshadowing in much detail.

  2. Nitrogenous nutrients and primary production in a tropical oceanic environment

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.; Devassy, V.P.

    Measurements of the concentrations of nitrogenous nutrients and primary production were made at 10 stations along 8 degrees N and 10 degrees N in the tropical oceanic Lakshadweep waters Inorganic nitrogen (NO3, NO2 and NH4) accounted for less than...

  3. Anoxic and oxic phototrophic primary production during the Precambrian

    DEFF Research Database (Denmark)

    Ebey-Honeycutt, Christina Marie; Bjerrum, Christian J.; Canfield, Donald Eugene

    2009-01-01

    of the mixed layer often lies above the base of the photic zone . Thus, an ecosystem model for the Precambrian should reflect the net primary production (NPP) of oxygenic phototrophs in the mixed layer and anoxygenic phototrophs below (NPPox and NPPred, respectively). Satelite data and a vertically generalized...

  4. Egg production of turbot, Scophthalmus maximus, in the Baltic Sea

    Science.gov (United States)

    Nissling, Anders; Florin, Ann-Britt; Thorsen, Anders; Bergström, Ulf

    2013-11-01

    In the brackish water Baltic Sea turbot spawn at ~ 6-9 psu along the coast and on offshore banks in ICES SD 24-29, with salinity influencing the reproductive success. The potential fecundity (the stock of vitellogenic oocytes in the pre-spawning ovary), egg size (diameter and dry weight of artificially fertilized 1-day-old eggs) and gonad dry weight were assessed for fish sampled in SD 25 and SD 28. Multiple regression analysis identified somatic weight, or total length in combination with Fulton's condition factor, as main predictors of fecundity and gonad dry weight with stage of maturity (oocyte packing density or leading cohort) as an additional predictor. For egg size, somatic weight was identified as main predictor while otolith weight (proxy for age) was an additional predictor. Univariate analysis using GLM revealed significantly higher fecundity and gonad dry weight for turbot from SD 28 (3378-3474 oocytes/g somatic weight) compared to those from SD 25 (2343 oocytes/g somatic weight), with no difference in egg size (1.05 ± 0.03 mm diameter and 46.8 ± 6.5 μg dry weight; mean ± sd). The difference in egg production matched egg survival probabilities in relation to salinity conditions suggesting selection for higher fecundity as a consequence of poorer reproductive success at lower salinities. This supports the hypothesis of higher size-specific fecundity towards the limit of the distribution of a species as an adaptation to harsher environmental conditions and lower offspring survival probabilities. Within SD 28 comparisons were made between two major fishing areas targeting spawning aggregations and a marine protected area without fishing. The outcome was inconclusive and is discussed with respect to potential fishery induced effects, effects of the salinity gradient, effects of specific year-classes, and effects of maturation status of sampled fish.

  5. 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.

    Planktonic foraminifera collected in sediment traps in the Arabian Sea during 1986 and 1987 responded to the southern Asian monsoon with changes in productivity, relative abundance of species and isotopic shell chemistry. Most species...

  6. Fission product behaviour in the primary circuit of an HTR

    International Nuclear Information System (INIS)

    Decken, C.B. von der; Iniotakis, N.

    1981-01-01

    The knowledge of fission product behaviour in the primary circuit of a High Temperature Reactor (HTR) is an essential requirement for the estimations of the availability of the reactor plant in normal operation, of the hazards to personnel during inspection and repair and of the potential danger to the environment from severe accidents. On the basis of the theoretical and experimental results obtained at the ''Institute for Reactor Components'' of the KFA Juelich /1/,/2/ the transport- and deposition behaviour of the fission- and activation products in the primary circuit of the PNP-500 reference plant has been investigated thoroughly. Special work had been done to quantify the uncertainties of the investigations and to calculate or estimate the dose rate level at different components of the primary cooling circuit. The contamination and the dose rate level in the inspection gap in the reactor pressure vessel is discussed in detail. For these investigations in particular the surface structure and the composition of the material, the chemical state of the fission products in the cooling gas, the composition of the cooling gas and the influence of dust on the transport- and deposition behaviour of the fission products have been taken into account. The investigations have been limited to the nuclides Ag-110m; Cs-134 and Cs-137

  7. Towards 250 m mapping of terrestrial primary productivity over Canada

    Science.gov (United States)

    Gonsamo, A.; Chen, J. M.

    2011-12-01

    Terrestrial ecosystems are an important part of the climate and global change systems. Their role in climate change and in the global carbon cycle is yet to be well understood. Dataset from satellite earth observation, coupled with numerical models provide the unique tools for monitoring the spatial and temporal dynamics of territorial carbon cycle. The Boreal Ecosystems Productivity Simulator (BEPS) is a remote sensing based approach to quantifying the terrestrial carbon cycle by that gross and net primary productivity (GPP and NPP) and terrestrial carbon sinks and sources expressed as net ecosystem productivity (NEP). We have currently implemented a scheme to map the GPP, NPP and NEP at 250 m for first time over Canada using BEPS model. This is supplemented by improved mapping of land cover and leaf area index (LAI) at 250 m over Canada from MODIS satellite dataset. The results from BEPS are compared with MODIS GPP product and further evaluated with estimated LAI from various sources to evaluate if the results capture the trend in amount of photosynthetic biomass distributions. Final evaluation will be to validate both BEPS and MODIS primary productivity estimates over the Fluxnet sites over Canada. The primary evaluation indicate that BEPS GPP estimates capture the over storey LAI variations over Canada very well compared to MODIS GPP estimates. There is a large offset of MODIS GPP, over-estimating the lower GPP value compared to BEPS GPP estimates. These variations will further be validated based on the measured values from the Fluxnet tower measurements over Canadian. The high resolution GPP (NPP) products at 250 m will further be used to scale the outputs between different ecosystem productivity models, in our case the Canadian carbon budget model of Canadian forest sector CBM-CFS) and the Integrated Terrestrial Ecosystem Carbon model (InTEC).

  8. Primary production in the Delta: Then and now

    Science.gov (United States)

    Cloern, James E.; Robinson, April; Richey, Amy; Grenier, Letitia; Grossinger, Robin; Boyer, Katharyn E.; Burau, Jon; Canuel, Elizabeth A.; DeGeorge, John F.; Drexler, Judith Z.; Enright, Chris; Howe, Emily R.; Kneib, Ronald; Mueller-Solger, Anke; Naiman, Robert J.; Pinckney, James L.; Safran, Samuel M.; Schoellhamer, David H.; Simenstad, Charles A.

    2016-01-01

    To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850). Here we describe an approach for using these metrics of land use change to: (1) produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2) convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3) use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

  9. Primary Production in the Delta: Then and Now

    Directory of Open Access Journals (Sweden)

    James E. Cloern

    2016-10-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss3art1To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850. Here we describe an approach for using these metrics of land use change to: (1 produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2 convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3 use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

  10. Mesopelagic Prokaryotes Alter Surface Phytoplankton Production during Simulated Deep Mixing Experiments in Eastern Mediterranean Sea Waters

    Directory of Open Access Journals (Sweden)

    Or Hazan

    2018-01-01

    Full Text Available Mesopelagic prokaryotes (archaea and bacteria, which are transported together with nutrient-rich intermediate-water to the surface layer by deep convection in the oceans (e.g., winter mixing, upwelling systems, can interact with surface microbial populations. This interaction can potentially affect production rates and biomass of surface microbial populations, and thus play an important role in the marine carbon cycle and oceanic carbon sequestration. The Eastern Mediterranean Sea (EMS is one of the most oligotrophic and warm systems in the world's oceans, with usually very shallow winter mixing (<200 m and lack of large-size spring algal blooms. In this study, we collected seawater (0–1,500 m in 9 different cruises at the open EMS during both the stratified and the mixed seasons. We show that the EMS is a highly oligotrophic regime, resulting in low autotrophic biomass and primary productivity and relatively high heterotrophic prokaryotic biomass and production. Further, we simulated deep water mixing in on-board microcosms using Levantine surface (LSW, ~0.5 m and intermediate (LIW, ~400 m waters at a 9:1 ratio, respectively and examined the responses of the microbial populations to such a scenario. We hypothesized that the LIW, being nutrient-rich (e.g., N, P and a “hot-spot” for microbial activity (due to the warm conditions that prevail in these depths, may supply the LSW with not only key-limiting nutrients but also with viable and active heterotrophic prokaryotes that can interact with the ambient surface microbial population. Indeed, we show that LIW heterotrophic prokaryotes negatively affected the surface phytoplankton populations, resulting in lower chlorophyll-a levels and primary production rates. This may be due to out-competition of phytoplankton by LIW populations for resources and/or by a phytoplankton cell lysis via viral infection. Our results suggest that phytoplankton in the EMS may not likely form blooms, even after

  11. NODC Standard Product: Climatic atlas of the Arctic Seas 2004 - Database of the Barents, Kara, Laptev, and White Seas - Oceanography and marine biology (NODC Accession 0098061)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Atlas presents primary data on meteorology, oceanography, and hydrobiology from the Barents, Kara, Laptev, and White Seas, which were collected during the...

  12. HANPP Collection: Human Appropriation of Net Primary Productivity (HANPP) by Country and Product

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Human Appropriation of Net Primary Productivity (HANPP) portion of the HANPP Collection represents a digital map of human appropriation of net...

  13. RADIOECOLOGICAL STUDIES IN MARINE ENVIRONMENT. A STUDY ON THE CONCENTRATION OF MIXED FISSION PRODUCTS IN GREEK SEA WATERS AND OF 137CS IN FISH AND SEA PLANTS

    International Nuclear Information System (INIS)

    DANALI-KOTSAKI, S.; FLOROU-GAZI, H.

    1982-12-01

    Full text: The concentrations of mixed fission products in sea water and of 137 Cs in fish and sea plants are different for samples collected from different sampling areas. This difference is more remarkable the year where the level of the world wide fall-out is higher, especially with regards to M. F. P. concentrations in sea water samples. Increases or decreases to M.F.P. concentrations in sea water samples result to increases or decreases of 137 Cs in fish and sea plants. (author)

  14. Measurement and Elemental Analysis of Muria Sea Water for Primary Water of PWR

    International Nuclear Information System (INIS)

    Dwi Biyantoro; Kris Tri Basuki

    2007-01-01

    Treatment process of water of free mineral and study area of processing of sea water to meet the need of water cooling of PWR. Desalination is a separation process used to reduce the dissolved salt content of saline water. All desalination processes involve three liquid streams: the saline feedwater (brackish water or seawater), low salinity product water, and very saline concentrate. Seawater Muria Jepara is feed type 1 with content salt is low and relative suspension and weight metals is low. There are two types of membrane process used for desalination: reverse osmosis (RO) and electrodialysis (ED). The starting of process is difficult and expensive. However, starting since 1950, desalination process appear to be economically practical for ordinary use. There are 3 key elements significantly affect to the technical performance and long term characteristic type, i.e. 1) energy, 2) corrosivity of seawater, and 3) desalination process technology. These elements closely inter related and important for design improvements and technical performance optimization. From the analysis of sea water of gulf Muria Jepara was found as follows : Fe = 0.176 ± 0.012 ppm, Pb = 0.612 ± 0.017 ppm, Cd = 52.567 ± 0.750 ppm, Cu = 0.044 ± 0.005 ppm, Zn = 0.061 ± 0.003 ppm, Mn = 0.057 ± 0.003 ppm, Ca between = 365.256 - 368.654 ppm, Na between = 9572.000 - 9775.000 ppm, Mg between 759.000 - 779.00 ppm and Ni = 0.524 ± 0.005 ppm. Cost production of process using reverse osmosis as around 0.9 - 1 US$/m3, while using electrodialysis is around 1.2 US$/m3, and by using evaporation process or distillation process is around 1.4 - 1.6 US$/m3. (author)

  15. Fission and corrosion products behavior in primary circuits of LMFBR's

    International Nuclear Information System (INIS)

    Feuerstein, H.; Thorley, A.W.

    1987-08-01

    Most of the 20 presented papers report items belonging to more than one session. The equipment results of primary circuits of LMFBR's relative to corrosion and fission products, release and chemistry of fuel, measurement techniques and analytical procedures of sodium sampling, difficulties with radionuclides and particles, reactor experiences with EBR-II, FFTF, BR10, BOR60, BN350, BN600, JOYO, and KNK-II, DFR, PFR, RAPSODIE, PHENIX, and SUPERPHENIX, and at least the verification of codes for calculation models of radioactive products accumulation and distribution are described. All 20 papers presented at the meeting are separately indexed in the database. (DG)

  16. Variations of Terrestrial Net Primary Productivity in East Asia

    Directory of Open Access Journals (Sweden)

    Fangmin Zhang

    2012-01-01

    Full Text Available Due to the heterogeneity and complexity of terrestrial ecosystems of East Asia, a better understanding of relationships between climate change and net primary productivity (NPP distribution is important to predict future carbon dynamics. The objective of this study is to analyze the temporal-spatial patterns of NPP in East Asia (10°S - 55°N, 60 - 155°E from 1982 to 2006 using the process-based Boreal Ecosystem Productivity Simulator (BEPS model. Prior to the regional simulation, the annual simulated NPP was validated using field observed NPP demonstrating the ability of BEPS to simulate NPP in different ecosystems of East Asia.

  17. Long-term patterns of benthic irradiance and kelp production in the central Beaufort sea reveal implications of warming for Arctic inner shelves

    Science.gov (United States)

    Bonsell, Christina; Dunton, Kenneth H.

    2018-03-01

    This study synthesizes a multidecadal dataset of annual growth of the Arctic endemic kelp Laminaria solidungula and corresponding measurements of in situ benthic irradiance from Stefansson Sound in the central Beaufort Sea. We incorporate long-term data on sea ice concentration (National Sea Ice Data Center) and wind (National Weather Service) to assess how ice extent and summer wind dynamics affect the benthic light environment and annual kelp production. We find evidence of significant changes in sea ice extent in Stefansson Sound, with an extension of the ice-free season by approximately 17 days since 1979. Although kelp elongation at 5-7 m depths varies significantly among sites and years (3.8-49.8 cm yr-1), there is no evidence for increased production with either earlier ice break-up or a longer summer ice-free period. This is explained by very low light transmittance to the benthos during the summer season (mean daily percent surface irradiance ± SD: 1.7 ± 3.6 to 4.5 ± 6.6, depending on depth, with light attenuation values ranging from 0.5 to 0.8 m-1), resulting in minimal potential for kelp production on most days. Additionally, on month-long timescales (35 days) in the ice-free summer, benthic light levels are negatively related to wind speed. The frequent, wind-driven resuspension of sediments following ice break-up significantly reduce light to the seabed, effectively nullifying the benefits of an increased ice-free season on annual kelp growth. Instead, benthic light and primary production may depend substantially on the 1-3 week period surrounding ice break-up when intermediate sea ice concentrations reduce wind-driven sediment resuspension. These results suggest that both benthic and water column primary production along the inner shelf of Arctic marginal seas may decrease, not increase, with reductions in sea ice extent.

  18. Regulation of primary productivity rate in the equatorial Pacific

    International Nuclear Information System (INIS)

    Barber, R.T.; Chavez, F.P.

    1991-01-01

    Analysis of the Chl-specific rate of primary productivity (P B ) as a function of subsurface nutrient concentration at >300 equatorial stations provides an answer to the question: What processes regulate primary productivity rate in the high-nutrient, low-chlorophyll waters of the equatorial Pacific? In the western Pacific where there is a gradient in 60-m [NO 3 ] from 0 to ∼12 μM, the productivity rate is a linear function of nutrient concentration; in the eastern Pacific where the gradient is from 12 to 28 μM, the productivity rate is independent of nutrient concentration and limited to ∼36 mg C(mg Chl) -1 d -1 , or a mean euphotic zone C-specific growth rate (μ) of 0.47 d -1 . However, rates downstream of the Galapagos Islands are not limited; they are 46.4 mg C(mg Chl) -1 d -1 and μ = 0.57 d -1 , very close to the predicted nutrient-regulated rates in the absence of other limitation. This pattern of rate regulation can be accounted for by a combination of eolian Fe, subsurface nutrients, and sedimentary Fe derived from the Galapagos platform. In the low-nutrient western Pacific the eolian supply of Fe is adequate to allow productivity rate to be set by subsurface nutrient concentration. In the nutrient-rich easter equatorial region eolian Fe is inadequate to support productivity rates proportional to the higher nutrient concentrations, so in this region eolian Fe is rate limiting. Around the Galapagos Islands productivity rates reach levels consistent with nutrient concentrations; sedimentary Fe from the Galapagos platform seems adequate to support increased nutrient-regulated productivity rates in this region

  19. Corrosion products in the primary circuits of PWRs

    International Nuclear Information System (INIS)

    Darras, R.

    1983-01-01

    The characteristics of PWR primary circuits are recalled, particularly the chemical specifications of the medium and the various materials used (austenitic steel, nickel alloys, cobalt-based alloys and zirconium alloys). The behaviour of these materials as regards general corrosion in nominal and transient conditions is then outlined briefly, special emphasis being laid on the effect of the determining parameters on the quantity of corrosion products formed. The release of the latter into the primary coolant is caused by two main processes: solubilization and erosion. Particular attention was given therefore to the laws governing the solubility of the oxides involved, especially as a function of temperature and pH. Erosion, or release in the form of solid particles, is relatively severe during transient events. As these corrosion products are then carried through all circuits, they cause deposits to form in favourable places on the walls as a result either of precipitation of soluble species or of sedimentation followed by consolidation of suspended particles. The presence of corrosion products in the primary circuits creates a particular impact since they become radioactive as they pass through the core and especially when they remain in it in the form of deposits; as a result, the products are capable of contaminating the entire system. Finally, although long-term reliability is obviously an essential condition for materials developed, attention must also be given to problems associated with a build-up of corrosion products in the cooling circuits and efforts made to minimize them. To that end, a number of precautions are recommended, and various remedies can be applied: selecting materials which are not readily activated, keeping structures clean, purifying fluids properly, restricting solubilization and precipitation, and perhaps, periodic decontamination. (author)

  20. Sea Surface Height Determination In The Arctic Using Cryosat-2 SAR Data From Primary Peak Empirical Retrackers

    DEFF Research Database (Denmark)

    Jain, Maulik; Andersen, Ole Baltazar; Dall, Jørgen

    2015-01-01

    extraction. The primary peak retrackers involve the application of retracking algorithms on just the primary peak of the waveform instead of the complete reflected waveform. These primary peak empirical retrackers are developed for Cryosat-2 SAR data. This is the first time SAR data in the Arctic...... and five parameter beta retrackers. In the case of SAR-lead data, it is concluded that the proposed primary peak retrackers work better as compared with the traditional retrackers (OCOG, threshold, five parameter beta) as well as the ESA Retracker.......SAR waveforms from Cryosat-2 are processed using primary peak empirical retrackers to determine the sea surface height in the Arctic. The empirical retrackers investigated are based on the combination of the traditional OCOG (Offset Center of Gravity) and threshold methods with primary peak...

  1. Bacterial Production and Enzymatic Activities in Deep-Sea Sediments of the Pacific Ocean: Biogeochemical Implications of Different Temperature Constraints

    Science.gov (United States)

    Danovaro, R.; Corinaldesi, C.; dell'Anno, A.

    2002-12-01

    The deep-sea bed, acting as the ultimate sink for organic material derived from the upper oceans primary production, is now assumed to play a key role in biogeochemical cycling of organic matter on global scale. Early diagenesis of organic matter in marine sediments is dependent upon biological processes (largely mediated by bacterial activity) and by molecular diffusion. Organic matter reaching the sea floor by sedimentation is subjected to complex biogeochemical transformations that make organic matter largely unsuitable for direct utilization by benthic heterotrophs. Extracellular enzymatic activities in the sediment is generally recognized as the key step in the degradation and utilization of organic polymers by bacteria and a key role in biopolymeric carbon mobilization is played by aminopeptidase, alkaline phosphatase and glucosidase activities. In the present study we investigated bacterial density, bacterial C production and exo-enzymatic activities (aminopeptidase, glucosidase and phosphatase activity) in deep-sea sediments of the Pacific Ocean in relation with the biochemical composition of sediment organic matter (proteins, carbohydrates and lipids), in order to gather information on organic matter cycling and diagenesis. Benthic viral abundance was also measured to investigate the potential role of viruses on microbial loop functioning. Sediment samples were collected at eight stations (depth ranging from 2070-3100 m) along two transects located at the opposite side (north and south) of ocean seismic ridge Juan Fernandez (along latitudes 33° 20' - 33° 40'), constituted by the submerged vulcanoes, which connects the Chilean coasts to Rapa Nui Island. Since the northern and southern sides of this ridge apparently displayed small but significant differences in deep-sea temperature (related to the general ocean circulation), this sampling strategy allowed also investigating the role of different temperature constraints on bacterial activity and

  2. Hydrogen Production Costs of Various Primary Energy Sources

    International Nuclear Information System (INIS)

    Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

    2005-11-01

    Many studies on the economical aspects of hydrogen energy technologies have been conducted with the increase of the technical and socioeconomic importance of the hydrogen energy. However, there is still no research which evaluates the economy of hydrogen production from the primary energy sources in consideration of Korean situations. In this study, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations such as feedstock price, electricity rate, and load factor. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S. The present study focuses on the possible future technology scenario defined by NAS. The scenario assumes technological improvement that may be achieved if present research and development (R and D) programs are successful. The production costs by the coal and natural gas are 1.1 $/kgH 2 and 1.36 $/kgH 2 , respectively. However, the fossil fuels are susceptible to the price variation depending on the oil and the raw material prices, and the hydrogen production cost also depends on the carbon tax. The economic competitiveness of the renewable energy sources such as the wind, solar, and biomass are relatively low when compared with that of the other energy sources. The estimated hydrogen production costs from the renewable energy sources range from 2.35 $/kgH 2 to 6.03 $/kgH 2 . On the other hand, the production cost by nuclear energy is lower than that of natural gas or coal when the prices of the oil and soft coal are above $50/barrel and 138 $/ton, respectively. Taking into consideration the recent rapid increase of the oil and soft coal prices and the limited fossil resource, the nuclear-hydrogen option appears to be the most economical way in the future

  3. Regionally and seasonally differentiated primary production in the North Atlantic

    Science.gov (United States)

    Sathyendranath, Shubha; Longhurst, Alan; Caverhill, Carla M.; Platt, Trevor

    1995-10-01

    A bio-geochemical classification of the N. Atlantic Basin is presented according to which the basin is first divided into four primary algal domains: Polar, West-Wind, Trades and Coastal. These are in turn sub-divided into smaller provinces. The classification is based on differences in the physical environment which are likely to influence regional algal dynamics. The seasonally-differentiated parameters of the photosynthesis-light curve ( P-I curve) and parameters that define the vertical structure in chlorophyll profile are then established for each province, based on an analysis of an archive of over 6000 chlorophyll profiles, and over 1800 P-I curves. These are then combined with satellite-derived chlorophyll data for the N. Atlantic, and information on cloud cover, to compute primary production at the annual scale. using a model that computes spectral transmission of light underwater, and spectral, photosynthetic response of phytoplankton to available light. The results are compared with earlier, satellite-derived, estimates of basin-scale primary production.

  4. Global net primary production and heterotrophic respiration for 1987

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, R.E. Jr.; Piper, S.C.; Nemani, R. [Univ. of Montana, Missoula, MT (United States)]|[Scripps Institute of Oceanography, La Jolla, CA (United States)] [and others

    1995-06-01

    An ecosystem process model, BIOME-BGC, was parameterized and used to simulate the actual net primary production and heterotrophic respiration using daily climatic data, land cover type, leaf area index gridded to 1{degree} latitude by 1{degree} longitude grid cells for the year 1987. Global net primary production was 52 Pg C. These estimates were validated directly by two different methods. First, the grid cells were aggregated and used as inputs to a 3D atmospheric transport model, to compare CO{sub 2} station data with predictions. We simulated the intra-annual variation of atmospheric CO{sub 2} well for the northern hemisphere, but not for the southern hemisphere. Second, we calculated the net {sup 13}C uptake of vegetation, which is a function of water use efficiency. The {sup 13}C/{sup 12}C ratios agreed with measured data, indicating a strong limitation of global primary processes by the hydrologic cycle, especially precipitation. These are different from other global carbon models as we can simulate the year-to-year variation of climate, including El Nino, on the global carbon cycle.

  5. Palaeoceanographic controls on geochemical characteristics of organic-rich Exshaw mudrocks: role of enhanced primary production

    Energy Technology Data Exchange (ETDEWEB)

    Caplan, M.L.; Bustin, R.M. [University of British Columbia, Vancouver (Canada). Dept. of Earth and Ocean Sciences

    1999-07-01

    Organic-rich source rocks have generally been attributed to enhanced preservation of organic matter under anoxic bottom waters. Here geochemical analysis of kerogen and whole rock samples of organic-rich (lithofacies B{sub 1}) and organic-lean (lithofacies B{sub 2}) laminated mudrocks of the Devonian-Carboniferous Exshaw Formation, Alberta, highlight the importance of primary production in governing the quantity and quality of organic matter. Lower Si/Al, K/Al, Ti/Al and quartz/clay ratios in lithofacies B{sub 2}, similar maceral types and the laminated fabric of the two lithofacies indicate that the quality and quantity of organic matter are not related to grain size, redox or organic matter source changes. High Total Organic Carbon (TOC) and Hydrogen Index (HI), low Oxidation Index (Ox.I. ratio of oxygen functional groups to aliphatic groups derived by FTIR), lighter {delta}{sup 15}N{sub tot} and heavier {delta}{sup 13}C{sub org} isotopes indicate that kerogen of lithofacies B{sub 1} accumulated during periods of high organic-carbon production and delivery of relatively fresh, labile, well-preserved organic matter to the sea floor. In contrast, low TOC, HI, high Ox.I., heavier {delta}{sup 15}N{sub tot} and lighter {delta}{sup 13}C{sub org} isotopes indicate low primary productivity and delivery, high recycling and poor preservation of organic matter during accumulation of lithofacies B{sub 2}. (author)

  6. Operability Guidelines For Product Tanker In Heavy Weather In The Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Mudronja Luka

    2014-06-01

    Full Text Available This paper presents operability guidelines for seafarers on a product tanker which navigates in the Adriatic Sea during heavy weather. Tanker route starts from the Otranto strait in the south to the island Krk in the north of Adriatic Sea. Heavy weather is caused by south wind called jugo (blowing from E-SE to SS-E, sirocco family. Operability guidelines are given based on an operability criteria platform for presenting ship seakeeping characteristics. Operability criteria considered in this paper are propeller emergence, deck wetness and bow acceleration of a product tanker. Limiting values of mentioned criteria determine sustainable speed. Heavy weather is described by extreme sea state of 7.5 m wave height. Wave spectrum used in this paper is Tabain spectrum which is developed specifically for Adriatic Sea. Seafarer's approach of decisions making in extreme weather is also shown and servers as a guideline for further research of the authors.

  7. SMOS sea ice product: Operational application and validation in the Barents Sea marginal ice zone

    DEFF Research Database (Denmark)

    Kaleschke, Lars; Tian-Kunze, Xiangshan; Maaß, Nina

    2016-01-01

    system for ship route optimisation has been developed and was tested during this field campaign with the ice-strengthened research vessel RV Lance. The ship cruise was complemented with coordinated measurements from a helicopter and the research aircraft Polar 5. Sea ice thickness was measured using...... an electromagnetic induction (EM) system from the bow of RV Lance and another EM-system towed below the helicopter. Polar 5 was equipped among others with the L-band radiometer EMIRAD-2. The experiment yielded a comprehensive data set allowing the evaluation of the operational forecast and route optimisation system...

  8. Molecular biology in studies of oceanic primary production

    International Nuclear Information System (INIS)

    LaRoche, J.; Falkowski, P.G.; Geider, R.

    1992-01-01

    Remote sensing and the use of moored in situ instrumentation has greatly improved our ability to measure phytoplankton chlorophyll and photosynthesis on global scales with high temporal resolution. However, the interpretation of these measurements and their significance with respect to the biogeochemical cycling of carbon relies on their relationship with physiological and biochemical processes in phytoplankton. For example, the use of satellite images of surface chlorophyll to estimate primary production is often based on the functional relationship between photosynthesis and irradiance. A variety of environmental factors such as light, temperature, nutrient availability affect the photosynthesis/irradiance (P vs I) relationship in phytoplankton. We present three examples showing how molecular biology can be used to provide basic insight into the factors controlling primary productivity at three different levels of complexity: 1. Studies of light intensity regulation in unicellular alga show how molecular biology can help understand the processing of environmental cues leading to the regulation of photosynthetic gene expression. 2. Probing of the photosynthetic apparatus using molecular techniques can be used to test existing mechanistic models derived from the interpretation of physiological and biophysical measurements. 3. Exploratory work on the expression of specific proteins during nutrient-limited growth of phytoplankton may lead to the identification and production of molecular probes for field studies

  9. Estimation of new production in the North Sea: consequences for temporal and spatial variability of phytoplankton

    DEFF Research Database (Denmark)

    Richardson, Katherine; Bo Pedersen, Flemming

    1998-01-01

    By coupling knowledge of oceanographic processes and phytoplankton responses to light and nutrient availability, we estimate a total potential new (sensu Dugdale and Goering,1967) production for the North Sea of approximately 15.6 million tons C per year. In a typical year, about 40......% of this production will be associated with the spring bloom in the surface waters of the seasonally stratified (central and northern) North Sea. About 40% is predicted to occur in the coastal waters while the remaining new production is predicted to take place in sub-surface chlorophyll peaks occuring in association...... with fronts in the North Sea during summer month. By considering the inter-annual variation in heat, wind and nutrient availability (light and tidal energy input are treated as non-varying from year to year), the inter-annual variability in the new production occuring in these different regions is estimated...

  10. Counterintuitive effects of global warming-induced wind patterns on primary production in the Northern Humboldt Current System.

    Science.gov (United States)

    Mogollón, Rodrigo; R Calil, Paulo H

    2018-04-14

    It has been hypothesized that global warming will strengthen upwelling-favorable winds in the Northern Humboldt Current System (NHCS) as a consequence of the increase of the land-sea thermal gradient along the Peruvian coast. The effect of strengthened winds in this region is assessed with the use of a coupled physical-biogeochemical model forced with projected and climatological winds. Strengthened winds induce an increase in primary production of 2% per latitudinal degree from 9.5°S to 5°S. In some important coastal upwelling sites primary production is reduced. This is due to a complex balance between nutrient availability, nutrient use efficiency, as well as eddy- and wind-driven factors. Mesoscale activity induces a net offshore transport of inorganic nutrients, thus reducing primary production in the coastal upwelling region. Wind mixing, in general disadvantageous for primary producers, leads to shorter residence times in the southern and central coastal zones. Overall, instead of a proportional enhancement in primary production due to increased winds, the NHCS becomes only 5% more productive (+5 mol C m -2 year -1 ), 10% less limited by nutrients and 15% less efficient due to eddy-driven effects. It is found that regions with a initial strong nutrient limitation are more efficient in terms of nutrient assimilation which makes them more resilient in face of the acceleration of the upwelling circulation. © 2018 John Wiley & Sons Ltd.

  11. Software sensor for primary metabolite production case of alcoholic fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Roux, G.; Dahhou, B.; Queinnec, I. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France)]|[Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France); Goma, G. [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France)

    1995-12-31

    This paper investigate the application of an observer for state and parameter estimation to batch, continuous and fed batch fermentations for alcohol production taken as model for a primary metabolite production. This observer is provided to palliate the lack of suitable sensors for on-line biomass and ethanol concentrations measurements and to estimate the time varying specific growth rate. Estimates are obtained from an interlaced structure filter based on a `modified extended Kalman filter` by using on-line measurements of carbon dioxide outflow rate and substrate concentration. The filter algorithm was tested during batch, continuous and fed batch fermentation processes. The filter behaviour observed in the experiments gives good results with an agreement theory/practice. (authors) 18 refs.

  12. Regional Changes in the Sea Ice Cover and Ice Production in the Antarctic

    Science.gov (United States)

    Comiso, Josefino C.

    2011-01-01

    Coastal polynyas around the Antarctic continent have been regarded as sea ice factories because of high ice production rates in these regions. The observation of a positive trend in the extent of Antarctic sea ice during the satellite era has been intriguing in light of the observed rapid decline of the ice extent in the Arctic. The results of analysis of the time series of passive microwave data indicate large regional variability with the trends being strongly positive in the Ross Sea, strongly negative in the Bellingshausen/Amundsen Seas and close to zero in the other regions. The atmospheric circulation in the Antarctic is controlled mainly by the Southern Annular Mode (SAM) and the marginal ice zone around the continent shows an alternating pattern of advance and retreat suggesting the presence of a propagating wave (called Antarctic Circumpolar Wave) around the circumpolar region. The results of analysis of the passive microwave data suggest that the positive trend in the Antarctic sea ice cover could be caused primarily by enhanced ice production in the Ross Sea that may be associated with more persistent and larger coastal polynyas in the region. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate-of-increase in the net ice export of about 30,000 km2 per year. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 km3/year, which is almost identical, within error bars, to our estimate of the trend in ice production. In addition to the possibility of changes in SAM, modeling studies have also indicated that the ozone hole may have a role in that it causes the deepening of the lows in the western Antarctic region thereby causing strong winds to occur offthe Ross-ice shelf.

  13. Inorganic carbon addition stimulates snow algae primary productivity

    Science.gov (United States)

    Hamilton, T. L.; Havig, J. R.

    2017-12-01

    Earth has experienced glacial/interglacial oscillations throughout its history. Today over 15 million square kilometers (5.8 million square miles) of Earth's land surface is covered in ice including glaciers, ice caps, and the ice sheets of Greenland and Antarctica, most of which are retreating as a consequence of increased atmospheric CO2. Glaciers are teeming with life and supraglacial snow and ice surfaces are often red due to blooms of photoautotrophic algae. Recent evidence suggests the red pigmentation, secondary carotenoids produced in part to thrive under high irradiation, lowers albedo and accelerates melt. However, there are relatively few studies that report the productivity of snow algae communities and the parameters that constrain their growth on snow and ice surfaces. Here, we demonstrate that snow algae primary productivity can be stimulated by the addition of inorganic carbon. We found an increase in light-dependent carbon assimilation in snow algae microcosms amended with increasing amounts of inorganic carbon. Our snow algae communities were dominated by typical cosmopolitan snow algae species recovered from Alpine and Arctic environments. The climate feedbacks necessary to enter and exit glacial/interglacial oscillations are poorly understood. Evidence and models agree that global Snowball events are accompanied by changes in atmospheric CO2 with increasing CO2 necessary for entering periods of interglacial time. Our results demonstrate a positive feedback between increased CO2 and snow algal productivity and presumably growth. With the recent call for bio-albedo effects to be considered in climate models, our results underscore the need for robust climate models to include feedbacks between supraglacial primary productivity, albedo, and atmospheric CO2.

  14. Possibilities of Production and Storage of Hydrogen in the Black Sea

    International Nuclear Information System (INIS)

    Mehmet Haklidir; Fusun Servin Tut; Sule Kapkin

    2006-01-01

    Black Sea, a highly-isolated inland sea, is the largest anoxic zone in the world. Since the hydrogen sulphide zone was discovered in early 19. century in the Black Sea, it has been adopted that there is no life in the depths of the Black Sea and there are only bacteria live in the hydrogen sulphide layer. High content of organic matter, with maximum processes of bacterial sulfate reduction is the major source of this hydrogen sulphide zone. Hydrogen sulphide is one of the most poisonous gases in the world but it has great economic value to obtain hydrogen via dissociated into hydrogen and sulphur. Thus the Black Sea is not only has a serious environmental contamination but also has potential source of hydrogen energy, if a decomposition process can be developed. In this study, the sources of hydrogen sulphide, environmental impact of hydrogen sulphide in the Black Sea, the available techniques of hydrogen production from hydrogen sulphide and the possibilities of hydrogen storage by the natural sources in the Black Sea have been investigated. (authors)

  15. Cell-surface proteoglycan in sea urchin primary mesenchyme cell migration

    International Nuclear Information System (INIS)

    Lane, M.C.

    1989-01-01

    Early in the development of the sea urchin embryo, the primary mesenchyme cells (PMC) migrate along the basal lamina of the blastocoel. Migration is inhibited in L. pictus embryos cultured in sulfate-free seawater and in S. purpuratus embryos exposed to exogenous β-D-xylosides. An in vitro assay was developed to test the migratory capacity of normal PMC on normal and treated blastocoelic matrix. Sulfate deprivation and exposure to exogenous xyloside render PMC nonmotile on either matrix. Materials removed from the surface of normal PMC by treatment with 1 M urea restored migratory ability to defective cells, whereas a similar preparation isolated from the surface of epithelial cells at the same stage did not. Migration also resumed when cells were removed from the xyloside or returned to normal seawater. The urea extract was partially purified and characterized by radiolabeling, gel electrophoresis, fluorography, ion exchange chromatography, and western blotting. The PMC synthesize a large chondroitin sulfate/dermatan sulfate proteoglycan that is present in an active fraction isolated by chromatography. Chondroitinase ABC digestion of live cells blocked migration reversibly, further supporting the identification of the chondroitin sulfate/dermatan sulfate proteoglycan as the active component in the urea extract. Much of the incorporated sulfate was distributed along the filopodia in 35 SO 4 -labelled PMC by autoradiography. The morphology of normal and treated S. purpuratus PMC was examined by scanning electron microscopy, and differences in spreading, particularly of the extensive filopodia present on the cells, was observed. A model for the role of the chondroitin sulfate/dermatan sulfate proteoglycan in cell detachment during migration is proposed

  16. Food components of the Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Qasim, S.Z.; Ansari, Z.A.

    is inverse. The Andaman Sea is oligotrophic in nature with low primary and secondary productivity and hence the production of large quantities of detritus appears to supplement the nutritional inadequacy of these waters...

  17. Shifts in North Sea forage fish productivity and potential fisheries yield

    DEFF Research Database (Denmark)

    Worsøe Clausen, Lotte; Rindorf, Anna; van Deurs, Mikael

    2018-01-01

    productivity. Furthermore, from an ecosystem-based fisheries management perspective, a link between functional complementarity and productivity, indicates that ecosystem resilience may decline with productivity. Based on this, we advise that system productivity, perhaps monitored as forage fish growth, becomes......1. Forage fish populations support large scale fisheries and are key components of marine ecosystems across the world, linking secondary production to higher trophic levels. While climate-induced changes in the North Sea zooplankton community are described and documented in literature......, the associated bottom-up effects and consequences for fisheries remain largely unidentified. 2. We investigated the temporal development in forage fish productivity and the associated influence on fisheries yield of herring, sprat, Norway pout and sandeel in the North Sea. Using principal component analysis, we...

  18. Absence of remote earthquake triggering within the Coso and Salton Sea geothermal production fields

    Science.gov (United States)

    Zhang, Qiong; Lin, Guoqing; Zhan, Zhongwen; Chen, Xiaowei; Qin, Yan; Wdowinski, Shimon

    2017-01-01

    Geothermal areas are long recognized to be susceptible to remote earthquake triggering, probably due to the high seismicity rates and presence of geothermal fluids. However, anthropogenic injection and extraction activity may alter the stress state and fluid flow within the geothermal fields. Here we examine the remote triggering phenomena in the Coso geothermal field and its surrounding areas to assess possible anthropogenic effects. We find that triggered earthquakes are absent within the geothermal field but occur in the surrounding areas. Similar observation is also found in the Salton Sea geothermal field. We hypothesize that continuous geothermal operation has eliminated any significant differential pore pressure between fractures inside the geothermal field through flushing geothermal precipitations and sediments out of clogged fractures. To test this hypothesis, we analyze the pore-pressure-driven earthquake swarms, and they are found to occur outside or on the periphery of the geothermal production field. Therefore, our results suggest that the geothermal operation has changed the subsurface fracture network, and differential pore pressure is the primary controlling factor of remote triggering in geothermal fields.

  19. Seasonal patterns in phytoplankton photosynthetic parameters and primary production at a coastal NW Mediterranean site

    Directory of Open Access Journals (Sweden)

    Josep M. Gasol

    2016-09-01

    Full Text Available We carried out monthly photosynthesis-irradiance (P-E experiments with the 14C-method for 12 years (2003–2014 to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a coastal sampling station in the NW Mediterranean Sea. Our goal was to obtain seasonal trends and to establish the basis for detecting future changes of primary production in this oligotrophic area. The maximal photosynthetic rate PBmax ranged 30-fold (0.5-15 mg C mg Chl a–1 h–1, averaged 3.7 mg C mg Chl a–1 h–1 (±0.25 SE and was highest in August and lowest in April and December. We only observed photoinhibition twice. The initial or light-limited slope of the P-E relationship, αB, was low, averaging 0.007 mg C mg Chl a–1 h–1 (μmol photons m–2 s–1–1 (±0.001 SE, range 0.001-0.045 and showed the lowest values in spring (April-June. The light saturation parameter or saturation irradiance, EK, averaged 711 μmol photons m–2 s–1 (± 58.4 SE and tended to be higher in spring and lower in winter. Phytoplankton assemblages were typically dominated by picoeukaryotes in early winter, diatoms in late autumn and late winter, dinoflagellates in spring and cyanobacteria in summer. Total particulate primary production averaged 1.45 mg C m-3 h–1 (±0.13 SE with highest values in winter (up to 8.50 mg C m-3 h–1 and lowest values in summer (summer average, 0.30 mg C m-3 h–1, while chlorophyll-specific primary production averaged 2.49 mg C mg Chl a–1 h–1 (±0.19, SE and peaked in summer (up to 12.0 mg C mg Chl a–1 h–1 in August. 14C-determined phytoplankton growth rates varied between ca. 0.3 d–1 in winter and 0.5 d–1 in summer and were within 60-80% of the maximal rates of growth, based on PBmax. Chlorophyll a was a good predictor of primary production only in the winter and autumn. Seasonality appeared to explain most of the variability in the studied variables, while

  20. Seasonal patterns in phytoplankton photosynthetic parameters and primary production at a coastal NW Mediterranean site

    KAUST Repository

    Gasol, Josep M.

    2016-10-11

    We carried out monthly photosynthesis-irradiance (P-E) experiments with the 14C-method for 12 years (2003–2014) to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a coastal sampling station in the NW Mediterranean Sea. Our goal was to obtain seasonal trends and to establish the basis for detecting future changes of primary production in this oligotrophic area. The maximal photosynthetic rate PBmax ranged 30-fold (0.5-15 mg C mg Chl a–1 h–1), averaged 3.7 mg C mg Chl a–1 h–1 (±0.25 SE) and was highest in August and lowest in April and December. We only observed photoinhibition twice. The initial or light-limited slope of the P-E relationship, αB, was low, averaging 0.007 mg C mg Chl a–1 h–1 (μmol photons m–2 s–1)–1 (±0.001 SE, range 0.001-0.045) and showed the lowest values in spring (April-June). The light saturation parameter or saturation irradiance, EK, averaged 711 μmol photons m–2 s–1 (±58.4 SE) and tended to be higher in spring and lower in winter. Phytoplankton assemblages were typically dominated by picoeukaryotes in early winter, diatoms in late autumn and late winter, dinoflagellates in spring and cyanobacteria in summer. Total particulate primary production averaged 1.45 mg C m–3 h–1 (±0.13 SE) with highest values in winter (up to 8.50 mg C m–3 h–1) and lowest values in summer (summer average, 0.30 mg C m–3 h–1), while chlorophyll-specific primary production averaged 2.49 mg C mg Chl a–1 h–1 (±0.19, SE) and peaked in summer (up to 12.0 mg C mg Chl a–1 h–1 in August). 14C-determined phytoplankton growth rates varied between ca. 0.3 d–1 in winter and 0.5 d–1 in summer and were within 60-80% of the maximal rates of growth, based on PBmax. Chlorophyll a was a good predictor of primary production only in the winter and autumn. Seasonality appeared to explain most of the variability in the studied variables, while

  1. SEA-MAP: A cost effective method for production from deepwater reservoirs

    International Nuclear Information System (INIS)

    Wybro, P.G.; Chaisson, M.

    1994-01-01

    SEA Engineering Marginal field Autonomous Production (SEAMAP) based on a small tension leg platform is a concept for commercially viable production from deepwater reservoirs. Considerable engineering effort has and is still being made to find ways of commercially developing the deepwater Gulf of Mexico reserves. The limited number of actual deepwater developments would appear to indicate the energy industry at present remains reluctant to proceed with the development of many of the known discoveries. The major deterrents have been the major investment required in order to implement the development plans combined with uncertainties regarding reservoir performance. Mindful of this situation, SEA-MAP evolved from a perceived need for a low cost deepwater production system viable for relatively small reserves. The capital risk exposure is more sustainable and the major part of the facilities can be relocated to another site. Conversely, field production can be increased at a later stage with additional SEA-MAP platforms SEA-MAP offers a potential means, with minimum capital expenditure, of initiating production autonomously from a deepwater field, obtaining reservoir data and thereafter producing and performing workover activities during the field life. After producing from the field for a period, it may be determined that additional wells are needed. Such a situation leads into a logical phased development comprising more than one small platform or the relocation of an existing structure. Deepwater development can thus be approached cautiously, with minimized capital risk, minimal start-up investment and subsequent self-financing phased production

  2. The Governance of Multi-Use Platforms at Sea for Energy Production and Aquaculture: Challenges for Policy Makers in European Seas

    NARCIS (Netherlands)

    Stuiver, Marian; Soma, Katrine; Koundouri, Phoebe; Burg, Van Den Sander; Gerritsen, Alwin; Rockmann, C.

    2016-01-01

    European seas are encountering an upsurge in competing marine activities and infrastructures. Traditional exploitation such as fisheries, tourism, transportation, and oil production are accompanied by new sustainable economic activities such as offshore windfarms, aquaculture, and tidal and wave

  3. The economic feasibility of seaweed production in the North Sea

    NARCIS (Netherlands)

    Burg, van den Sander W.K.; Duijn, van Arie Pieter; Bartelings, Heleen; Krimpen, van Marinus M.; Poelman, Marnix

    2016-01-01

    Seaweeds are increasingly seen as an alternative to land-grown products in food and feed applications. Interest in production of seaweeds in temperate waters is rising, in particular in combination with offshore wind energy generation. This article reports an investigation of the economic

  4. Hydrogen Production Costs of Various Primary Energy Sources

    International Nuclear Information System (INIS)

    Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

    2005-01-01

    The limited resource and environmental impacts of fossil fuels are becoming more and more serious problems in the world. Consequently, hydrogen is in the limelight as a future alternative energy due to its clean combustion and inexhaustibility and a transition from the traditional fossil fuel system to a hydrogen-based energy system is under considerations. Several countries are already gearing the industries to the hydrogen economy to cope with the limitations of the current fossil fuels. Unfortunately, hydrogen has to be chemically separated from the hydrogen compounds in nature such as water by using some energy sources. In this paper, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S

  5. Monitoring residue in animals and primary products of animal origin

    Directory of Open Access Journals (Sweden)

    Janković Saša

    2008-01-01

    Full Text Available The objective of control and systematic monitoring of residue is to secure, by the examination of a corresponding number of samples, the efficient monitoring of the residue level in tissues and organs of animals, as well as in primary products of animal origin. This creates possibilities for the timely taking of measures toward the securing of food hygiene of animal origin and the protection of public health. Residue can be a consequence of the inadequate use of medicines in veterinary medicine and pesticides in agriculture and veterinary medicine, as well as the polluting of the environment with toxic elements, dioxins, polychlorinated biphenyls, and others. Residue is being monitored in Serbia since 1972, and in 2004, national monitoring was brought to the level of EU countries through significant investments by the Ministry of Agriculture, Forestry and Water Management. This is also evident in the EU directives which permit exports of all kinds of meat and primary products of animal origin, covered by the Residue Monitoring Program. The program of systematic examinations of residue has been coordinated with the requirements of the European Union, both according to the type of examined substance, as well as according to the number of samples and the applied analytical techniques. In addition to the development of methods and the including of new harmful substances into the monitoring programme, it is also necessary to coordinate the national regulations that define the maximum permitted quantities of certain medicines and contaminants with the EU regulations, in order to protect the health of consumers as efficiently as possible, and for the country to take equal part in international trade.

  6. Satellite Driven Estimation of Primary Productivity of Agroecosystems in India

    Science.gov (United States)

    Patel, N. R.; Dadhwal, V. K.; Agrawal, S.; Saha, S. K.

    2011-08-01

    Earth observation driven ecosystem modeling have played a major role in estimation of carbon budget components such as gross primary productivity (GPP) and net primary production (NPP) over terrestrial ecosystems, including agriculture. The present study therefore evaluate satellite-driven vegetation photosynthesis (VPM) model for GPP estimation over agro-ecosystems in India by using time series of the Normalized Difference Vegetation Index (NDVI) from SPOT-VEGETATION, cloud cover observation from MODIS, coarse-grid C3/C4 crop fraction and decadal grided databases of maximum and minimum temperatures. Parameterization of VPM parameters e.g. maximum light use efficiency (ɛ*) and Tscalar was done based on eddy-covariance measurements and literature survey. Incorporation of C3/C4 crop fraction is a modification to commonly used constant maximum LUE. Modeling results from VPM captured very well the geographical pattern of GPP and NPP over cropland in India. Well managed agro-ecosystems in Trans-Gangetic and upper Indo-Gangetic plains had the highest magnitude of GPP with peak GPP during kharif occurs in sugarcane-wheat system (western UP) and it occurs in rice-wheat system (Punjab) during Rabi season. Overall, croplands in these plains had more annual GPP (> 1000 g C m-2) and NPP (> 600 g C m-2) due to input-intensive cultivation. Desertic tracts of western Rajasthan showed the least GPP and NPP values. Country-level contribution of croplands to national GPP and NPP amounts to1.34 Pg C year-1 and 0.859 Pg C year-1, respectively. Modeled estimates of cropland NPP agrees well with ground-based estimates for north-western India (R2 = 0.63 and RMSE = 108 g C m-2). Future research will focus on evaluating the VPM model with medium resolution sensors such as AWiFS and MODIS for rice-wheat system and validating with eddy-covariance measurements.

  7. Modeling of allergen proteins found in sea food products

    Directory of Open Access Journals (Sweden)

    Nataly Galán-Freyle

    2012-06-01

    Full Text Available Shellfish are a source of food allergens, and their consumption is the cause of severe allergic reactions in humans. Tropomyosins, a family of muscle proteins, have been identified as the major allergens in shellfish and mollusks species. Nevertheless, few experimentally determined three-dimensional structures are available in the Protein Data Base (PDB. In this study, 3D models of several homologous of tropomyosins present in marine shellfish and mollusk species (Chaf 1, Met e1, Hom a1, Per v1, and Pen a1 were constructed, validated, and their immunoglobulin E binding epitopes were identified using bioinformatics tools. All protein models for these allergens consisted of long alpha-helices. Chaf 1, Met e1, and Hom a1 had six conserved regions with sequence similarities to known epitopes, whereas Per v1 and Pen a1 contained only one. Lipophilic potentials of identified epitopes revealed a high propensity of hydrophobic amino acids in the immunoglobulin E binding site. This information could be useful to design tropomyosin-specific immunotherapy for sea food allergies.

  8. Synthesis of integrated primary production in the Arctic Ocean: II. In situ and remotely sensed estimates

    Science.gov (United States)

    Hill, Victoria J.; Matrai, Patricia A.; Olson, Elise; Suttles, S.; Steele, Mike; Codispoti, L. A.; Zimmerman, Richard C.

    2013-03-01

    Recent warming of surface waters, accompanied by reduced ice thickness and extent may have significant consequences for climate-driven changes of primary production (PP) in the Arctic Ocean (AO). However, it has been difficult to obtain a robust benchmark estimate of pan-Arctic PP necessary for evaluating change. This paper provides an estimate of pan-Arctic PP prior to significant warming from a synthetic analysis of the ARCSS-PP database of in situ measurements collected from 1954 to 2007 and estimates derived from satellite-based observations from 1998 to 2007. Vertical profiles of in situ chlorophyll a (Chl a) and PP revealed persistent subsurface peaks in biomass and PP throughout the AO during most of the summer period. This was contradictory with the commonly assumed exponential decrease in PP with depth on which prior satellite-derived estimates were based. As remotely sensed Chl a was not a good predictor of integrated water column Chl a, accurate satellite-based modeling of vertically integrated primary production (IPPsat), requires knowledge of the subsurface distribution of phytoplankton, coincident with the remotely sensed ocean color measurements. We developed an alternative approach to modeling PP from satellite observations by incorporating climatological information on the depths of the euphotic zone and the mixed layer that control the distribution of phytoplankton that significantly improved the fidelity of satellite derived PP to in situ observations. The annual IPP of the Arctic Ocean combining both in situ and satellite based estimates was calculated here to be a minimum of 466 ± 94 Tg C yr-1 and a maximum of 993 ± 94 Tg C yr-1, when corrected for subsurface production. Inflow shelf seas account for 75% of annual IPP, while the central basin and Beaufort northern sea were the regions with the lowest annual integrated productivity, due to persistently stratified, oligotrophic and ice-covered conditions. Although the expansion of summertime

  9. Algal species composition, photosynthetic pigments and primary productivity in relation to temperature variations in the coastal waters of Kalpakkam

    International Nuclear Information System (INIS)

    Rajadurai, M.; Poornima, E.H.; Rao, V.N.R.; Venugopalan, V.P.

    2002-01-01

    With increase in the number of nuclear and fossil fuel power plants being commissioned along the sea coast to meet the growing demands of the society, more and more of the heated effluents from them find their way into the sea, elevated temperature of the waters may affect the phytoplankton, periphyton and the phytobenthos and any harmful effect on these algae may have a cascading effect on the higher level of the food chain especially those that are ecologically and commercially valuable. Therefore, it is necessary to gain sufficient knowledge on the response of these algae to elevated temperatures which will help us to arrive at a meaningful assessment on the temperature effects and to formulate optimum discharge criteria with regard to thermal effluents from power stations. Fifteen sites were chosen along the East Coast near the Madras Atomic power Station (MAPS) and surface water and sediments were analyzed for various parameters such as temperature, algal species composition, pigments and primary productivity

  10. Photosynthetic production in the central Arctic Ocean during the record sea-ice minimum in 2012

    NARCIS (Netherlands)

    Fernández-Méndez, M.; Katlein, C.; Rabe, B.; Nicolaus, M.; Peeken, I.; Bakker, K.; Flores, H.; Boetius, A.

    2015-01-01

    The ice-covered central Arctic Ocean is characterized by low primary productivity due to light and nutrient limitations. The recent reduction in ice cover has the potential to substantially increase phytoplankton primary production, but little is yet known about the fate of the ice-associated

  11. The remote sensing of ocean primary productivity - Use of a new data compilation to test satellite algorithms

    Science.gov (United States)

    Balch, William; Evans, Robert; Brown, Jim; Feldman, Gene; Mcclain, Charles; Esaias, Wayne

    1992-01-01

    Global pigment and primary productivity algorithms based on a new data compilation of over 12,000 stations occupied mostly in the Northern Hemisphere, from the late 1950s to 1988, were tested. The results showed high variability of the fraction of total pigment contributed by chlorophyll, which is required for subsequent predictions of primary productivity. Two models, which predict pigment concentration normalized to an attenuation length of euphotic depth, were checked against 2,800 vertical profiles of pigments. Phaeopigments consistently showed maxima at about one optical depth below the chlorophyll maxima. CZCS data coincident with the sea truth data were also checked. A regression of satellite-derived pigment vs ship-derived pigment had a coefficient of determination. The satellite underestimated the true pigment concentration in mesotrophic and oligotrophic waters and overestimated the pigment concentration in eutrophic waters. The error in the satellite estimate showed no trends with time between 1978 and 1986.

  12. Estimating Net Primary Productivity Using Satellite and Ancillary Data

    Science.gov (United States)

    Choudhury, Bhaskar J.

    2002-01-01

    The net primary productivity (C) or the annual rate of carbon accumulation per unit ground area by terrestrial plant communities is the difference of gross photosynthesis (A(sub g)) and respiration (R) per unit ground area. Available field observations show that R is a large and variable fraction of A(sub g), although it is generally recognized that there are considerable difficulties in determining these fluxes, and thus pose challenge in assessing the accuracy. Further uncertainties arise in extrapolating field measurements (which are acquired over a hectare or so area) to regional scale. Here, an approach is presented for determining these fluxes using satellite and ancillary data to be representative of regional scale and allow assessment of interannual variation. A, has been expressed as the product of radiation use efficiency for gross photosynthesis by an unstressed canopy and intercepted photosynthetically active radiation, which is then adjusted for stresses due to soil water shortage and temperature away from optimum. R has been calculated as the sum of growth and maintenance components (respectively, R(sub g) and R(sub m)).The R(sub m) has been determined from nitrogen content of plant tissue per unit ground area, while R(sub g) has been obtained as a fraction of the difference of A(sub g) and R(sub m). Results for five consecutive years (1986-1990) are presented for the Amazon-Tocontins, Mississippi, and Ob River basins.

  13. The SEA of the Future: Building the Productivity Infrastructure. Volume 3

    Science.gov (United States)

    Gross, Betheny, Ed.; Jochim, Ashley, Ed.

    2014-01-01

    "The SEA of the Future" is an education publication series examining how state education agencies can shift from a compliance to a performance-oriented organization through strategic planning and performance management tools to meet growing demands to support education reform while improving productivity. This volume, the third in the…

  14. Shifts in North Sea forage fish productivity and potential fisheries yield

    NARCIS (Netherlands)

    Clausen, Lotte W.; Rindorf, Anna; Deurs, van Mikael; Dickey-Collas, Mark; Hintzen, Niels T.

    2018-01-01

    1. Forage fish populations support large scale fisheries and are key components of marine ecosystems across the world, linking secondary production to higher trophic levels. While climate-induced changes in the North Sea zooplankton community are described and documented in literature, the

  15. Thalassic biogas production from sea wrack biomass using different microbial seeds: cow manure, marine sediment and sea wrack-associated microflora.

    Science.gov (United States)

    Marquez, Gian Powell B; Reichardt, Wolfgang T; Azanza, Rhodora V; Klocke, Michael; Montaño, Marco Nemesio E

    2013-04-01

    Sea wrack (dislodged sea grasses and seaweeds) was used in biogas production. Fresh water scarcity in island communities where sea wrack could accumulate led to seawater utilization as liquid substrate. Three microbial seeds cow manure (CM), marine sediment (MS), and sea wrack-associated microflora (SWA) were explored for biogas production. The average biogas produced were 2172±156 mL (MS), 1223±308 mL (SWA) and 551±126 mL (CM). Though methane potential (396.9 mL(CH4) g(-1) volatile solid) computed from sea wrack proximate values was comparable to other feedstocks, highest methane yield was low (MS=94.33 mL(CH4) g(-1) VS). Among the microbial seeds, MS proved the best microbial source in utilizing sea wrack biomass and seawater. However, salinity (MS=42‰) observed exceeded average seawater salinity (34‰). Hence, methanogenic activity could have been inhibited. This is the first report on sea wrack biomass utilization for thalassic biogas production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Polynyas and Ice Production Evolution in the Ross Sea (PIPERS)

    Science.gov (United States)

    Ackley, S. F.

    2017-12-01

    One focus of the PIPERS cruise into the Ross Sea ice cover during April-June 2017 was the Terra Nova Bay (TNB) polynya where joint measurements of air-ice-ocean wave interaction were conducted over twelve days. In Terra Nova Bay, measurements were made in three katabatic wind events each with sustained winds over 35 ms-1 and air temperatures below -15C. Near shore, intense wave fields with wave amplitudes of over 2m and 7-9 sec periods built and large amounts of frazil ice crystals grew. The frazil ice gathered initially into short and narrow plumes that eventually were added laterally to create longer and wider streaks or bands. Breaking waves within these wider streaks were dampened which appeared to enhance the development of pancake ice. Eventually, the open water areas between the streaks sealed off, developing a complete ice cover of 100 percent concentration (80-90 percent pancakes, 20-10 percent frazil) over a wide front (30km). The pancakes continued to grow in diameter and thickness as waves alternately contracted and expanded the ice cover, with the thicker larger floes further diminishing the wave field and lateral motion between pancakes until the initial pancake ice growth ceased. The equilibrium thickness of the ice was 20-30cm in the pancake ice. While the waves had died off however, katabatic wind velocities were sustained and resulted in a wide area of concentrated, rafted, pancake ice that was rapidly advected downstream until the end of the katabatic event. High resolution TerraSar-X radar satellite imagery showed the length of the ice area produced in one single event extended over 300km or ten times the length of the open water area during one polynya event. The TNB polynya is therefore an "ice factory" where frazil ice is manufactured into pancake ice floes that are then pushed out of the assembly area and advected, rafted (and occasionally piled up into "dragon skin" ice), until the katabatic wind dies off at the coastal source.

  17. High biological productivity in the central Arabian Sea during the summer monsoon driven by Ekman pumping and lateral advection

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Madhupratap, M.; DileepKumar, M.; Muraleedharan, P.M.; DeSouza, S.N.; Gauns, M.; Sarma, V.V.S.S.

    Open oceans are generally oligotrophic and support less biological production. Results from the central Arabian Sea show that it may be an exception to this. We provide the observational evidence of fairly high biological production (up to 1700 mg C...

  18. Contribution of sea ice microbial production to Antarctic benthic communities is driven by sea ice dynamics and composition of functional guilds.

    Science.gov (United States)

    Wing, Stephen R; Leichter, James J; Wing, Lucy C; Stokes, Dale; Genovese, Sal J; McMullin, Rebecca M; Shatova, Olya A

    2018-04-28

    Organic matter produced by the sea ice microbial community (SIMCo) is an important link between sea ice dynamics and secondary production in near-shore food webs of Antarctica. Sea ice conditions in McMurdo Sound were quantified from time series of MODIS satellite images for Sept. 1 through Feb. 28 of 2007-2015. A predictable sea ice persistence gradient along the length of the Sound and evidence for a distinct change in sea ice dynamics in 2011 were observed. We used stable isotope analysis (δ 13 C and δ 15 N) of SIMCo, suspended particulate organic matter (SPOM) and shallow water (10-20 m) macroinvertebrates to reveal patterns in trophic structure of, and incorporation of organic matter from SIMCo into, benthic communities at eight sites distributed along the sea ice persistence gradient. Mass-balance analysis revealed distinct trophic architecture among communities and large fluxes of SIMCo into the near-shore food web, with the estimates ranging from 2 to 84% of organic matter derived from SIMCo for individual species. Analysis of patterns in density, and biomass of macroinvertebrate communities among sites allowed us to model net incorporation of organic matter from SIMCo, in terms of biomass per unit area (g/m 2 ), into benthic communities. Here, organic matter derived from SIMCo supported 39 to 71 per cent of total biomass. Furthermore, for six species, we observed declines in contribution of SIMCo between years with persistent sea ice (2008-2009) and years with extensive sea ice breakout (2012-2015). Our data demonstrate the vital role of SIMCo in ecosystem function in Antarctica and strong linkages between sea ice dynamics and near-shore secondary productivity. These results have important implications for our understanding of how benthic communities will respond to changes in sea ice dynamics associated with climate change and highlight the important role of shallow water macroinvertebrate communities as sentinels of change for the Antarctic marine

  19. Counterintuitive effect of fall mixed layer deepening on eukaryotic new production in the Sargasso Sea

    Science.gov (United States)

    Fawcett, S. E.; Lomas, M. W.; Ward, B. B.; Sigman, D. M.

    2012-12-01

    The Sargasso Sea is characterized by a short period of deep vertical mixing in the late winter and early spring, followed by strong thermal stratification during the summer. Stratification persists into the fall, impeding the upward flux of nitrate from depth so that recycled forms of nitrogen (N) such as ammonium are thought to support most primary production. We collected particles from surface waters during March, July, October, and December, used flow cytometry to separate the prokaryotic and eukaryotic phytoplankton, and analyzed their respective 15N/14N. In all months, the 15N/14N of the prokaryotic genera, Prochlorococcus and Synechococcus, was low, indicative of reliance on recycled N throughout the year. In July, the 15N/14N of eukaryotic phytoplankton was variable but consistently higher than that of the prokaryotes, reflecting eukaryotic consumption of subsurface nitrate. Two eukaryotic profiles from October and December were similar to those from July. In three other fall profiles, the eukaryotes had a 15N/14N similar to that of the prokaryotes, suggesting a switch toward greater reliance on recycled N. This change in the dominant N source supporting eukaryotic production appears to be driven by the density structure of the upper water column. The very shallow low-density surface "mixed layer" (≤20 m) that develops in early-to-mid summer does not contribute to stratification at the base of the euphotic zone, and subsurface nitrate can mix up into the lower euphotic zone, facilitating continued production. The deepening of the mixed layer into the fall, typically taken as an indication of weaker overall stratification, actually strengthens the isolation of the euphotic zone as a whole, reducing the upward supply of nitrate to the photosynthetically active layer. The same counterintuitive dynamic explains the latitudinal patterns in a set of three October depth profiles. Two northern stations (32°N and 27°N) were characterized by a thick, low

  20. Shallow methylmercury production in the marginal sea ice zone of the central Arctic Ocean.

    Science.gov (United States)

    Heimbürger, Lars-Eric; Sonke, Jeroen E; Cossa, Daniel; Point, David; Lagane, Christelle; Laffont, Laure; Galfond, Benjamin T; Nicolaus, Marcel; Rabe, Benjamin; van der Loeff, Michiel Rutgers

    2015-05-20

    Methylmercury (MeHg) is a neurotoxic compound that threatens wildlife and human health across the Arctic region. Though much is known about the source and dynamics of its inorganic mercury (Hg) precursor, the exact origin of the high MeHg concentrations in Arctic biota remains uncertain. Arctic coastal sediments, coastal marine waters and surface snow are known sites for MeHg production. Observations on marine Hg dynamics, however, have been restricted to the Canadian Archipelago and the Beaufort Sea (Ocean (79-90 °N) profiles for total mercury (tHg) and MeHg. We find elevated tHg and MeHg concentrations in the marginal sea ice zone (81-85 °N). Similar to other open ocean basins, Arctic MeHg concentration maxima also occur in the pycnocline waters, but at much shallower depths (150-200 m). The shallow MeHg maxima just below the productive surface layer possibly result in enhanced biological uptake at the base of the Arctic marine food web and may explain the elevated MeHg concentrations in Arctic biota. We suggest that Arctic warming, through thinning sea ice, extension of the seasonal sea ice zone, intensified surface ocean stratification and shifts in plankton ecodynamics, will likely lead to higher marine MeHg production.

  1. Biodispersant production by sea bacteria and its application to oil spills at sea

    International Nuclear Information System (INIS)

    Mayol, M.A.; Pita, A.; Bergueiro, J.R.; Rallo, M.; Somoza, S.

    1998-01-01

    The feasibility of developing natural dispersants (biodispersants) for use in response to a marine oil spill was discussed. In this study biochemical tests were conducted with Bacillus and Coccus Gram Positive bacteria in order to select the one marine microorganism which is capable of producing biodispersants to degrade crude oil. Different carbon sources and salt concentrations were used in the experiments. A second experiment was conducted in which the production of biodispersants by the pure microbial strain were studied by measuring interfacial tension, determined by using the Longman method. The surfactant efficacy and the dispersant stability of Arabian Light crude oil was also studied. The biological oxygen demand at five days, biological oxygen demand at the end of the biodegradation, the biodegradation constant and the biochemical stabilization constant were determined during the degradation process. 23 refs., 9 tabs.,4 figs

  2. The Governance of Multi-Use Platforms at Sea for Energy Production and Aquaculture: Challenges for Policy Makers in European Seas

    Directory of Open Access Journals (Sweden)

    Marian Stuiver

    2016-04-01

    Full Text Available European seas are encountering an upsurge in competing marine activities and infrastructures. Traditional exploitation such as fisheries, tourism, transportation, and oil production are accompanied by new sustainable economic activities such as offshore windfarms, aquaculture, and tidal and wave energy. One proposed solution to overcome possible competing claims at sea lies in combining these economic activities as part of Multi-Use Platforms at Sea (MUPS. MUPS can be understood as areas at sea, designated for a combination of activities, either completely integrated in a platform or in shared marine space. MUPS can potentially benefit from each other in terms of infrastructure, maintenance, etc. Developing MUPS in the marine environment demands adequate governance. In this article, we investigate four European sites to find out how governance arrangements may facilitate or complicate MUPs. In particular, we apply a framework specifying policy, economic, social, technical, environmental, and legal (PESTEL factors to explore governance arrangements in four case study sites in different sea basins around Europe (the Mediterranean Sea, the Atlantic Ocean, the North Sea, and the Baltic Sea. The article concludes with policy recommendations on a governance regime for facilitating the development of MUPS in the future.

  3. Limitation of productivity by trace metals in the sea

    International Nuclear Information System (INIS)

    Morel, F.M.M.; Price, N.M.; Hudson, R.J.M.

    1991-01-01

    Some trace metals such as Fe, Ni, Cu, and Zn are essential for the growth of phytoplankton. The concentrations of these essential trace elements in seawater are so low as to limit their availability to aquatic microbiota. Trace element uptake is ultimately limited by kinetics of reaction with transport ligands or by diffusion to the cell. From what the authors know of the characteristics of the uptake systems of phytoplankton and their trace metal requirements they can estimate that Fe and Zn may at some times in some place limit phytoplankton productivity, which is in accord with available field data on trace metal enrichments

  4. Effects of topography on simulated net primary productivity at landscape scale.

    Science.gov (United States)

    Chen, X F; Chen, J M; An, S Q; Ju, W M

    2007-11-01

    Local topography significantly affects spatial variations of climatic variables and soil water movement in complex terrain. Therefore, the distribution and productivity of ecosystems are closely linked to topography. Using a coupled terrestrial carbon and hydrological model (BEPS-TerrainLab model), the topographic effects on the net primary productivity (NPP) are analyzed through four modelling experiments for a 5700 km(2) area in Baohe River basin, Shaanxi Province, northwest of China. The model was able to capture 81% of the variability in NPP estimated from tree rings, with a mean relative error of 3.1%. The average NPP in 2003 for the study area was 741 gCm(-2)yr(-1) from a model run including topographic effects on the distributions of climate variables and lateral flow of ground water. Topography has considerable effect on NPP, which peaks near 1350 m above the sea level. An elevation increase of 100 m above this level reduces the average annual NPP by about 25 gCm(-2). The terrain aspect gives rise to a NPP change of 5% for forests located below 1900 m as a result of its influence on incident solar radiation. For the whole study area, a simulation totally excluding topographic effects on the distributions of climatic variables and ground water movement overestimated the average NPP by 5%.

  5. Large historical growth in global terrestrial gross primary production

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J. E.; Berry, J. A.; Seibt, U.; Smith, S. J.; Montzka, S. A.; Launois, T.; Belviso, S.; Bopp, L.; Laine, M.

    2017-04-05

    Growth in terrestrial gross primary production (GPP) may provide a feedback for climate change, but there is still strong disagreement on the extent to which biogeochemical processes may suppress this GPP growth at the ecosystem to continental scales. The consequent uncertainty in modeling of future carbon storage by the terrestrial biosphere constitutes one of the largest unknowns in global climate projections for the next century. Here we provide a global, measurement-based estimate of historical GPP growth using long-term atmospheric carbonyl sulfide (COS) records derived from ice core, firn, and ambient air samples. We interpret these records using a model that relates changes in the COS concentration to changes in its sources and sinks, the largest of which is proportional to GPP. The COS history was most consistent with simulations that assume a large historical GPP growth. Carbon-climate models that assume little to no GPP growth predicted trajectories of COS concentration over the anthropogenic era that differ from those observed. Continued COS monitoring may be useful for detecting ongoing changes in GPP while extending the ice core record to glacial cycles could provide further opportunities to evaluate earth system models.

  6. Spatial scaling of net primary productivity using subpixel landcover information

    Science.gov (United States)

    Chen, X. F.; Chen, Jing M.; Ju, Wei M.; Ren, L. L.

    2008-10-01

    Gridding the land surface into coarse homogeneous pixels may cause important biases on ecosystem model estimations of carbon budget components at local, regional and global scales. These biases result from overlooking subpixel variability of land surface characteristics. Vegetation heterogeneity is an important factor introducing biases in regional ecological modeling, especially when the modeling is made on large grids. This study suggests a simple algorithm that uses subpixel information on the spatial variability of land cover type to correct net primary productivity (NPP) estimates, made at coarse spatial resolutions where the land surface is considered as homogeneous within each pixel. The algorithm operates in such a way that NPP obtained from calculations made at coarse spatial resolutions are multiplied by simple functions that attempt to reproduce the effects of subpixel variability of land cover type on NPP. Its application to a carbon-hydrology coupled model(BEPS-TerrainLab model) estimates made at a 1-km resolution over a watershed (named Baohe River Basin) located in the southwestern part of Qinling Mountains, Shaanxi Province, China, improved estimates of average NPP as well as its spatial variability.

  7. Investigating smoke's influence on primary production throughout the Amazon

    Science.gov (United States)

    Flanner, M. G.; Mahowald, N. M.; Zender, C. S.; Randerson, J. T.; Tosca, M. G.

    2007-12-01

    Smoke from annual burning in the Amazon causes large reduction in surface insolation and increases the diffuse fraction of photosynthetically-active radiation (PAR). These effects have competing influence on gross primary production (GPP). Recent studies indicate that the sign of net influence depends on aerosol optical depth, but the magnitude of smoke's effect on continental-scale carbon cycling is very poorly constrained and may constitute an important term of fire's net impact on carbon storage. To investigate widespread effects of Amazon smoke on surface radiation properties, we apply a version of the NCAR Community Atmosphere Model with prognostic aerosol transport, driven with re-analysis winds. Carbon aerosol emissions are derived from the Global Fire Emissions Database (GFED). We use AERONET observations to identify model biases in aerosol optical depth, single-scatter albedo, and surface radiative forcing, and prescribe new aerosol optical properties based on field observations to improve model agreement with AERONET data. Finally, we quantify a potential range of smoke-induced change in large-scale GPP based on: 1) ground measurements of GPP in the Amazon as a function of aerosol optical depth and diffuse fraction of PAR, and 2) empirical functions of ecosystem-scale photosynthesis rates currently employed in models such as the Community Land Model (CLM).

  8. Optimization and kinetic studies of sea mango (Cerbera odollam) oil for biodiesel production via supercritical reaction

    International Nuclear Information System (INIS)

    Ang, Gaik Tin; Ooi, San Nee; Tan, Kok Tat; Lee, Keat Teong; Mohamed, Abdul Rahman

    2015-01-01

    Highlights: • Sea mango oil as feedstock for biodiesel via non-catalytic supercritical reaction. • Extracted sea mango oil with high FFA could produce high yield of FAME. • Employment of Response Surface Methodology for optimization of FAME. • Kinetic study for reversible transesterification and esterification reactions. - Abstract: Sea mango (Cerbera odollam) oil, which is rich in free fatty acids, was utilized to produce fatty acid methyl esters (FAME) via supercritical transesterification reaction. Sea mango oil was extracted from seeds and was subsequently reacted with methanol in a batch-type supercritical reactor. Response surface methodology (RSM) analysis was used to optimize important parameters, including reaction temperature, reaction time and the molar ratio of methanol to oil. The optimum conditions were found as 380 °C, 40 min and 45:1 mol/mol, respectively, to achieve 78% biodiesel content. The first kinetic modelling of FAME production from sea mango oil incorporating reversible transesterification and reversible esterification was verified simultaneously. The kinetic parameters, including reaction rate constants, k, the pre-exponential constant, A, and the activation energy, Ea, for transesterification and esterification were determined using an ordinary differential equation (ODE45) solver. The highest activation energy of 40 kJ/mol and the lowest reaction rate constant of 2.50 × 10 −5 dm 3 /mol s verified that the first stepwise reaction of TG to produce DG was the rate-limiting step

  9. Design considerations of fission and corrosion product in primary system of MONJU

    International Nuclear Information System (INIS)

    Yanagisawa, T.; Akagane, K.; Yamamoto, K.; Kawashima, K.

    1976-01-01

    General influence of fission and corrosion products in primary system on MONJU plant design is reviewed. Various research and development works are now in progress to decrease the generation rate, to remove the products more effectively and to develop the methods of evaluation the behaviour of radioactive products. The inventory and distribution of fission and corrosion products in the primary circuit of MONJU are given. The radiation levels on the primary components are estimated to be several roentgens per hour. (author)

  10. Phase analysis of corrosion products of carbon steel in sea water

    International Nuclear Information System (INIS)

    Garcia R, J.; Yee M, H.; Maldonado M, H.; Nunez, L.; Reguera, E.

    1998-01-01

    Nowadays carbon steel continues being the most widely used metallic material in marine and coastal buildings. The economic losses, due to corrosion processes, of those countries with important industrial and social activities in coastal regions are highly significant. In this sense the evaluation of the corrosion process of carbon steel and other materials in seawater or in coastal zones is a primary task for protection methods or to predict the hfe of an specific installation. In this communication we present the phases analysis, using XRD and Moessbauer techniques, of corrosion products of a carbon steel (CT3, equivalent to AISI C1020) exposed in two natural corrosion stations in the Caribbean sea (Cuba). The exposition time run from days to 36 months and the evaluated rust are characteristic of samples totally immersed in seawater, from the splash zone and form coastal zones at different distance from the shoreline. Quantitative phase analysis shown presence of magnetite (Fe 3 O 4 ), maghemite (y-Fe 2 O 3 ), akaganeite (B-FeOOH), lepidocrocite (y-FeOOH) and goethite (a-FeOOH) as iron bearing phases, and CaCO 3 (Calcite and aragonite), these last ones mainly in the immersed samples. Quantitative phase analysis by XRD was implemented as a linear combination of the patterns characteristic of all the detected phases and an appropriate model for the background. The quantitative results were used in kinetic models to understand the phase transformation between the iron oxides and oxy hydroxides in the studied conditions. The XRD qualitative and quantitative results were corroborated by Moessbauer spectroscopy in the temperature range of 20 to 300 K. (Author)

  11. Reducing the uncertainty of the primary damage production in Fe

    International Nuclear Information System (INIS)

    Bjorkas, C.; Nordlund, K.

    2007-01-01

    Full text of publication follows: One of the key questions for understanding neutron irradiation damage buildup in fission and fusion reactor steels is knowing the primary damage state produced by neutron-induced atomic recoils in Fe. Supporting this is our recent study revealing that the initial damage in Fe 0.9 Cr 0.1 is essentially the same as in pure Fe [1]. In spite of decades of study, the question of what the amount and distribution of defects in Fe is, has remained highly unclear. Different computer simulations modules have given a good qualitative understanding of the cascade development [1,2]. However, quantitative differences of more than a factor of three have remained in the predicted clustered defect production numbers [2]. The disagreements between the potentials pose problems for finding a reliable predictive model for the behavior of Fe under irradiation. In this study we analyze the initial damage as predicted by three recent interatomic potentials for Fe. These are well suited for a comparison because they have very different physical motivations and functional forms, but are comparable in overall quality and in particular reproduce the energetics of interstitials in different configurations well. The potentials are those by Ackland and Mendelev et al. (AMS) [3], the 'magnetic' potential by Dudarev and Derlet (DD) [4] and the Tersoff-like analytical potential by Mueller, Erhart and Albe (MEA) [5]. The DD and MEA potentials were modified by us to describe high-energy repulsive interactions well. All potentials were then used in recoil collision cascade simulations carried out and analyzed in exactly the same manner for all potentials. Analysis of the resulting damage showed a much smaller uncertainty regarding the damage production than that of previous potentials. The total defect production numbers essentially agree within the statistical uncertainty for the three potentials. Some differences remains regarding the defect clustered fractions, but

  12. Nutrient dynamics and primary production in a pristine coastal mangrove ecosystem: Andaman Islands, India

    Science.gov (United States)

    Jenkins, E. N.; Nickodem, K.; Siemann, A. L.; Hoeher, A.; Sundareshwar, P. V.; Ramesh, R.; Purvaja, R.; Banerjee, K.; Manickam, S.; Haran, H.

    2012-12-01

    Mangrove ecosystems play a key role in supporting coastal food webs and nutrient cycles in the coastal zone. Their strategic position between the land and the sea make them important sites for land-ocean interaction. As part of an Indo-US summer field course we investigated changes in the water chemistry in a pristine mangrove creek located at Wright Myo in the Andaman Islands, India. This study was conducted during the wet season (June 2012) to evaluate the influence of the coastal mangrove wetlands on the water quality and productivity in adjoining pelagic waters. Over a full tidal cycle spanning approximately 24 hrs, we measured nutrient concentrations and other ancillary parameters (e.g. dissolved oxygen, turbidity, salinity, etc.) hourly to evaluate water quality changes in incoming and ebbing tides. Nutrient analyses had the following concentration ranges (μM): nitrite 0.2-0.9, nitrate 2.0-11.5, ammonium 1.3-7.5, dissolved inorganic phosphate 0.7-2.8. The dissolved inorganic nitrogen to dissolved inorganic phosphate (DIN/DIP) ratio was very low relative to an optimal ratio, suggesting growth is nitrogen limited. In addition, we conducted primary production assays to investigate the factors that controlled primary production in this pristine creek. The experiment was carried out in situ using the Winkler method at low and high tide. Four-hour incubation of light and dark bottles representing a fixed control, non-fertilized, fertilized with nitrate, and fertilized with phosphate enabled the measurement of both net oxygen production and dark respiration. The low tide experiment suggests the ecosystem is heterotrophic because the oxygen measured in the light bottles was consistently less than that of the dark bottles. This result may be an experimental artifact of placing the glass bottles in the sun for too long prior to incubation, potentially leading to photolysis of large organic molecules in the light bottles. The high tide experiment also displayed

  13. NW European shelf under climate warming: implications for open ocean – shelf exchange, primary production, and carbon absorption

    Directory of Open Access Journals (Sweden)

    M. Gröger

    2013-06-01

    Full Text Available Shelves have been estimated to account for more than one-fifth of the global marine primary production. It has been also conjectured that shelves strongly influence the oceanic absorption of anthropogenic CO2 (carbon shelf pump. Owing to their coarse resolution, currently applied global climate models are inappropriate to investigate the impact of climate change on shelves and regional models do not account for the complex interaction with the adjacent open ocean. In this study, a global ocean general circulation model and biogeochemistry model were set up with a distorted grid providing a maximal resolution for the NW European shelf and the adjacent northeast Atlantic. Using model climate projections we found that already a~moderate warming of about 2.0 K of the sea surface is linked with a reduction by ~ 30% of the biological production on the NW European shelf. If we consider the decline of anthropogenic riverine eutrophication since the 1990s, the reduction of biological production amounts is even larger. The relative decline of NW European shelf productivity is twice as strong as the decline in the open ocean (~ 15%. The underlying mechanism is a spatially well confined stratification feedback along the continental shelf break. This feedback reduces the nutrient supply from the deep Atlantic to about 50%. In turn, the reduced productivity draws down CO2 absorption in the North Sea by ~ 34% at the end of the 21st century compared to the end of the 20th century implying a strong weakening of shelf carbon pumping. Sensitivity experiments with diagnostic tracers indicate that not more than 20% of the carbon absorbed in the North Sea contributes to the long-term carbon uptake of the world ocean. The rest remains within the ocean's mixed layer where it is exposed to the atmosphere. The predicted decline in biological productivity, and decrease of phytoplankton concentration (in the North Sea by averaged 25% due to reduced nutrient imports from

  14. Estimating Next Primary Productivity using Satellite and Ancillary Data

    Science.gov (United States)

    Choudhury, B. J.

    The net primary productivity (C) or annual rate of carbon accumulation per unit ground area by terrestrial plant communities is the difference of the rate of gross photosynthesis (Ag) and autotrophic respiration (R) per unit ground area. Although available observations show that R is a large and variable fraction of Ag, viz., 0.3 to 0.7, it is generally recognized that much uncertainties exist in this fraction due to difficulties associated with the needed measurements. Additional uncertainties arise when these measurements are extrapolated to regional or global land surface using empirical equations, for example, using regression equations relating C to mean annual precipitation and air temperature. Here, a process- based approach has been taken to calculate Ag and R using satellite and ancillary data. Ag has been expressed as a product of radiation use efficiency, magnitude of intercepted photosynthetically active radiation (PAR), and normalized by stresses due to soil water shortage and air temperature away from the optimum range. A biophysical model has been used to determine the radiation use efficiency from the maximum rate of carbon assimilation by a leaf, foliage temperature, and the fraction of diffuse PAR incident on a canopy. All meteorological data (PAR, air temperature, precipitation, etc.) needed for the calculation are derived from satellite observations, while a land use, land cover data (based on satellite and ground measurements) have been used to assess the maximum rate of carbon assimilation by a leaf of varied cover type based on field measurements. R has been calculated as the sum of maintenance and growth components. The maintenance respiration of foliage and live fine roots at a standard temperature of different land cover has been determined from their nitrogen content using field and satellite measurements, while that of living fraction of woody stem (viz., sapwood) from the seasonal maximum leaf area index as determined from satellite

  15. Benthic Light Availability Improves Predictions of Riverine Primary Production

    Science.gov (United States)

    Kirk, L.; Cohen, M. J.

    2017-12-01

    Light is a fundamental control on photosynthesis, and often the only control strongly correlated with gross primary production (GPP) in streams and rivers; yet it has received far less attention than nutrients. Because benthic light is difficult to measure in situ, surrogates such as open sky irradiance are often used. Several studies have now refined methods to quantify canopy and water column attenuation of open sky light in order to estimate the amount of light that actually reaches the benthos. Given the additional effort that measuring benthic light requires, we should ask if benthic light always improves our predictions of GPP compared to just open sky irradiance. We use long-term, high-resolution dissolved oxygen, turbidity, dissolved organic matter (fDOM), and irradiance data from streams and rivers in north-central Florida, US across gradients of size and color to build statistical models of benthic light that predict GPP. Preliminary results on a large, clear river show only modest model improvements over open sky irradiance, even in heavily canopied reaches with pulses of tannic water. However, in another spring-fed river with greater connectivity to adjacent wetlands - and hence larger, more frequent pulses of tannic water - the model improved dramatically with the inclusion of fDOM (model R2 improved from 0.28 to 0.68). River shade modeling efforts also suggest that knowing benthic light will greatly enhance our ability to predict GPP in narrower, forested streams flowing in particular directions. Our objective is to outline conditions where an assessment of benthic light conditions would be necessary for riverine metabolism studies or management strategies.

  16. Influence of oil pollution to the total biological productivity of the Caspian sea

    International Nuclear Information System (INIS)

    Salmanov, M.A.

    2005-01-01

    Full text : As a result of a numerous researches it was defined that among all the species of pollutants polluting water reservoirs, oil and its components has a leading role. In this respect the Caspian Sea is in a special condition, as it exists as an isolated water reservoirs it had a direct relation with oil and oil products earlier than others and more than the rest. For this reason the oil in the Caspian Sea in its turn has become a permanent substrate. The main reservoirs of contamination of environmental medium of the Caspian Sea by oil and oil products are oil industries, oil pipelines, oil processing ventures, oil transportation, oil-gas service and oil drilling. At the same time oil components due to dried lands appear in the sea by river floods that are a heavy showers. Oil is a complex environmental compound of carbohydrogenes and distributed in environmental medium. Its characteristic that no other pollutant as dangerous it hasn't been and cannot be compared with oil according to the range of distribution, amount of pollutant resources and range of pressure to all the compounds of environmental medium. During the involvement of oil in the hydrosphere deep, often inattentive changes of its chemical, physiological and microbiological features and even reconstruction of all the hydrospheric profile take place. Being dynamic and mobile it penetrates toxic metals increasing their emigrational ability, subsides to the bottom and oppresses benthofauna. At the same time oil products in water reservoirs in common negatively influence to the balance of oxygen and position of biocenoses in the surface layers of sea water. In the given information the results of many years and monitoring character of researches about the influence of pollution in the base of total biological productivity of the Caspian Sea are presented (as well as oil pollution). It was defined that in the basins of the North (Makachkala - from Berbash, Bautina, Shevchenko fleet), Middle (Sand

  17. Sea ice contribution to the air-sea CO(2) exchange in the Arctic and Southern Oceans

    DEFF Research Database (Denmark)

    Rysgaard...[], Søren; Bendtsen, Jørgen; Delille, B.

    2011-01-01

    Although salt rejection from sea ice is a key process in deep-water formation in ice-covered seas, the concurrent rejection of CO(2) and the subsequent effect on air-sea CO(2) exchange have received little attention. We review the mechanisms by which sea ice directly and indirectly controls the air......-sea CO(2) exchange and use recent measurements of inorganic carbon compounds in bulk sea ice to estimate that oceanic CO(2) uptake during the seasonal cycle of sea-ice growth and decay in ice-covered oceanic regions equals almost half of the net atmospheric CO(2) uptake in ice-free polar seas. This sea......-sea CO(2) exchange during winter, and (3) release of CO(2)-depleted melt water with excess total alkalinity during sea-ice decay and (4) biological CO(2) drawdown during primary production in sea ice and surface oceanic waters....

  18. Altered primary production during mass-extinction events

    NARCIS (Netherlands)

    van de Schootbrugge, B.; Gollner, S.

    2013-01-01

    The Big Five mass-extinction events are characterized by dramatic changes in primary producers. Initial disturbance to primary producers is usually followed by a succession of pioneers that represent qualitative and quantitative changes in standing crops of land plants and/or phytoplankton. On land,

  19. Denali Ice Core MSA: A Record of North Pacific Primary Productivity

    Science.gov (United States)

    Polashenski, D.; Osterberg, E. C.; Winski, D.; Kreutz, K. J.; Wake, C. P.; Ferris, D. G.; Introne, D.; Campbell, S. W.

    2017-12-01

    The high nutrient, low chlorophyll region of the North Pacific is one of the most biologically productive marine ecosystems in the world and forms the basis of commercial, sport, and subsistence fisheries worth more than a billion dollars annually. Marine phytoplankton prove to be important both as the primary producers in these ecosystems and as a major source of biogenic sulfur emissions which have long been hypothesized to serve as a biological control on Earth's climate system. Despite their importance, the record of marine phytoplankton abundance and the flux of biogenic sulfur from these regions is not well constrained. In situ measurements of marine phytoplankton from oceanographic cruises over the past several decades are limited in both spatial and temporal resolution. Meanwhile, marine sediment records may provide insight on million year timescales, but lack decadal resolution due to slow sediment deposition rates and bioturbation. In this study, we aim to investigate changes in marine phytoplankton productivity of the northeastern subarctic Pacific Ocean (NSPO) over the twentieth century using the methanesulfonic acid (MSA) record from the Mt. Hunter ice cores drilled in Denali National Park, Alaska. These parallel, 208 meter long ice cores were drilled during the 2013 field season on the Mt. Hunter plateau (63° N, 151° W, 4,000 m above sea level). Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) modeling is used to identify likely source areas in the NSPO for MSA being transported to the core site. SeaWiFS satellite imagery allows for a direct comparison of chlorophyll a concentrations in these source areas with MSA concentrations in the core record through time. Our findings suggest that the Denali ice core MSA record reflects changes in the biological productivity of marine phytoplankton and shows a significant decline in MSA beginning in 1961. We investigate several hypotheses for potential mechanisms driving this MSA decline

  20. Gemstones and Mineral Products in the Red Sea / Indian Ocean Trade of the First Millennium

    OpenAIRE

    Seland, Eivind Heldaas

    2017-01-01

    This article addresses the role of minerals and mineral products in general and gemstones in particular in Red Sea and Western Indian .cean trade in the frst millennium. It is argued that texts from the early part of the period provide a plausible, albeit approximate overview of the origin and distribution of most kinds of precious stones, and that stable climatic and topographic factors infuencing commercial patterns enable us also to discuss the more fragmentary evidence of the later part o...

  1. A multisensor approach to sea ice classification for the validation of DMSP-SSM/I passive microwave derived sea ice products

    Science.gov (United States)

    Steffen, K.; Schweiger, A. J.

    1990-01-01

    The validation of sea ice products derived from the Special Sensor Microwave Imager (SSM/I) on board a DMSP platform is examined using data from the Landsat MSS and NOAA-AVHRR sensors. Image processing techniques for retrieving ice concentrations from each type of imagery are developed and results are intercompared to determine the ice parameter retrieval accuracy of the SSM/I NASA-Team algorithm. For case studies in the Beaufort Sea and East Greenland Sea, average retrieval errors of the SSM/I algorithm are between 1.7 percent for spring conditions and 4.3 percent during freeze up in comparison with Landsat derived ice concentrations. For a case study in the East Greenland Sea, SSM/I derived ice concentration in comparison with AVHRR imagery display a mean error of 9.6 percent.

  2. Differential response of winter cooling on biological production in the northeastern Arabian Sea and northwestern Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Jyothibabu, R.; Maheswaran, P.A; Madhu, N.V.; Asharaf, T.T.M.; Gerson, V.J.; Haridas, P.; Venugopal, P.; Revichandran, C.; Nair, K.K.C.; Gopalakrishnan, T.C.

    The northern parts of the twin seas bordering the Indian subcontinent, the Arabian Sea (AS) and Bay of Bengal (BOB), were studied during the winter monsoon. Higher biological production was observed in the AS (chlorophyll a 47.5 mg m sup(-2...

  3. Subsidence due to gas production in the Wadden Sea: How to ensure no harm will be done to nature

    NARCIS (Netherlands)

    Thienen-Visser, K. van; Breunese, J.N.; Muntendam-Bos, A.G.

    2015-01-01

    The Wadden Sea is a shallow tidal sea in the north of the Netherlands where gas production is ongoing since 1986. Due to the sensitive nature of this area, gas extraction induced subsidence must remain within the "effective subsidence capacity" for the two tidal basins (Pinkegat and Zoutkamperlaag)

  4. Iron from melting glaciers fuels phytoplankton blooms in the Amundsen Sea (Southern Ocean): Phytoplankton characteristics and productivity

    NARCIS (Netherlands)

    Alderkamp, A.C.; Mills, M.M.; van Dijken, G.L.; Laan, P.; Thuróczy, C.-E.; Gerringa, L.J.A.; de Baar, H.J.W.; Payne, C.D.; Visser, R.J.W.; Buma, A.G.J.; Arrigo, K.R.

    2012-01-01

    The phytoplankton community composition and productivity in waters of the Amundsen Sea and surrounding sea ice zone were characterized with respect to iron (Fe) input from melting glaciers. High Fe input from glaciers such as the Pine Island Glacier, and the Dotson and Crosson ice shelves resulted

  5. Hydrogen Production from Sea Wave for Alternative Energy Vehicles for Public Transport in Trapani (Italy

    Directory of Open Access Journals (Sweden)

    Vincenzo Franzitta

    2016-10-01

    Full Text Available The coupling of renewable energy and hydrogen technologies represents in the mid-term a very interesting way to match the tasks of increasing the reliable exploitation of wind and sea wave energy and introducing clean technologies in the transportation sector. This paper presents two different feasibility studies: the first proposes two plants based on wind and sea wave resource for the production, storage and distribution of hydrogen for public transportation facilities in the West Sicily; the second applies the same approach to Pantelleria (a smaller island, including also some indications about solar resource. In both cases, all buses will be equipped with fuel-cells. A first economic analysis is presented together with the assessment of the avoidable greenhouse gas emissions during the operation phase. The scenarios addressed permit to correlate the demand of urban transport to renewable resources present in the territories and to the modern technologies available for the production of hydrogen from renewable energies. The study focuses on the possibility of tapping the renewable energy potential (wind and sea wave for the hydrogen production by electrolysis. The use of hydrogen would significantly reduce emissions of particulate matter and greenhouse gases in urban districts under analysis. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in different technical fields that show a good replicability.

  6. Net community production from autonomous oxygen observations in the Sargasso Sea

    Science.gov (United States)

    Feen, M.; Estapa, M. L.

    2016-02-01

    Optical sensors on autonomous floats provide high-resolution profiles of oxygen concentration over time. Improved spatiotemporal resolution in our measurements of oxygen will allow for better estimates of net community production and a greater understanding of the biological pump. Two autonomous profiling floats (NAVIS BGCi, Sea-Bird) equipped with SBE-63 optodes to measure dissolved oxygen were deployed in the Sargasso Sea on a series of five Bermuda Atlantic Time-series Study (BATS) cruises from July 2013 to April 2014. In situ calibration of the oxygen sensors to Winkler titration bottle samples at BATS did not show systematic drift in the oxygen sensors over time. Calibrations were applied to determine oxygen concentrations in profiles collected in the Sargasso Sea at 1.5 to 2.5 day intervals over a year. Oxygen concentrations were used to quantify sub-mixed layer net community production. Changes in production rates from this study were compared with upper water column biology and particle flux measurements obtained independently from optical sensors on the profiling floats, allowing us to examine processes controlling carbon export into the deep ocean.

  7. Preparation of a primary target for the production of fission products in a nuclear reactor

    International Nuclear Information System (INIS)

    Arino, H.; Cosolito, F.J.; George, K.D.; Thornton, A.K.

    1976-01-01

    A primary target for the production of fission products in a nuclear reactor, such as uranium or plutonium fission products, is comprised of an enclosed, cylindrical vessel, preferably comprised of stainless steel, having a thin, continuous, uniform layer of fissionable material, integrally bonded to its inner walls and a port permitting access to the interior of the vessel. A process is also provided for depositing uranium material on to the inner walls of the vessel. Upon irradiation of the target with neutrons from a nuclear reactor, radioactive fission products, such as molybdenum-99, are formed, and thereafter separated from the target by the introduction of an acidic solution through the port to dissolve the irradiated inner layer. The irradiation and dissolution are thus effected in the same vessel without the necessity of transferring the fissionable material and fission products to a separate chemical reactor. Subsequently, the desired isotopes are extracted and purified. Molybdenum-99 decays to technetium-99m which is a valuable medical diagnostic radioisotope. 3 claims, 1 drawing figure

  8. The South China Sea Mesoscale Eddy Experiment (S-MEE) and Its Primary Findings

    Science.gov (United States)

    Zhang, Z.; Tian, J.; Zhao, W.; Qiu, B.

    2016-02-01

    South China Sea (SCS), the largest marginal sea in the northwestern Pacific, have strong eddy activities as revealed by both satellite and in situ observations. The 3D structures of the SCS mesoscale eddies and their lifecycles, including the generation and dissipation processes, are, however, still not well understood at present because of the lack of well-designed field observations. In order to address the above two scientific issues (3D structure and lifecycle of SCS mesoscale eddies), the SCS Mesoscale Eddy Experiment (S-MEE for short) was designed and conducted in the period from October 2013 to June 2014. As part of S-MEE, two bottom-anchored subsurface mooring arrays with one consisting of 10 moorings and the other 7 moorings, were deployed along the historical pathway of the mesoscale eddies in the northern SCS. All the moorings were equipped with ADCPs, RCMs, CTDs and temperature chains to make continues measurements of horizontal current velocity and temperature/salinity in the whole water column. During the S-MEE, a total of 5 distinct mesoscale eddies were observed to cross the mooring arrays, among which one anticyclonic and cyclonic eddy pair was fully captured by the mooring arrays. In addition to moored observations, we also conducted two transects across the center of the anticyclonic eddy and made high-resolution hydrographic and turbulent mixing measurements. Based on the data collected by the S-MEE and concurrent satellite-derived observations, we constructed the full-depth 3D structure of the eddy pair and analyzed its generation and dissipation mechanisms. We found that the eddies extend from the surface to the sea bottom and display prominent tilted structures in the vertical. By conducting an eddy energy budget analysis, we further identified that generation of submesoscale motions constitutes the dominant mechanism for the oceanic eddy dissipation.

  9. Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species

    OpenAIRE

    Collier, Catherine J.; Ow, Yan X.; Langlois, Lucas; Uthicke, Sven; Johansson, Charlotte L.; O'Brien, Katherine R.; Hrebien, Victoria; Adams, Matthew P.

    2017-01-01

    Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km) in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant) occurs, for three seagrass species (Cymodocea serrulata, Halodule uninervis, and Zostera muelleri). To obtain whole plant net production...

  10. Denitrification processes in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    rate in the vicinity of 30 Tg Ny@u-1@@, but the extent of benthic contribution remains unknown. A decoupling of denitrification from primary production, unique to the Arabian Sea, is revealed by nitrite, Electron Transport System (ETS) activity...

  11. Prophage-Encoded Staphylococcal Enterotoxin A: Regulation of Production in Staphylococcus aureus Strains Representing Different Sea Regions

    Directory of Open Access Journals (Sweden)

    Nikoleta Zeaki

    2015-12-01

    Full Text Available The present study investigates the nature of the link between the staphylococcal enterotoxin A (SEA gene and the lifecycle of Siphoviridae bacteriophages, including the origin of strain variation regarding SEA production after prophage induction. Five strains representing three different genetic lines of the sea region were studied under optimal and prophage-induced growth conditions and the Siphoviridae lifecycle was followed through the phage replicative form copies and transcripts of the lysogenic repressor, cro. The role of SOS response on prophage induction was addressed through recA transcription in a recA-disruption mutant. Prophage induction was found to increase the abundance of the phage replicative form, the sea gene copies and transcripts and enhance SEA production. Sequence analysis of the sea regions revealed that observed strain variances were related to strain capacity for prophage induction, rather than sequence differences in the sea region. The impact of SOS response activation on the phage lifecycle was demonstrated by the absence of phage replicative form copies in the recA-disruption mutant after prophage induction. From this study it emerges that all aspects of SEA-producing strain, the Siphoviridae phage and the food environment must be considered when evaluating SEA-related hazards.

  12. Primary production in the Bay of Bengal during southwest monsoon of 1978

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattathiri, P.M.A.; Devassy, V.P.; Radhakrishna, K.

    Measurements of primary production, chlorophyll a and particulate organic carbon were made at 33, 43 and 44 stations respectively during August-September of 1978. The average surface production, chlorophyll a and particulate organic carbon values...

  13. Primary Productivity, NASA Aqua MODIS and GOES Imager, 0.1 degrees, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from NASA Aqua MODIS Chl a and NOAA GOES Imager SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific...

  14. Primary Productivity, NASA Aqua MODIS, 4.4 km, Global, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from NASA Aqua MODIS Chl a SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific evaluation by professional...

  15. Effects of composition of labile organic matter on biogenic production of methane in the coastal sediments of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Gonsalves, M.J.B.D.; Fernandes, C.E.G.; Fernandes, S.O.; Kirchman, D.L.; LokaBharathi, P.A.

    the high sedimentation rates in the Arabian Sea (Ramaswamy et al. 1991). These rates could also be enhanced by the delivery of fine-grained riverine particles which in turn contribute to enhancing methane production (Kvenvolden & Lorenson 2001...

  16. Variation of paleo-productivity and terrigenous input in the eastern Arabian Sea during the past 100 ka

    Digital Repository Service at National Institute of Oceanography (India)

    Ishfaq, A.M.; Pattan, J.N.; Matta, V.M.; Banakar, V.K.

    A 4.1m long sediment core from the eastern Arabian Sea is studied using multiple geochemical proxies to understand the variation of productivity and terrigenous matter supply during the past 100 ka. The temporal variation in element concentration...

  17. Relative Importance of Chemoautotrophy for Primary Production in a Light Exposed Marine Shallow Hydrothermal System

    Directory of Open Access Journals (Sweden)

    Gonzalo V. Gomez-Saez

    2017-04-01

    Full Text Available The unique geochemistry of marine shallow-water hydrothermal systems promotes the establishment of diverse microbial communities with a range of metabolic pathways. In contrast to deep-sea vents, shallow-water vents not only support chemosynthesis, but also phototrophic primary production due to the availability of light. However, comprehensive studies targeting the predominant biogeochemical processes are rare, and consequently a holistic understanding of the functioning of these ecosystems is currently lacking. To this end, we combined stable isotope probing of lipid biomarkers with an analysis of the bacterial communities to investigate if chemoautotrophy, in parallel to photoautotrophy, plays an important role in autotrophic carbon fixation and to identify the key players. The study was carried out at a marine shallow-water hydrothermal system located at 5 m water depth off Dominica Island (Lesser Antilles, characterized by up to 55°C warm hydrothermal fluids that contain high amounts of dissolved Fe2+. Analysis of the bacterial diversity revealed Anaerolineae of the Chloroflexi as the most abundant bacterial class. Furthermore, the presence of key players involved in iron cycling generally known from deep-sea hydrothermal vents (e.g., Zetaproteobacteria and Geothermobacter, supported the importance of iron-driven redox processes in this hydrothermal system. Uptake of 13C-bicarbonate into bacterial fatty acids under light and dark conditions revealed active photo- and chemoautotrophic communities, with chemoautotrophy accounting for up to 65% of the observed autotrophic carbon fixation. Relatively increased 13C-incorporation in the dark allowed the classification of aiC15:0, C15:0, and iC16:0 as potential lipid biomarkers for bacterial chemoautotrophy in this ecosystem. Highest total 13C-incorporation into fatty acids took place at the sediment surface, but chemosynthesis was found to be active down to 8 cm sediment depth. In conclusion

  18. Use of radio-active carbon (/sup 14/C) for measuring organic production in the sea

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, E S

    1952-01-01

    A method for measuring the photosynthesis of plankton algae in a water sample by means of assimilated /sup 14/C is described. It is shown that the assimilation of /sup 14/C in organic matter otherwise than by photosynthesis is of quite insignificant importance. An account is given of the isotope effect in photosynthesis. Two different methods for the measurement of production of matter per surface unit are described. In the first method samples of water are taken from the various depths and transferred to bottles with glass stoppers. After addition of /sup 14/C, the bottles are suspended at the depths from which the samples were taken, and left there from noon to sunset, for instance. In the other method the bottles are placed in a water-bath which is illuminated by a definite light intensity. The penetration of light in the sea is determined at the same time. The production of matter per surface unit is calculated by means of a formula involving the determination of the depth at which 1 per cent of the total amount of green and blue light occurs, and measurement of the intensities of assimilation in water-bath. The formula, which applies to the tropics, has been derived by comparing the results from all tropical stations, at which observations by the two methods were made simultaneously. The values found for production of matter on a section across the Indian Ocean are recorded. The net production of matter for all sea regions on the globe is estimated at about 1.5 x 10/sup +10/ tons of carbon per year, which is slightly less than the amount produced on land, and the hitherto accepted figures for the production of matter in the sea have proved to be greatly exaggerated.

  19. Short-term to seasonal variability in factors driving primary productivity in a shallow estuary: Implications for modeling production

    Science.gov (United States)

    Canion, Andy; MacIntyre, Hugh L.; Phipps, Scott

    2013-10-01

    The inputs of primary productivity models may be highly variable on short timescales (hourly to daily) in turbid estuaries, but modeling of productivity in these environments is often implemented with data collected over longer timescales. Daily, seasonal, and spatial variability in primary productivity model parameters: chlorophyll a concentration (Chla), the downwelling light attenuation coefficient (kd), and photosynthesis-irradiance response parameters (Pmchl, αChl) were characterized in Weeks Bay, a nitrogen-impacted shallow estuary in the northern Gulf of Mexico. Variability in primary productivity model parameters in response to environmental forcing, nutrients, and microalgal taxonomic marker pigments were analysed in monthly and short-term datasets. Microalgal biomass (as Chla) was strongly related to total phosphorus concentration on seasonal scales. Hourly data support wind-driven resuspension as a major source of short-term variability in Chla and light attenuation (kd). The empirical relationship between areal primary productivity and a combined variable of biomass and light attenuation showed that variability in the photosynthesis-irradiance response contributed little to the overall variability in primary productivity, and Chla alone could account for 53-86% of the variability in primary productivity. Efforts to model productivity in similar shallow systems with highly variable microalgal biomass may benefit the most by investing resources in improving spatial and temporal resolution of chlorophyll a measurements before increasing the complexity of models used in productivity modeling.

  20. Modelling size-fractionated primary production in the Atlantic Ocean from remote sensing

    Science.gov (United States)

    Brewin, Robert J. W.; Tilstone, Gavin H.; Jackson, Thomas; Cain, Terry; Miller, Peter I.; Lange, Priscila K.; Misra, Ankita; Airs, Ruth L.

    2017-11-01

    Marine primary production influences the transfer of carbon dioxide between the ocean and atmosphere, and the availability of energy for the pelagic food web. Both the rate and the fate of organic carbon from primary production are dependent on phytoplankton size. A key aim of the Atlantic Meridional Transect (AMT) programme has been to quantify biological carbon cycling in the Atlantic Ocean and measurements of total primary production have been routinely made on AMT cruises, as well as additional measurements of size-fractionated primary production on some cruises. Measurements of total primary production collected on the AMT have been used to evaluate remote-sensing techniques capable of producing basin-scale estimates of primary production. Though models exist to estimate size-fractionated primary production from satellite data, these have not been well validated in the Atlantic Ocean, and have been parameterised using measurements of phytoplankton pigments rather than direct measurements of phytoplankton size structure. Here, we re-tune a remote-sensing primary production model to estimate production in three size fractions of phytoplankton (10 μm) in the Atlantic Ocean, using measurements of size-fractionated chlorophyll and size-fractionated photosynthesis-irradiance experiments conducted on AMT 22 and 23 using sequential filtration-based methods. The performance of the remote-sensing technique was evaluated using: (i) independent estimates of size-fractionated primary production collected on a number of AMT cruises using 14C on-deck incubation experiments and (ii) Monte Carlo simulations. Considering uncertainty in the satellite inputs and model parameters, we estimate an average model error of between 0.27 and 0.63 for log10-transformed size-fractionated production, with lower errors for the small size class (10 μm), and errors generally higher in oligotrophic waters. Application to satellite data in 2007 suggests the contribution of cells 2 μm to total

  1. Nutrient availability limits biological production in Arctic sea ice melt ponds

    DEFF Research Database (Denmark)

    Sørensen, Heidi Louise; Thamdrup, Bo; Jeppesen, Erik

    2017-01-01

    nutrient limitation in melt ponds. We also document that the addition of nutrients, although at relative high concentrations, can stimulate biological productivity at several trophic levels. Given the projected increase in first-year ice, increased melt pond coverage during the Arctic spring and potential......Every spring and summer melt ponds form at the surface of polar sea ice and become habitats where biological production may take place. Previous studies report a large variability in the productivity, but the causes are unknown. We investigated if nutrients limit the productivity in these first...... additional nutrient supply from, e.g. terrestrial sources imply that biological activity of melt ponds may become increasingly important for the sympagic carbon cycling in the future Arctic....

  2. The impact of global warming on seasonality of ocean primary production

    Directory of Open Access Journals (Sweden)

    S. Henson

    2013-06-01

    Full Text Available The seasonal cycle (i.e. phenology of oceanic primary production (PP is expected to change in response to climate warming. Here, we use output from 6 global biogeochemical models to examine the response in the seasonal amplitude of PP and timing of peak PP to the IPCC AR5 warming scenario. We also investigate whether trends in PP phenology may be more rapidly detectable than trends in annual mean PP. The seasonal amplitude of PP decreases by an average of 1–2% per year by 2100 in most biomes, with the exception of the Arctic which sees an increase of ~1% per year. This is accompanied by an advance in the timing of peak PP by ~0.5–1 months by 2100 over much of the globe, and particularly pronounced in the Arctic. These changes are driven by an increase in seasonal amplitude of sea surface temperature (where the maxima get hotter faster than the minima and a decrease in the seasonal amplitude of the mixed layer depth and surface nitrate concentration. Our results indicate a transformation of currently strongly seasonal (bloom forming regions, typically found at high latitudes, into weakly seasonal (non-bloom regions, characteristic of contemporary subtropical conditions. On average, 36 yr of data are needed to detect a climate-change-driven trend in the seasonal amplitude of PP, compared to 32 yr for mean annual PP. Monthly resolution model output is found to be inadequate for resolving phenological changes. We conclude that analysis of phytoplankton seasonality is not necessarily a shortcut to detecting climate change impacts on ocean productivity.

  3. Climate engineering and the ocean: effects on biogeochemistry and primary production

    Science.gov (United States)

    Lauvset, Siv K.; Tjiputra, Jerry; Muri, Helene

    2017-12-01

    Here we use an Earth system model with interactive biogeochemistry to project future ocean biogeochemistry impacts from the large-scale deployment of three different radiation management (RM) climate engineering (also known as geoengineering) methods: stratospheric aerosol injection (SAI), marine sky brightening (MSB), and cirrus cloud thinning (CCT). We apply RM such that the change in radiative forcing in the RCP8.5 emission scenario is reduced to the change in radiative forcing in the RCP4.5 scenario. The resulting global mean sea surface temperatures in the RM experiments are comparable to those in RCP4.5, but there are regional differences. The forcing from MSB, for example, is applied over the oceans, so the cooling of the ocean is in some regions stronger for this method of RM than for the others. Changes in ocean net primary production (NPP) are much more variable, but SAI and MSB give a global decrease comparable to RCP4.5 (˜ 6 % in 2100 relative to 1971-2000), while CCT gives a much smaller global decrease of ˜ 3 %. Depending on the RM methods, the spatially inhomogeneous changes in ocean NPP are related to the simulated spatial change in the NPP drivers (incoming radiation, temperature, availability of nutrients, and phytoplankton biomass) but mostly dominated by the circulation changes. In general, the SAI- and MSB-induced changes are largest in the low latitudes, while the CCT-induced changes tend to be the weakest of the three. The results of this work underscore the complexity of climate impacts on NPP and highlight the fact that changes are driven by an integrated effect of multiple environmental drivers, which all change in different ways. These results stress the uncertain changes to ocean productivity in the future and advocate caution at any deliberate attempt at large-scale perturbation of the Earth system.

  4. Production of Arctic Sea-ice Albedo by fusion of MISR and MODIS data

    Science.gov (United States)

    Kharbouche, Said; Muller, Jan-Peter

    2017-04-01

    We have combined data from the NASA MISR and MODIS spectro-radiometers to create a cloud-free albedo dataset specifically for sea-ice. The MISR (Multi-Angular Spectro-Radiometer) instrument on board Terra satellite has a unique ability to create high-quality Bidirectional Reflectance (BRF) over a 7 minute time interval per single overpass, thanks to its 9 cameras of different view angles (±70°,±60°,±45°,±26°). However, as MISR is limited to narrow spectral bands (443nm, 555nm, 670nm, 865nm), which is not sufficient to mask cloud effectively and robustly, we have used the sea-ice mask MOD09 product (Collection 6) from MODIS (Moderate resolution Imaging Spectoradiometer) instrument, which is also on board Terra satellite and acquiring data simultaneously. Only We have created a new and consistent sea-ice (for Arctic) albedo product that is daily, from 1st March to 22nd September for each and every year between 2000 to 2016 at two spatial grids, 1km x 1km and 5km x 5km in polar stereographic projection. Their analysis is described in a separate report [1]. References [1] Muller & Kharbouche, Variation of Arctic's Sea-ice Albedo between 2000 and 2016 by fusion of MISR and MODIS data. This conference. Acknowledgements This work was supported by www.QA4ECV.eu, a project of European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 607405. We thank our colleagues at JPL and NASA LaRC for processing these data, especially Sebastian Val and Steve Protack.

  5. Benthic primary producers are key to sustain the Wadden Sea food web

    NARCIS (Netherlands)

    Christianen, M.J.A.; Middelburg, J.J.; Holthuijsen, S.J.; Jouta, J.; Compton, T.J.; Heide, van der T.; Piersma, T.; Sinninghe Damsté, J.S.; Veer, van der H.W.; Schouten, S.; Olff, H.

    2017-01-01

    Coastal food webs can be supported by local benthic or pelagic primary producers and by the import of organic matter. Distinguishing between these energy sources is essential for our understanding of ecosystem functioning. However, the relative contribution of these components to the food web at the

  6. Oil companies make the deep-sea production reliable; Les petroliers fiabilisent la production par grands fonds

    Energy Technology Data Exchange (ETDEWEB)

    Jemain, A.

    2002-06-01

    Today, oil companies have to face important technical challenges in deep offshore operations like drilling wells with more than 3000 m of water depth, but the main problem concerns the reliability of underwater production equipments with respect to their pressure and fatigue resistance and to their durability. New solutions have to be found to fluidify the crude in deep sea conditions (thermal insulation, 'pipe in pipe' system, electrical heating, additives, inhibitors..) and to prevent the formation of paraffin and hydrates (flow assurance), and also to reduce the weight of risers (use of low density high grade composite materials). (J.S.)

  7. Effect of the fast pyrolysis temperature on the primary and secondary products of lignin

    NARCIS (Netherlands)

    Zhou, Shuai; Garcia-Perez, Manuel; Pecha, Brennan; Kersten, Sascha R.A.; McDonald, Armando G.; Westerhof, Roel Johannes Maria

    2013-01-01

    This paper presents results on the primary pyrolysis products of organosolv lignin at temperatures between 360 and 700 °C. To study the primary products, a vacuum screen heater (heating rate of 8000 °C/s, deep vacuum of 0.7 mbar, and very fast cooling at the wall temperature of −100 °C) was used.

  8. Net primary productivity of subalpine meadows in Yosemite National Park in relation to climate variability

    Science.gov (United States)

    Peggy E. Moore; Jan W. van Wagtendonk; Julie L. Yee; Mitchel P. McClaran; David N. Cole; Neil K. McDougald; Matthew L. Brooks

    2013-01-01

    Subalpine meadows are some of the most ecologically important components of mountain landscapes, and primary productivity is important to the maintenance of meadow functions. Understanding how changes in primary productivity are associated with variability in moisture and temperature will become increasingly important with current and anticipated changes in climate....

  9. Primary production, nutrient dynamics and mineralisation in a northeastern Greenland fjord during the summer thaw

    DEFF Research Database (Denmark)

    Rysgaard, S.; Finster, K.; Dahlgaard, H.

    1996-01-01

    This investigation represents the first integrated study of primary production, nutrient dynamics and mineralisation in a northeastern fjord of Greenland. The data presented represent conditions and activities during the early summer thaw (first 2 weeks of July). Primary production (5.3 mmol C m(...

  10. Can the primary algae production be measured precisely?

    International Nuclear Information System (INIS)

    Olesen, M.; Lundsgaard, C.

    1996-01-01

    Algae production in seawater is extremely important as a basic link in marine food chains. Evaluation of the algae quantity is based on 14CO 2 tracer techniques while natural circulation and light absorption in seawater is taken insufficiently into account. Algae production can vary by 500% in similar nourishment conditions, but varying water mixing conditions. (EG)

  11. Linking climate, gross primary productivity, and site index across forests of the western United States

    Science.gov (United States)

    Aaron R. Weiskittel; Nicholas L. Crookston; Philip J. Radtke

    2011-01-01

    Assessing forest productivity is important for developing effective management regimes and predicting future growth. Despite some important limitations, the most common means for quantifying forest stand-level potential productivity is site index (SI). Another measure of productivity is gross primary production (GPP). In this paper, SI is compared with GPP estimates...

  12. Yields of primary products from chloroethylenes in air under electron beam irradiation

    International Nuclear Information System (INIS)

    Hakoda, Teruyuki; Hashimoto, Shoji; Kojima, Takuji

    2003-01-01

    The quantitative analysis of toxic primary irradiation products was carried out for the development of the purification technology of chloroethylenes/air mixtures using an electron beam (EB). Degradation of chloroethylenes in humid air proceeded through the formation of primary products retaining a carbon-carbon (C-C) bond such as chloroacetyl chlorides and chloroacetyl aldehyde as well as that of primary products of COCl 2 and HCOCl through C-C bond cleavage. Chloroethylenes having one carbon bonded to two Cl atoms was decomposed into the primary products retaining a C-C bond prior to breaking a C-C bond. The number of Cl atoms of a chloroethylene molecule enhanced the formation ratio of primary products retaining a C-C bond. On the other hand, chloroethylene having two carbons bonded to one Cl atom was degraded thought the scission of a C-C bond predominantly C-C bond maintenance. (author)

  13. Contrasts in Sea Ice Formation and Production in the Arctic Seasonal and Perennial Ice Zones

    Science.gov (United States)

    Kwok, R.

    2006-01-01

    Four years (1997-2000) of RADARSAT Geophysical Processor System (RGPS) data are used to contrast the sea ice deformation and production regionally, and in the seasonal (SIZ) and perennial (PIZ) ice zones. Ice production is of seasonal ice in openings during the winter. 3-day estimates of these quantities are provided within Lagrangian elements initially 10 km on a side. A distinct seasonal cycle is seen in both zones with these estimates highest in the late fall and with seasonal minimums in the mid-winter. Regional divergence over the winter could be up to 30%. Spatially, the highest deformation is in the SIZ north of coastal Alaska. Both ice deformation and production are higher in the SIZ: deformation-related ice production in the SIZ (approx.0.5 m) is 1.5-2.3 times that of the PIZ (approx.0.3 m) - this is connected to ice strength and thickness. Atmospheric forcing and boundary layer structure contribute to only the seasonal and interannual variability. Seasonal ice growth in ice fractures accounts for approx.25-40% of the total ice production of the Arctic Ocean. By itself, this deformation-ice production relationship could be considered a negative feedback when thickness is perturbed. However, the overall effect on ice production in the face of increasing seasonal and thinner/weaker ice coverage could be modified by: local destabilization of the water column promoting overturning of warmer water due to increased brine rejection; and, the upwelling of the pynocline associated with increased occurrence of large shear motion in sea ice.

  14. Hematopoietic Stem Cell Transplantation in Primary Immunodeficiency Patients in the Black Sea Region of Turkey

    Directory of Open Access Journals (Sweden)

    Alişan Yıldıran

    2017-12-01

    Full Text Available Hematopoietic stem cell transplantation is a promising curative therapy for many combined primary immunodeficiencies and phagocytic disorders. We retrospectively reviewed pediatric cases of patients diagnosed with primary immunodeficiencies and scheduled for hematopoietic stem cell transplantation. We identified 22 patients (median age, 6 months; age range, 1 month to 10 years with various diagnoses who received hematopoietic stem cell transplantation. The patient diagnoses included severe combined immunodeficiency (n=11, Chediak-Higashi syndrome (n=2, leukocyte adhesion deficiency (n=2, MHC class 2 deficiency (n=2, chronic granulomatous syndrome (n=2, hemophagocytic lymphohistiocytosis (n=1, Wiskott-Aldrich syndrome (n=1, and Omenn syndrome (n=1. Of the 22 patients, 7 received human leukocyte antigen-matched related hematopoietic stem cell transplantation, 12 received haploidentical hematopoietic stem cell transplantation, and 2 received matched unrelated hematopoietic stem cell transplantation. The results showed that 5 patients had graft failure. Fourteen patients survived, yielding an overall survival rate of 67%. Screening newborn infants for primary immunodeficiency diseases may result in timely administration of hematopoietic stem cell transplantation.

  15. Hematopoietic Stem Cell Transplantation in Primary Immunodeficiency Patients in the Black Sea Region of Turkey.

    Science.gov (United States)

    Yıldıran, Alişan; Çeliksoy, Mehmet Halil; Borte, Stephan; Güner, Şükrü Nail; Elli, Murat; Fışgın, Tunç; Özyürek, Emel; Sancak, Recep; Oğur, Gönül

    2017-12-01

    Hematopoietic stem cell transplantation is a promising curative therapy for many combined primary immunodeficiencies and phagocytic disorders. We retrospectively reviewed pediatric cases of patients diagnosed with primary immunodeficiencies and scheduled for hematopoietic stem cell transplantation. We identified 22 patients (median age, 6 months; age range, 1 month to 10 years) with various diagnoses who received hematopoietic stem cell transplantation. The patient diagnoses included severe combined immunodeficiency (n=11), Chediak-Higashi syndrome (n=2), leukocyte adhesion deficiency (n=2), MHC class 2 deficiency (n=2), chronic granulomatous syndrome (n=2), hemophagocytic lymphohistiocytosis (n=1), Wiskott-Aldrich syndrome (n=1), and Omenn syndrome (n=1). Of the 22 patients, 7 received human leukocyte antigen-matched related hematopoietic stem cell transplantation, 12 received haploidentical hematopoietic stem cell transplantation, and 2 received matched unrelated hematopoietic stem cell transplantation. The results showed that 5 patients had graft failure. Fourteen patients survived, yielding an overall survival rate of 67%. Screening newborn infants for primary immunodeficiency diseases may result in timely administration of hematopoietic stem cell transplantation.

  16. Spatial and temporal variability of chlorophyll and primary productivity in surface waters of southern Chile (41.5 43° S)

    Science.gov (United States)

    Iriarte, J. L.; González, H. E.; Liu, K. K.; Rivas, C.; Valenzuela, C.

    2007-09-01

    The southern fjord region of Chile is a unique ecosystem characterized by complex marine-terrestrial-atmospheric interactions that result in high biological production. Since organic nitrogen from terrestrial and atmospheric compartments is highly significant in this region (>40%), as is the low NO 3:PO 4 ratio in surface waters, it is suggested that fertilization from inorganic and organic nitrogen sources has a strong influence on both phytoplankton biomass/primary production and harmful algae bloom dynamics. The data presented in this paper provide an opportunity to improve our knowledge of phytoplankton dynamics on temporal and spatial mesoscales. Ocean color data from NASA (SeaWiFS) for chlorophyll and primary production estimates and in situ surface measurement of inorganic nutrients, phytoplankton biomass, and primary productivity revealed that the coastal waters of southern Chile have a classical spring and autumn chlorophyll bloom cycle in which primary production is co-limited by strong seasonal changes in light and nitrate. During spring blooms, autotrophic biomass (such as chlorophyll a, Chl- a) and primary production estimates reached 25 mg Chl- a m -3 and 23 mg C m -3 h -1, respectively, and micro-phytoplankton accounted for a significant portion of the biomass (60%) in spring. The contribution of phytoplankton size classes to total chlorophyll a revealed the dominance of nanoplankton (>50%) in winter and post-bloom periods (<1.0 mg Chl- a m -3).

  17. PROMOTION OF PRIMARY PRODUCTS - A VIEW FROM THE CLOISTER

    OpenAIRE

    Quilkey, John J.

    1986-01-01

    This paper is a discourse on how promotion may contribute to the efficiency of consumption. The view is taken that, through its addition to the quantity of search with respect to product characteristics, promotion may enable consumers to allocate their expenditures more efficiently and yield additional revenue to producers of the promoted product. The central plea is for consistency in the identification of promotion objectives, the implementation of the promotion program and monitoring of th...

  18. Global resistance and resilience of primary production following extreme drought are predicted by mean annual precipitation

    Science.gov (United States)

    Stuart-Haëntjens, E. J.; De Boeck, H. J.; Lemoine, N. P.; Gough, C. M.; Kröel-Dulay, G.; Mänd, P.; Jentsch, A.; Schmidt, I. K.; Bahn, M.; Lloret, F.; Kreyling, J.; Wohlgemuth, T.; Stampfli, A.; Anderegg, W.; Classen, A. T.; Smith, M. D.

    2017-12-01

    Extreme drought is increasing globally in frequency and intensity, with uncertain consequences for the resistance and resilience of key ecosystem functions, including primary production. Primary production resistance, the capacity of an ecosystem to withstand change in primary production following extreme climate, and resilience, the degree to which primary production recovers, vary among and within ecosystem types, obscuring global patterns of resistance and resilience to extreme drought. Past syntheses on resistance have focused climatic gradients or individual ecosystem types, without assessing interactions between the two. Theory and many empirical studies suggest that forest production is more resistant but less resilient than grassland production to extreme drought, though some empirical studies reveal that these trends are not universal. Here, we conducted a global meta-analysis of sixty-four grassland and forest sites, finding that primary production resistance to extreme drought is predicted by a common continuum of mean annual precipitation (MAP). However, grasslands and forests exhibit divergent production resilience relationships with MAP. We discuss the likely mechanisms underlying the mixed production resistance and resilience patterns of forests and grasslands, including different plant species turnover times and drought adaptive strategies. These findings demonstrate the primary production responses of forests and grasslands to extreme drought are mixed, with far-reaching implications for Earth System Models, ecosystem management, and future studies of extreme drought resistance and resilience.

  19. Production, optimisation and characterisation of angiotensin converting enzyme inhibitory peptides from sea cucumber (Stichopus japonicus) gonad.

    Science.gov (United States)

    Zhong, Chan; Sun, Le-Chang; Yan, Long-Jie; Lin, Yi-Chen; Liu, Guang-Ming; Cao, Min-Jie

    2018-01-24

    In this study, production of bioactive peptides with angiotensin converting enzyme (ACE) inhibitory activity from sea cucumber (Stichopus japonicus) gonad using commercial protamex was optimised by response surface methodology (RSM). As a result, the optimal condition to achieve the highest ACE inhibitory activity in sea cucumber gonad hydrolysate (SCGH) was hydrolysis for 1.95 h and E/S of 0.75%. For further characterisation, three individual peptides (EIYR, LF and NAPHMR) were purified and identified. The peptide NAPHMR showed the highest ACE inhibitory activity with IC 50 of 260.22 ± 3.71 μM. NAPHMR was stable against simulated gastrointestinal digestion and revealed no significant cytotoxicity toward Caco-2 cells. Molecular docking study suggested that Arg, His and Asn residues in NAPHMR interact with the S2 pocket or Zn 2+ binding motifs of ACE via hydrogen or π-bonds, potentially contributing to ACE inhibitory effect. Sea cucumber gonad is thus a potential resource to produce ACE inhibitory peptides for preparation of functional foods.

  20. Epibenthic diversity and productivity on a heavily trawled Barents Sea bank (Tromsøflaket

    Directory of Open Access Journals (Sweden)

    Monika Kędra

    2017-04-01

    Full Text Available Shallow Arctic banks have been observed to harbour rich communities of epifaunal organisms, but have not been well-studied with respect to composition or function due to sampling challenges. In order to determine how these banks function in the Barents Sea ecosystem, we used a combination of video and trawl/dredge sampling at several locations on a heavily trawled bank, Tromsøflaket – located at the southwestern entrance to the Barents Sea. We describe components of the benthic community, and calculate secondary production of dominant epifaunal organisms. Forty-six epibenthic taxa were identified, and sponges were a significant part of the surveyed benthic communities. There were differences in diversity and production among areas, mainly related to the intensity of trawling activities. Gamma was the most diverse and productive area, with highest species abundance and biomass. Trawled areas had considerably lower species numbers, and significant differences in epifaunal abundance and biomass were found between all trawled and untrawled areas. Trawling seems to have an impact on the sponge communities: mean individual poriferan biomass was higher in untrawled areas, and, although poriferans were observed in areas subjected to more intensive trawling, they were at least five times less frequent than in untrawled areas.

  1. Increase in Export Production in the Marginal Seas of the Northwestern Pacific in Response to Anthropogenic N Input

    Science.gov (United States)

    Lee, K.; Ko, Y. H.; Moon, J. Y.

    2017-12-01

    The relative abundance of nitrate (N) over phosphorus (P) has increased significantly over the period since 1980 in the marginal seas (Yellow, East China and East seas) bordering the northwestern Pacific Ocean, located downstream of the populated and industrialized Asian continent. Analysis of datasets for anthropogenic N input, satellite chlorophyll-a (Chl-a), and seawater nutrient data ( 200,000 data points) reveal that transport of N originating from China has been responsible for enhancements of Chl-a in the marginal seas of the northwestern Pacific Ocean. In particular, the contribution of anthropogenic N to new production in these marginal seas is expected to grow considerably in the coming decades. This anthropogenically driven increase in the N content may potentially lead to a long-term change of these marginal seas from being N-limited to P-limited.

  2. Scaling Gross Primary Production (GPP) over boreal and deciduous forest landscapes in support of MODIS GPP product validation.

    Science.gov (United States)

    David P. Turner; William D. Ritts; Warren B. Cohen; Stith T. Gower; Maosheng Zhao; Steve W. Running; Steven C. Wofsy; Shawn Urbanski; Allison L. Dunn; J.W. Munger

    2003-01-01

    The Moderate Resolution Imaging Radiometer (MODIS) is the primary instrument in the NASA Earth Observing System for monitoring the seasonality of global terrestrial vegetation. Estimates of 8-day mean daily gross primary production (GPP) at the 1 km spatial resolution are now operationally produced by the MODIS Land Science Team for the global terrestrial surface using...

  3. Primary defect production by high energy displacement cascades in molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Selby, Aaron P. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Xu, Donghua, E-mail: xudh@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Juslin, Niklas; Capps, Nathan A. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Oak Ridge National Laboratory, P.O. Box 2008, MS6003, Oak Ridge, TN 37831 (United States)

    2013-06-15

    We report molecular dynamics simulations of primary damage in molybdenum produced by high energy displacement cascades on the femto- to pico-second and Angstrom to nanometer scales. Clustering directly occurred for both interstitials and vacancies in the 1–50 keV cascade energy range explored. Point defect survival efficiency and partitioning probabilities into different sized clusters were quantified. The results will provide an important reference for kinetic models to describe the microstructural evolution in Mo under ion or neutron irradiations over much longer time and length scales.

  4. GHG emissions from primary aluminum production in China: Regional disparity and policy implications

    International Nuclear Information System (INIS)

    Hao, Han; Geng, Yong; Hang, Wen

    2016-01-01

    Highlights: • GHG emissions from primary aluminum production in China were accounted. • The impact of regional disparity of power generation was considered for this study. • GHG emissions factor of China’s primary aluminum production was 16.5 t CO_2e/t Al ingot in 2013. • Total GHG emissions from China’s primary aluminum production were 421 mt CO_2e in 2013. - Abstract: China is the world-leading primary aluminum production country, which contributed to over half of global production in 2014. Primary aluminum production is power-intensive, for which power generation has substantial impact on overall Greenhouse Gas (GHG) emissions. In this study, we explore the impact of regional disparity of China’s power generation system on GHG emissions for the sector of primary aluminum production. Our analysis reveals that the national GHG emissions factor (GEF) of China’s primary aluminum production was 16.5 t CO_2e/t Al ingot in 2013, with province-level GEFs ranging from 8.2 to 21.7 t CO_2e/t Al ingot. There is a high coincidence of provinces with high aluminum productions and high GEFs. Total GHG emissions from China’s primary aluminum production were 421 mt CO_2e in 2013, approximately accounting for 4% of China’s total GHG emissions. Under the 2020 scenario, GEF shows a 13.2% reduction compared to the 2013 level, but total GHG emissions will increase to 551 mt CO_2e. Based on our analysis, we recommend that the government should further promote energy efficiency improvement, facilitate aluminum industry redistribution with low-carbon consideration, promote secondary aluminum production, and improve aluminum industry data reporting and disclosure.

  5. Sensible use of primary energy in organic greenhouse production

    NARCIS (Netherlands)

    Stanghellini, C.; Baptista, F.; Eriksson, Evert; Gilli, Celine; Giuffrida, F.; Kempkes, F.L.K.; Munoz, P.; Stepowska, Agnieszka; Montero, J.I.

    2016-01-01

    Review of the major sources for energy consumption in organic greenhouse horticulture and analyse of the options available to reduce energy consumption or, at least, increase the energy use efficiency of organic production in greenhouses. At the moment, the best way to match demand and availability

  6. Computing the Net Primary Productivity for a Savanna- Dominated ...

    African Journals Online (AJOL)

    komla

    2003-05-19

    May 19, 2003 ... productivity of CO2 (between 1–2% per year) continues, a doubling of the CO2 ... The work ... Numerous isotope mass balance equa-tions are proposed to ..... Terrestrial ecoregions of the world: a new map of life on earth.

  7. Sustainable Production of Asphalt using Biomass as Primary Process Fuel

    DEFF Research Database (Denmark)

    Bühler, Fabian; Nguyen, Tuong-Van; Elmegaard, Brian

    2016-01-01

    is the heating and drying of aggregate,where natural gas, fuel oil or LPG is burned in a direct-fired rotary dryer. Replacing this energy source with amore sustainable one presents several technical and economic challenges, as high temperatures, short startuptimes and seasonal production variations are required...

  8. Products of tungstate ion interaction with primary aliphatic amines

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Sejfullina, I.I.; Purich, A.N.; Babinets, S.K.

    1982-01-01

    Using the methods of conductometric titration, IR-spectroscopic and thermographic analyses precipitates formed in the process of interaction of diluted aqueous solutions of sodium tungstate with alcoholic solutions of dodecyl-, tetradecyl- and octadecylamine have been studied. It is shown that as a result of interaction tungstates of corresponding amines are formed. The structure and thermal stability of singled out products are determined

  9. Interannual Variation in Phytoplankton Class-Specific Primary Production at a Global Scale

    Science.gov (United States)

    Rousseaux, Cecile Severine; Gregg, Watson W.

    2014-01-01

    We used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of 4 phytoplankton groups to the total primary production. First we assessed the contribution of each phytoplankton groups to the total primary production at a global scale for the period 1998-2011. Globally, diatoms were the group that contributed the most to the total phytoplankton production (50, the equivalent of 20 PgC y-1. Coccolithophores and chlorophytes each contributed to 20 (7 PgC y-1 of the total primary production and cyanobacteria represented about 10 (4 PgC y(sub-1) of the total primary production. Primary production by diatoms was highest in high latitude (45) and in major upwelling systems (Equatorial Pacific and Benguela system). We then assessed interannual variability of this group-specific primary production over the period 1998-2011. Globally the annual relative contribution of each phytoplankton groups to the total primary production varied by maximum 4 (1-2 PgC y-1. We assessed the effects of climate variability on the class-specific primary production using global (i.e. Multivariate El Nio Index, MEI) and regional climate indices (e.g. Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability as indicated by significant correlation (p 0.05) between the MEI and the class-specific primary production from all groups except coccolithophores. In the Atlantic, climate variability as indicated by NAO was significantly correlated to the primary production of 2 out of the 4 groups in the North Central Atlantic (diatomscyanobacteria) and in the North Atlantic (chlorophytes and coccolithophores). We found that climate variability as indicated by SAM had only a limited effect on the class-specific primary production in the Southern Ocean. These results provide a modeling and

  10. Effects of different algae in diet on growth and interleukin (IL-10 production of juvenile sea cucumber Apostichopus japonicus

    Directory of Open Access Journals (Sweden)

    Md Anisuzzaman

    2017-10-01

    Full Text Available Abstract The experiment was conducted to investigate the effects of different algae in diet on growth, survival, and interleukin-10 productions of sea cucumber. At first, a 9-week feeding trail was conducted to evaluate the growth performance and survival of the sea cucumber fed one of the six experimental diets containing ST (Sargassum thunbergii, UL (Ulva lactuca, UP (Undaria pinnatifida, LJ (Laminaria japonica, SS (Schizochytrium sp., and NO (Nannochloropsis oculata in a recirculating aquaculture system. The result showed that survival was not significantly different among the dietary treatments, and the specific growth rate (SGR of sea cucumber fed the UL diet (1.58% d−1 was significantly higher than that of sea cucumber fed the other diets (P < 0.05, except for the LJ and NO diets. Secondly, interleukin (IL-10 gene expression was determined where mice splenocytes were stimulated with 10 μg ml−1 of sea cucumber extracts for 2 h. The result showed that IL-10 gene expression levels were significantly increased in UL, LJ, and NO diets fed sea cucumber extracts compared to other experimental diets. The results suggest that dietary inclusion with Ulva lactuca, Laminaria japonica, and Nannochloropsis oculata algae may improve the growth of juvenile sea cucumber and could upregulate IL-10 gene expression in mice splenocytes. Such detailed information could be helpful in further development of more appropriate diets for sea cucumber culture.

  11. Modeling UV-B Effects on Primary Production Throughout the Southern Ocean Using Multi-Sensor Satellite Data

    Science.gov (United States)

    Lubin, Dan

    2001-01-01

    This study has used a combination of ocean color, backscattered ultraviolet, and passive microwave satellite data to investigate the impact of the springtime Antarctic ozone depletion on the base of the Antarctic marine food web - primary production by phytoplankton. Spectral ultraviolet (UV) radiation fields derived from the satellite data are propagated into the water column where they force physiologically-based numerical models of phytoplankton growth. This large-scale study has been divided into two components: (1) the use of Total Ozone Mapping Spectrometer (TOMS) and Special Sensor Microwave Imager (SSM/I) data in conjunction with radiative transfer theory to derive the surface spectral UV irradiance throughout the Southern Ocean; and (2) the merging of these UV irradiances with the climatology of chlorophyll derived from SeaWiFS data to specify the input data for the physiological models.

  12. Influences of Scavenging and Removal of Surfactants by Bubble Processing on Primary Marine Aerosol Production from North Atlantic Seawater

    Science.gov (United States)

    Duplessis, P.; Chang, R.; Frossard, A. A.; Keene, W. C.; Maben, J. R.; Long, M. S.; Beaupre, S. R.; Kieber, D. J.; Kinsey, J. D.; Zhu, Y.; Lu, X.; Bisgrove, J.

    2017-12-01

    Primary marine aerosol particles (PMA) are produced by bursting bubbles from breaking waves at the air-sea interface and significantly modulate atmospheric chemical transformations and cloud properties. Surfactants in bulk seawater rapidly (seconds) adsorb onto fresh bubble surfaces forming organic films that influence size, rise velocity, bursting behavior, and associated PMA emissions. During a cruise on the R/V Endeavor in September and October 2016, PMA production from biologically productive and oligotrophic seawater was investigated at four stations in the western North Atlantic Ocean. PMA were produced in a high-capacity generator via turbulent mixing of seawater and clean air in a Venturi nozzle. When the flow of fresh seawater through the generator was turned off, surfactant depletion via bubble processing resulted in greater PMA mass production efficiencies per unit air detrained but had no consistent influence on number production efficiencies. The greater (factor of 3) production efficiencies of organic matter associated with PMA generated with the Venturi relative to those generated with frits during previous campaigns contributed to a faster depletion of surfactants from the seawater reservoir and corresponding divergence in response.

  13. A model of regional primary production for use with coarse resolution satellite data

    Science.gov (United States)

    Prince, S. D.

    1991-01-01

    A model of crop primary production, which was originally developed to relate the amount of absorbed photosynthetically active radiation (APAR) to net production in field studies, is discussed in the context of coarse resolution regional remote sensing of primary production. The model depends on an approximately linear relationship between APAR and the normalized difference vegetation index. A more comprehensive form of the conventional model is shown to be necessary when different physiological types of plants or heterogeneous vegetation types occur within the study area. The predicted variable in the new model is total assimilation (net production plus respiration) rather than net production alone or harvest yield.

  14. The change in the primary production of Danish coastal waters

    International Nuclear Information System (INIS)

    Edelvang, K.; Erichsen, A.; Gustavson, K.; Bundgaard, K.; Dahl-Madsen, K.I.

    2001-01-01

    model simulations cover the period January to October 1999. The model is calibrated against point measurements from existing measuring stations from NERI (National Environmental Research Institute of Denmark) and validated with satellite image from SeaWiFS. The scenarios presented in this study are based on this DECO model setup. (LN)

  15. Thermal Responses of Growth and Toxin Production in Four Prorocentrum Species from the Central Red Sea

    KAUST Repository

    Aynousah, Arwa

    2017-06-01

    Harmful algae studies, in particular toxic dinoflagellates, and their response to global warming in the Red Sea are still limited. This study was aimed to be the first to characterize the identity, thermal responses and toxin production of four Prorocentrum strains isolated from the Central Red Sea, Saudi Arabia. Morphological and molecular phylogenetic analysis identified the strains as P. elegans, P. rhathymum and P. emarginatum. However, the identity of strain P. sp.6 is currently unresolved, albeit sharing close affinity with P. leve. Growth experiments showed that all species could grow at 24-32°C, but only P. sp.6 survived the 34°C treatment. The optimum temperatures (Topt) estimated from the Gaussian model corresponded to 27.17, 29.33, 26.87, and 27.64°C for P. sp.6, P. elegans, P. rhathymum and P. emarginatum, respectively. However, some discrepancy with the Topt derived from the growth performance were observed for P. elegans and P. emarginatum, as thermal responses differed from the typical Gaussian fit. The Prorocentrum species examined showed a sharp decrease after the optimum temperature resulting in very high activation energies for the fall slope, especially for P. elegans and P. emarginatum. The minimum critical temperature limit for growth was not detected within the range of temperatures examined. Subsequently, high performance liquid chromatography coupled with mass spectrometry (HPLC-MS) analysis revealed all species as non okadaic acid (OA, common toxin of the Prorocentrum genus) producers at any temperature treatment. However, other forms of toxin (i.e. fast acting toxins) not examined here could be produced. Therefore, further investigations are required. The results of this study provided significant contribution to our knowledge regarding the presence, thermal response and toxin production of four Prorocentrum species from the Central Red Sea, Saudi Arabia.

  16. IR-BASED SATELLITE PRODUCTS FOR THE MONITORING OF ATMOSPHERIC WATER VAPOR OVER THE BLACK SEA

    Directory of Open Access Journals (Sweden)

    VELEA LILIANA

    2016-03-01

    Full Text Available The amount of precipitable water (TPW in the atmospheric column is one of the important information used weather forecasting. Some of the studies involving the use of TPW relate to issues like lightning warning system in airports, tornadic events, data assimilation in numerical weather prediction models for short-range forecast, TPW associated with intense rain episodes. Most of the available studies on TPW focus on properties and products at global scale, with the drawback that regional characteristics – due to local processes acting as modulating factors - may be lost. For the Black Sea area, studies on the climatological features of atmospheric moisture are available from sparse or not readily available observational databases or from global reanalysis. These studies show that, although a basin of relatively small dimensions, the Black Sea presents features that may significantly impact on the atmospheric circulation and its general characteristics. Satellite observations provide new opportunities for extending the knowledge on this area and for monitoring atmospheric properties at various scales. In particular, observations in infrared (IR spectrum are suitable for studies on small-scale basins, due to the finer spatial sampling and reliable information in the coastal areas. As a first step toward the characterization of atmospheric moisture over the Black Sea from satellite-based information, we investigate three datasets of IR-based products which contain information on the total amount of moisture and on its vertical distribution, available in the area of interest. The aim is to provide a comparison of these data with regard to main climatological features of moisture in this area and to highlight particular strengths and limits of each of them, which may be helpful in the choice of the most suitable dataset for a certain application.

  17. Interannual Variation in Phytoplankton Class-specific Primary Production at a Global Scale

    Science.gov (United States)

    Rousseaux, Cecile; Gregg, Watson

    2014-01-01

    Phytoplankton is responsible for over half of the net primary production on earth. The knowledge on the contribution of various phytoplankton groups to the total primary production is still poorly understood. Data from satellite observations suggest that for upwelling regions, photosynthetic rates by microplankton is higher than that of nanoplankton but that when the spatial extent is considered, the production by nanoplankton is comparable or even larger than microplankton. Here, we used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of 4 phytoplankton groups to the total primary production. Globally, diatoms were the group that contributed the most to the total phytoplankton production (approx. 50%) followed by coccolithophores and chlorophytes. Primary production by diatoms was highest in high latitude (>45 deg) and in major upwelling systems (Equatorial Pacific and Benguela system). We assessed the effects of climate variability on the class-specific primary production using global (i.e. Multivariate El Nino Index, MEI) and 'regional' climate indices (e.g. Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability. These results provide a modeling and data assimilation perspective to phytoplankton partitioning of primary production and contribute to our understanding of the dynamics of the carbon cycle in the oceans at a global scale.

  18. Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments

    Czech Academy of Sciences Publication Activity Database

    Wilcox, K. R.; Shi, Z.; Gherardi, L. A.; Lemoine, N. P.; Koerner, S. E.; Hoover, D. L.; Bork, E.; Byrne, K. M.; Cahill, J.; Collins, S. L.; Evans, S.M.; Gilgen, Anna K.; Holub, Petr; Jiang, L.; Knapp, A. K.; LeCain, D.; Liang, J.; Garcia-Palacios, P.; Penuelas, J.; Pockman, W. T.; Smith, M. D.; Sun, S.; White, S. R.; Yahdjian, L.; Zhu, K.; Luo, Y.

    2017-01-01

    Roč. 23, č. 10 (2017), s. 4376-4385 ISSN 1354-1013 Institutional support: RVO:86652079 Keywords : net primary productivity * terrestrial ecosystems * temperate grassland * biomass allocation * plant-communities * tallgrass prairie * climate extremes * use efficiency * united-states * global-change * aboveground net primary productivity * belowground net primary productivity * biomass allocation * climate change * grasslands * meta-analysis * root biomass Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 8.502, year: 2016

  19. Will Global Change Effect Primary Productivity in Coastal Ecosystems?

    Science.gov (United States)

    Rothschild, Lynn J.; Peterson, David L. (Technical Monitor)

    1997-01-01

    Algae are the base of coastal food webs because they provide the source of organic carbon for the remaining members of the community. Thus, the rate that they produce organic carbon to a large extent controls the productivity of the entire ecosystem. Factors that control algal productivity range from the physical (e.g., temperature, light), chemical (e.g., nutrient levels) to the biological (e.g., grazing). Currently, levels of atmospheric carbon dioxide surficial fluxes of ultraviolet radiation are rising. Both of these environmental variables can have a profound effect on algal productivity. Atmospheric carbon dioxide may increase surficial levels of dissolved inorganic carbon. Our laboratory and field studies of algal mats and phytoplankton cultures under ambient and elevated levels of pCO2 show that elevated levels of inorganic carbon can cause an increase in photosynthetic rates. In some cases, this increase will cause an increase in phytoplankton numbers. There may be an increase in the excretion of fixed carbon, which in turn may enhance bacterial productivity. Alternatively, in analogy with studies on the effect of elevated pCO2 on plants, the phytoplankton could change their carbon to nitrogen ratios, which will effect the feeding of the planktonic grazers. The seasonal depletion of stratospheric ozone has resulted in elevated fluxes of UVB radiation superimposed on the normal seasonal variation. Present surface UV fluxes have a significant impact on phytoplankton physiology, including the inhibition of the light and dark reactions of photosynthesis, inhibition of nitrogenase activity, inhibition of heterocyst formation, reduction in motility, increased synthesis of the UV-screening pigment scytonemin, and mutation. After reviewing these issues, recent work in our lab on measuring the effect of UV radiation on phytoplankton in the San Francisco Bay Estuary will be presented.

  20. LIFE CYCLE OF THE PHARMACEUTICAL PRODUCT AND PRIMARY STRATEGIC GOALS

    Directory of Open Access Journals (Sweden)

    Cristina\tCIOT

    2015-12-01

    Full Text Available In addition to innovation, production at high standards, market and marketing policy, pharmaceutical companies need strategies that could cope with apparent contradictions, convergences and divergences, centralisation and involution, at the global and local level, focus and liberty, domestic production and external supply, ownership and alliances, networks and hierarchies, science or market orientation, all these being part of the essence of a profitable and expanding pharmaceutical company. Specialists appreciate that the 20 century will remain in the collective memory for its technological achievements, including a better understanding of the atomic structure, „information explosion” encouraged by the progress of the computer technology, the news from space exploration. If one wants to evaluate its importance in terms of impact on people’s lives, the 20 century could be called THE DRUG AREA. Many experts agree that, at the end of this century, pharmaceutical products would have a higher importance for our lives due to the special progress in neurobiology, immunology, molecular biology, cellular differentiation, cell membrane and genetic studies. In the pharmaceutical industry, important funds are directed towards research and development, while few understand and appreciate the contribution brought by the pharmaceutical marketing system and by the professionals in this field. These ones make the drug accessible at the right time and place, in the required quantity, at a reasonable price and with all the information required.

  1. Bacterial abundance and production in the central and eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Raghukumar, S.; Gauns, M.

    bacterial densities of about 1 x 10 sup(9) cells L sup(-1) were observed during the intermonsoon periods of September and April/May compared to the southwest monsoon period of July/August and the winter period of February/March. Although primary production...

  2. Seasonal and spatial variation of bacterial production and abundance in the northern Levantine Sea

    Directory of Open Access Journals (Sweden)

    N. YUCEL

    2017-03-01

    Full Text Available Spatial and temporal heterogeneity in bacterial production and abundance in relation to ambient bio-physicochemical parameters has been investigated in the Levantine Sea. Five stations with different trophic states in an area extending from highly eutrophic Mersin bay to the mesotrophic Rhodes gyre area including the oligotrophic offshore waters were sampled four times. Integrated bacterial production varied between 6.1 and 90.3 µg C m-2 d-1 with higher rates occurring during September 2012 in offshore waters. Bacterial abundance ranged between 0.18 and 7.3 x 105 cells ml-1 within the euphotic zone and was generally higher up to 100 meters throughout the study period. In offshore waters, bacterial production (0.401 to 0.050 µg C m-3 d-1, abundance (4.5 to 1.6 x 105 cells ml-1 and depth of the productive layer decreased from 150 to 75 meters westward along the transect. Although the highest abundance was observed in July 2012 in offshore waters, the highest activity was measured in September 2012. These results indicated that the temperature played a key role in regulating bacterial abundance and production in the area. High chlorophyll concentrations in March did not correspond to high bacterial abundance and production at the same time. Increase in dissolved organic carbon content following spring phytoplankton bloom and the increase in temperature in the mean time might have enhanced the bacterial activity towards summer.

  3. Seasonality and toxin production of Pyrodinium bahamense in a Red Sea lagoon.

    Science.gov (United States)

    Banguera-Hinestroza, E; Eikrem, W; Mansour, H; Solberg, I; Cúrdia, J; Holtermann, K; Edvardsen, B; Kaartvedt, S

    2016-05-01

    Harmful algal blooms of the dinoflagellate Pyrodinium bahamense have caused human and economic losses in the last decades. This study, for the first time, documents a bloom of P. bahamense in the Red Sea. The alga was recurrently present in a semi-enclosed lagoon throughout nearly 2 years of observations. The highest cell densities (10 4 -10 5 cellsL -1 ) were recorded from September to beginning of December at temperatures and salinities of ∼26-32°C and ∼41, respectively. The peak of the bloom was recorded mid-November, before a sharp decrease in cell numbers at the end of December. Minimum concentrations in summer were at ∼10 3 cellsL -1 . A saxitoxin ELISA immunoassay of cultures and water samples confirmed the toxicity of the strain found in the Red Sea. Moreover, a gene expression analysis of the saxitoxin gene domain SxtA4 showed that transcript production peaked at the culmination of the bloom, suggesting a relation between transcript production, sudden cells increment-decline, and environmental factors. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Seasonality and toxin production of Pyrodinium bahamense in a Red Sea lagoon

    KAUST Repository

    Banguera Hinestroza, Eulalia

    2016-03-19

    Harmful algal blooms of the dinoflagellate Pyrodinium bahamense have caused human and economic losses in the last decades. This study, for the first time, documents a bloom of P. bahamense in the Red Sea. The alga was recurrently present in a semi-enclosed lagoon throughout nearly 2 years of observations. The highest cell densities (104-105 cells L-1) were recorded from September to beginning of December at temperatures and salinities of ~26-32 °C and ~41, respectively. The peak of the bloom was recorded mid-November, before a sharp decrease in cell numbers at the end of December. Minimum concentrations in summer were at ~103 cells L-1. A saxitoxin ELISA immunoassay of cultures and water samples confirmed the toxicity of the strain found in the Red Sea. Moreover, a gene expression analysis of the saxitoxin gene domain SxtA4 showed that transcript production peaked at the culmination of the bloom, suggesting a relation between transcript production, sudden cells increment-decline, and environmental factors. © 2016 Elsevier B.V.

  5. Productivity and abundance of large sponge populations on Flinders Reef flats, Coral Sea

    Science.gov (United States)

    Wilkinson, Clive R.

    1987-04-01

    Large populations of flattened sponges with cyanobacterial symbionts were observed on the shallow reef-flats of the Flinders Reefs, Coral Sea. Estimates of these populations indicated as many as 60 individuals with a total wet biomass of 1.2 kg per m2 in some areas. Along a metre wide transect across 1.3 km of reef flat the population was estimated at 530 kg wet weight sponge (mean 411 g m-2). The four prominent species had instantaneous P/R ratios between 1.3 and 1.8 at optimum light such that photosynthetic productivity was calculated to provide between 61 and 80% of sponge energy requirements in summer and 48 to 64% in winter. While such sponge beds are a prominent feature of these reefs, they appear to contribute less than 10% of gross reef-flat productivity.

  6. Zooplankton biomass and production in the North Sea during the Autumn Circulation experiment, October 1987–March 1988

    DEFF Research Database (Denmark)

    Hay, S.J.; Kiørboe, Thomas; Matthews, A.

    1991-01-01

    Distribution and abundance of zooplankton in the North Sea during the Autumn Circulation Experiment (October 1987–March 1988) were examined. From shipboard egg production incubations and the distributions of eggs, nauplii and females, the productivity of various copepod species was described. Aga...

  7. Primary Screening of 10 - Hydroxy - 2 - Decenoic Acid Productive Strains

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper, eleven strains, which vere screened strictly from raw royal.jelly, soil and honeycomb etc. by means of dilution plate and spread plate methods, were cultured at 28°C for60 h with shaking. To determine whether they could yield 10-Hydroxy-2-decenoic acid during fermentation, gas chromatography and gas chromatography-mass spectrometry methods were used. The results showed that the strains BH002 and BH004. were both identified as Crvtococcaceae. where BH002 was primarily classified into Candida for possessing the abilities. The 10-HDA productivity of Candida BH002 and that of BH004 were 0.327% and 0.2648% respectively.

  8. Solubility of simulated PWR primary circuit corrosion products

    International Nuclear Information System (INIS)

    Kunig, R.H.; Sandler, Y.L.

    1986-08-01

    The solubility behavior of non-stoichiometric nickel ferrites, nickel-cobalt ferrites, and magnetite, as model substances for the corrosion products (''crud'') formed in nuclear pressurized water reactors, was studied in a flow system in aqueous solutions of lithium hydroxide, boric acid, and hydrogen with pH, temperature, and hydrogen concentrations as parameters. Below the temperature region of 300 to 330 0 C, at hydrogen concentrations of 25 to 40 cm 3 /kg H 2 O as used during reactor operation, the solubility of nickel-cobalt ferrite is the same as that of Ni and Co/sub x/Fe/sub 3-x/O 4 (x 3 /kg of hydrogen, the equilibrium iron and nickel solubilities increase congruently down to about 100 0 C, in a manner consistent with the solubility of Fe 3 O 4 , but sharply decline at lower temperatures, apparently due to formation of a borated layer. A cooldown experiment on a time scale of a typical Westinghouse reactor shutdown, as well as static experiments carried out on various ferrite samples at 60 0 C show that after addition of oxygen or peroxide evolution of nickel (and possibly cobalt) above the equilibrium solubility in hydrogen depends on the presence of dissociation products prior to oxidation. Thermodynamic calculations of various reduction and oxidative decomposition reactions for stoichiometric and non-stoichiometric nickel ferrite and cobalt ferrite are presented. Their significance to evolutions of nickel and cobalt on reactor shutdown is discussed. 30 refs., 38 figs., 34 tabs

  9. Primary production measurements at three reservoirs in the state of Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Jureidini, P.; Chinez, S.J.; Agudo, E.G.

    1983-01-01

    Primary production measurements were carried out at three reservoirs in the state of Sao Paulo, Barra Bonita, Paiva Castro and Ponte nova using the 14 C technique. Meanwhile, several physical and chemical parameters of these water were also evaluated, in order to find out the limnological conditions of these reservoirs. Primary production rates ranged from 7,6mg C/m 3 d at Ponte Nova, to 247,2mg C/m 3 d at Barra Bonita. There seems to be god correlation between water quality data and primary production measurements. Regarding the results, it may be stated that the Barra Bonita reservoir has reached the eutrophic level, while the other two exibit mesotrophic levels. As a way of testing the water quality data collected was used in Churchill and Nicholas model, issuing results in agreement with those of the primary production measurements. (Author) [pt

  10. HANPP Collection: Global Patterns in Human Appropriation of Net Primary Productivity (HANPP)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Global Patterns in Human Appropriation of Net Primary Productivity (HANPP) portion of the HANPP Collection represents a digital map of human appropriation of net...

  11. Safety assessment of smoke flavouring primary products by the European Food Safety Authority

    NARCIS (Netherlands)

    Theobald, A.; Arcella, D.; Carere, A.; Croera, C.; Engel, K.H.; Gott, D.; Gurtler, R.; Meier, D.; Pratt, I.; Rietjens, I.M.C.M.; Simon, R.; Walker, R.

    2012-01-01

    This paper summarises the safety assessments of eleven smoke flavouring primary products evaluated by the European Food Safety Authority (EFSA). Data on chemical composition, content of polyaromatic hydrocarbons and results of genotoxicity tests and subchronic toxicity studies are presented and

  12. NODC Standard Format Primary Productivity 1 (F029) Data (1958-1983) (NODC Accession 0014152)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains data from measurements of primary productivity. The data are collected to provide information on nutrient levels and nutrient flow in offshore...

  13. Primary productivity in the Karwar Bay, Karnataka, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, U.G.; Naik, R.K.; Nayak, V.N.

    The measurement of primary production is of great importance because of its significance to the problems of aquatic ecology and fishery management. The interaction of light intensity, temperature and nutrient levels determines the photosynthetic...

  14. Remote sensing of oceanic primary production: Computations using a spectral model

    Digital Repository Service at National Institute of Oceanography (India)

    Sathyendranath, S.; Platt, T.; Caverhill, C.M.; Warnock, R.E.; Lewis, M.R.

    A spectral model of underwater irradiance is coupled with a spectral version of the photosynthesis-light relationship to compute oceanic primary production. The results are shown to be significantly different from those obtained using...

  15. Phytoplankton pigments and primary production around the oil fields off Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    JiyalalRam, M.J.; Ramaiah, Neelam; Mehta, P.; Krishnakumari, L.; Nair, V.R.

    Studies on phytoplankton pigments, primary productivity and particulate organic carbon were made at 21 locations off Bombay (Maharashtra, India) and adjacent waters during the 48th cruise of @iORV Sagar Kanya@@ in December 1988 to January 1989...

  16. Primary productivity of marine macrophytes in the coral reef lagoon of the Kadmat Island, Lakshadweep

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.; Shaikh, N.

    n situ primary productivity measurements were carried out with different macrophyte species (belonging to four groups) dominating the benthic communities in the coral reef lagoon of the Kadmat Island of the Lakshadweep Archipelago...

  17. Corrosion products behaviour under VVER primary coolant conditions

    International Nuclear Information System (INIS)

    Grygar, T.; Zmitko, M.

    2002-01-01

    The aim of this work was to collect data on thermodynamic stability of Cr, Fe, and Ni oxides, mechanisms of hydrothermal corrosion of stainless steels and to compare the real observation with the theory. We found that the electrochemical potential and pH in PWR and VVER are close to the thermodynamic boundary between two fields of stable spinel type oxides. The ways of degradation of the passivating layers due to changes in water chemistry were considered and PWR and VVER systems were found to be potentially endangered by reductive attack. In certain VVER systems the characteristics of the passivating layer on steels and also concentration of soluble corrosion products seem to be in contradiction with the theoretical expectations. (author)

  18. NOx from cement production - reduction by primary measures

    DEFF Research Database (Denmark)

    Jensen, Lars Skaarup

    1999-01-01

    cement production processes cement is typically produced by thermally treating a mixture of limestone and clay minerals in kiln systems consisting of a rotary kiln and a calciner. Clinker burning at a temperature of about 1450 °C takes place in the internally fired rotary kiln and calcination, which...... rotary kilns, while NOx formation from fuel-N and reduction of NOx take place in calciners. NOx formation in the rotary kiln is mainly governed by the necessary clinker burning temperature and is not very amenable to control, while net NOx formation in calciners depends strongly on calciner design......, calciner operation, fuel properties and on the NOx level from the rotary kiln. The low-NOx calciner types presently marketed are based on combinations of reburning, air staging and temperature control and seem equivalent in their ability to restrict NOx formation. If fuels with a significant volatile...

  19. Spatial and Temporal Variation in Primary Productivity (NDVI) of Coastal Alaskan Tundra: Decreased Vegetation Growth Following Earlier Snowmelt

    Science.gov (United States)

    Gamon, John A.; Huemmrich, K. Fred; Stone, Robert S.; Tweedie, Craig E.

    2015-01-01

    In the Arctic, earlier snowmelt and longer growing seasons due to warming have been hypothesized to increase vegetation productivity. Using the Normalized Difference Vegetation Index (NDVI) from both field and satellite measurements as an indicator of vegetation phenology and productivity, we monitored spatial and temporal patterns of vegetation growth for a coastal wet sedge tundra site near Barrow, Alaska over three growing seasons (2000-2002). Contrary to expectation, earlier snowmelt did not lead to increased productivity. Instead, productivity was associated primarily with precipitation and soil moisture, and secondarily with growing degree days, which, during this period, led to reduced growth in years with earlier snowmelt. Additional moisture effects on productivity and species distribution, operating over a longer time scale, were evident in spatial NDVI patterns associated with microtopography. Lower, wetter regions dominated by graminoids were more productive than higher, drier locations having a higher percentage of lichens and mosses, despite the earlier snowmelt at the more elevated sites. These results call into question the oft-stated hypothesis that earlier arctic growing seasons will lead to greater vegetation productivity. Rather, they agree with an emerging body of evidence from recent field studies indicating that early-season, local environmental conditions, notably moisture and temperature, are primary factors determining arctic vegetation productivity. For this coastal arctic site, early growing season conditions are strongly influenced by microtopography, hydrology, and regional sea ice dynamics, and may not be easily predicted from snowmelt date or seasonal average air temperatures alone. Our comparison of field to satellite NDVI also highlights the value of in-situ monitoring of actual vegetation responses using field optical sampling to obtain detailed information on surface conditions not possible from satellite observations alone.

  20. Methylmercury bioaccumulation in stream food webs declines with increasing primary production

    Science.gov (United States)

    Walters, David; D.F. Raikow,; C.R. Hammerschmidt,; M.G. Mehling,; A. Kovach,; J.T. Oris,

    2015-01-01

    Opposing hypotheses posit that increasing primary productivity should result in either greater or lesser contaminant accumulation in stream food webs. We conducted an experiment to evaluate primary productivity effects on MeHg accumulation in stream consumers. We varied light for 16 artificial streams creating a productivity gradient (oxygen production =0.048–0.71 mg O2 L–1 d–1) among streams. Two-level food webs were established consisting of phytoplankton/filter feeding clam, periphyton/grazing snail, and leaves/shredding amphipod (Hyalella azteca). Phytoplankton and periphyton biomass, along with MeHg removal from the water column, increased significantly with productivity, but MeHg concentrations in these primary producers declined. Methylmercury concentrations in clams and snails also declined with productivity, and consumer concentrations were strongly correlated with MeHg concentrations in primary producers. Heterotroph biomass on leaves, MeHg in leaves, and MeHg in Hyalella were unrelated to stream productivity. Our results support the hypothesis that contaminant bioaccumulation declines with stream primary production via the mechanism of bloom dilution (MeHg burden per cell decreases in algal blooms), extending patterns of contaminant accumulation documented in lakes to lotic systems.

  1. Wave disturbance overwhelms top-down and bottom-up control of primary production in California kelp forests.

    Science.gov (United States)

    Reed, Daniel C; Rassweiler, Andrew; Carr, Mark H; Cavanaugh, Kyle C; Malone, Daniel P; Siegel, David A

    2011-11-01

    We took advantage of regional differences in environmental forcing and consumer abundance to examine the relative importance of nutrient availability (bottom-up), grazing pressure (top-down), and storm waves (disturbance) in determining the standing biomass and net primary production (NPP) of the giant kelp Macrocystis pyrifera in central and southern California. Using a nine-year data set collected from 17 sites we show that, despite high densities of sea urchin grazers and prolonged periods of low nutrient availability in southern California, NPP by giant kelp was twice that of central California where nutrient concentrations were consistently high and sea urchins were nearly absent due to predation by sea otters. Waves associated with winter storms were consistently higher in central California, and the loss of kelp biomass to winter wave disturbance was on average twice that of southern California. These observations suggest that the more intense wave disturbance in central California limited NPP by giant kelp under otherwise favorable conditions. Regional patterns of interannual variation in NPP were similar to those of wave disturbance in that year-to-year variation in disturbance and NPP were both greater in southern California. Our findings provide strong evidence that regional differences in wave disturbance overwhelmed those of nutrient supply and grazing intensity to determine NPP by giant kelp. The important role of disturbance in controlling NPP revealed by our study is likely not unique to giant kelp forests, as vegetation dynamics in many systems are dominated by post-disturbance succession with climax communities being relatively uncommon. The effects of disturbance frequency may be easier to detect in giant kelp because it is fast growing and relatively short lived, with cycles of disturbance and recovery occurring on time scales of years. Much longer data sets (decades to centuries) will likely be needed to properly evaluate the role of

  2. SeaWiFS technical report series. Volume 32: Level-3 SeaWiFS data products. Spatial and temporal binning algorithms

    Science.gov (United States)

    Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Acker, James G. (Editor); Campbell, Janet W.; Blaisdell, John M.; Darzi, Michael

    1995-01-01

    The level-3 data products from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) are statistical data sets derived from level-2 data. Each data set will be based on a fixed global grid of equal-area bins that are approximately 9 x 9 sq km. Statistics available for each bin include the sum and sum of squares of the natural logarithm of derived level-2 geophysical variables where sums are accumulated over a binning period. Operationally, products with binning periods of 1 day, 8 days, 1 month, and 1 year will be produced and archived. From these accumulated values and for each bin, estimates of the mean, standard deviation, median, and mode may be derived for each geophysical variable. This report contains two major parts: the first (Section 2) is intended as a users' guide for level-3 SeaWiFS data products. It contains an overview of level-0 to level-3 data processing, a discussion of important statistical considerations when using level-3 data, and details of how to use the level-3 data. The second part (Section 3) presents a comparative statistical study of several binning algorithms based on CZCS and moored fluorometer data. The operational binning algorithms were selected based on the results of this study.

  3. Estimation of sea level muon energy spectrum at high latitude from the latest primary nucleon spectra near the top of the atmosphere

    CERN Document Server

    Haldar, T K; Bhattacharya, D P; 10.1023/A:1024822518795

    2003-01-01

    Vertical muon energy spectra at sea level have been estimated from a directly measured primary cosmic-ray nucleon spectrum. The hadronic energy moments have been calculated from the CERN LEBC EHS data on the Lorentz invariant cross-section results on pp to pi /sup +or-/X and pp to K/sup +or-/X inclusive reactions and are duly corrected for A-A collisions. Finally, the sea level muon energy spectra have been calculated from the decay of conventional mesons, using standard formulation. The estimated muon spectra are found to be in good agreement with the directly measured muon spectra obtained from different experiments. (32 refs).

  4. Photosynthetic oxygen production in a warmer ocean: the Sargasso Sea as a case study.

    Science.gov (United States)

    Richardson, Katherine; Bendtsen, Jørgen

    2017-09-13

    Photosynthetic O 2 production can be an important source of oxygen in sub-surface ocean waters especially in permanently stratified oligotrophic regions of the ocean where O 2 produced in deep chlorophyll maxima (DCM) is not likely to be outgassed. Today, permanently stratified regions extend across approximately 40% of the global ocean and their extent is expected to increase in a warmer ocean. Thus, predicting future ocean oxygen conditions requires a better understanding of the potential response of photosynthetic oxygen production to a warmer ocean. Based on our own and published observations of water column processes in oligotrophic regions, we develop a one-dimensional water column model describing photosynthetic oxygen production in the Sargasso Sea to quantify the importance of photosynthesis for the downward flux of O 2 and examine how it may be influenced in a warmer ocean. Photosynthesis is driven in the model by vertical mixing of nutrients (including eddy-induced mixing) and diazotrophy and is found to substantially increase the downward O 2 flux relative to physical-chemical processes alone. Warming (2°C) surface waters does not significantly change oxygen production at the DCM. Nor does a 15% increase in re-mineralization rate (assuming Q 10  = 2; 2°C warming) have significant effect on net sub-surface oxygen accumulation. However, changes in the relative production of particulate (POM) and dissolved organic material (DOM) generate relatively large changes in net sub-surface oxygen production. As POM/DOM production is a function of plankton community composition, this implies plankton biodiversity and food web structure may be important factors influencing O 2 production in a warmer ocean.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Author(s).

  5. Bathymetric controls on Pliocene North Atlantic and Arctic sea surface temperature and deepwater production

    Science.gov (United States)

    Robinson, M.M.; Valdes, P.J.; Haywood, A.M.; Dowsett, H.J.; Hill, D.J.; Jones, S.M.

    2011-01-01

    The mid-Pliocene warm period (MPWP; ~. 3.3 to 3.0. Ma) is the most recent interval in Earth's history in which global temperatures reached and remained at levels similar to those projected for the near future. The distribution of global warmth, however, was different than today in that the high latitudes warmed more than the tropics. Multiple temperature proxies indicate significant sea surface warming in the North Atlantic and Arctic Oceans during the MPWP, but predictions from a fully coupled ocean-atmosphere model (HadCM3) have so far been unable to fully predict the large scale of sea surface warming in the high latitudes. If climate proxies accurately represent Pliocene conditions, and if no weakness exists in the physics of the model, then model boundary conditions may be in error. Here we alter a single boundary condition (bathymetry) to examine if Pliocene high latitude warming was aided by an increase in poleward heat transport due to changes in the subsidence of North Atlantic Ocean ridges. We find an increase in both Arctic sea surface temperature and deepwater production in model experiments that incorporate a deepened Greenland-Scotland Ridge. These results offer both a mechanism for the warming in the North Atlantic and Arctic Oceans indicated by numerous proxies and an explanation for the apparent disparity between proxy data and model simulations of Pliocene northern North Atlantic and Arctic Ocean conditions. Determining the causes of Pliocene warmth remains critical to fully understanding comparisons of the Pliocene warm period to possible future climate change scenarios. ?? 2011.

  6. Observations of Recent Arctic Sea Ice Volume Loss and Its Impact on Ocean-Atmosphere Energy Exchange and Ice Production

    Science.gov (United States)

    Kurtz, N. T.; Markus, T.; Farrell, S. L.; Worthen, D. L.; Boisvert, L. N.

    2011-01-01

    Using recently developed techniques we estimate snow and sea ice thickness distributions for the Arctic basin through the combination of freeboard data from the Ice, Cloud, and land Elevation Satellite (ICESat) and a snow depth model. These data are used with meteorological data and a thermodynamic sea ice model to calculate ocean-atmosphere heat exchange and ice volume production during the 2003-2008 fall and winter seasons. The calculated heat fluxes and ice growth rates are in agreement with previous observations over multiyear ice. In this study, we calculate heat fluxes and ice growth rates for the full distribution of ice thicknesses covering the Arctic basin and determine the impact of ice thickness change on the calculated values. Thinning of the sea ice is observed which greatly increases the 2005-2007 fall period ocean-atmosphere heat fluxes compared to those observed in 2003. Although there was also a decline in sea ice thickness for the winter periods, the winter time heat flux was found to be less impacted by the observed changes in ice thickness. A large increase in the net Arctic ocean-atmosphere heat output is also observed in the fall periods due to changes in the areal coverage of sea ice. The anomalously low sea ice coverage in 2007 led to a net ocean-atmosphere heat output approximately 3 times greater than was observed in previous years and suggests that sea ice losses are now playing a role in increasing surface air temperatures in the Arctic.

  7. Productivity and recovery of forage fish under climate change and fishing: North Sea sandeel as a case study

    DEFF Research Database (Denmark)

    Lindegren, Martin; van Deurs, Mikael; MacKenzie, Brian

    2018-01-01

    -east Atlantic, acting as a key prey for predatory fish and sea birds, as well as supporting a large commercial fishery. In this case study, we investigate the underlying factors affecting recruitment and how these in turn affect productivity of the North Sea sandeel using long-term data and modelling. Our...... results demonstrate how sandeel productivity in the central North Sea (Dogger Bank) depends on a combination of external and internal regulatory factors, including fishing and climate effects, as well as density dependence and food availability of the preferred zooplankton prey (Calanus finmarchicus...... and Temora longicornis). Furthermore, our model scenarios suggest that while fishing largely contributed to the abrupt stock decline during the late 1990s and the following period of low biomass, a complete recovery of the stock to the highly productive levels of the early 1980s would only be possible...

  8. Hydrogen sulfide production and volatilization in a polymictic eutrophic saline lake, Salton Sea, California.

    Science.gov (United States)

    Reese, Brandi Kiel; Anderson, Michael A; Amrhein, Christopher

    2008-11-15

    The Salton Sea is a large shallow saline lake located in southern California that is noted for high sulfate concentrations, substantial algal productivity, and very warm water column temperatures. These conditions are well-suited for sulfide production, and sulfide has been implicated in summer fish kills, although no studies have been conducted to specifically understand hydrogen sulfide production and volatilization there. Despite polymictic mixing patterns and relatively short accumulation periods, the amount of sulfide produced is comparable to meromictic lakes. Sulfide levels in the Salton Sea reached concentrations of 1.2 mmol L(-1) of total free sulfide in the hypolimnion and 5.6 mmol L(-1) in the sediment pore water. Strong winds in late July mixed H2S into the surface water, where it depleted the entire water column of dissolved oxygen and reached a concentration of 0.1 mmol L(-1). Sulfide concentrations exceeded the toxicity threshold of tilapia (Oreochromis mossambicus) and combined with strong anoxia throughout the water column, resulted in a massive fish kill. The mixing of sulfide into the surface waters also increased atmospheric H2S concentrations, reaching 1.0 micromol m(-3). The flux of sulfide from the sediment into the water column was estimated to range from 2-3 mmol m(-2) day(-1) during the winter and up to 8 mmol m(-2) day(-1) during the summer. Application of the two-layer model for volatilization indicates that up to 19 mmol m(-2) day(-1) volatilized from the surface during the mixing event. We estimate that as much as 3400 Mg year(-1) or approximately 26% of sulfide that diffused into the water column from the deepest sediments may have been volatilized to the atmosphere.

  9. New approaches to the measurement of chlorophyll, related pigments and productivity in the sea

    Science.gov (United States)

    Booth, C. R.; Keifer, D. A.

    1989-01-01

    In the 1984 SBIR Call for Proposals, NASA solicited new methods to measure primary production and chlorophyll in the ocean. Biospherical Instruments Inc. responded to this call with a proposal first to study a variety of approaches to this problem. A second phase of research was then funded to pursue instrumentation to measure the sunlight stimulated naturally occurring fluorescence of chlorophyll in marine phytoplankton. The monitoring of global productivity, global fisheries resources, application of above surface-to-underwater optical communications systems, submarine detection applications, correlation, and calibration of remote sensing systems are but some of the reasons for developing inexpensive sensors to measure chlorophyll and productivity. Normally, productivity measurements are manpower and cost intensive and, with the exception of a very few expensive multiship research experiments, provide no contemporaneous data. We feel that the patented, simple sensors that we have designed will provide a cost effective method for large scale, synoptic, optical measurements in the ocean. This document is the final project report for a NASA sponsored SBIR Phase 2 effort to develop new methods for the measurements of primary production in the ocean. This project has been successfully completed, a U.S. patent was issued covering the methodology and sensors, and the first production run of instrumentation developed under this contract has sold out and been delivered.

  10. Heterotrophic bacterial production, respiration, and growth efficiency associated with upwelling intensity in the Ulleung Basin, East Sea

    Science.gov (United States)

    Kim, Bomina; Kim, Sung-Han; Kwak, Jung Hyun; Kang, Chang-Keun; Lee, Sang Heon; Hyun, Jung-Ho

    2017-09-01

    We investigated bacterial production (BP) and respiration (BR), as well as the physico-chemical properties of the water column, to elucidate the effect of upwelling on heterotrophic bacterial metabolic activities and growth efficiency (BGE) in July 2012 and May 2013 in the Ulleung Basin (UB), East/Japan Sea. The upwelled conditions were characterized by higher chlorophyll-a (Chl-a) concentrations resulting from the upward shift of the nitracline compared to that of the non-upwelled condition. Analyses of the size fractions of Chl-a and pigment composition revealed that large size phytoplankton (> 20 μm), mainly consisting of diatoms, appeared to be the major phytoplankton component. BP and BR were significantly correlated with Chl-a (P 0.05). These results suggest that bacterial metabolic activities are stimulated by the availability of organic resources enhanced by upwelling in the UB. Further statistical analysis showed that the difference in BP and BGE with variations in upwelling intensity were significant (P = 0.018 for BP, P = 0.035 for BGE), but the difference in BR was not significant (P = 0.321). These results suggest that metabolic energy is partitioned more for BP under a strong upwelling condition, i.e. high nutrient and Chl-a conditions. In contrast, the energy generated via respiration was partitioned more for maintaining metabolism rather than for biomass production under weakly or non-upwelled conditions, i.e. stratified and low Chl-a conditions. Overall, our results suggest that any changes in upwelling intensity would significantly affect the carbon cycle associated with the fate of primary production, and the role of the microbial loop in the UB where changes in the intensity and frequency of upwelling associated with climatic changes are in progress.

  11. Isolation and Fatty Acid Profile of Selected Microalgae Strains from the Red Sea for Biofuel Production

    Directory of Open Access Journals (Sweden)

    Khalid M. Abu-Salah

    2013-05-01

    Full Text Available The isolation of lipid-rich autochthonous strains of microalgae is a crucial stage for the development of a microalgae-based biofuel production plant, as these microalgae already have the necessary adaptations to withstand competition, predation and the temperatures observed at each production site. This is particularly important in extreme climates such as in Saudi Arabia. Resorting to fluorescence activated cell sorting (FACS we screened for and isolated several microalgal strains from samples collected from the Red Sea. Relying on the fluorescence of BODIPY 505/515 (4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diazasindacene and growth performance, four promising candidates were identified and the total lipid content and fatty acid profile was assessed for biofuels production. Selected isolates were classified as chlorophytes, belonging to three different genera: Picochlorum, Nannochloris and Desmochloris. The lipid contents were assessed microscopically by means of BODIPY 505/515-associated fluorescence to detect intracellular lipid bodies, which revealed several lipid drops in all selected strains. This result was confirmed by lipid gravimetric determination, which demonstrated that all strains under study presented inner cell lipid contents ranging from 20% to 25% of the biomass dry weight. Furthermore, the fatty acid methyl esters profile of all strains seems ideal for biodiesel production due to a low degree of polyunsaturated fatty acid methyl esters and high amount of palmitic and oleic acids.

  12. Environmental, biochemical and genetic drivers of DMSP degradation and DMS production in the Sargasso Sea.

    Science.gov (United States)

    Levine, Naomi Marcil; Varaljay, Vanessa A; Toole, Dierdre A; Dacey, John W H; Doney, Scott C; Moran, Mary Ann

    2012-05-01

    Dimethylsulfide (DMS) is a climatically relevant trace gas produced and cycled by the surface ocean food web. Mechanisms driving intraannual variability in DMS production and dimethylsulfoniopropionate (DMSP) degradation in open-ocean, oligotrophic regions were investigated during a 10-month time-series at the Bermuda Atlantic Time-series Study site in the Sargasso Sea. Abundance and transcription of bacterial DMSP degradation genes, DMSP lyase enzyme activity, and DMS and DMSP concentrations, consumption rates and production rates were quantified over time and depth. This interdisciplinary data set was used to test current hypotheses of the role of light and carbon supply in regulating upper-ocean sulfur cycling. Findings supported UV-A-dependent phytoplankton DMS production. Bacterial DMSP degraders may also contribute significantly to DMS production when temperatures are elevated and UV-A dose is moderate, but may favour DMSP demethylation under low UV-A doses. Three groups of bacterial DMSP degraders with distinct intraannual variability were identified and niche differentiation was indicated. The combination of genetic and biochemical data suggest a modified 'bacterial switch' hypothesis where the prevalence of different bacterial DMSP degradation pathways is regulated by a complex set of factors including carbon supply, temperature and UV-A dose. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  13. Deposition and incorporation of corrosion product to primary coolant suppressing method

    International Nuclear Information System (INIS)

    Tsuzuki, Yasuo; Hasegawa, Naoyoshi; Fujioka, Tsunaaki.

    1992-01-01

    In a PWR type nuclear power plant, the concentration of dissolved nitrogen in primary coolants is increased by controlling the nitrogen partial pressure in a volume controlling tank gas phase portion or addition of water in a primary system water supply tank containing dissolved nitrogen to a primary system. Then ammonium is formed by a reaction with hydrogen dissolved in the primary coolants in the field of radiation rays, to control the concentration of ammonium in the coolants within a range from 0.5 to 3.5 ppm, and operate the power plant. As a result, deposition and incorporation of corrosion products to the structural materials of the primary system equipments during plant operation (pH 6.8 to 8.0) are suppressed. In other words, deposition of particulate corrosion products on the surface of fuel cladding tubes and the inner surface of pipelines in the primary system main equipments is prevented and incorporation of ionic radioactive corrosion products to the oxide membranes on the inner surface of the pipelines of the primary system main equipments is suppressed, to greatly reduce the radiation dose rate of the primary system pipelines. Thus, operator's radiation exposure can be decreased upon shut down of the plant. (N.H.)

  14. Hot-spots of primary productivity: An Alternative interpretation to Conventional upwelling models

    Science.gov (United States)

    van Ruth, Paul D.; Ganf, George G.; Ward, Tim M.

    2010-12-01

    The eastern Great Australian Bight (EGAB) forms part of the Southern and Indian Oceans and is an area of high ecological and economic importance. Although it supports a commercial fishery, quantitative estimates of the primary productivity underlying this industry are open to debate. Estimates range from 500 mg C m -2 day -1. Part of this variation may be due to the unique upwelling circulation of shelf waters in summer/autumn (November-April), which shares some similarities with highly productive eastern boundary current upwelling systems, but differs due to the influence of a northern boundary current, the Flinders current, and a wide continental shelf. This study examines spatial variations in primary productivity in the EGAB during the upwelling seasons of 2005 and 2006. Daily integral productivity calculated using the vertically generalised production model (VGPM) showed a high degree of spatial variation. Productivity was low (modelled with the VGPM, which uses surface measures of phytoplankton biomass to calculate productivity. Macro-nutrient concentrations could not be used to explain the difference in the low and high productivities (silica > 1 μmol L -1, nitrate/nitrite > 0.4 μmol L -1, phosphate > 0.1 μmol L -1). Mixing patterns or micro-nutrient concentrations are possible explanations for spatial variations in primary productivity in the EGAB. On a global scale, daily rates of primary productivity of the EGAB lie between the highly productive eastern boundary current upwelling systems, and less productive coastal regions of western and south eastern Australia, and the oligotrophic ocean. However, daily productivity rates in the upwelling hotspots of the EGAB rival productivities in Benguela and Humboldt currents.

  15. Estimation of livestock appropriation of net primary productivity in Texas Drylands

    Science.gov (United States)

    Robert Washington-Allen; Jody Fitzgerald; Stephanie Grounds; Faisar Jihadi; John Kretzschmar; Kathryn Ramirez; John Mitchell

    2009-01-01

    The ecological state of US Drylands is unknown. This research is developing procedures to determine the impact of the ecological footprint of grazing livestock on the productive capacity of US Drylands. A pilot geodatabase was developed for the state of Texas that includes 2002 data for county boundaries, net primary productivity (NPP) derived from the Moderate...

  16. Patterns of new versus recycled primary production in the terrestrial biosphere

    Science.gov (United States)

    Nitrogen (N) and phosphorus (P) availability regulate plant productivity throughout the terrestrial biosphere, influencing the patterns and magnitude of net primary production (NPP) by land plants both now and into the future. These nutrients enter ecosystems via geologic and atmospheric pathways, a...

  17. PRIMARY PRODUCTION OF SEAGRASS BEDS IN SOUTH SULAWESI (INDONESIA) - A COMPARISON OF HABITATS, METHODS AND SPECIES

    NARCIS (Netherlands)

    ERFTEMEIJER, PLA; OSINGA, R; MARS, AE

    Primary production of tropical seagrass meadows was studied between April and August 1990 in South Sulawesi, Indonesia. Oxygen evolution studies in enclosures over seagrass vegetation revealed gross community production values between 900 and 4400 mg C m-2 day-1. Assumed community respiration ranged

  18. Bioprospecting Deep-Sea Actinobacteria for Novel Anti-infective Natural Products

    Directory of Open Access Journals (Sweden)

    Dongbo Xu

    2018-04-01

    Full Text Available The global prevalence of drug resistance has created an urgent need for the discovery of novel anti-infective drugs. The major source of antibiotics in current clinical practice is terrestrial actinobacteria; the less-exploited deep-sea actinobacteria may serve as an unprecedented source of novel natural products. In this study, we evaluated 50 actinobacteria strains derived from diverse deep water sponges and environmental niches for their anti-microbial activities against a panel of pathogens including Candida albicans, Clostridium difficile, Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA, and Pseudomonas aeruginosa. More than half of the tested strains (27 were identified as active in at least one assay. The rare earth salt lanthanum chloride (LaCl3 was shown to be as an effective elicitor. Among the 27 strains, the anti-microbial activity of 15 were induced or enhanced by the addition of LaCl3. This part of study focused on one strain R818, in which potent antifungal activity was induced by the addition of LaCl3. We found that the LaCl3-activated metabolites in R818 are likely antimycin-type compounds. One of them, compound 1, has been purified. Spectroscopic analyses including HR-MS and 1D NMR indicated that this compound is urauchimycin D. The antifungal activity of compound 1 was confirmed with a minimal inhibitory concentration (MIC of 25 μg/mL; the purified compound also showed a moderate activity against C. difficile. Additional notable strains are: strain N217 which showed both antifungal and antibacterial (including P. aeruginosa activities and strain M864 which showed potent activity against C. difficile with an MIC value (0.125 μg/mL lower than those of vancomycin and metronidazole. Our preliminary studies show that deep-sea actinobacteria is a promising source of anti-infective natural products.

  19. Changes in water chemistry and primary productivity of a reactor cooling reservoir (Par Pond)

    International Nuclear Information System (INIS)

    Tilly, L.J.

    1975-01-01

    Water chemistry and primary productivity of a reactor cooling reservoir have been studied for 8 years. Initially the primary productivity increased sixfold, and the dissolved solids doubled. The dissolved-solids increase appears to have been caused by additions of makeup water from the Savannah River and by evaporative concentration during the cooling process. As the dissolved-solids concentrations and the conductivity of makeup water leveled off, the primary productivity stabilized. Major cation and anion concentrations generally followed total dissolved solids through the increase and plateau; however, silica concentrations declined steadily during the initial period of increased plankton productivity. Standing crops of net seston and centrifuge seston did not increase during this initial period. The collective data show the effects of thermal input to a cooling reservoir, illustrate the need for limnological studies before reactor siting, and suggest the possibility of using makeup-water additions to power reactor cooling basins as a reservoir management tool

  20. Recruitment and condition of juvenile sandeel on the Faroe shelf in relation to primary production

    DEFF Research Database (Denmark)

    Eliasen, Kirstin; Reinert, Jákup; Gaard, Eilif

    The food of early-life sandeel is dominated by zooplankton, which again depends on primary production. On the Faroe Shelf, measurements of accumulated new primary production and chlorophyll a during spring and summer have been carried out since 1990 and 1997, respectively. Large inter...... availability. We compare the time series from the sandeel 0-group surveys with data on phytoplankton production and biomass. The results confirm that survival and condition of the early-life stages of sandeel on the Faroe Shelf is dependent on the magnitude of the primary production. Although the sandeel......-annual variations in the onset of the spring bloom and its intensity have been observed. Since 1974 juvenile sandeels have been sampled annually on the Faroe shelf. These results also show large variations – both in number and in average length. Here, we investigate the variations in recruitment in relation to food...

  1. Comparison of TOPEX/Poseidon Sea Level and Linear Model Results forced by Various Wind Products for the Tropical Pacific

    Science.gov (United States)

    Hackert, Eric C.; Busalacchi, Antonio J.

    1997-01-01

    The goal of this paper is to compare TOPEX/Posaidon (T/P) sea level with sea level results from linear ocean model experiments forced by several different wind products for the tropical Pacific. During the period of this study (October 1992 - October 1995), available wind products include satellite winds from the ERS-1 scatterometer product of [HALP 97] and the passive microwave analysis of SSMI winds produced using the variational analysis method (VAM) of [ATLA 91]. In addition, atmospheric GCM winds from the NCEP reanalysis [KALN 96], ECMWF analysis [ECMW94], and the Goddard EOS-1 (GEOS-1) reanalysis experiment [SCHU 93] are available for comparison. The observed ship wind analysis of FSU [STRI 92] is also included in this study. The linear model of [CANE 84] is used as a transfer function to test the quality of each of these wind products for the tropical Pacific. The various wind products are judged by comparing the wind-forced model sea level results against the T/P sea level anomalies. Correlation and RMS difference maps show how well each wind product does in reproducing the T/P sea level signal. These results are summarized in a table showing area average correlations and RMS differences. The large-scale low-frequency temporal signal is reproduced by all of the wind products, However, significant differences exist in both amplitude and phase on regional scales. In general, the model results forced by satellite winds do a better job reproducing the T/P signal (i.e. have a higher average correlation and lower RMS difference) than the results forced by atmospheric model winds.

  2. Screening for biohydrogen production by cyanobacteria isolated from the Baltic Sea and Finnish lakes

    Energy Technology Data Exchange (ETDEWEB)

    Allahverdiyeva, Yagut; Leino, Hannu; Shunmugam, Sumathy; Aro, Eva-Mari [Department of Biochemistry and Food Chemistry, Plant Physiology and Molecular Biology, University of Turku, Tykistokatu 6 A, FIN-20014 Turku (Finland); Saari, Lyudmila; Fewer, David P.; Sivonen, Kaarina [Department of Applied Chemistry and Microbiology, University of Helsinki, P.O. Box 56, FI-00014 (Finland)

    2010-02-15

    Cyanobacteria are the only bacteria capable of performing oxygenic photosynthesis in which they harness solar energy and convert it into chemical energy stored in carbohydrates. Under specific conditions, cyanobacteria can use solar energy to produce also molecular hydrogen. Biodiversity among cyanobacteria for H{sub 2} production has not been efficiently studied. Here we report the screening of 400 cyanobacterial strains isolated from the Baltic Sea and Finnish lakes for efficient H{sub 2} producers. Approximately 50% of these strains produced detectable amounts of H{sub 2}. Ten strains produced similar or up to 4 times as much of H{sub 2} as the hydrogenase mutants of Anabaena PCC 7120 and Nostoc punctiforme ATCC 29133 specifically engineered in different laboratories to produce higher amounts of H{sub 2}. All ten H{sub 2} producers are N{sub 2}-fixing filamentous, heterocystous strains, seven of them are benthic and three are planktonic strains. Different culturing parameters, such as light intensity, cell density, pH and temperature had a pronounced effect on the H{sub 2} production rates of the two good H{sub 2} producers, Calothrix 336/3 and XPORK 5E strains. Notably, the culture conditions for optimal H{sub 2} production varied between different cyanobacterial strains. (author)

  3. Carrot Loss during Primary Production : Field Waste and Pack House Waste.

    OpenAIRE

    Bond, Rebekka

    2016-01-01

    Background: it has been suggested that roughly one-third of all food produced for human consumption is lost or wasted globally. The reduction of loss and waste is seen as an important societal issue with considerable ethical, ecological and economic implications. Fruit and vegetables have the highest wastage rates of any food products; (45 %). And a big part of this waste occurs during production, but empirical data on loss during primary production is limited. Carrots are an important hortic...

  4. Comment on 'The remote sensing of ocean primary productivity - Use of a new data compilation to test satellite algorithms' by William Balch et al

    Science.gov (United States)

    Platt, Trevor; Sathyendranath, Shubha

    1993-01-01

    Various conclusions by Balch et al. (1992) about the current state of modeling primary production in the sea (lack of improvement in primary production models, since 1957, utility of analytical models, and merits or weaknesses of complex models) are commented on. It is argued that since they are based on a false premise, these conclusions are not robust, and that the approach used by Balch et al. (the model of Platt and Sathyendranath, 1988) was inadequate for the question they set out to address. The present criticism is based mainly on the issue of whether implementation was correct with respect to parameter selection. It is concluded that the findings of Balch et al. with respect to the model of Platt and Sathyendranath is unreliable. Balch replies that satellite-derived estimates of primary production should be compared directly to that measured in situ in as many regions as possible. This will provide a first-order estimate of the magnitude of the error involved in estimating primary production from space.

  5. Assessing Drivers of Coastal Primary Production in Northern Marguerite Bay, Antarctica

    Directory of Open Access Journals (Sweden)

    Patrick D. Rozema

    2017-06-01

    Full Text Available The coastal ocean of the climatically-sensitive west Antarctic Peninsula is experiencing changes in the physical and (photochemical properties that strongly affect the phytoplankton. Consequently, a shift from diatoms, pivotal in the Antarctic food web, to more mobile and smaller flagellates has been observed. We seek to identify the main drivers behind primary production (PP without any assumptions beforehand to obtain the best possible model of PP. We employed a combination of field measurements and modeling to discern and quantify the influences of variability in physical, (photochemical, and biological parameters on PP in northern Marguerite Bay. Field data of high-temporal resolution (November 2013–March 2014 collected at a long-term monitoring site here were combined with estimates of PP derived from photosynthesis-irradiance incubations and modeled using mechanistic and statistical models. Daily PP varied greatly and averaged 1,764 mg C m−2 d−1 with a maximum of 6,908 mg C m−2 d−1 after the melting of sea ice and the likely release of diatoms concentrated therein. A non-assumptive random forest model (RF with all possibly relevant parameters (MRFmax showed that variability in PP was best explained by light availability and chlorophyll a followed by physical (temperature, mixed layer depth, and salinity and chemical (phosphate, total nitrogen, and silicate water column properties. The predictive power from the relative abundances of diatoms, cryptophytes, and haptophytes (as determined by pigment fingerprinting to PP was minimal. However, the variability in PP due to changes in species composition was most likely underestimated due to the contrasting strategies of these phytoplankton groups as we observed significant negative relations between PP and the relative abundance of flagellates groups. Our reduced model (MRFmin showed how light availability, chlorophyll a, and total nitrogen concentrations can be used to obtain the best

  6. Primary marine aerosol emissions from the Mediterranean Sea during pre-bloom and oligotrophic conditions: correlations to seawater chlorophyll a from a mesocosm study

    OpenAIRE

    Schwier , A. N.; Rose , C.; Asmi , E.; Ebling , A. M.; Landing , W. M.; Marro , S.; Pedrotti , M.-L.; Sallon , A.; Iuculano , F.; Agusti , S.; Tsiola , A.; Pitta , P.; Louis , J.; Guieu , C.; Gazeau , F.

    2015-01-01

    The effect of ocean acidification and changing water conditions on primary (and secondary) marine aerosol emissions is not well understood on a regional or a global scale. To investigate this effect as well as the indirect effect on aerosol that changing biogeochemical parameters can have, ~ 52 m3 pelagic mesocosms were deployed for several weeks in the Mediterranean Sea during both winter pre-bloom and summer oligotrophic conditions and were subjected to various levels of C...

  7. Temperature dependence of CO2-enhanced primary production in the European Arctic Ocean

    KAUST Repository

    Holding, J. M.

    2015-08-31

    The Arctic Ocean is warming at two to three times the global rate1 and is perceived to be a bellwether for ocean acidification2, 3. Increased CO2 concentrations are expected to have a fertilization effect on marine autotrophs4, and higher temperatures should lead to increased rates of planktonic primary production5. Yet, simultaneous assessment of warming and increased CO2 on primary production in the Arctic has not been conducted. Here we test the expectation that CO2-enhanced gross primary production (GPP) may be temperature dependent, using data from several oceanographic cruises and experiments from both spring and summer in the European sector of the Arctic Ocean. Results confirm that CO2 enhances GPP (by a factor of up to ten) over a range of 145–2,099 μatm; however, the greatest effects are observed only at lower temperatures and are constrained by nutrient and light availability to the spring period. The temperature dependence of CO2-enhanced primary production has significant implications for metabolic balance in a warmer, CO2-enriched Arctic Ocean in the future. In particular, it indicates that a twofold increase in primary production during the spring is likely in the Arctic.

  8. Responses of primary production, leaf litter decomposition and associated communities to stream eutrophication

    International Nuclear Information System (INIS)

    Dunck, Bárbara; Lima-Fernandes, Eva; Cássio, Fernanda; Cunha, Ana; Rodrigues, Liliana; Pascoal, Cláudia

    2015-01-01

    We assessed the eutrophication effects on leaf litter decomposition and primary production, and on periphytic algae, fungi and invertebrates. According to the subsidy-stress model, we expected that when algae and decomposers were nutrient limited, their activity and diversity would increase at moderate levels of nutrient enrichment, but decrease at high levels of nutrients, because eutrophication would lead to the presence of other stressors and overwhelm the subsidy effect. Chestnut leaves (Castanea sativa Mill) were enclosed in mesh bags and immersed in five streams of the Ave River basin (northwest Portugal) to assess leaf decomposition and colonization by invertebrates and fungi. In parallel, polyethylene slides were attached to the mesh bags to allow colonization by algae and to assess primary production. Communities of periphytic algae and decomposers discriminated the streams according to the trophic state. Primary production decomposition and biodiversity were lower in streams at both ends of the trophic gradient. - Highlights: • Algae and decomposers discriminated the streams according to the eutrophication level. • Primary production and litter decomposition are stimulated by moderate eutrophication. • Biodiversity and process rates were reduced in highly eutrophic streams. • Subsidy-stress model explained biodiversity and process rates under eutrophication. - Rates of leaf litter decomposition, primary production and richness of periphytic algae, fungi and invertebrates were lower in streams at both ends of the trophic gradient

  9. Variation of phytoplankton biomass and primary production in Daya Bay during spring and summer

    International Nuclear Information System (INIS)

    Song Xingyu; Huang Liangmin; Zhang Jianlin; Huang, Xiaoping; Zhang Junbin; Yin Jianqiang; Tan Yehui; Liu Sheng

    2004-01-01

    Environmental factors, phytoplankton biomass (Chl a) and primary production of two water areas in Daya Bay (Dapeng'ao Bay and Aotou Bay) were investigated during the transition period from spring to summer. Chl a ranged from 3.20 to 13.62 and 13.43 to 26.49 mg m -3 in Dapeng'ao Bay and Aotou Bay respectively, if data obtained during red tides are excluded. Primary production varied between 239.7 and 1001.4 mgC m -2 d -1 in Dapeng'ao Bay. The regional distribution of Chl a and primary production were mostly consistent from spring to summer in both bays. Seasonal transition characters have been found in Daya Bay from spring to summer, including high values of DO, nitrate and silicate. Size structures of phytoplankton and its primary production do not change very much from spring to summer, with micro-phytoplankton dominating and contributing about 50% of the whole. In Daya Bay, phytoplankton is limited by nitrogen in spring, and by phosphate in summer. Artificial impacts are evident from high temperature effluent from nuclear power stations, aquaculture and sewage. During the investigation, a red tide occurred in Aotou Bay, with a maximum Chl a of 103.23 mg m -3 at surface and primary production of 2721.9 mgC m -2 d -1 in the red tide center. Raised water temperature and nutrient supply from land-sources help to stimulate annual red tides

  10. Distribution and production of plankton communities in the subtropical convergence zone of the Sargasso Sea. II. Protozooplankton and copepods

    DEFF Research Database (Denmark)

    Andersen, Nikolaj G.; Nielsen, Torkel Gissel; Jakobsen, Hans Henrik

    2011-01-01

    the potential reasons why Atlantic eels Anguilla spp. use this area for spawning, we investigated the distribution and productivity of the zooplankton community across the Subtropical Convergence Zone (STCZ) in the Sargasso Sea in March and April 2007. The vertical and horizontal distributions of protozoans...

  11. Modeling the nitrogen cycling and plankton productivity in the Black Sea using a three-dimensional interdisciplinary model

    NARCIS (Netherlands)

    Grégoire, M.; Soetaert, K.E.R.; Nezlin, N.; Kostianoy, A.

    2004-01-01

    A six-compartment ecosystem model defined by a simple nitrogen cycle is coupled with a general circulation model in the Black Sea so as to examine the seasonal variability of the ecohydrodynamics. Model results show that the annual cycle of the biological productivity of the whole basin is

  12. The co-production of power and knowledge around the mussel fisheries transition in the Dutch Wadden Sea

    NARCIS (Netherlands)

    van der Molen, Franke; Puente Rodriguez, Daniel

    2013-01-01

    Governance practices are places where knowledge and power interconnect. In this paper, the stabilization of a governance practice concerning mussel fisheries in the Dutch Wadden Sea is described and analyzed in terms of the co-production of knowledge and power. In this governance practice,

  13. Distribution of meiobenthos at bathyal depths in the Mediterranean Sea. A comparison between sites of contrasting productivity

    Directory of Open Access Journals (Sweden)

    Anastasios Tselepides

    2004-12-01

    Full Text Available In order to study the distribution of meiobenthos (Metazoa and Foraminifera at bathyal depths along a west-east productivity gradient in the Mediterranean Sea, stations along the continental slopes of the Balearic Sea, west Ionian and east Ionian Seas were sampled during the DESEAS Trans-Mediterranean Cruise in June-July 2001. Standing stock of total meiobenthos differed considerably among the sampling stations, with marked differences occurring between sampling depths and sites. At 600 m depth, meiobenthic abundances were slightly higher over the Balearic continental slope, whereas at the deeper stations (800 m and 1500-1700 m, abundances were significantly higher in the west Ionian Sea. Significant relationships were found between the abundances of major groups and the chloroplastic pigments, indicating that food availability is a major factor controlling the distribution of meiobenthos. Apart from the overall differences in productivity between the western and eastern Mediterranean Sea, local hydrographic features and topographic differences greatly influence the spatial variability of the environmental parameters within each sub-basin and thus the distribution of meiobenthos in the bathyal zone.

  14. Seasonal variability of primary production in a fjord ecosystem of the Chilean Patagonia: Implications for the transfer of carbon within pelagic food webs

    Science.gov (United States)

    Montero, Paulina; Daneri, Giovanni; González, Humberto E.; Iriarte, Jose Luis; Tapia, Fabián J.; Lizárraga, Lorena; Sanchez, Nicolas; Pizarro, Oscar

    2011-03-01

    We characterized the seasonal cycle of productivity in Reloncaví Fjord (41°30'S), Chilean Patagonia. Seasonal surveys that included measurements of gross primary production, community respiration, bacterioplankton secondary production, and sedimentation rates along the fjord were combined with continuous records of water-column temperature variability and wind forcing, as well as satellite-derived data on regional patterns of wind stress, sea surface temperatures, and surface chlorophyll concentrations. The hydrography and perhaps fjord productivity respond to the timing and intensity of wind forcing over a larger region. Seasonal changes in the direction and intensity of winds, along with a late-winter improvement in light conditions, may determine the timing of phytoplankton blooms and potentially modulate productivity cycles in the region. Depth-integrated gross primary production estimates were higher (0.4-3.8 g C m -2 d -1) in the productive season (October, February, and May), and lower (0.1-0.2 g C m -2 d -1) in the non-productive season (August). These seasonal changes were also reflected in community respiration and bacterioplankton production rates, which ranged, respectively, from 0.3 to 4.8 g C m -2 d -1 and 0.05 to 0.4 g C m -2 d -1 during the productive and non-productive seasons and from 0.05 to 0.6 g C m -2 d -1 and 0.05 to 0.2 g C m -2 d -1 during the same two periods. We found a strong, significant correlation between gross primary production and community respiration (Spearman, r=0.95; p100%, suggesting the use of allochthonous carbon sources by bacterioplankton when the levels of gross primary production are low. Low primary production rates were associated with a greater contribution of small cells to autotrophic biomass, highlighting the importance of small-sized plankton and bacteria for carbon cycling and fluxes during the less productive winter months. Fecal pellet sedimentation was minimal during this period, also suggesting that most of

  15. Interview and questionnaire guide: Quantification of food losses and waste in primary production

    DEFF Research Database (Denmark)

    Svanes, Erik; Hartikainen, Hanna; Mogensen, Lisbeth

    production in the Nordic countries. Other aims were to estimate the amount of side flow and to gain knowledge about the reasons behind it, how it can be reduced, how it is treated and how it can be better utilized.This guide contains a catalogue of questions that may be used for interviews and questionnaires...... with primary producers and other stakeholders within primary production. It also contains the justification behind the questions and some tips on how to conduct interviews.......This interview guide was developed within the Nordic project “Food losses and waste in primary production” (Franke et al. 2016). One of the main purposes of the project was to test research methods for the quantification of food losses and waste (in the project called 'side flow') from primary...

  16. Quantification of dimethyl sulfide (DMS production in the sea anemone Aiptasia sp. to simulate the sea-to-air flux from coral reefs

    Directory of Open Access Journals (Sweden)

    F. Franchini

    2017-12-01

    Full Text Available The production of dimethyl sulfide (DMS is poorly quantified in tropical reef environments but forms an essential process that couples marine and terrestrial sulfur cycles and affects climate. Here we quantified net aqueous DMS production and the concentration of its cellular precursor dimethylsulfoniopropionate (DMSP in the sea anemone Aiptasia sp., a model organism to study coral-related processes. Bleached anemones did not show net DMS production whereas symbiotic anemones produced DMS concentrations (mean ± standard error of 160.7 ± 44.22 nmol g−1 dry weight (DW after 48 h incubation. Symbiotic and bleached individuals showed DMSP concentrations of 32.7 ± 6.00 and 0.6 ± 0.19 µmol g−1 DW, respectively. We applied these findings to a Monte Carlo simulation to demonstrate that net aqueous DMS production accounts for only 20 % of gross aqueous DMS production. Monte Carlo-based estimations of sea-to-air fluxes of gaseous DMS showed that reefs may release 0.1 to 26.3 µmol DMS m−2 coral surface area (CSA d−1 into the atmosphere with 40 % probability for rates between 0.5 and 1.5 µmol m−2 CSA d−1. These predictions were in agreement with directly quantified fluxes in previous studies. Conversion to a flux normalised to sea surface area (SSA (range 0.1 to 17.4, with the highest probability for 0.3 to 1.0 µmol DMS m−2 SSA d−1 suggests that coral reefs emit gaseous DMS at lower rates than the average global oceanic DMS flux of 4.6 µmol m−2 SSA d−1 (19.6 Tg sulfur per year. The large difference between simulated gross and quantified net aqueous DMS production in corals suggests that the current and future potential for its production in tropical reefs is critically governed by DMS consumption processes. Hence, more research is required to assess the sensitivity of DMS-consumption pathways to ongoing environmental change in order to address the impact of predicted

  17. Quantification of dimethyl sulfide (DMS) production in the sea anemone Aiptasia sp. to simulate the sea-to-air flux from coral reefs

    Science.gov (United States)

    Franchini, Filippo; Steinke, Michael

    2017-12-01

    The production of dimethyl sulfide (DMS) is poorly quantified in tropical reef environments but forms an essential process that couples marine and terrestrial sulfur cycles and affects climate. Here we quantified net aqueous DMS production and the concentration of its cellular precursor dimethylsulfoniopropionate (DMSP) in the sea anemone Aiptasia sp., a model organism to study coral-related processes. Bleached anemones did not show net DMS production whereas symbiotic anemones produced DMS concentrations (mean ± standard error) of 160.7 ± 44.22 nmol g-1 dry weight (DW) after 48 h incubation. Symbiotic and bleached individuals showed DMSP concentrations of 32.7 ± 6.00 and 0.6 ± 0.19 µmol g-1 DW, respectively. We applied these findings to a Monte Carlo simulation to demonstrate that net aqueous DMS production accounts for only 20 % of gross aqueous DMS production. Monte Carlo-based estimations of sea-to-air fluxes of gaseous DMS showed that reefs may release 0.1 to 26.3 µmol DMS m-2 coral surface area (CSA) d-1 into the atmosphere with 40 % probability for rates between 0.5 and 1.5 µmol m-2 CSA d-1. These predictions were in agreement with directly quantified fluxes in previous studies. Conversion to a flux normalised to sea surface area (SSA) (range 0.1 to 17.4, with the highest probability for 0.3 to 1.0 µmol DMS m-2 SSA d-1) suggests that coral reefs emit gaseous DMS at lower rates than the average global oceanic DMS flux of 4.6 µmol m-2 SSA d-1 (19.6 Tg sulfur per year). The large difference between simulated gross and quantified net aqueous DMS production in corals suggests that the current and future potential for its production in tropical reefs is critically governed by DMS consumption processes. Hence, more research is required to assess the sensitivity of DMS-consumption pathways to ongoing environmental change in order to address the impact of predicted degradation of coral reefs on DMS production in tropical coastal ecosystems and its impact on

  18. Nutrients and primary production in a shallow stratified ecosystem in the Iroise Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Birrien, J; Wafar, M.V.M.; LeCorre, P.; Riso, R.

    stream_size 22 stream_content_type text/plain stream_name J_Plankton_Res_13_721.pdf.txt stream_source_info J_Plankton_Res_13_721.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  19. Effects of ocean acidification on primary production in a coastal North Sea phytoplankton community

    OpenAIRE

    Eberlein, Tim; Wohlrab, Sylke; Rost, Bjoern; John, Uwe; Bach, Lennart T.; Riebesell, Ulf; Van de Waal, Dedmer B.

    2017-01-01

    El efecto de la contaminación sobre el reclutamiento ha sido insuficientemente estudiado. Este trabajo trata el tema del reclutamiento en sitios ubicados a diferentes distancias de dos importantes fuentes de contaminación. Se caracterizó la composición y estructura de las asociaciones de reclutas de corales pétreos (escleractinios y milepóridos) al oeste de la Ciudad de La Habana, Cuba. Esta área está influenciada por la contaminación urbana del río Almendares y del emisario submarino constru...

  20. Primary productivity and nitrogen fixation by Trichodesmium spp. in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Parab, S.G.; Matondkar, S.G.P.

    was around 28 degrees C and nitrate content was as low as 0.34 mu M. After the northeast monsoon, Trichodesmium erythraeum developed in the offshore area and then spread to coastal waters. Both species of Trichodesmium together produced a total of 0.263 Tg...

  1. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Gustavsson, Leif [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

    2010-04-15

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

  2. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    International Nuclear Information System (INIS)

    Sathre, Roger; Gustavsson, Leif; Bergh, Johan

    2010-01-01

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO 2equiv if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

  3. Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Sathre, Roger; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

    2010-04-15

    In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission. (author)

  4. Primary production in a shallow water lake with special reference to a reed swamp

    International Nuclear Information System (INIS)

    Andersen, F.Oe.

    1976-01-01

    Phytoplankton gross primary production ( 14 C method) in the shallow, eutrophic Danish Lake Arresoe in 1973 was 980 g C m -2 . Calculated net primary production was near zero. Macrophyte net primary production was measured by harvesting the maximum biomass, and above ground values were between 420 and 1325 g ash free dry wt m -2 , while below ground values were between 2480 and 8570 g ash free dry wt m -2 . The reed swamps were mapped on aerial photographs, and the composition of the macrophyte vegetation was determined. A comparison of macrophyte vegetation in 1944 and 1972 showed a reduction in species diversity, especially of submerged species. The seasonal variations in physical and chemical data indicated strong eutrophication in Arresoe. (author)

  5. Plant Growth Optimization by Vegetable Production System in HI-SEAS Analog Habitat

    Science.gov (United States)

    Ehrlich, Joshua W.; Massa, Gioia D.; Wheeler, Raymond M.; Gill, Tracy R.; Quincy, Charles D.; Roberson, Luke B.; Binsted, Kim; Morrow, Robert C.

    2017-01-01

    The Vegetable Production System (Veggie) is a scientific payload designed to support plant growth for food production under microgravity conditions. The configuration of Veggie consists of an LED lighting system with modular rooting pillows designed to contain substrate media and time-release fertilizer. The pillows were designed to be watered passively using capillary principles but have typically been watered manually by the astronauts in low-Earth orbit (LEO). The design of Veggie allows cabin air to be drawn through the plant enclosure for thermal and humidity control and for supplying CO2 to the plants. Since its delivery to the International Space Station (ISS) in 2014, Veggie has undergone several experimental trials by various crews. Ground unit testing of Veggie was conducted during an 8-month Mars analog study in a semi-contained environment of a simulated habitat located at approximately 8,200 feet (2,500 m) elevation on the Mauna Loa volcano on the Island of Hawaii. The Hawaii Space Exploration Analog and Simulation (HI-SEAS) offered conditions (habitat, mission, communications, etc.) intended to simulate a planetary exploration mission. This paper provides data and analyses to show the prospect for optimized use of the current Veggie design for human habitats. Lessons learned during the study may provide opportunities for updating the system design and operational parameters for current Veggie experiments being conducted onboard the ISS and for payloads on future deep space missions.

  6. Light production by the arm tips of the deep-sea cephalopod Vampyroteuthis infernalis.

    Science.gov (United States)

    Robison, Bruce H; Reisenbichler, Kim R; Hunt, James C; Haddock, Steven H D

    2003-10-01

    The archaic, deep-sea cephalopod Vampyroteuthis infernalis occurs in dark, oxygen-poor waters below 600 m off Monterey Bay, California. Living specimens, collected gently with a remotely operated vehicle (ROV) and quickly transported to a laboratory ashore, have revealed two hitherto undescribed means of bioluminescent expression for the species. In the first, light is produced by a new type of organ located at the tips of all eight arms. In the second, a viscous fluid containing microscopic luminous particles is released from the arm tips to form a glowing cloud around the animal. Both modes of light production are apparently linked to anti-predation strategies. Use of the tip-lights is readily educed by contact stimuli, while fluid expulsion has a much higher triggering threshold. Coelenterazine and luciferase are the chemical precursors of light production. This paper presents observations on the structure and operation of the arm-tip light organs, the character of the luminous cloud, and how the light they produce is incorporated into behavioral patterns.

  7. Corrosion product behaviour in the primary circuit of the KNK nuclear reactor facility

    International Nuclear Information System (INIS)

    Stamm, H.H.; Stade, K.Ch.

    1976-01-01

    During nuclear operation of the KNK facility from 1972 until September 1974 the composition and behaviour of radionuclides occuring in the primary circuit were investigated. Besides traces of 140 Ba/ 140 La, no fission product activity was detectable in the KNK primary circuit. The fuel element purification from sodium deposits (prior to transport to the reprocessing plant) did not yield any indication of a fuel element failure during KNK-I operation. The activity inventory of the primary loop was exclusively made up of activated corrosion products and 22 Na. The main activity was due to 65 Zn, followed by 54 Mn, 22 Na, sup(110m)Ag, 182 Ta, 60 Co and 124 Sb. It was found that the sorption of 65 Zn and 54 Mn on crucibles made from nickel was condiserably higher than on vessels made from other materials. This observation was confirmed both in tests with material samples from the primary circuit and for disks of gate valves of the primary circuit. sup(110m)Ag did hardly exhibit any sorption effects and had been dissolved largely homogeneously in the hot primary coolant. In the first primary cold trap which was removed from the circuit after some 20,000 hours of operation, only 65 Zn and 54 Mn were detected in addition to traces of 60 Co and 182 Ta. (author)

  8. Climate-induced interannual variability of marine primary and export production in three global coupled climate carbon cycle models

    Directory of Open Access Journals (Sweden)

    B. Schneider

    2008-04-01

    Full Text Available Fully coupled climate carbon cycle models are sophisticated tools that are used to predict future climate change and its impact on the land and ocean carbon cycles. These models should be able to adequately represent natural variability, requiring model validation by observations. The present study focuses on the ocean carbon cycle component, in particular the spatial and temporal variability in net primary productivity (PP and export production (EP of particulate organic carbon (POC. Results from three coupled climate carbon cycle models (IPSL, MPIM, NCAR are compared with observation-based estimates derived from satellite measurements of ocean colour and results from inverse modelling (data assimilation. Satellite observations of ocean colour have shown that temporal variability of PP on the global scale is largely dominated by the permanently stratified, low-latitude ocean (Behrenfeld et al., 2006 with stronger stratification (higher sea surface temperature; SST being associated with negative PP anomalies. Results from all three coupled models confirm the role of the low-latitude, permanently stratified ocean for anomalies in globally integrated PP, but only one model (IPSL also reproduces the inverse relationship between stratification (SST and PP. An adequate representation of iron and macronutrient co-limitation of phytoplankton growth in the tropical ocean has shown to be the crucial mechanism determining the capability of the models to reproduce observed interactions between climate and PP.

  9. Consumer preferences regarding the introduction of new organic products. The case of the Mediterranean sea bass (Dicentrarchus labrax) in Italy.

    Science.gov (United States)

    Mauracher, C; Tempesta, T; Vecchiato, D

    2013-04-01

    The introduction of new products on the market poses several challenges; in particular, whether the characteristics of the proposed product will be judged positively by potential consumers. This paper analyses the preferences of consumers regarding the introduction on the Italian market of a new product: organic Mediterranean sea bass. The aim of this study is to assess the importance given by consumers to four main characteristics of sea bass (country of origin, size, production method - organic or conventional - and price) so as to be able to formulate marketing strategies. We applied a choice experiment (CE) in order to define not only the ordinal ranking of preferences but also the willingness to pay (WTP) for the key characteristics of the newly-introduced product. We found that consumers show a higher WTP for the sea bass country of origin than for the breeding method used. Our results suggest that while organic aquaculture might be a new and important strategy for diversification, if suitable communication, either from a public policy or commercial perspective, and labelling/certification are not taken into consideration, the added value of the production method might not be perceived by the final consumers. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Mean annual precipitation predicts primary production resistance and resilience to extreme drought.

    Science.gov (United States)

    Stuart-Haëntjens, Ellen; De Boeck, Hans J; Lemoine, Nathan P; Mänd, Pille; Kröel-Dulay, György; Schmidt, Inger K; Jentsch, Anke; Stampfli, Andreas; Anderegg, William R L; Bahn, Michael; Kreyling, Juergen; Wohlgemuth, Thomas; Lloret, Francisco; Classen, Aimée T; Gough, Christopher M; Smith, Melinda D

    2018-04-27

    Extreme drought is increasing in frequency and intensity in many regions globally, with uncertain consequences for the resistance and resilience of ecosystem functions, including primary production. Primary production resistance, the capacity to withstand change during extreme drought, and resilience, the degree to which production recovers, vary among and within ecosystem types, obscuring generalized patterns of ecological stability. Theory and many observations suggest forest production is more resistant but less resilient than grassland production to extreme drought; however, studies of production sensitivity to precipitation variability indicate that the processes controlling resistance and resilience may be influenced more by mean annual precipitation (MAP) than ecosystem type. Here, we conducted a global meta-analysis to investigate primary production resistance and resilience to extreme drought in 64 forests and grasslands across a broad MAP gradient. We found resistance to extreme drought was predicted by MAP; however, grasslands (positive) and forests (negative) exhibited opposing resilience relationships with MAP. Our findings indicate that common plant physiological mechanisms may determine grassland and forest resistance to extreme drought, whereas differences among plant residents in turnover time, plant architecture, and drought adaptive strategies likely underlie divergent resilience patterns. The low resistance and resilience of dry grasslands suggests that these ecosystems are the most vulnerable to extreme drought - a vulnerability that is expected to compound as extreme drought frequency increases in the future. Copyright © 2018. Published by Elsevier B.V.

  11. Black Sea Mixed Layer Sensitivity to Various Wind and Thermal Forcing Products on Climatological Time Scales

    National Research Council Canada - National Science Library

    Kara, A. B; Jurlburt, Harley; Wallcraft, Alan; Bourassa, Mark

    2005-01-01

    This study describes atmospheric forcing parameters constructed from different global climatologies, applied to the Black Sea, and investigates the sensitivity of HYbrid Coordinate Ocean Model (HYCOM...

  12. Food waste quantification in primary production - The Nordic countries as a case study.

    Science.gov (United States)

    Hartikainen, Hanna; Mogensen, Lisbeth; Svanes, Erik; Franke, Ulrika

    2018-01-01

    Our understanding of food waste in the food supply chain has increased, but very few studies have been published on food waste in primary production. The overall aims of this study were to quantify the total amount of food waste in primary production in Finland, Sweden, Norway and Denmark, and to create a framework for how to define and quantify food waste in primary production. The quantification of food waste was based on case studies conducted in the present study and estimates published in scientific literature. The chosen scope of the study was to quantify the amount of edible food (excluding inedible parts like peels and bones) produced for human consumption that did not end up as food. As a result, the quantification was different from the existing guidelines. One of the main differences is that food that ends up as animal feed is included in the present study, whereas this is not the case for the recently launched food waste definition of the FUSIONS project. To distinguish the 'food waste' definition of the present study from the existing definitions and to avoid confusion with established usage of the term, a new term 'side flow' (SF) was introduced as a synonym for food waste in primary production. A rough estimate of the total amount of food waste in primary production in Finland, Sweden, Norway and Denmark was made using SF and 'FUSIONS Food Waste' (FFW) definitions. The SFs in primary production in the four Nordic countries were an estimated 800,000 tonnes per year with an additional 100,000 tonnes per year from the rearing phase of animals. The 900,000 tonnes per year of SF corresponds to 3.7% of the total production of 24,000,000 tonnes per year of edible primary products. When using the FFW definition proposed by the FUSIONS project, the FFW amount was estimated at 330,000 tonnes per year, or 1% of the total production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Enhanced dissolved lipid production as a response to the sea surface warming

    Science.gov (United States)

    Novak, Tihana; Godrijan, Jelena; Pfannkuchen, Daniela Marić; Djakovac, Tamara; Mlakar, Marina; Baricevic, Ana; Tanković, Mirta Smodlaka; Gašparović, Blaženka

    2018-04-01

    The temperature increase in oceans reflects on marine ecosystem functioning and surely has consequences on the marine carbon cycle and carbon sequestration. In this study, we examined dissolved lipid, lipid classes and dissolved organic carbon (DOC) production in the northern Adriatic Sea, isolated diatom Chaetoceros pseudocurvisetus batch cultures grown in a wide temperature range (10-30 °C) and in contrasting nutrient regimes, phosphorus (P)-depleted and P-replete conditions. Additionally, lipids and DOC were analyzed in the northern Adriatic (NA) in two stations characterized with different P availability, occupied from February to August 2010 that covered a temperature range from 9.3 to 31.1 °C. To gain insight into factors governing lipid and lipid classes' production in the NA, apart from temperature (T), Chlorophyll a, phytoplankton community abundance and structure, nutrient concentrations were measured together with hydrographic parameters. We found enhanced accumulation of dissolved lipids, particulary glycolipids, with increasing T, especially during the highest in situ temperature. The effect of T on enhanced dissolved lipid release is much more pronounced under P-deplete conditions indicating that oligotrophic regions might be more vulnerable to T rise. Temperature between 25 and 30 °C is a threshold T range for C. pseudocurvisetus, at which a significant part of lipid production is directed toward the dissolved phase. Unlike monocultures, there are multiple factors influencing produced lipid composition, distribution and cycling in the NA that may counteract the T influence. The possible role of enhanced dissolved lipid concentration for carbon sequestration at elevated T is discussed. On the one hand, lipids are buoyant and do not sink, which enhances their retention at the surface layer. In addition, they are surface active, and therefore prone to adsorb on sinking particles, contributing to the C sequestration.

  14. Warming Increases the Proportion of Primary Production Emitted as Methane from Freshwater Mesocosms

    OpenAIRE

    2010-01-01

    Abstract Methane and carbon dioxide are the dominant gaseous end products of the remineralisation of organic carbon and also the two largest contributors to the anthropogenic greenhouse effect. We investigated whether warming altered the balance of methane efflux relative to primary production and ecosystem respiration in a freshwater mesocosm experiment. Whole ecosystem CH4 efflux was strongly related to temperature with an apparent activation energy of 0.85eV. Furthermore, CH4 ef...

  15. Comparison between remote sensing and a dynamic vegetation model for estimating terrestrial primary production of Africa.

    Science.gov (United States)

    Ardö, Jonas

    2015-12-01

    Africa is an important part of the global carbon cycle. It is also a continent facing potential problems due to increasing resource demand in combination with climate change-induced changes in resource supply. Quantifying the pools and fluxes constituting the terrestrial African carbon cycle is a challenge, because of uncertainties in meteorological driver data, lack of validation data, and potentially uncertain representation of important processes in major ecosystems. In this paper, terrestrial primary production estimates derived from remote sensing and a dynamic vegetation model are compared and quantified for major African land cover types. Continental gross primary production estimates derived from remote sensing were higher than corresponding estimates derived from a dynamic vegetation model. However, estimates of continental net primary production from remote sensing were lower than corresponding estimates from the dynamic vegetation model. Variation was found among land cover classes, and the largest differences in gross primary production were found in the evergreen broadleaf forest. Average carbon use efficiency (NPP/GPP) was 0.58 for the vegetation model and 0.46 for the remote sensing method. Validation versus in situ data of aboveground net primary production revealed significant positive relationships for both methods. A combination of the remote sensing method with the dynamic vegetation model did not strongly affect this relationship. Observed significant differences in estimated vegetation productivity may have several causes, including model design and temperature sensitivity. Differences in carbon use efficiency reflect underlying model assumptions. Integrating the realistic process representation of dynamic vegetation models with the high resolution observational strength of remote sensing may support realistic estimation of components of the carbon cycle and enhance resource monitoring, providing suitable validation data is available.

  16. Twenty-million-year relationship between mammalian diversity and primary productivity

    Science.gov (United States)

    Fritz, Susanne A.; Eronen, Jussi T.; Schnitzler, Jan; Hof, Christian; Janis, Christine M.; Mulch, Andreas; Böhning-Gaese, Katrin; Graham, Catherine H.

    2016-01-01

    At global and regional scales, primary productivity strongly correlates with richness patterns of extant animals across space, suggesting that resource availability and climatic conditions drive patterns of diversity. However, the existence and consistency of such diversity–productivity relationships through geological history is unclear. Here we provide a comprehensive quantitative test of the diversity–productivity relationship for terrestrial large mammals through time across broad temporal and spatial scales. We combine >14,000 occurrences for 690 fossil genera through the Neogene (23–1.8 Mya) with regional estimates of primary productivity from fossil plant communities in North America and Europe. We show a significant positive diversity–productivity relationship through the 20-million-year record, providing evidence on unprecedented spatial and temporal scales that this relationship is a general pattern in the ecology and paleo-ecology of our planet. Further, we discover that genus richness today does not match the fossil relationship, suggesting that a combination of human impacts and Pleistocene climate variability has modified the 20-million-year ecological relationship by strongly reducing primary productivity and driving many mammalian species into decline or to extinction. PMID:27621451

  17. Evaluation and identification of histamine-forming bacteria on fish products of middle Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Rocco Mancusi

    2013-04-01

    Full Text Available Regulation EU 2073/2005 sets maximum concentration for histamine in fish and products thereof. To meet these criteria, manufacturers have to define performance objectives, such as the maximum allowed prevalence and number/activity of histamine-producing bacteria at relevant stage of production. In order to assess the presence and decarboxylase activity of contaminant bacteria we examined 51 samples of blue fish caught and processed in Emilia Romagna region. We collected 50 gr of fish (skin and gills or the entire product from 10 sample units from every lot. Analytical samples were cultured in Trypticase Soy Broth supplemented with histidine and pyridoxal HCl. Histamine was measured with an electrochemical biosensor after incubation at both 37°C for 24 h and 18-22°C for 48 h. Enrichments that showed relevant enzymatic activity were seeded on Niven agar to isolate suspected colonies and DNA extracts from these bacteria were analyzed by polymerase chain reaction (PCR for detecting specific sequences of the gene encoding pyridoxaldependent histidine decarboxylase (HDC. Overall, 29.4% samples showed relevant production of histamine in broth cultures (above a cut-off value set at 250 ng/mL and 53.3% of them (8 out of 15 samples allowed detection of HDC positive strains. All of them were typed as Morganella, which appears to be the most common of fish caught in middle Adriatic sea. Ten out of the twelve positive samples with enrichment cultures incubated at both 37 and 18-22°C (83% showed higher decarboxylase activity at room temperature, suggesting the presence of psychrotolerant strains. In addition, the prevalence of histamine-producing bacteria was higher at retail than at production level, probably as a consequence of manipulations and cross-contamination. The risk correlated to development of histamine-producing psychrotolerans bacteria cannot be controlled only with storage temperature: it is necessary for the food business operators to

  18. Shrubland primary production and soil respiration diverge along European climate gradient

    DEFF Research Database (Denmark)

    Reinsch, Sabine; Koller, Eva; Sowerby, Alwyn

    2017-01-01

    uncertain. Here we show the responses of ecosystem C to 8-12 years of experimental drought and night-time warming across an aridity gradient spanning seven European shrublands using indices of C assimilation (aboveground net primary production: aNPP) and soil C efflux (soil respiration: Rs). The changes...

  19. Joint control of terrestrial gross primary productivity by plant phenology and physiology

    DEFF Research Database (Denmark)

    Xia, Jianyang; Niu, Shuli; Ciais, Philippe

    2015-01-01

    Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate–carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of b...

  20. Effects of precipitation changes on aboveground net primary production and soil respiration in a switchgrass field

    Science.gov (United States)

    This study attempted to test whether switchgrass aboveground net primary production (ANPP) responds to precipitation (PPT) changes in a double asymmetry pattern as framed by Knapp et al. (2016), and whether it is held true for other ecosystem processes such as soil respiration (SR). Data were colle...

  1. Studies on the primary productivity of a polluted mangrove pond in ...

    African Journals Online (AJOL)

    The primary productivity of a polluted mangrove pond in Lagos was investigated for six months (October 2010-March 2011) using the chlorophyll-a method. Air and water temperatures were high (≥21°C) while transparency was lower than 11.5 cm at the mangrove pond. Total suspended solids were ≥2.0 mg/L while total ...

  2. Seasonal patterns in phytoplankton photosynthetic parameters and primary production at a coastal NW Mediterranean site

    KAUST Repository

    Gasol, Josep M.; Cardelú s, Clara; Moran, Xose Anxelu G.; Balagué , Vanessa; Forn, Irene; Marrasé , Cè lia; Massana, Ramon; Pedró s-Alió , Carlos; Sala, M. Montserrat; Simó , Rafel; Vaqué , Dolors; Estrada, Marta

    2016-01-01

    We carried out monthly photosynthesis-irradiance (P-E) experiments with the 14C-method for 12 years (2003–2014) to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a

  3. Estimating climate change effects on net primary production of rangelands in the United States

    Science.gov (United States)

    Matthew C. Reeves; Adam L. Moreno; Karen E. Bagne; Steven W. Running

    2014-01-01

    The potential effects of climate change on net primary productivity (NPP) of U.S. rangelands were evaluated using estimated climate regimes from the A1B, A2 and B2 global change scenarios imposed on the biogeochemical cycling model, Biome-BGC from 2001 to 2100. Temperature, precipitation, vapor pressure deficit, day length, solar radiation, CO2 enrichment and nitrogen...

  4. Evaluation of MODIS gross primary productivity for Africa using eddy covariance data

    CSIR Research Space (South Africa)

    Sjöström, M

    2013-04-01

    Full Text Available MOD17A2 provides operational gross primary production (GPP) data globally at 1 km spatial resolution and 8-day temporal resolution. MOD17A2 estimates GPP according to the light use efficiency (LUE) concept assuming a fixed maximum rate of carbon...

  5. Variance-based sensitivity analysis of BIOME-BGC for gross and net primary production

    NARCIS (Netherlands)

    Raj, R.; Hamm, N.A.S.; van der Tol, C.; Stein, A.

    2014-01-01

    Parameterization and calibration of a process-based simulator (PBS) is a major challenge when simulating gross and net primary production (GPP and NPP). The large number of parameters makes the calibration computationally expensive and is complicated by the dependence of several parameters on other

  6. Creating a regional MODIS satellite-driven net primary production dataset for european forests

    NARCIS (Netherlands)

    Neumann, Mathias; Moreno, Adam; Thurnher, Christopher; Mues, Volker; Härkönen, Sanna; Mura, Matteo; Bouriaud, Olivier; Lang, Mait; Cardellini, Giuseppe; Thivolle-Cazat, Alain; Bronisz, Karol; Merganic, Jan; Alberdi, Iciar; Astrup, Rasmus; Mohren, Frits; Zhao, Maosheng; Hasenauer, Hubert

    2016-01-01

    Net primary production (NPP) is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm

  7. Joint control of terrestrial gross primary productivity by plant phenology and physiology

    NARCIS (Netherlands)

    Xia, J.; Niu, S.; Ciais, P.; Janssens, I.A.; Chen, J.; Ammann, C.; Arain, A.; Blanken, P.D.; Cescatti, A.; Moors, E.J.

    2015-01-01

    Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate–carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of

  8. Cell specific primary production of autotrophic and mixotrophic phytoplankton in acidified lakes of the Bohemian Forest

    Czech Academy of Sciences Publication Activity Database

    Znachor, Petr; Nedoma, Jiří

    2004-01-01

    Roč. 112, - (2004), s. 141-155 ISSN 0342-1120 R&D Projects: GA ČR(CZ) GA206/98/0727; GA ČR(CZ) GA206/97/0072 Keywords : autoradiography * mixotrophy * primary production Subject RIV: EH - Ecology, Behaviour

  9. Seasonal primary production in different sectors of the EEZ of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarupria, J.S.; Bhargava, R.M.S.

    The seasonal and regional variations in the primary production, based on the data collected at 562 stations over the period from 1962 to 1988, are presented. The entire Indian Exclusive Economic Zone (EEZ), measuring 2.01 million km super(2...

  10. UV radiation and natural fluorescence linked primary production in Antarctic waters

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; KrishnaKumari, L.; Bhattathiri, P.M.A.; Chandramohan, D.

    Primary productivity and chlorophyll values have been measured using an underwater profiling radiometer for the first time in the waters around Indian Antarctic Station (70°46'S & 11°44'E) in the summer of 1994. The profiles include natural...

  11. Increased light-use efficiency sustains net primary productivity of shaded coffee plants in agroforestry system.

    Science.gov (United States)

    Charbonnier, Fabien; Roupsard, Olivier; le Maire, Guerric; Guillemot, Joannès; Casanoves, Fernando; Lacointe, André; Vaast, Philippe; Allinne, Clémentine; Audebert, Louise; Cambou, Aurélie; Clément-Vidal, Anne; Defrenet, Elsa; Duursma, Remko A; Jarri, Laura; Jourdan, Christophe; Khac, Emmanuelle; Leandro, Patricia; Medlyn, Belinda E; Saint-André, Laurent; Thaler, Philippe; Van Den Meersche, Karel; Barquero Aguilar, Alejandra; Lehner, Peter; Dreyer, Erwin

    2017-08-01

    In agroforestry systems, shade trees strongly affect the physiology of the undergrown crop. However, a major paradigm is that the reduction in absorbed photosynthetically active radiation is, to a certain extent, compensated by an increase in light-use efficiency, thereby reducing the difference in net primary productivity between shaded and non-shaded plants. Due to the large spatial heterogeneity in agroforestry systems and the lack of appropriate tools, the combined effects of such variables have seldom been analysed, even though they may help understand physiological processes underlying yield dynamics. In this study, we monitored net primary productivity, during two years, on scales ranging from individual coffee plants to the entire plot. Absorbed radiation was mapped with a 3D model (MAESPA). Light-use efficiency and net assimilation rate were derived for each coffee plant individually. We found that although irradiance was reduced by 60% below crowns of shade trees, coffee light-use efficiency increased by 50%, leaving net primary productivity fairly stable across all shade levels. Variability of aboveground net primary productivity of coffee plants was caused primarily by the age of the plants and by intraspecific competition among them (drivers usually overlooked in the agroforestry literature) rather than by the presence of shade trees. © 2017 John Wiley & Sons Ltd.

  12. Improved estimates of net primary productivity from MODIS satellite data at regional and local scales

    Science.gov (United States)

    Yude Pan; Richard Birdsey; John Hom; Kevin McCullough; Kenneth Clark

    2006-01-01

    We compared estimates of net primary production (NPP) from the MODIS satellite with estimates from a forest ecosystem process model (PnET-CN) and forest inventory and analysis (FIA) data for forest types of the mid-Atlantic region of the United States. The regional means were similar for the three methods and for the dominant oak? hickory forests in the region. However...

  13. Modeling gross primary production of an evergreen needleleaf forest using MODIS and climate data

    Science.gov (United States)

    Xiangming Xiao; Qingyuan Zhang; David Hollinger; John Aber; Berrien, III Moore

    2005-01-01

    Forest canopies are composed of photosynthetically active vegetation (PAV, chloroplasts) and nonphotosynthetic vegetation (NPV, e.g., cell wall, vein, branch). The fraction of photosynthetically active radiation (PAR) absorbed by the canopy (FAPAR) should be partitioned into FAPARPAV and FAPARNPV. Gross primary production (...

  14. Primary oxidation and reduction products in x-irradiated aspartic acid

    International Nuclear Information System (INIS)

    Adams, S.M.; Budzinski, E.E.; Box, H.C.

    1976-01-01

    The primary reduction products identified by ESR--ENDOR spectroscopy in single crystals of DL-aspartic acid hydrochloride irradiated at 4.2degreeK are anions formed by addition of an electron to the carbonyl oxygen atoms of the carboxylic acid groups. The main consequence of the oxidation process is to produce a hole centered mainly on atomic chlorine

  15. Evaluation of MODIS gross primary productivity for Africa using eddy covariance data

    NARCIS (Netherlands)

    Sjostrom, M.; Zhao, M.; Archibald, S.; Veenendaal, E.M.

    2013-01-01

    MOD17A2 provides operational gross primary production (GPP) data globally at 1 km spatial resolution and 8-day temporal resolution. MOD17A2 estimates GPP according to the light use efficiency (LUE) concept assuming a fixed maximum rate of carbon assimilation per unit photosynthetically active

  16. Estimating primary production from oxygen time series: A novel approach in the frequency domain

    NARCIS (Netherlands)

    Cox, T.J.S.; Maris, T.; Soetaert, K.; Kromkamp, J.C.; Meire, P.; Meysman, F.J.R.

    2015-01-01

    Based on an analysis in the frequency domain of the governing equation of oxygen dynamics in aquatic systems, we derive a new method for estimating gross primary production (GPP) from oxygen time series. The central result of this article is a relation between time averaged GPP and the amplitude of

  17. Vegetation-specific model parameters are not required for estimating gross primary production

    Czech Academy of Sciences Publication Activity Database

    Yuan, W.; Cai, W.; Liu, S.; Dong, W.; Chen, J.; Altaf Arain, M.; Blanken, P. D.; Cescatti, A.; Wohlfahrt, G.; Georgiadis, T.; Genesio, L.; Gianelle, D.; Grelle, A.; Kiely, G.; Knohl, A.; Liu, D.; Marek, Michal V.; Merbold, L.; Montagnani, L.; Panferov, O.; Peltoniemi, M.; Rambal, S.; Raschi, A.; Varlagin, A.; Xia, J.

    2014-01-01

    Roč. 292, NOV 24 2014 (2014), s. 1-10 ISSN 0304-3800 Institutional support: RVO:67179843 Keywords : light use efficiency * gross primary production * model parameters Subject RIV: EH - Ecology, Behaviour Impact factor: 2.321, year: 2014

  18. Relationships between net primary productivity and forest stand age in U.S. forests

    Science.gov (United States)

    Liming He; Jing M. Chen; Yude Pan; Richard Birdsey; Jens. Kattge

    2012-01-01

    Net primary productivity (NPP) is a key flux in the terrestrial ecosystem carbon balance, as it summarizes the autotrophic input into the system. Forest NPP varies predictably with stand age, and quantitative information on the NPP-age relationship for different regions and forest types is therefore fundamentally important for forest carbon cycle modeling. We used four...

  19. Radioactivity of fission products in cistern waters along the Croatian coast of the Adriatic Sea

    International Nuclear Information System (INIS)

    Franic, Z.; Marovic, G.

    1997-01-01

    Measurements of radioactive contamination of water samples from cisterns collecting rainwater from roofs etc. with fission products have been carried out along the Croatian coast of the Adriatic Sea since 1968. An exponential decline of radioactivity followed the nuclear moratorium.After the nuclear accident at Chernobyl, higher levels of 137 Cs and 90 Sr were detected again, cistern waters being the only environmental samples in Croatia in which elevated 90 Sr activities persisted for several years. For the pre-Chernobyl period, the mean residence time of 90 Sr in cistern waters being order of magnitude several years was similar to that calculated for fallout.Contrary, for the post-Chernobyl time, S r mean residence time was calculated to be considerably shorter, reflecting the tropospheric mean residence time.Therefore, the pre-Chernobyl) and the post-Chernobyl mean residence times of 90 Sr in cistern waters reflect the mechanism by which strontium was released to the atmosphere. The annual dose for the critical adult population received from 90 Sr, 137 Cs and 90 Cs by drinking cistern water was estimated to be a few per cent of the dose from natural background radiation. (authors)

  20. Evaluation of MERIS products from Baltic Sea coastal waters rich in CDOM

    Science.gov (United States)

    Beltrán-Abaunza, J. M.; Kratzer, S.; Brockmann, C.

    2014-05-01

    In this study, retrievals of the medium resolution imaging spectrometer (MERIS) reflectances and water quality products using four different coastal processing algorithms freely available are assessed by comparison against sea-truthing data. The study is based on a pair-wise comparison using processor-dependent quality flags for the retrieval of valid common macro-pixels. This assessment is required in order to ensure the reliability of monitoring systems based on MERIS data, such as the Swedish coastal and lake monitoring system (http://vattenkvalitet.se). The results show that the pre-processing with the Improved Contrast between Ocean and Land (ICOL) processor, correcting for adjacency effects, improves the retrieval of spectral reflectance for all processors. Therefore, it is recommended that the ICOL processor should be applied when Baltic coastal waters are investigated. Chlorophyll was retrieved best using the FUB (Free University of Berlin) processing algorithm, although overestimations in the range 18-26.5%, dependent on the compared pairs, were obtained. At low chlorophyll concentrations (definition at relatively low chlorophyll concentrations in the presence of high CDOM attenuation.

  1. Transport of radioactive corrosion products in primary system of sodium-cooled fast breeder reactor 'MONJU'

    International Nuclear Information System (INIS)

    Matuo, Youichirou; Hasegawa, Masanori; Maegawa, Yoshiharu; Miyahara, Shinya

    2011-01-01

    Radioactive corrosion products (CP) are primary cause of personal radiation exposure during maintenance work at FBR plants with no breached fuel. The PSYCHE code has been developed based on the Solution-Precipitation model for analysis of CP transfer behavior. We predicted and analyzed the CP solution and precipitation behavior of MONJU to evaluate the applicability of the PSYCHE code to MONJU, using the parameters verified in the calculations for JOYO. From the calculation result pertaining to the MONJU system, distribution of 54 Mn deposited in the primary cooling system over 20 years of operation is predicted to be approximately 7 times larger than that of 60 Co. In particular, predictions show a notable tendency for 54 Mn precipitation to be distributed in the primary pump and cold-leg. The calculated distribution of 54 Mn and 60 Co in the primary cooling system of MONJU agreed with tendencies of measured distribution of JOYO. (author)

  2. A new phase in the production of quality-controlled sea level data

    DEFF Research Database (Denmark)

    Quartly, Graham D.; Legeais, Jean François; Ablain, Michaël

    2017-01-01

    Sea level is an essential climate variable (ECV) that has a direct effect on many people through inundations of coastal areas, and it is also a clear indicator of climate changes due to external forcing factors and internal climate variability. Regional patterns of sea level change inform us...... and predict these phenomena, and thereby alleviate some of the environmental conditions associated with them. All such studies rely on the existence of long-term consistent high-accuracy datasets of sea level. The Climate Change Initiative (CCI) of the European Space Agency was established in 2010 to provide...... improved time series of some ECVs, including sea level, with the purpose of providing such data openly to all to enable the widest possible utilisation of such data. Now in its second phase, the Sea Level CCI project (SL-cci) merges data from nine different altimeter missions in a clear, consistent...

  3. Implications of sea-ice biogeochemistry for oceanic production and emissions of dimethyl sulfide in the Arctic

    Directory of Open Access Journals (Sweden)

    H. Hayashida

    2017-06-01

    Full Text Available Sea ice represents an additional oceanic source of the climatically active gas dimethyl sulfide (DMS for the Arctic atmosphere. To what extent this source contributes to the dynamics of summertime Arctic clouds is, however, not known due to scarcity of field measurements. In this study, we developed a coupled sea ice–ocean ecosystem–sulfur cycle model to investigate the potential impact of bottom-ice DMS and its precursor dimethylsulfoniopropionate (DMSP on the oceanic production and emissions of DMS in the Arctic. The results of the 1-D model simulation were compared with field data collected during May and June of 2010 in Resolute Passage. Our results reproduced the accumulation of DMS and DMSP in the bottom ice during the development of an ice algal bloom. The release of these sulfur species took place predominantly during the earlier phase of the melt period, resulting in an increase of DMS and DMSP in the underlying water column prior to the onset of an under-ice phytoplankton bloom. Production and removal rates of processes considered in the model are analyzed to identify the processes dominating the budgets of DMS and DMSP both in the bottom ice and the underlying water column. When openings in the ice were taken into account, the simulated sea–air DMS flux during the melt period was dominated by episodic spikes of up to 8.1 µmol m−2 d−1. Further model simulations were conducted to assess the effects of the incorporation of sea-ice biogeochemistry on DMS production and emissions, as well as the sensitivity of our results to changes of uncertain model parameters of the sea-ice sulfur cycle. The results highlight the importance of taking into account both the sea-ice sulfur cycle and ecosystem in the flux estimates of oceanic DMS near the ice margins and identify key uncertainties in processes and rates that should be better constrained by new observations.

  4. Biofilm Formation and Heat Stress Induce Pyomelanin Production in Deep-Sea Pseudoalteromonas sp. SM9913.

    Science.gov (United States)

    Zeng, Zhenshun; Cai, Xingsheng; Wang, Pengxia; Guo, Yunxue; Liu, Xiaoxiao; Li, Baiyuan; Wang, Xiaoxue

    2017-01-01

    Pseudoalteromonas is an important bacterial genus present in various marine habitats. Many strains of this genus are found to be surface colonizers on marine eukaryotes and produce a wide range of pigments. However, the exact physiological role and mechanism of pigmentation were less studied. Pseudoalteromonas sp. SM9913 (SM9913), an non-pigmented strain isolated from the deep-sea sediment, formed attached biofilm at the solid-liquid interface and pellicles at the liquid-air interface at a wide range of temperatures. Lower temperatures and lower nutrient levels promoted the formation of attached biofilm, while higher nutrient levels promoted pellicle formation of SM9913. Notably, after prolonged incubation at higher temperatures growing planktonically or at the later stage of the biofilm formation, we found that SM9913 released a brownish pigment. By comparing the protein profile at different temperatures followed by qRT-PCR, we found that the production of pigment at higher temperatures was due to the induction of melA gene which is responsible for the synthesis of homogentisic acid (HGA). The auto-oxidation of HGA can lead to the formation of pyomelanin, which has been shown in other bacteria. Fourier Transform Infrared Spectrometer analysis confirmed that the pigment produced in SM9913 was pyomelanin-like compound. Furthermore, we demonstrated that, during heat stress and during biofilm formation, the induction level of melA gene was significantly higher than that of the hmgA gene which is responsible for the degradation of HGA in the L-tyrosine catabolism pathway. Collectively, our results suggest that the production of pyomelanin of SM9913 at elevated temperatures or during biofilm formation might be one of the adaptive responses of marine bacteria to environmental cues.

  5. Biofilm Formation and Heat Stress Induce Pyomelanin Production in Deep-Sea Pseudoalteromonas sp. SM9913

    Directory of Open Access Journals (Sweden)

    Zhenshun Zeng

    2017-09-01

    Full Text Available Pseudoalteromonas is an important bacterial genus present in various marine habitats. Many strains of this genus are found to be surface colonizers on marine eukaryotes and produce a wide range of pigments. However, the exact physiological role and mechanism of pigmentation were less studied. Pseudoalteromonas sp. SM9913 (SM9913, an non-pigmented strain isolated from the deep-sea sediment, formed attached biofilm at the solid–liquid interface and pellicles at the liquid–air interface at a wide range of temperatures. Lower temperatures and lower nutrient levels promoted the formation of attached biofilm, while higher nutrient levels promoted pellicle formation of SM9913. Notably, after prolonged incubation at higher temperatures growing planktonically or at the later stage of the biofilm formation, we found that SM9913 released a brownish pigment. By comparing the protein profile at different temperatures followed by qRT-PCR, we found that the production of pigment at higher temperatures was due to the induction of melA gene which is responsible for the synthesis of homogentisic acid (HGA. The auto-oxidation of HGA can lead to the formation of pyomelanin, which has been shown in other bacteria. Fourier Transform Infrared Spectrometer analysis confirmed that the pigment produced in SM9913 was pyomelanin-like compound. Furthermore, we demonstrated that, during heat stress and during biofilm formation, the induction level of melA gene was significantly higher than that of the hmgA gene which is responsible for the degradation of HGA in the L-tyrosine catabolism pathway. Collectively, our results suggest that the production of pyomelanin of SM9913 at elevated temperatures or during biofilm formation might be one of the adaptive responses of marine bacteria to environmental cues.

  6. Primary production in a tropical large lake: The role of phytoplankton composition

    Energy Technology Data Exchange (ETDEWEB)

    Darchambeau, F., E-mail: francois.darchambeau@ulg.ac.be [Chemical Oceanography Unit, University of Liège, Liège (Belgium); Sarmento, H., E-mail: hugo.sarmento@gmail.com [Department of Hydrobiology, Federal University of São Carlos, 13565-905 São Carlos, São Paulo (Brazil); Descy, J.-P., E-mail: jean-pierre.descy@unamur.be [Research Unit in Environmental and Evolutionary Biology, University of Namur, Namur (Belgium)

    2014-03-01

    Phytoplankton biomass and primary production in tropical large lakes vary at different time scales, from seasons to centuries. We provide a dataset made of 7 consecutive years of phytoplankton biomass and production in Lake Kivu (Eastern Africa). From 2002 to 2008, bi-weekly samplings were performed in a pelagic site in order to quantify phytoplankton composition and biomass, using marker pigments determined by HPLC. Primary production rates were estimated by 96 in situ {sup 14}C incubations. A principal component analysis showed that the main environmental gradient was linked to a seasonal variation of the phytoplankton assemblage, with a clear separation between diatoms during the dry season and cyanobacteria during the rainy season. A rather wide range of the maximum specific photosynthetic rate (P{sub Bm}) was found, ranging between 1.15 and 7.21 g carbon g{sup −1} chlorophyll a h{sup −1}, and was best predicted by a regression model using phytoplankton composition as an explanatory variable. The irradiance at the onset of light saturation (I{sub k}) ranged between 91 and 752 μE m{sup −2} s{sup −1} and was linearly correlated with the mean irradiance in the mixed layer. The inter-annual variability of phytoplankton biomass and production was high, ranging from 53 to 100 mg chlorophyll a m{sup −2} (annual mean) and from 143 to 278 g carbon m{sup −2} y{sup −1}, respectively. The degree of seasonal mixing determined annual production, demonstrating the sensitivity of tropical lakes to climate variability. A review of primary production of other African great lakes allows situating Lake Kivu productivity in the same range as that of lakes Tanganyika and Malawi, even if mean phytoplankton biomass was higher in Lake Kivu. - Highlights: • We provide a 7-year dataset of primary production in a tropical great lake. • Specific photosynthetic rate was determined by community composition. • Annual primary production varied between 143 and 278 mg C m

  7. Primary production in a tropical large lake: The role of phytoplankton composition

    International Nuclear Information System (INIS)

    Darchambeau, F.; Sarmento, H.; Descy, J.-P.

    2014-01-01

    Phytoplankton biomass and primary production in tropical large lakes vary at different time scales, from seasons to centuries. We provide a dataset made of 7 consecutive years of phytoplankton biomass and production in Lake Kivu (Eastern Africa). From 2002 to 2008, bi-weekly samplings were performed in a pelagic site in order to quantify phytoplankton composition and biomass, using marker pigments determined by HPLC. Primary production rates were estimated by 96 in situ 14 C incubations. A principal component analysis showed that the main environmental gradient was linked to a seasonal variation of the phytoplankton assemblage, with a clear separation between diatoms during the dry season and cyanobacteria during the rainy season. A rather wide range of the maximum specific photosynthetic rate (P Bm ) was found, ranging between 1.15 and 7.21 g carbon g −1 chlorophyll a h −1 , and was best predicted by a regression model using phytoplankton composition as an explanatory variable. The irradiance at the onset of light saturation (I k ) ranged between 91 and 752 μE m −2 s −1 and was linearly correlated with the mean irradiance in the mixed layer. The inter-annual variability of phytoplankton biomass and production was high, ranging from 53 to 100 mg chlorophyll a m −2 (annual mean) and from 143 to 278 g carbon m −2 y −1 , respectively. The degree of seasonal mixing determined annual production, demonstrating the sensitivity of tropical lakes to climate variability. A review of primary production of other African great lakes allows situating Lake Kivu productivity in the same range as that of lakes Tanganyika and Malawi, even if mean phytoplankton biomass was higher in Lake Kivu. - Highlights: • We provide a 7-year dataset of primary production in a tropical great lake. • Specific photosynthetic rate was determined by community composition. • Annual primary production varied between 143 and 278 mg C m −2 y −1 . • Pelagic production was highly

  8. The impact of the snow cover on sea-ice thickness products retrieved by Ku-band radar altimeters

    Science.gov (United States)

    Ricker, R.; Hendricks, S.; Helm, V.; Perovich, D. K.

    2015-12-01

    Snow on sea ice is a relevant polar climate parameter related to ocean-atmospheric interactions and surface albedo. It also remains an important factor for sea-ice thickness products retrieved from Ku-band satellite radar altimeters like Envisat or CryoSat-2, which is currently on its mission and the subject of many recent studies. Such satellites sense the height of the sea-ice surface above the sea level, which is called sea-ice freeboard. By assuming hydrostatic equilibrium and that the main scattering horizon is given by the snow-ice interface, the freeboard can be transformed into sea-ice thickness. Therefore, information about the snow load on hemispherical scale is crucial. Due to the lack of sufficient satellite products, only climatological values are used in current studies. Since such values do not represent the high variability of snow distribution in the Arctic, they can be a substantial contributor to the total sea-ice thickness uncertainty budget. Secondly, recent studies suggest that the snow layer cannot be considered as homogenous, but possibly rather featuring a complex stratigraphy due to wind compaction and/or ice lenses. Therefore, the Ku-band radar signal can be scattered at internal layers, causing a shift of the main scattering horizon towards the snow surface. This alters the freeboard and thickness retrieval as the assumption that the main scattering horizon is given by the snow-ice interface is no longer valid and introduces a bias. Here, we present estimates for the impact of snow depth uncertainties and snow properties on CryoSat-2 sea-ice thickness retrievals. We therefore compare CryoSat-2 freeboard measurements with field data from ice mass-balance buoys and aircraft campaigns from the CryoSat Validation Experiment. This unique validation dataset includes airborne laser scanner and radar altimeter measurements in spring coincident to CryoSat-2 overflights, and allows us to evaluate how the main scattering horizon is altered by the

  9. Statistical characterization of global Sea Surface Salinity for SMOS level 3 and 4 products

    Science.gov (United States)

    Gourrion, J.; Aretxabaleta, A. L.; Ballabrera, J.; Mourre, B.

    2009-04-01

    The Soil Moisture and Ocean Salinity (SMOS) mission of the European Space Agency will soon provide sea surface salinity (SSS) estimates to the scientific community. Because of the numerous geophysical contamination sources and the instrument complexity, the salinity products will have a low signal to noise ratio at level 2 (individual estimates??) that is expected to increase up to mission requirements (0.1 psu) at level 3 (global maps with regular distribution) after spatio-temporal accumulation of the observations. Geostatistical methods such as Optimal Interpolation are being implemented at the level 3/4 production centers to operate this noise reduction step. The methodologies require auxiliary information about SSS statistics that, under Gaussian assumption, consist in the mean field and the covariance of the departures from it. The present study is a contribution to the definition of the best estimates for mean field and covariances to be used in the near-future SMOS level 3 and 4 products. We use complementary information from sparse in-situ observations and imperfect outputs from state-of-art model simulations. Various estimates of the mean field are compared. An alternative is the use of a SSS climatology such as the one provided by the World Ocean Atlas 2005. An historical SSS dataset from the World Ocean Database 2005 is reanalyzed and combined with the recent global observations obtained by the Array for Real-Time Geostrophic Oceanography (ARGO). Regional tendencies in the long-term temporal evolution of the near-surface ocean salinity are evident, suggesting that the use of a SSS climatology to describe the current mean field may introduce biases of magnitude similar to the precision goal. Consequently, a recent SSS dataset may be preferred to define the mean field needed for SMOS level 3 and 4 production. The in-situ observation network allows a global mapping of the low frequency component of the variability, i.e. decadal, interannual and seasonal

  10. Fueling Plankton Production by a Meandering Frontal Jet: A Case Study for the Alboran Sea (Western Mediterranean)

    Science.gov (United States)

    Oguz, Temel; Macias, Diego; Garcia-Lafuente, Jesus; Pascual, Ananda; Tintore, Joaquin

    2014-01-01

    A three dimensional biophysical model was employed to illustrate the biological impacts of a meandering frontal jet, in terms of efficiency and persistency of the autotrophic frontal production, in marginal and semi-enclosed seas. We used the Alboran Sea of the Western Mediterranean as a case study. Here, a frontal jet with a width of 15–20 km, characterized by the relatively low density Atlantic water mass, flows eastward within the upper 100 m as a marked meandering current around the western and the eastern anticyclonic gyres prior to its attachment to the North African shelf/slope topography of the Algerian basin. Its inherent nonlinearity leads to the development of a strong ageostrophic cross-frontal circulation that supplies nutrients into the nutrient-starved euphotic layer and stimulates phytoplankton growth along the jet. Biological production is larger in the western part of the basin and decreases eastwards with the gradual weakening of the jet. The higher production at the subsurface levels suggests that the Alboran Sea is likely more productive than predicted by the satellite chlorophyll data. The Mediterranean water mass away from the jet and the interiors of the western and eastern anticyclonic gyres remain unproductive. PMID:25372789

  11. Chemical aspects of fission product transport in the primary circuit of a light water reactor

    International Nuclear Information System (INIS)

    Bowsher, B.R.; Dickinson, S.; Nichols, A.L.; Ogden, J.S.; Potter, P.E.

    1985-01-01

    The transport and fission products in the primary circuit of a light water reactor are of fundamental importance in assessing the consequences of severe accidents. Recent experimental studies have concentrated upon the behaviour of simulant fission product species such as caesium iodide, caesium hydroxide and tellurium, in terms of their vapour deposition characteristics onto metals representative of primary circuit materials. An induction furnace has been used to generate high-density/structural materials aerosols for subsequent analysis, and similar equipment has been incorporated into a glove-box to study lightly-irradiated UO/sub 2/ clad in Zircaloy. Analytical techniques are being developed to assist in the identification of fission product chemical species released from the fuel at temperatures from 1000 to 2500 0 C. Matrix isolation-infrared spectroscopy has been used to identify species in the vapour phase, and specific data using this technique are reported

  12. Chemical aspects of fission product transport in the primary circuit of a light water reactor

    International Nuclear Information System (INIS)

    Bowsher, B.R.; Dickinson, S.; Nichols, A.L.; Ogden, J.S.; Potter, P.E.

    1985-01-01

    The transport and deposition of fission products in the primary circuit of a light water reactor are of fundamental importance in assessing the consequences of severe accidents. Recent experimental studies have concentrated upon the behavior of simulant fission product species such as cesium iodide, cesium hydroxide and tellurium, in terms of their vapor deposition characteristics onto metals representative of primary circuit materials. An induction furnace has been used to generate high density/structural materials aerosols for subsequent analysis, and similar equipment has been incorporated into a glove-box to study lightly-irradiated UO 2 clad in Zircaloy. Analytical techniques are being developed to assist in the identification of fission product chemical species released from the fuel at temperatures from 1000 to 2500 0 C. Matrix isolation-infrared spectroscopy has been used to identify species in the vapor phase, and specific data using this technique are reported

  13. Modelling the behaviour of corrosion products in the primary heat transfer circuits of pressurised water reactors

    International Nuclear Information System (INIS)

    Rodliffe, R.S.; Polley, M.V.; Thornton, E.W.

    1985-05-01

    The redistribution of corrosion products from the primary circuit surfaces of a water reactor can result in increased flow resistance, poorer heat transfer performance, fuel failure and radioactive contamination of circuit surfaces. The environment is generally sufficiently well controlled to ensure that the first three effects are not limiting. The last effect is of particular importance since radioactive corrosion products are major contributors to shutdown fields and since it is necessary to ensure that the radiation exposure of personnel is as low as reasonably achievable. This review focusses attention on the principles which must form the basis for any mechanistic model describing the formation, transport and deposition of radioactive corrosion products. It is relevant to all water reactors in which the primary heat transfer medium is predominantly single-phase water and in which steam is generated in a secondary circuit, i.e. including CANDU pressurised heavy water reactors, Sovient VVERs, etc. (author)

  14. Effects of composition of labile organic matter on biogenic production of methane in the coastal sediments of the Arabian Sea.

    Science.gov (United States)

    Gonsalves, Maria-Judith; Fernandes, Christabelle E G; Fernandes, Sheryl Oliveira; Kirchman, David L; Bharathi, P A Loka

    2011-11-01

    Coastal regions are potential zones for production of methane which could be governed by ecological/environmental differences or even sediment properties of a niche. In order to test the hypothesis that methanogenesis in most marine sediments could be driven more by proteins than by carbohydrates and lipid content of labile organic matter (LOM), incubation experiments were carried out with sediments from different environmental niches to measure methane production. The methane production rates were examined in relationship to the sediment biochemistry, i.e., carbohydrates, proteins, and lipids. The gas production measured by head space method ranged from 216 ng g( -1) day( -1) in the mangrove sediments to 3.1 μg g( -1) day( -1) in the shallow Arabian Sea. LOM ranged from 1.56 to 2.85 mg g( -1) in the shallow Arabian Sea, from 3.35 to 5.43 mg g( -1) in the mangrove estuary, and from 0.66 to 0.70 mg g( -1) in the sandy sediments with proteins contributing maximum to the LOM pool. Proteins influenced methane production in the clayey sediments of shallow depths of the Arabian Sea (r = 0.933, p methane production. The gas production was more pronounced in shallow and surface sediments and it decreased with depth apparently governed by the decrease in lability index. Thus, the lability index and protein content are important factors that determine methane production rates in these coastal ecosystems.

  15. Behaviour of fission products in PWR primary coolant and defected fuel rods evaluation

    International Nuclear Information System (INIS)

    Bourgeois, P.; Stora, J.P.

    1979-01-01

    The activity surveillance of the PWR primary coolant by γ spectometry gives some informations on fuel failures. The activity of different nuclides e.g. Xenons, Kryptons, Iodines, can be correlated with the number of the defected fuel rods. Therefore the precharacterization with eventually a prelocalization of the related fuel assemblies direct the sipping-test and allows a saving of time during refueling. A model is proposed to calculate the number of the defected rods from the activity measurements of the primary coolant. A semi-empirical model of the release of the fission products has been built from the activity measurements of the primary coolant in a 900 MWe PWR. This model allows to calculate the number of the defected rods and also a typical parameter of the mean damage. Fission product release is described by three stages: release from uranium dioxide, transport across the gas gap and behaviour in the primary coolant. The model of release from the oxide considers a diffusion process in the grains with trapping. The release then occurs either directly to free surfaces or with a delay due to a transit into closed porosity of the oxide. The amount released is the same for iodine and rare gas. With the gas gap transit is associated a transport time and a probability of trapping for the iodines. In the primary coolant the purification and the radioactive decay are considered. (orig.)

  16. Allochthonous Carbon--a Major Driver of Bacterioplankton Production in the Subarctic Northern Baltic Sea.

    Science.gov (United States)

    Figueroa, D; Rowe, O F; Paczkowska, J; Legrand, C; Andersson, A

    2016-05-01

    Heterotrophic bacteria are, in many aquatic systems, reliant on autochthonous organic carbon as their energy source. One exception is low-productive humic lakes, where allochthonous dissolved organic matter (ADOM) is the major driver. We hypothesized that bacterial production (BP) is similarly regulated in subarctic estuaries that receive large amounts of riverine material. BP and potential explanatory factors were measured during May-August 2011 in the subarctic Råne Estuary, northern Sweden. The highest BP was observed in spring, concomitant with the spring river-flush and the lowest rates occurred during summer when primary production (PP) peaked. PLS correlations showed that ∼60% of the BP variation was explained by different ADOM components, measured as humic substances, dissolved organic carbon (DOC) and coloured dissolved organic matter (CDOM). On average, BP was threefold higher than PP. The bioavailability of allochthonous dissolved organic carbon (ADOC) exhibited large spatial and temporal variation; however, the average value was low, ∼2%. Bioassay analysis showed that BP in the near-shore area was potentially carbon limited early in the season, while BP at seaward stations was more commonly limited by nitrogen-phosphorus. Nevertheless, the bioassay indicated that ADOC could contribute significantly to the in situ BP, ∼60%. We conclude that ADOM is a regulator of BP in the studied estuary. Thus, projected climate-induced increases in river discharge suggest that BP will increase in subarctic coastal areas during the coming century.

  17. Development of Procedures for the Analysis of Components of Dumped Chemical Weapons and Their Principal Transformation Products in Sea Water

    International Nuclear Information System (INIS)

    Saveleva, E. I.; Koryagina, N. L.; Radilov, A. S.; Khlebnikova, N. S.; Khrustaleva, V. S.

    2007-01-01

    A package of chemical analytical procedures was developed for the detection of products indicative of the presence of damped chemical weapons in the Baltic Sea. The principal requirements imposed upon the procedures were the following: high sensitivity, reliable identification of target compounds, wide range of components covered by survey analysis, and lack of interferences from sea salts. Thiodiglycol, a product of hydrolysis of sulfur mustard reportedly always detected in the sites of damping chemical weapons in the Baltic Sea, was considered the principal marker. We developed a high-sensitivity procedure for the determination of thiodiglycol in sea water, involving evaporation of samples to dryness in a vacuum concentrator, followed by tert-butyldimethylsilylation of the residue and GCMS analysis in the SIM mode with meta-fluorobenzoic acid as internal reference. The detection limit of thiodiglycol was 0.001 mg/l, and the procedure throughput was up to 30 samples per day. The same procedure, but with BSTFA as derivatizing agent instead of MTBSTFA, was used for preparing samples for survey analysis of nonvolatile components. In this case, full mass spectra were measured in the GCMS analysis. The use of BSTFA was motivated by the fact that trimethylsilyl derivatives are much wider represented in electronic mass spectral databases. The identification of sulfur mustard, volatile transformation products of sulfur mustard and lewisite, as well as chloroacetophenone in sea water was performed by means of GCMS in combination with SPME. The survey GC-MS analysis was focused on the identification of volatile and nonvolatile toxic chemicals whose mass spectra are included in the OPCW database (3219 toxic chemicals, precursors, and transformation products) with the use of AMDIS software (version 2.62). Using 2 GC-MS instruments, we could perform the survey analysis for volatile and nonvolatile components of up to 20 samples per day. Thus, the package of three procedures

  18. Thermal Responses of Growth and Toxin Production in Four Prorocentrum Species from the Central Red Sea

    KAUST Repository

    Aynousah, Arwa

    2017-01-01

    Prorocentrum strains isolated from the Central Red Sea, Saudi Arabia. Morphological and molecular phylogenetic analysis identified the strains as P. elegans, P. rhathymum and P. emarginatum. However, the identity of strain P. sp.6 is currently unresolved

  19. In silico exploration of Red Sea Bacillus genomes for natural product biosynthetic gene clusters

    KAUST Repository

    Othoum, Ghofran K; Bougouffa, Salim; Razali, Rozaimi; Bokhari, Ameerah; Alamoudi, Soha; Antunes, André ; Gao, Xin; Hoehndorf, Robert; Arold, Stefan T.; Gojobori, Takashi; Hirt, Heribert; Mijakovic, Ivan; Bajic, Vladimir B.; Lafi, Feras Fawzi; Essack, Magbubah

    2018-01-01

    are better potential sources for novel antibiotics. Moreover, the genome of the Red Sea strain B. paralicheniformis Bac48 is more enriched in modular PKS genes compared to B. licheniformis strains and other B. paralicheniformis strains. This may be linked

  20. NODC Standard Product: Sea level data (TOGA and PSMSL) through August 1994 (NODC Accession 0095192)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data on this CD-ROM are provided in two main directories. One directory contains Tropical Ocean-Global Atmosphere (TOGA) project sea level data, file formats,...

  1. Fluctuations in productivity and denitrification in the southeastern Arabian Sea during the Late Quaternary

    Digital Repository Service at National Institute of Oceanography (India)

    Kessarkar, P; Rao, V.P; Naqvi, S.W.A.; Chivas, A.R.; Saino, T.

    Sedimentological and stable isotopic characteristics of sediments have been studied in a core from the southeastern Arabian Sea containing records of the past 70 ka. Palaeoproductivity proxies such as organic carbon (C sub(org)), total nitrogen (TN...

  2. Relationships between primary production and irradiance in coral reef algal communities

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Shallow water algal turf communities are the major primary producers on coral reefs. High rates of primary production are maintained despite extremely high light intensities and exposure to ultraviolet wavelengths. The relationships between the light intensity and primary production in these assemblages are typical of algae adapted to a high light environment [low α (initial slope), high I/sub k/ (saturating light intensity), and high I/sub c/ (compensation point light intensity)]. Seasonal variations in algal standing crop due to herbivory and daylength result in some characteristic photoadaptive changes in α I/sub k/, and I/sub c/ and changes in Pnet/sub max/ rates (maximum net photosynthetic rate achieved at light saturation) on both a chlorophyll α and an areal basis. Exposure to UV wavelength results in significantly higher respiration rates but no changes in α, Pnet/sub max/, or I/sub k/, when compared with these parameters for the same algal communities incubated at the same light intensities without UV wavelengths. The apparent lack of photoinhibition in these algae allows calculation of the daily integrated production from the P vs. I parameters. This integrated production is highest in July (3.1 +/- 0.2 g C m -2 d -1 ) and is reduced by 30% from this maximum in December (2.1 +/- 0.1 g C m -2 d -1 )

  3. Assessing the impact of urbanization on regional net primary productivity in Jiangyin County, China.

    Science.gov (United States)

    Xu, C; Liu, M; An, S; Chen, J M; Yan, P

    2007-11-01

    Urbanization is one of the most important aspects of global change. The process of urbanization has a significant impact on the terrestrial ecosystem carbon cycle. The Yangtze Delta region has one of the highest rates of urbanization in China. In this study, carried out in Jiangyin County as a representative region within the Yangtze Delta, land use and land cover changes were estimated using Landsat TM and ETM+ imagery. With these satellite data and the BEPS process model (Boreal Ecosystem Productivity Simulator), the impacts of urbanization on regional net primary productivity (NPP) and annual net primary production were assessed for 1991 and 2002. Landsat-based land cover maps in 1991 and 2002 showed that urban development encroached large areas of cropland and forest. Expansion of residential areas and reduction of vegetated areas were the major forms of land transformation in Jiangyin County during this period. Mean NPP of the total area decreased from 818 to 699 gCm(-2)yr(-1) during the period of 1991 to 2002. NPP of cropland was only reduced by 2.7% while forest NPP was reduced by 9.3%. Regional annual primary production decreased from 808 GgC in 1991 to 691 GgC in 2002, a reduction of 14.5%. Land cover changes reduced regional NPP directly, and the increasing intensity and frequency of human-induced disturbance in the urbanized areas could be the main reason for the decrease in forest NPP.

  4. Efficiency of chlorophyll in gross primary productivity: A proof of concept and application in crops.

    Science.gov (United States)

    Gitelson, Anatoly A; Peng, Yi; Viña, Andrés; Arkebauer, Timothy; Schepers, James S

    2016-08-20

    One of the main factors affecting vegetation productivity is absorbed light, which is largely governed by chlorophyll. In this paper, we introduce the concept of chlorophyll efficiency, representing the amount of gross primary production per unit of canopy chlorophyll content (Chl) and incident PAR. We analyzed chlorophyll efficiency in two contrasting crops (soybean and maize). Given that they have different photosynthetic pathways (C3 vs. C4), leaf structures (dicot vs. monocot) and canopy architectures (a heliotrophic leaf angle distribution vs. a spherical leaf angle distribution), they cover a large spectrum of biophysical conditions. Our results show that chlorophyll efficiency in primary productivity is highly variable and responds to various physiological and phenological conditions, and water availability. Since Chl is accessible through non-destructive, remotely sensed techniques, the use of chlorophyll efficiency for modeling and monitoring plant optimization patterns is practical at different scales (e.g., leaf, canopy) and under widely-varying environmental conditions. Through this analysis, we directly related a functional characteristic, gross primary production with a structural characteristic, canopy chlorophyll content. Understanding the efficiency of the structural characteristic is of great interest as it allows explaining functional components of the plant system. Copyright © 2016 Elsevier GmbH. All rights reserved.

  5. Major activated corrosion products cobalt, silver and antimony in the primary coolant of PWR power plants

    International Nuclear Information System (INIS)

    Xu Mingxia

    2012-01-01

    The production of the major activated corrosion products such as cobalt, silver and antimony in the primary coolant of PWR power plants and the impacts on the increase of the dose rates caused by these corrosion products during the shutdown are described in the paper. Investigating the corrosion product behavior during the operation and shutdown periods aims at detecting the appearance of these radiological pollutants in the early time and searching relevant solutions that may enable eventually to decrease the dose rate. The solutions may include: Replacing critical material in the primary system's equipment and components, which contact with primary coolant circuit to possibly limit the source term, Elaborating strictly the specific chemical and shutdown procedure to optimize the purification capacity and to minimize the over-contaminations; Improving purification techniques according to the real operation circumstance, and limiting the impacts of these pollutants. It is obvious in the real practices that implementing appropriate solution will be benefit to decrease or limit the pollutants species like cobalt, silver and antimony. (author)

  6. Combined constraints on global ocean primary production using observations and models

    Science.gov (United States)

    Buitenhuis, Erik T.; Hashioka, Taketo; Quéré, Corinne Le

    2013-09-01

    production is at the base of the marine food web and plays a central role for global biogeochemical cycles. Yet global ocean primary production is known to only a factor of 2, with previous estimates ranging from 38 to 65 Pg C yr-1 and no formal uncertainty analysis. Here, we present an improved global ocean biogeochemistry model that includes a mechanistic representation of photosynthesis and a new observational database of net primary production (NPP) in the ocean. We combine the model and observations to constrain particulate NPP in the ocean with statistical metrics. The PlankTOM5.3 model includes a new photosynthesis formulation with a dynamic representation of iron-light colimitation, which leads to a considerable improvement of the interannual variability of surface chlorophyll. The database includes a consistent set of 50,050 measurements of 14C primary production. The model best reproduces observations when global NPP is 58 ± 7 Pg C yr-1, with a most probable value of 56 Pg C yr-1. The most probable value is robust to the model used. The uncertainty represents 95% confidence intervals. It considers all random errors in the model and observations, but not potential biases in the observations. We show that tropical regions (23°S-23°N) contribute half of the global NPP, while NPPs in the Northern and Southern Hemispheres are approximately equal in spite of the larger ocean area in the South.

  7. An improvement of satellite-based algorithm for gross primary production estimation optimized over Korea

    Science.gov (United States)

    Pi, Kyoung-Jin; Han, Kyung-Soo; Kim, In-Hwan; Kim, Sang-Il; Lee, Min-Ji

    2011-11-01

    Monitoring the global gross primary production (GPP) is relevant to understanding the global carbon cycle and evaluating the effects of interannual climate variation on food and fiber production. GPP, the flux of carbon into ecosystems via photosynthetic assimilation, is an important variable in the global carbon cycle and a key process in land surface-atmosphere interactions. The Moderate-resolution Imaging Spectroradiometer (MODIS) is one of the primary global monitoring sensors. MODIS GPP has some of the problems that have been proven in several studies. Therefore this study was to solve the regional mismatch that occurs when using the MODIS GPP global product over Korea. To solve this problem, we estimated each of the GPP component variables separately to improve the GPP estimates. We compared our GPP estimates with validation GPP data to assess their accuracy. For all sites, the correlation was close with high significance (R2 = 0.8164, RMSE = 0.6126 g.C.m-2.d-1, bias = -0.0271 g.C.m-2.d-1). We also compared our results to those of other models. The component variables tended to be either over- or under-estimated when compared to those in other studies over the Korean peninsula, although the estimated GPP was better. The results of this study will likely improve carbon cycle modeling by capturing finer patterns with an integrated method of remote sensing. Keywords: VEGETATION, Gross Primary Production, MODIS.

  8. Productive vegetation: relationships between net primary productivity, vegetation types and climate change in the Wet Tropics bioregion

    International Nuclear Information System (INIS)

    Ramirez, Vanessa Valdez; Williams, Stephen E.; VanDerWal, Jeremy

    2007-01-01

    Full text: Full text: There is now ample evidence demonstrating the impacts of climate change on biodiversity and human society (Walther ef a/. 2002). Numerous studies have shown climate change is one of the most significant threats to tropical forests, such as the Wet Tropics Heritage Area, due to their high biodiversity and endemism (Pounds ef al. 1999; Hughes 2000; Parmesan and Yohe 2003). Williams ef al. (2003) suggested that small shifts in net primary productivity (NPP) as a result of climate change could lead to potentially massive follow-on effects for the extremely diverse and vulnerable rainforest flora and fauna. It is therefore crucial to explore the relationships between NPP and local biodiversity, especially to create models for different climate change scenarios. Nevertheless, NPP in the Wet Tropics has yet to be estimated. This is the first study to provide a general NPP estimate for the Wet Tropics bioregion using climate surrogates (Schuur 2003). This technique estimates NPP in an accurate, repeatable, and cost-effective way. NPP values were linked to vegetation types and examined under various climatic and environmental conditions. Results show a significant difference in productivity according to vegetation types and climatic variables, with temperature and rainfall seasonality as the most important determining variables. Additionally, lowland and upland vegetations showed a significant difference in productivity patterns throughout the year. Vegetation types located above 1000 metres in altitude had the lowest values of mean annual productivity due to their high rainfall and low temperatures; vegetation types located below 600 metres showed increased productivity values during the wet season (December-March). Net primary productivity will certainly be impacted by changes in temperature and rainfall, due to climate change. Although an increase in NPP values can be predicted for upland areas, the more widely distributed lowlands will drastically

  9. New and improved data products from the Permanent Service for Mean Sea Level (PSMSL)

    Science.gov (United States)

    Matthews, Andrew; Bradshaw, Elizabeth; Gordon, Kathy; Hibbert, Angela; Jevrejeva, Svetlana; Rickards, Lesley; Tamisiea, Mark; Williams, Simon

    2015-04-01

    The Permanent Service for Mean Sea Level (PSMSL) is the internationally recognised global sea level data bank for long term sea level change information from tide gauges. Established in 1933, the PSMSL continues to be responsible for the collection, publication, analysis and interpretation of sea level data. The PSMSL operates under the auspices of the International Council for Science (ICSU) and is one of the main data centres for both the International Association for the Physical Sciences of the Oceans (IAPSO) and the International Association of Geodesy (IAG). The PSMSL continues to work closely with other members of the sea level community through the Intergovernmental Oceanographic Commission's Global Sea Level Observing System (GLOSS). Currently, the PSMSL data bank for monthly and annual sea level data holds over 65,000 station-years of data from over 2200 stations. Data from each site are carefully quality controlled and, wherever possible, reduced to a common datum, whose stability is monitored through a network of geodetic benchmarks. Last year, the PSMSL also made available a data bank of measurements taken from in-situ ocean bottom pressure recorders from over 60 locations across the globe. Here, we present an overview of the data available at the PSMSL, and describe some of the ongoing work that aims to provide more information to users of our data. In particular, we describe the ongoing work with the Système d'Observation du Niveau des Eaux Littorales (SONEL) to use measurements from continuous GNSS records located near tide gauges to provide PSMSL data within a geocentric reference frame. We also highlight changes to the method used to present estimated sea level trends to account for seasonal cycles and autocorrelation in the data, and provide an estimate of the error of the trend.

  10. Sea ice contribution to the air-sea CO{sub 2} exchange in the Arctic and Southern Oceans

    Energy Technology Data Exchange (ETDEWEB)

    Rysgaard, Soeren (Greenland Climate Research Centre, Greenland Inst. of Natural Resources, Nuuk, Greenland (Denmark); Centre for Earth Observation Science, CHR Faculty of Environment Earth and Resources, Univ. of Manitoba, Winnipeg (Canada)), e-mail: rysgaard@natur.gl; Bendtsen, Joergen (Greenland Climate Research Centre, Greenland Inst. of Natural Resources, Nuuk, Greenland (Denmark); Centre for Ice and Climate, Niels Bohr Inst., Univ. of Copenhagen, Copenhagen O (Denmark)); Delille, Bruno (Unit' e d' Oceanographie Chimique, Interfacultary Centre for Marine Research, Universite de Liege, Liege (Belgium)); Dieckmann, Gerhard S. (Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany)); Glud, Ronnie N. (Greenland Climate Research Centre, Greenland Inst. of Natural Resources, Nuuk, Greenland (Denmark); Scottish Association of Marine Sciences, Scotland UK, Southern Danish Univ. and NordCee, Odense M (Denmark)); Kennedy, Hilary; Papadimitriou, Stathys (School of Ocean Sciences, Bangor Univ., Menai Bridge, Anglesey, Wales (United Kingdom)); Mortensen, John (Greenland Climate Research Centre, Greenland Inst. of Natural Resources, Nuuk, Greenland (Denmark)); Thomas, David N. (School of Ocean Sciences, Bangor Univ., Menai Bridge, Anglesey, Wales (United Kingdom); Finnish Environment Inst. (SYKE), Marine Research Centre, Helsinki (Finland)); Tison, Jean-Louis (Glaciology Unit, Dept. of Earth and Environmental Sciences, Universite Libre de Bruxelles, Bruxelles, (Belgium))

    2011-11-15

    Although salt rejection from sea ice is a key process in deep-water formation in ice-covered seas, the concurrent rejection of CO{sub 2} and the subsequent effect on air-sea CO{sub 2} exchange have received little attention. We review the mechanisms by which sea ice directly and indirectly controls the air-sea CO{sub 2} exchange and use recent measurements of inorganic carbon compounds in bulk sea ice to estimate that oceanic CO{sub 2} uptake during the seasonal cycle of sea-ice growth and decay in ice-covered oceanic regions equals almost half of the net atmospheric CO{sub 2} uptake in ice-free polar seas. This sea-ice driven CO{sub 2} uptake has not been considered so far in estimates of global oceanic CO{sub 2} uptake. Net CO{sub 2} uptake in sea-ice-covered oceans can be driven by; (1) rejection during sea-ice formation and sinking of CO{sub 2}-rich brine into intermediate and abyssal oceanic water masses, (2) blocking of air-sea CO{sub 2} exchange during winter, and (3) release of CO{sub 2}-depleted melt water with excess total alkalinity during sea-ice decay and (4) biological CO{sub 2} drawdown during primary production in sea ice and surface oceanic waters

  11. Evaluation of MERIS products from Baltic Sea coastal waters rich in CDOM

    Directory of Open Access Journals (Sweden)

    J. M. Beltrán-Abaunza

    2014-05-01

    Full Text Available In this study, retrievals of the medium resolution imaging spectrometer (MERIS reflectances and water quality products using four different coastal processing algorithms freely available are assessed by comparison against sea-truthing data. The study is based on a pair-wise comparison using processor-dependent quality flags for the retrieval of valid common macro-pixels. This assessment is required in order to ensure the reliability of monitoring systems based on MERIS data, such as the Swedish coastal and lake monitoring system (http://vattenkvalitet.se. The results show that the pre-processing with the Improved Contrast between Ocean and Land (ICOL processor, correcting for adjacency effects, improves the retrieval of spectral reflectance for all processors. Therefore, it is recommended that the ICOL processor should be applied when Baltic coastal waters are investigated. Chlorophyll was retrieved best using the FUB (Free University of Berlin processing algorithm, although overestimations in the range 18–26.5%, dependent on the compared pairs, were obtained. At low chlorophyll concentrations (−3, data dispersion dominated in the retrievals with the MEGS (MERIS ground segment processor processor. The lowest bias and data dispersion were obtained with MEGS for suspended particulate matter, for which overestimations in the range of 8–16% were found. Only the FUB retrieved CDOM (coloured dissolved organic matter correlate with in situ values. However, a large systematic underestimation appears in the estimates that nevertheless may be corrected for by using a local correction factor. The MEGS has the potential to be used as an operational processing algorithm for the Himmerfjärden bay and adjacent areas, but it requires further improvement of the atmospheric correction for the blue bands and better definition at relatively low chlorophyll concentrations in the presence of high CDOM attenuation.

  12. Production, characterization and application of monoclonal antibodies to the coelomocytes of sea urchin Strongylocentrotus intermedius.

    Science.gov (United States)

    Wang, Yinan; Meng, Shaodong; Zhang, Jialin; Ding, Jun; Li, Qiang

    2018-04-01

    Sea urchin is one of marine animals with high economic and great scientific research values. Axial organ is a glandular organ that has been presumed as coelomocytes origin site. In this paper, two monoclonal antibodies (3G10 and 6B3) against coelomocytes of sea urchin Strongylocentrotus intermedius were developed by hybridoma technique. The mAbs were characterized by indirect immunofluorescence assay test (IIFAT), flow cytometry (FCM) and western blot assay. Results showed that mAb 3G10 recognized a protein of a molecular weight of 17 kDa in the spherule cells, while mAb 6B3 reacted with a protein of a molecular weight of 35 kDa in the phagocytes. Furthermore, specificity analysis revealed that the two mAbs could react with the coelomocytes of sea urchin S. nudus and Hemicentrotus pulcherrimus, but not with those of other common echinoderms including sea cucumber Apostichopus japonicus and starfish Asterias rollestoni. To determine whether the coelomocytes exist in the axial organ of sea urchin, the IIFAT assays were carried out based on the two mAbs. Result showed that positive fluorescence signals were distributed in the organ. It was revealed that the axial organ was rich in coelomocytes, which suggests that the organ may play as a producing source or reservoir in the ontogenesis of coelomocytes of sea urchin. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. NODC Standard Product: International ocean atlas Volume 2 - Biological atlas of the Arctic Seas 2000 - Plankton of the Barents and Kara Seas (1 disc set) (NODC Accession 0098568)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Presented in this CD-ROM are physical and biological data for the region extending from the Barents Sea to the Kara Sea during 158 scientific cruises for the period...

  14. Adapted to change: Low energy requirements in a low and unpredictable productivity environment, the case of the Galapagos sea lion

    Science.gov (United States)

    Villegas-Amtmann, Stella; McDonald, Birgitte I.; Páez-Rosas, Diego; Aurioles-Gamboa, David; Costa, Daniel P.

    2017-06-01

    The rate of energy expenditure and acquisition are fundamental components of an animals' life history. Within mammals, the otariids (sea lions and fur seals) exhibit energetically expensive life styles, which can be challenging in equatorial regions where resources are particularly limited and unpredictable. To better understand how this energetically expensive life history pattern functions in an energetically challenging equatorial system, we concurrently measured the field metabolic rate (FMR) and foraging behavior of lactating Galapagos sea lions (GSL) rearing pups and yearlings. Females with pups tended to forage to the north, diving deeper, epi and mesopelagically compared to females with yearlings, which foraged to the west and performed dives to the sea bed that were shallower. FMR did not differ between females with pups or yearlings but, increased significantly with % time spent at-sea. Females with yearlings had higher water influx, suggesting greater food intake, but had lower body condition. The FMR (4.08±0.6 W/kg) of GSL is the lowest measured for any otariid, but is consistent with Galapagos fur seals which also exhibit low FMR. The observation that these two otariids have reduced energy requirements is consistent with an adaptation to the reduced prey availability of the Galapagos marine environment compared to other more productive marine systems.

  15. MODIS/Terra Gross Primary Productivity 8-Day L4 Global 1km SIN Grid V055

    Data.gov (United States)

    National Aeronautics and Space Administration — The Terra/MODIS Gross Primary Productivity (GPP) product (MOD17A2) is a cumulative composite of GPP values based on the radiation-use efficiency concept that is...

  16. Cytokine modulation by stress hormones and antagonist specific hormonal inhibition in rainbow trout (Oncorhynchus mykiss) and gilthead sea bream (Sparus aurata) head kidney primary cell culture.

    Science.gov (United States)

    Khansari, Ali Reza; Parra, David; Reyes-López, Felipe E; Tort, Lluís

    2017-09-01

    A tight interaction between endocrine and immune systems takes place mainly due to the key role of head kidney in both hormone and cytokine secretion, particularly under stress situations in which the physiological response promotes the synthesis and release of stress hormones which may lead into immunomodulation as side effect. Although such interaction has been previously investigated, this study evaluated for the first time the effect of stress-associated hormones together with their receptor antagonists on the expression of cytokine genes in head kidney primary cell culture (HKPCC) of the freshwater rainbow trout (Oncorhynchus mykiss) and the seawater gilthead sea bream (Sparus aurata). The results showed a striking difference when comparing the response obtained in trout and seabream. Cortisol and adrenocorticotropic hormone (ACTH) decreased the expression of immune-related genes in sea bream but not in rainbow trout and this cortisol effect was reverted by the antagonist mifepristone but not spironolactone. On the other hand, while adrenaline reduced the expression of pro-inflammatory cytokines (IL-1β, IL-6) in rainbow trout, the opposite effect was observed in sea bream showing an increased expression (IL-1β, IL-6). Interestingly, this effect was reverted by antagonist propranolol but not phentolamine. Overall, our results confirm the regional interaction between endocrine and cytokine messengers and a clear difference in the sensitivity to the hormonal stimuli between the two species. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Primary producers and production in Hornsund and Kongsfjorden – comparison of two fjord systems

    Directory of Open Access Journals (Sweden)

    Smoła Zofia T.

    2017-09-01

    Full Text Available Hornsund and Kongsfjorden are two similar-sized Arctic fjords on the West coast of Spitsbergen. They are influenced by cold coastal Arctic water (Hornsund and warmer Atlantic water (Kongsfjorden. Environmental conditions affect the timing, quantity, spatial distribution (horizontal and vertical of spring and summer blooms of protists as well as the taxonomic composition of those assemblages. Here, we compile published data and unpublished own measurement from the past two decades to compare the environmental factors and primary production in two fjord systems. Kongsfjorden is characterized by a deeper euphotic zone, higher biomass and greater proportion of autotrophic species. Hornsund seems to obtain more nutrients due to the extensive seabird colonies and exhibits higher turbidity compared to Kongsfjorden. The annual primary production in the analysed fjords ranges from 48 g C m−2 y−1 in Kongsfjorden to 216 g C m−2 y−1 in Hornsund, with a dominant component of microplankton (90% followed by macrophytes and microphytobenthos.

  18. Millennial-scale variability of marine productivity and terrigenous matter supply in the western Bering Sea over the past 180 kyr

    Directory of Open Access Journals (Sweden)

    J.-R. Riethdorf

    2013-06-01

    Full Text Available We used piston cores recovered in the western Bering Sea to reconstruct millennial-scale changes in marine productivity and terrigenous matter supply over the past ~180 kyr. Based on a geochemical multi-proxy approach, our results indicate closely interacting processes controlling marine productivity and terrigenous matter supply comparable to the situation in the Okhotsk Sea. Overall, terrigenous inputs were high, whereas export production was low. Minor increases in marine productivity occurred during intervals of Marine Isotope Stage 5 and interstadials, but pronounced maxima were recorded during interglacials and Termination I. The terrigenous material is suggested to be derived from continental sources on the eastern Bering Sea shelf and to be subsequently transported via sea ice, which is likely to drive changes in surface productivity, terrigenous inputs, and upper-ocean stratification. From our results we propose glacial, deglacial, and interglacial scenarios for environmental change in the Bering Sea. These changes seem to be primarily controlled by insolation and sea-level forcing which affect the strength of atmospheric pressure systems and sea-ice growth. The opening history of the Bering Strait is considered to have had an additional impact. High-resolution core logging data (color b*, XRF scans strongly correspond to the Dansgaard–Oeschger climate variability registered in the NGRIP ice core and support an atmospheric coupling mechanism of Northern Hemisphere climates.

  19. Estimators of primary production for interpretation of remotely sensed data on ocean color

    Science.gov (United States)

    Platt, Trevor; Sathyendranath, Shubha

    1993-01-01

    The theoretical basis is explained for some commonly used estimators of daily primary production in a vertically uniform water column. These models are recast into a canonical form, with dimensionless arguments, to facilitate comparison with each other and with an analytic solution. The limitations of each model are examined. The values of the photoadaptation parameter I(k) observed in the ocean are analyzed, and I(k) is used as a scale to normalize the surface irradiance. The range of this scaled irradiance is presented. An equation is given for estimation of I(k) from recent light history. It is shown how the models for water column production can be adapted for estimation of the production in finite layers. The distinctions between model formulation, model implementation and model evaluation are discussed. Recommendations are given on the choice of algorithm for computation of daily production according to the degree of approximation acceptable in the result.

  20. Classification and calculation of primary failure modes in bread production line

    International Nuclear Information System (INIS)

    Tsarouhas, Panagiotis H.

    2009-01-01

    In this study, we describe the classification methodology over a 2-year period of the primary failure modes in categories based on failure data of bread production line. We estimate the probabilities of these categories applying the chi-square goodness of fit test, and we calculate their joint probabilities of mass function at workstation and line level. Then, we present numerical examples in order to predict the causes and frequencies of breakdowns for workstations and for the entire bread production line that will occur in the future. The methodology is meant to guide bread and bakery product manufacturers, improving the operation of the production lines. It can also be a useful tool to maintenance engineers, who wish to analyze and improve the reliability and efficiency of the manufacturing systems

  1. The Absorption of Light in Lakes: Negative Impact of Dissolved Organic Carbon on Primary Productivity

    OpenAIRE

    Thrane, Jan-Erik; Hessen, Dag O.; Andersen, Tom

    2014-01-01

    Colored dissolved organic matter (CDOM) absorbs a substantial fraction of photosynthetically active radiation (PAR) in boreal lakes. However, few studies have systematically estimated how this light absorption influences pelagic primary productivity. In this study, 75 boreal lakes spanning wide and orthogonal gradients in dissolved organic carbon (DOC) and total phosphorus (TP) were sampled during a synoptic survey. We measured absorption spectra of phytoplankton pigments, CDOM, and non-algal...

  2. Creating a Regional MODIS Satellite-Driven Net Primary Production Dataset for European Forests

    OpenAIRE

    Neumann, Mathias; Moreno, Adam; Thurnher, Christopher; Mues, Volker; Härkönen, Sanna; Mura, Matteo; Bouriaud, Olivier; Lang, Mait; Cardellini, Giuseppe; Thivolle-Cazat, Alain; Bronisz, Karol; Merganic, Jan; Alberdi, Iciar; Astrup, Rasmus; Mohren, Frits

    2016-01-01

    Net primary production (NPP) is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm provides valuable information for monitoring NPP at 1-km resolution. Since coarse-resolution global climate data are used, the global dataset may contain uncertainties for Europe. We used a 1-km daily g...

  3. Impacts of temperature on primary productivity and respiration in naturally structured macroalgal assemblages.

    Directory of Open Access Journals (Sweden)

    Leigh W Tait

    Full Text Available Rising global temperatures caused by human-mediated change has already triggered significant responses in organismal physiology, distribution and ecosystem functioning. Although the effects of rising temperature on the physiology of individual organisms are well understood, the effect on community-wide processes has remained elusive. The fixation of carbon via primary productivity is an essential ecosystem function and any shifts in the balance of primary productivity and respiration could alter the carbon balance of ecosystems. Here we show through a series of tests that respiration of naturally structured algal assemblages in southern New Zealand greatly increases with rising temperature, with implications for net primary productivity (NPP. The NPP of in situ macroalgal assemblages was minimally affected by natural temperature variation, possibly through photo-acclimation or temperature acclimation responses, but respiration rates and compensating irradiance were negatively affected. However, laboratory experiments testing the impacts of rising temperature on several photosynthetic parameters showed a decline in NPP, increasing respiration rates and increasing compensating irradiance. The respiration Q10 of laboratory assemblages (the difference in metabolic rates over 10°C averaged 2.9 compared to a Q10 of 2 often seen in other autotrophs. However, gross primary productivity (GPP Q10 averaged 2, indicating that respiration was more severely affected by rising temperature. Furthermore, combined high irradiance and high temperature caused photoinhibition in the laboratory, and resulted in 50% lower NPP at high irradiance. Our study shows that communities may be more severely affected by rising global temperatures than would be expected by responses of individual species. In particular, enhanced respiration rates and rising compensation points have the potential to greatly affect the carbon balance of macroalgal assemblages through declines in

  4. Primary and secondary metabolites production in signal grass around the year under nitrogen fertilizer

    OpenAIRE

    Syeda Maryam Hussain

    2016-01-01

    Plants produce a number of substances and products and primary and secondary metabolites (SM) are amongst them with many benefits but limitation as well. Usually, the fodder are not considered toxic to animals or as a source having higher SM. The Brachiaria decumbens has a considerable nutritional value, but it is considered as a toxic grass for causing photosensitization in animals, if the grass is not harvested for more than 30 days or solely. The absence of detailed information in the lite...

  5. Primary and heterotrophic productivity relate to multikingdom diversity in a hypersaline mat

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Hans C.; Brislawn, Colin J.; Dana, Karl; Flores-Wentz, Tobias; Cory, Alexandra B.; Fansler, Sarah J.; Fredrickson, James K.; Moran, James J.

    2017-10-01

    Benthic microbial ecosystems are widespread yet knowledge gaps still remain on the relationships between the diversity of species across kingdoms and productivity. Here, we ask two fundamental questions: 1) How does species diversity relate to the rates of primary and heterotrophic productivity? 2) How do diel variations in light-energy inputs influence productivity and microbiome diversity? To answer these questions, microbial mats from a magnesium sulfate hypersaline Lake were used to establish microcosms. Both the number and relatedness between bacterial and eukaryotic taxa in the microbiome were assayed via amplicon based sequencing of 16S and 18S rRNA genes over two diel cycles. These results correlated with biomass productivity obtained from substrate-specific 13C stable isotope incorporation that enabled comparisons between primary and heterotrophic productivity. Both bacterial and eukaryotic species richness and evenness were related only to the rates of 13C labeled glucose and acetate biomass incorporation. Interestingly, measures of these heterotrophic relationships changed from positive and negative correlations depending on carbon derived from glucose and acetate, respectively. Bacterial and eukaryotic diversity of this ecosystem is also controlled, in part, energy constraints imposed by changing irradiance over a diel cycle.

  6. Diagnosis of compliance of health care product processing in Primary Health Care

    Directory of Open Access Journals (Sweden)

    Camila Eugenia Roseira

    Full Text Available ABSTRACT Objective: identify the compliance of health care product processing in Primary Health Care and assess possible differences in the compliance among the services characterized as Primary Health Care Service and Family Health Service. Method: quantitative, observational, descriptive and inferential study with the application of structure, process and outcome indicators of the health care product processing at ten services in an interior city of the State of São Paulo - Brazil. Results: for all indicators, the compliance indices were inferior to the ideal levels. No statistically significant difference was found in the indicators between the two types of services investigated. The health care product cleaning indicators obtained the lowest compliance index, while the indicator technical-operational resources for the preparation, conditioning, disinfection/sterilization, storage and distribution of health care products obtained the best index. Conclusion: the diagnosis of compliance of health care product processing at the services assessed indicates that the quality of the process is jeopardized, as no results close to ideal levels were obtained at any service. In addition, no statistically significant difference in these indicators was found between the two types of services studied.

  7. Primary production and chlorophyll distributions in the subtropical and tropical waters of the Atlantic Ocean in the autumn of 2002

    Science.gov (United States)

    Vedernikov, V. I.; Gagarin, V. I.; Demidov, A. B.; Burenkov, V. I.; Stunzhas, P. A.

    2007-06-01

    In October and November 2002, high and relatively high values of the chlorophyll a concentration at the sea surface ( C chl) were observed in the English Channel (0.47 mg/m3), in the waters of the North Atlantic Current (0.25 mg/m3), in the tropical and subtropical anticyclonic gyres (0.07-0.42 mg/m3), and also in the southwestern region of the southern subtropical anticyclonic gyre (usually 0.11-0.23 mg/m3). The central regions of the southern subtropical anticyclonic gyre (SATG) and the North Atlantic tropical gyre (NATR) were characterized by lower values of C chl (0.02-0.08 mg/m3 for the SATG and 0.07-0.14 mg/m3 for the NATR). At most of the SATG stations, the values of the surface primary production ( C phs) varied from 2.5 to 5.5 mg C/m3 per day and were mainly defined by the fluctuations of C chl ( r = +0.78) rather than by those of the assimilation number ( r = +0.54). The low assimilation activity of phytoplankton in these waters (1.3-4.6 mg chl a per hour) pointed to a lack of nutrients. An analysis of the variability of their concentration and the composition of photosynthetic pigments showed that, in the waters north of 30° N, the growth of phytoplankton was mostly restricted by the deficiency of nitrogen, while, in more southern areas, at the majority of stations (about 60%), the phosphorus concentrations were the minimum. At the low concentrations of nitrates and nitrites, ammonium represented itself as a buffer that prevented planktonic algae from extreme degrees of nitric starvation. In the tropical waters and in the waters of the SATG, the primary production throughout the water column varied from 240 to 380 mg C/m2 30° per day. This level of productivity at stations with low values of C chl (photosynthesis based on in situ measurements point to the high efficiency of utilizing the penetrating solar radiation by phytoplankton on cloudy days.

  8. Connectedness of land use, nutrients, primary production, and fish assemblages in oxbow lakes

    Science.gov (United States)

    Miranda, Leandro E.; Andrews, Caroline S.; Kroger, Robert

    2013-01-01

    We explored the strength of connectedness among hierarchical system components associated with oxbow lakes in the alluvial valley of the Lower Mississippi River. Specifically, we examined the degree of canonical correlation between land use (agriculture and forests), lake morphometry (depth and size), nutrients (total nitrogen and total phosphorus), primary production (chlorophyll-a), and various fish assemblage descriptors. Watershed (p < 0.01) and riparian (p = 0.02) land use, and lake depth (p = 0.05) but not size (p = 0.28), were associated with nutrient concentrations. In turn, nutrients were associated with primary production (p < 0.01), and primary production was associated with sunfish (Centrarchidae) assemblages (p < 0.01) and fish biodiversity (p = 0.08), but not with those of other taxa and functional guilds. Multiple chemical and biological components of oxbow lake ecosystems are connected to landscape characteristics such as land use and lake depth. Therefore, a top-down hierarchical approach can be useful in developing management and conservation plans for oxbow lakes in a region impacted by widespread landscape changes due to agriculture.

  9. Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system.

    Science.gov (United States)

    Hicks, Natalie; Bulling, Mark T; Solan, Martin; Raffaelli, Dave; White, Piran C L; Paterson, David M

    2011-02-14

    Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production) to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB) are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO(2) concentrations (370, 600, and 1000 ppmv), temperature (6°C, 12°C, and 18°C) and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor) in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness. The effects of elevated CO(2) concentration, temperature and invertebrate diversity were not additive, rather they interacted to determine MPB biomass, and overall this effect was negative. Diversity effects were underpinned by strong species composition effects, illustrating the importance of individual species identity. Overall, our findings suggest that in natural systems, the complex interactions between changing environmental conditions and any associated changes in invertebrate assemblage structure are likely to reduce MPB biomass. Furthermore, these effects would be sufficient to affect the

  10. Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system

    Directory of Open Access Journals (Sweden)

    Raffaelli Dave

    2011-02-01

    Full Text Available Abstract Background Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO2 concentrations (370, 600, and 1000 ppmv, temperature (6°C, 12°C, and 18°C and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness. Results The effects of elevated CO2 concentration, temperature and invertebrate diversity were not additive, rather they interacted to determine MPB biomass, and overall this effect was negative. Diversity effects were underpinned by strong species composition effects, illustrating the importance of individual species identity. Conclusions Overall, our findings suggest that in natural systems, the complex interactions between changing environmental conditions and any associated changes in invertebrate assemblage structure are likely to reduce MPB biomass. Furthermore

  11. What controls phytoplankton production in nutrient-rich areas of the open sea

    Energy Technology Data Exchange (ETDEWEB)

    Weiler, C.S. (comp.)

    1991-06-25

    The oceans play a critical role in regulating the global carbon cycle. Deep-ocean waters are roughly 200% supersaturated with CO{sub 2} compared to surface waters, which are in contact with the atmosphere. This difference is due to the flux of photosynthetically derived organic material from surface to deep waters and its subsequent remineralization, i.e. the biological pump''. The pump is a complex phytoplankton-based ecosystem. the paradoxical nature of ocean regions containing high nutrients and low phytoplankton populations has intrigued biological oceanographers for many years. Hypotheses to explain the paradox include the regulation of productivity by light, temperature, zooplankton grazing, and trace metal limitation and/or toxicity. To date, none of the hypotheses, or combinations thereof, has emerged as a widely accepted explanation for why the nitrogen and phosphorus are not depleted in these regions of the oceans. Recently, new evidence has emerged which supports the hypothesis that iron limitation regulates primary production in these areas. This has stimulated discussions of the feasibility of fertilizing parts the Southern Ocean with iron, and thus sequestering additional atmospheric CO{sub 2} in the deep oceans, where it would remain over the next few centuries. The economic, social, and ethical concerns surrounding such a proposition, along with the outstanding scientific issues, call for rigorous discussion and debate on the regulation of productivity in these regions. To this end, The American Society of Limnology and Oceanography (ASLO) held a Special Symposium on the topic Feb. 22--24th, 1991. Participants included leading authorities, from the US and abroad, on physical, chemical, and biological oceanography, plant physiology, microbiology, and trace metal chemistry. Representatives from government agencies and industry were also present.

  12. What controls phytoplankton production in nutrient-rich areas of the open sea?

    Energy Technology Data Exchange (ETDEWEB)

    Weiler, C.S. [comp.

    1991-06-25

    The oceans play a critical role in regulating the global carbon cycle. Deep-ocean waters are roughly 200% supersaturated with CO{sub 2} compared to surface waters, which are in contact with the atmosphere. This difference is due to the flux of photosynthetically derived organic material from surface to deep waters and its subsequent remineralization, i.e. the ``biological pump``. The pump is a complex phytoplankton-based ecosystem. the paradoxical nature of ocean regions containing high nutrients and low phytoplankton populations has intrigued biological oceanographers for many years. Hypotheses to explain the paradox include the regulation of productivity by light, temperature, zooplankton grazing, and trace metal limitation and/or toxicity. To date, none of the hypotheses, or combinations thereof, has emerged as a widely accepted explanation for why the nitrogen and phosphorus are not depleted in these regions of the oceans. Recently, new evidence has emerged which supports the hypothesis that iron limitation regulates primary production in these areas. This has stimulated discussions of the feasibility of fertilizing parts the Southern Ocean with iron, and thus sequestering additional atmospheric CO{sub 2} in the deep oceans, where it would remain over the next few centuries. The economic, social, and ethical concerns surrounding such a proposition, along with the outstanding scientific issues, call for rigorous discussion and debate on the regulation of productivity in these regions. To this end, The American Society of Limnology and Oceanography (ASLO) held a Special Symposium on the topic Feb. 22--24th, 1991. Participants included leading authorities, from the US and abroad, on physical, chemical, and biological oceanography, plant physiology, microbiology, and trace metal chemistry. Representatives from government agencies and industry were also present.

  13. The Effect of Improving Primary Care Depression Management on Employee Absenteeism and Productivity A Randomized Trial

    Science.gov (United States)

    Rost, Kathryn; Smith, Jeffrey L.; Dickinson, Miriam

    2005-01-01

    Objective: To test whether an intervention to improve primary care depression management significantly improves productivity at work and absenteeism over 2 years. Setting and Subjects: Twelve community primary care practices recruiting depressed primary care patients identified in a previsit screening. Research Design: Practices were stratified by depression treatment patterns before randomization to enhanced or usual care. After delivering brief training, enhanced care clinicians provided improved depression management over 24 months. The research team evaluated productivity and absenteeism at baseline, 6, 12, 18, and 24 months in 326 patients who reported full-or part-time work at one or more completed waves. Results: Employed patients in the enhanced care condition reported 6.1% greater productivity and 22.8% less absenteeism over 2 years. Consistent with its impact on depression severity and emotional role functioning, intervention effects were more observable in consistently employed subjects where the intervention improved productivity by 8.2% over 2 years at an estimated annual value of $1982 per depressed full-time equivalent and reduced absenteeism by 28.4% or 12.3 days over 2 years at an estimated annual value of $619 per depressed full-time equivalent. Conclusions: This trial, which is the first to our knowledge to demonstrate that improving the quality of care for any chronic disease has positive consequences for productivity and absenteeism, encourages formal cost-benefit research to assess the potential return-on-investment employers of stable workforces can realize from using their purchasing power to encourage better depression treatment for their employees. PMID:15550800

  14. The effect of improving primary care depression management on employee absenteeism and productivity. A randomized trial.

    Science.gov (United States)

    Rost, Kathryn; Smith, Jeffrey L; Dickinson, Miriam

    2004-12-01

    To test whether an intervention to improve primary care depression management significantly improves productivity at work and absenteeism over 2 years. Twelve community primary care practices recruiting depressed primary care patients identified in a previsit screening. Practices were stratified by depression treatment patterns before randomization to enhanced or usual care. After delivering brief training, enhanced care clinicians provided improved depression management over 24 months. The research team evaluated productivity and absenteeism at baseline, 6, 12, 18, and 24 months in 326 patients who reported full-or part-time work at one or more completed waves. Employed patients in the enhanced care condition reported 6.1% greater productivity and 22.8% less absenteeism over 2 years. Consistent with its impact on depression severity and emotional role functioning, intervention effects were more observable in consistently employed subjects where the intervention improved productivity by 8.2% over 2 years at an estimated annual value of US 1982 dollars per depressed full-time equivalent and reduced absenteeism by 28.4% or 12.3 days over 2 years at an estimated annual value of US 619 dollars per depressed full-time equivalent. This trial, which is the first to our knowledge to demonstrate that improving the quality of care for any chronic disease has positive consequences for productivity and absenteeism, encourages formal cost-benefit research to assess the potential return-on-investment employers of stable workforces can realize from using their purchasing power to encourage better depression treatment for their employees.

  15. Modelling and numerical simulation of the corrosion product transport in the pressurised water reactor primary circuit

    International Nuclear Information System (INIS)

    Marchetto, C.

    2002-05-01

    During operation of pressurised water reactor, corrosion of the primary circuit alloys leads to the release of metallic species such as iron, nickel and cobalt in the primary fluid. These corrosion products are implicated in different transport phenomena and are activated in the reactor core where they are submitted to neutron flux. The radioactive corrosion products are afterwards present in the out of flux parts of primary circuit where they generate a radiation field. The first part of this study deals with the modelling of the corrosion: product transport phenomena. In particular, considering the current state of the art, corrosion and release mechanisms are described empirically, which allows to take into account the material surface properties. New mass balance equations describing the corrosion product behaviour are thus obtained. The numerical resolution of these equations is implemented in the second part of this work. In order to obtain large time steps, we choose an implicit time scheme. The associated system is linearized from the Newton method and is solved by a preconditioned GMRES method. Moreover, a time step auto-adaptive management based on Newton iterations is performed. Consequently, an efficient resolution has been implemented, allowing to describe not only the quasi-steady evolutions but also the fast transients. In a last step, numerical simulations are carried out in order to validate the new corrosion product transport modelling and to illustrate the capabilities of this modelling. Notably, the numerical results obtained indicate that the code allows to restore the on-site observations underlining the influence of material surface properties on reactor contamination. (author)

  16. Plastic scintillators in coincidence for the study of multi-particle production of sea level cosmic rays in dense medium

    Science.gov (United States)

    Chuang, L. S.; Chan, K. W.; Wada, M.

    1985-01-01

    Cosmic ray particles at sea level penetrate a thick layer of dense medium without appreciable interaction. These penetrating particles are identified with muons. The only appreciable interaction of muons are by knock on processes. A muon may have single, double or any number of knock on with atoms of the material so that one, two, three or more particles will come out from the medium in which the knock on processes occur. The probability of multiparticle production is expected to decrease with the increase of multiplicity. Measurements of the single, double, and triple particles generated in a dense medium (Fe and Al) by sea level cosmic rays at 22.42 N. Lat. and 114.20 E. Long. (Hong Kong) are presented using a detector composed of two plastic scintillators connected in coincidence.

  17. Fission product plateout and liftoff in the MHTGR primary system: A review

    International Nuclear Information System (INIS)

    Wichner, R.P.

    1991-04-01

    A review is presented of the technical basis for predicting radioactivity release resulting from depressurization of an MHTGR primary system. Consideration is restricted to so called dry events with no involvement of the steam system. The various types of deposition mechanisms effective for iodine, cesium, strontium, and silver are discussed in terms of their chemical characteristics and the nature of the materials in the primary system. Emphasis is given to iodine behavior, including means for estimating the quantity available for release, the types of plateout locations in the primary system, and the effect of dust on distribution and release. The behavior of fission products cesium, strontium, and silver in such accidents is presented qualitatively. A major part of the review deals with expected dust levels, types, and transport. Available information on the level and nature of dust in the HTGR primary system is reviewed. A summary is presented of dust deposition and liftoff mechanisms. It was concluded that recent approaches to dust liftoff modeling, based on turbulent burst concepts for removal from surfaces, probably offer advantages over the current shear ratio approach. This study concludes that iodine releases from dry depressurization events are likely to be extremely low, on the order of millicuries, due to a predictably low degree of chemical desorption, a low degree of dust liftoff, and a low involvement of iodine with dust. It was also concluded that deposition mechanisms controlling the distribution of fission product material in the primary system, and hence also controlling the degree of liftoff, depend strongly on the chemical nature of the individual elements. Therefore contrary to the current practice, both plateout and liftoff models should reflect those unique chemical and physical properties. 56 refs., 16 figs., 23 tabs

  18. Retrieval of daily gross primary production over Europe and Africa from an ensemble of SEVIRI/MSG products

    Science.gov (United States)

    Martínez, B.; Sanchez-Ruiz, S.; Gilabert, M. A.; Moreno, A.; Campos-Taberner, M.; García-Haro, F. J.; Trigo, I. F.; Aurela, M.; Brümmer, C.; Carrara, A.; De Ligne, A.; Gianelle, D.; Grünwald, T.; Limousin, J. M.; Lohila, A.; Mammarella, I.; Sottocornola, M.; Steinbrecher, R.; Tagesson, T.

    2018-03-01

    The main goal of this paper is to derive a method for a daily gross primary production (GPP) product over Europe and Africa taking the full advantage of the SEVIRI/MSG satellite products from the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) sensors delivered from the Satellite Application Facility for Land Surface Analysis (LSA SAF) system. Special attention is paid to model the daily GPP response from an optimized Montheith's light use efficiency model under dry conditions by controlling water shortage limitations from the actual evapotranspiration and the potential evapotranspiration (PET). The PET was parameterized using the mean daily air temperature at 2 m (Ta) from ERA-Interim data. The GPP product (MSG GPP) was produced for 2012 and assessed by direct site-level comparison with GPP from eddy covariance data (EC GPP). MSG GPP presents relative bias errors lower than 40% for the most forest vegetation types with a high agreement (r > 0.7) when compared with EC GPP. For drylands, MSG GPP reproduces the seasonal variations related to water limitation in a good agreement with site level GPP estimates (RMSE = 2.11 g m-2 day-1; MBE = -0.63 g m-2 day-1), especially for the dry season. A consistency analysis against other GPP satellite products (MOD17A2 and FLUXCOM) reveals a high consistency among products (RMSD Africa. The major GPP disagreement arises over moist biomes in central Africa (RMSD > 3.0 g m-2 day-1) and over dry biomes with MSG GPP estimates lower than FLUXCOM (MBD up to -3.0 g m-2 day-1). This newly derived product has the potential for analysing spatial patterns and temporal dynamics of GPP at the MSG spatial resolutions on a daily basis allowing to better capture the GPP dynamics and magnitude.

  19. Distortion product otoacoustic emissions: comparison of sequential vs. simultaneous presentation of primary tones.

    Science.gov (United States)

    Kumar, U Ajith; Maruthy, Sandeep; Chandrakant, Vishwakarma

    2009-03-01

    Distortion product otoacoustic emissions are one form of evoked otoacoustic emissions. DPOAEs provide the frequency specific information about the hearing status in mid and high frequency regions. But in most screening protocols TEOAEs are preferred as it requires less time compared to DPOAE. This is because, in DPOAE each stimulus is presented one after the other and responses are analyzed. Grason and Stadler Incorporation 60 (GSI-60) offer simultaneous presentation of four sets of primary tones at a time and checks for the DPOAE. In this mode of presentation, all the pairs are presented at a time and following that response is extracted separately whereas, in sequential mode primaries are presented in orderly fashion one after the other. In this article simultaneous and sequential protocols were used to compare the Distortion product otoacoustic emission amplitude, noise floor and administration time in individuals with normal hearing and mild sensori-neural (SN) hearing loss. In simultaneous protocols four sets of primary tones (i.e. 8 tones) were presented together whereas, in sequential presentation mode one set of primary tones was presented each time. Simultaneous protocol was completed in less than half the time required for the completion of sequential protocol. Two techniques yielded similar results at frequencies above 1000 Hz only in normal hearing group. In SN hearing loss group simultaneous presentation yielded signifi cantly higher noise floors and distortion product amplitudes. This result challenges the use of simultaneous presentation technique in neonatal hearing screening programmes and on other pathologies. This discrepancy between two protocols may be due to some changes in biomechanical process in the cochlear and/or due to higher distortion/noise produced by the system during the simultaneous presentation mode.

  20. CO2 Enhanced Oil Recovery from the Residual Zone - A Sustainable Vision for North Sea Oil Production

    Science.gov (United States)

    Stewart, Jamie; Haszeldine, Stuart; Wilkinson, Mark; Johnson, Gareth

    2014-05-01

    This paper presents a 'new vision for North Sea oil production' where previously unattainable residual oil can be produced with the injection of CO2 that has been captured at power stations or other large industrial emitters. Not only could this process produce incremental oil from a maturing basin, reducing imports, it also has the capability to store large volumes of CO2 which can offset the emissions of additional carbon produced. Around the world oil production from mature basins is in decline and production from UK oil fields peaked in 1998. Other basins around the world have a similar story. Although in the UK a number of tax regimes, such as 'brown field allowances' and 'new field allowances' have been put in place to re-encourage investment, it is recognised that the majority of large discoveries have already been made. However, as a nation our demand for oil remains high and in the last decade imports of crude oil have been steadily increasing. The UK is dependent on crude oil for transport and feedstock for chemical and plastics production. Combined with the necessity to provide energy security, there is a demand to re-assess the potential for CO2 Enhanced Oil Recovery (CO2-EOR) in the UK offshore. Residual oil zones (ROZ) exist where one of a number of natural conditions beyond normal capillary forces have caused the geometry of a field's oil column to be altered after filling [1]. When this re-structuring happens the primary interest to the hydrocarbon industry has in the past been in where the mobile oil has migrated to. However it is now considered that significant oil resource may exist in the residual zone play where the main oil column has been displaced. Saturations within this play are predominantly close to residual saturation (Sr) and would be similar to that of a water-flooded field [2]. Evidence from a number of hydrocarbon fairways shows that, under certain circumstances, these residual zones in US fields are comparable in thickness to the

  1. Effects of an oil production effluent on gametogenesis and gamete performance in the purple sea urchin (Strongylocentrotus purpuratus Stimpson)

    International Nuclear Information System (INIS)

    Krause, P.R.

    1994-01-01

    Adult organisms subjected to chronic discharges from a point source of pollution may exhibit several sublethal responses. One such response is the impairment of gamete production. This may be expressed in the amount and/or quality of gametes produced by adults. In this study the effects of chronic exposure to produced water (an oil production effluent) on the gametogenesis and gamete performance of the purple sea urchin (Strongylocentrotus purpuratus Stimpson) were examined using an in situ caging experiment. Adult purple sea urchins were kept in benthic cages arrayed down-field from a discharging diffuser at 13 sites, with distances ranging from 5 to 1,000 m. Cage exposures were maintained in the field for eight weeks, and each cage held 25 animals. Gametogenesis was examined for each sex by comparing a size-independent measure of relative gonads ass as determined by analysis of covariance. Results showed that there was a significant negative relationship between these estimates of relative gonad mass and distance from the outfall for both sexes, indicating that sea urchins living closer to the outfall produced significantly larger gonads. Gamete performance was measured through a fertilization kinetics bioassay that held the concentration of eggs constant and varied the amount of sperm added. The proportion of eggs fertilized under each sperm concentration was determined and the response fit to a model of fertilizability showed a positive relationship with distance away from the outfall. These findings indicate that although adult sea urchins exposed to a produced water outfall exhibit larger gonads, they suffer a marked decrease in a gamete performance

  2. Primary souring: A novel bacteria-free method for sour beer production.

    Science.gov (United States)

    Osburn, Kara; Amaral, Justin; Metcalf, Sara R; Nickens, David M; Rogers, Cody M; Sausen, Christopher; Caputo, Robert; Miller, Justin; Li, Hongde; Tennessen, Jason M; Bochman, Matthew L

    2018-04-01

    In the beverage fermentation industry, especially at the craft or micro level, there is a movement to incorporate as many local ingredients as possible to both capture terroir and stimulate local economies. In the case of craft beer, this has traditionally only encompassed locally sourced barley, hops, and other agricultural adjuncts. The identification and use of novel yeasts in brewing lags behind. We sought to bridge this gap by bio-prospecting for wild yeasts, with a focus on the American Midwest. We isolated 284 different strains from 54 species of yeast and have begun to determine their fermentation characteristics. During this work, we found several isolates of five species that produce lactic acid and ethanol during wort fermentation: Hanseniaspora vineae, Lachancea fermentati, Lachancea thermotolerans, Schizosaccharomyces japonicus, and Wickerhamomyces anomalus. Tested representatives of these species yielded excellent attenuation, lactic acid production, and sensory characteristics, positioning them as viable alternatives to lactic acid bacteria (LAB) for the production of sour beers. Indeed, we suggest a new LAB-free paradigm for sour beer production that we term "primary souring" because the lactic acid production and resultant pH decrease occurs during primary fermentation, as opposed to kettle souring or souring via mixed culture fermentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Size-fractionated dissolved primary production and carbohydrate composition of the coccolithophore Emiliania huxleyi

    Science.gov (United States)

    Borchard, C.; Engel, A.

    2015-02-01

    Extracellular release (ER) by phytoplankton is the major source of fresh dissolved organic carbon (DOC) in marine ecosystems and accompanies primary production during all growth phases. Little is known, so far, on size and composition of released molecules, and to which extent ER occurs passively, by leakage, or actively, by exudation. Here, we report on ER by the widespread and bloom-forming coccolithophore Emiliania huxleyi grown under steady-state conditions in phosphorus-controlled chemostats (N:P = 29, growth rate of μ = 0.2 d-1) at present-day and high-CO2 concentrations. 14C incubations were performed to determine primary production (PP), comprised of particulate (PO14C) and dissolved organic carbon (DO14C). Concentration and composition of particulate combined carbohydrates (pCCHO) and high-molecular-weight (>1 kDa, HMW) dissolved combined carbohydrates (dCCHO) were determined by ion chromatography. Information on size distribution of ER products was obtained by investigating distinct size classes (10 kDa was significantly different, with a higher mol% of arabinose. The mol% of acidic sugars increased and that of glucose decreased with increasing size of HMW-dCCHO. We conclude that larger polysaccharides follow different production and release pathways than smaller molecules, potentially serving distinct ecological and biogeochemical functions.

  4. Satellite remote sensing for estimating leaf area index, FPAR and primary production. A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Boresjoe Bronge, Laine [SwedPower AB, Stockholm (Sweden)

    2004-03-01

    Land vegetation is a critical component of several biogeochemical cycles that have become the focus of concerted international research effort. Most ecosystem productivity models, carbon budget models, and global models of climate, hydrology and biogeochemistry require vegetation parameters to calculate land surface photosynthesis, evapotranspiration and net primary production. Therefore, accurate estimates of vegetation parameters are increasingly important in the carbon cycle, the energy balance and in environmental impact assessment studies. The possibility of quantitatively estimating vegetation parameters of importance in this context using satellite data has been explored by numerous papers dealing with the subject. This report gives a summary of the present status and applicability of satellite remote sensing for estimating vegetation productivity by using vegetation index for calculating leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR). Some possible approaches for use of satellite data for estimating LAI, FPAR and net primary production (NPP) on a local scale are suggested. Recommendations for continued work in the Forsmark and Oskarshamn investigation areas, where vegetation data and NDVI-images based on satellite data have been produced, are also given.

  5. Satellite remote sensing for estimating leaf area index, FPAR and primary production. A literature review

    International Nuclear Information System (INIS)

    Boresjoe Bronge, Laine

    2004-03-01

    Land vegetation is a critical component of several biogeochemical cycles that have become the focus of concerted international research effort. Most ecosystem productivity models, carbon budget models, and global models of climate, hydrology and biogeochemistry require vegetation parameters to calculate land surface photosynthesis, evapotranspiration and net primary production. Therefore, accurate estimates of vegetation parameters are increasingly important in the carbon cycle, the energy balance and in environmental impact assessment studies. The possibility of quantitatively estimating vegetation parameters of importance in this context using satellite data has been explored by numerous papers dealing with the subject. This report gives a summary of the present status and applicability of satellite remote sensing for estimating vegetation productivity by using vegetation index for calculating leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR). Some possible approaches for use of satellite data for estimating LAI, FPAR and net primary production (NPP) on a local scale are suggested. Recommendations for continued work in the Forsmark and Oskarshamn investigation areas, where vegetation data and NDVI-images based on satellite data have been produced, are also given

  6. A multi-sites analysis on the ozone effects on Gross Primary Production of European forests

    Energy Technology Data Exchange (ETDEWEB)

    Proietti, C. [Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome (Italy); Anav, A. [Italian National Agency for New Technologies, Energy and the Environment (ENEA), C.R. Casaccia, Via Anguillarese 301, 00123 S. Maria di Galeria, Rome (Italy); University of Exeter, College of Engineering, Mathematics and Physical Sciences, Exeter (United Kingdom); De Marco, A. [Italian National Agency for New Technologies, Energy and the Environment (ENEA), C.R. Casaccia, Via Anguillarese 301, 00123 S. Maria di Galeria, Rome (Italy); Sicard, P. [ACRI-HE, 260 route du Pin Montard BP234, 06904 Sophia Antipolis-cedex (France); Vitale, M., E-mail: marcello.vitale@uniroma1.it [Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome (Italy)

    2016-06-15

    Ozone (O{sub 3}) is both a greenhouse gas and a secondary air pollutant causing adverse impacts on forests ecosystems at different scales, from cellular to ecosystem level. Specifically, the phytotoxic nature of O{sub 3} can impair CO{sub 2} assimilation that, in turn affects forest productivity. This study aims to evaluate the effects of tropospheric O{sub 3} on Gross Primary Production (GPP) at 37 European forest sites during the time period 2000–2010. Due to the lack of carbon assimilation data at O{sub 3} monitoring stations (and vice-versa) this study makes a first attempt to combine high resolution MODIS Gross Primary Production (GPP) estimates and O{sub 3} measurement data. Partial Correlations, Anomalies Analysis and the Random Forests Analysis (RFA) were used to quantify the effects of tropospheric O{sub 3} concentration and its uptake on GPP and to evaluate the most important factors affecting inter-annual GPP changes. Our results showed, along a North-West/South-East European transect, a negative impact of O{sub 3} on GPP ranging from 0.4% to 30%, although a key role of meteorological parameters respect to pollutant variables in affecting GPP was found. In particular, meteorological parameters, namely air temperature (T), soil water content (SWC) and relative humidity (RH) are the most important predictors at 81% of test sites. Moreover, it is interesting to highlight a key role of SWC in the Mediterranean areas (Spanish, Italian and French test sites) confirming that, soil moisture and soil water availability affect vegetation growth and photosynthesis especially in arid or semi-arid ecosystems such as the Mediterranean climate regions. Considering the pivotal role of GPP in the global carbon balance and the O{sub 3} ability to reduce primary productivity of the forests, this study can help in assessing the O{sub 3} impacts on ecosystem services, including wood production and carbon sequestration. - Highlights: • Assessment of the surface O{sub 3

  7. The Puzzle of HCN in Comets: Is it both a Product and a Primary Species?

    Science.gov (United States)

    Mumma, Michael J.; Bonev, Boncho P.; Charnley, Steven B.; Cordiner, Martin A.; DiSanti, Michael A.; Gibb, Erika L.; Magee-Sauer, Karen; Paganini, Lucas; Villanueva, Geronimo L.

    2014-11-01

    Hydrogen cyanide has long been regarded as a primary volatile in comets, stemming from its presence in dense molecular cloud cores and its supposed storage in the cometary nucleus. Here, we examine the observational evidence for and against that hypothesis, and argue that HCN may also result from near-nucleus chemical reactions in the coma. The distinction (product vs. primary species) is important for multiple reasons: 1. HCN is often used as a proxy for water when the dominant species (H2O) is not available for simultaneous measurement, as at radio wavelengths. 2. HCN is one of the few volatile carriers of nitrogen accessible to remote sensing. If HCN is mainly a product species, its precursor becomes the more important metric for compiling a taxonomic classification based on nitrogen chemistry. 3. The stereoisomer HNC is now confirmed as a product species. Could reaction of a primary precursor (X-CN) with a hydrocarbon co-produce both HNC and HCN? 4. The production rate for CN greatly exceeds that of HCN in some comets, demonstrating the presence of another (more important) precursor of CN. Several puzzling lines of evidence raise issues about the origin of HCN: a. The production rates of HCN measured through rotational (radio) and vibrational (infrared) spectroscopy agree in some comets - in others the infrared rate exceeds the radio rate substantially. b. With its strong dipole moment and H-bonding character, HCN should be linked more strongly in the nuclear ice to other molecules with similar properties (H2O, CH3OH), but instead its spatial release in some comets seems strongly coupled to volatiles that lack a dipole moment and thus do not form H-bonds (methane, ethane). c. The nucleus-centered rotational temperatures measured for H2O and other species (C2H6, CH3OH) usually agree within error, but those for HCN are often slightly smaller. d. In comet ISON, ALMA maps of HCN and the dust continuum show a slight displacement 80 km) in the centroids. We will

  8. Study on the production mechanism of Co-60 in the primary loop of HTR-10

    International Nuclear Information System (INIS)

    Wang Shouang; Xie Feng; Li Hong; Cao Jianzhu; Li Fu; Wei Liqiang

    2015-01-01

    Co-60 is an activated metallic erosion product, which is very important for waste management and decommissioning work of pressurized water reactor (PWR) power plants. Recent measurement on the samples from the primary loop of HTR-10 indicates the existence of Co-60. In current paper, the preliminary experimental results in HTR-10 will be introduced, and the production mechanism of Co-60 in the pebble bed high temperature gas-cooled reactors will be summarized and compared with that in PWRs and Germany High Temperature Nuclear Reactor (AVR). The further experiments with decomposing the post-irradiation graphite spheres of HTR-10 are put forward, which will promote the further study to testify the production sources of Co-60 and be of great significance in the waste minimization and the decommissioning work of HTR-10. (author)

  9. The Feasibility of Onsite Electrolysis as Primary and Clean Production Source of Fuel Hydrogen in Brazil

    International Nuclear Information System (INIS)

    COSTA, Andre R

    2006-01-01

    In accordance with the International Monetary Fund Brazil is currently the world's 12. largest and Latin America's largest economy, with a nominal GPD in the amount of US dollars 732,078 millions. Despite the fact that energy production is still heavily based on hydrocarbons, such as oil, natural gas and coal, the country is often indicated as one of the worldwide leaders in implementing renewable energy sources, primarily due to the spread utilization of bio-ethanol in transportation and the electricity production from hydropower. The purpose of this study is to assess the feasibility of onsite electrolysis as primary and clean source of fuel hydrogen in Brazil, indicating the main advantages of this production method. A perspective of the most significant challenges and actions to be taken regarding the accomplishment of a clean Brazilian hydrogen economy will be presented herein. (author)

  10. Primary production and algae diversity vs. pollution in xochimilco wet-lands

    Energy Technology Data Exchange (ETDEWEB)

    Pedroza-Pichardo, R.; Hernandez-Delgadillo, R.; Boll-Arguello, G.

    2009-07-01

    Xochimilco is an ancient endorheic lake located in the Valley of Mexico. Due to its shallow water and the freshwater springs that lined the canals, they are surround raised agricultural fields called chinampas. Since the Valley of Mexico was originally wetlands, the chinampas were the most productive means of agricultural production. Xochimilco are considered one of the most important urban lungs in Mexico City. However, it is not clear how the huge urbanization around is to know if there is a correlation between primary production (PP), algae diversity, BOD{sub 5} and faecal coliforms. Sample collection was done every month over a year at six different canals named: Embarcadero Celada, Embarcadero Nuevo Nativitas, Canal Las Abejas, Canal Zacapa, Canal Santo Domingo y Canal Nacional. (Author)

  11. Primary production and algae diversity vs. pollution in xochimilco wet-lands

    International Nuclear Information System (INIS)

    Pedroza-Pichardo, R.; Hernandez-Delgadillo, R.; Boll-Arguello, G.

    2009-01-01

    Xochimilco is an ancient endorheic lake located in the Valley of Mexico. Due to its shallow water and the freshwater springs that lined the canals, they are surround raised agricultural fields called chinampas. Since the Valley of Mexico was originally wetlands, the chinampas were the most productive means of agricultural production. Xochimilco are considered one of the most important urban lungs in Mexico City. However, it is not clear how the huge urbanization around is to know if there is a correlation between primary production (PP), algae diversity, BOD 5 and faecal coliforms. Sample collection was done every month over a year at six different canals named: Embarcadero Celada, Embarcadero Nuevo Nativitas, Canal Las Abejas, Canal Zacapa, Canal Santo Domingo y Canal Nacional. (Author)

  12. DNA markers as a tool for genetic traceability of primary product in agri-food chains

    Directory of Open Access Journals (Sweden)

    Daria Scarano

    2012-11-01

    Full Text Available The agri-food components of the Made in Italy are well known all over the world, therefore they may significantly contribute to the Italian economy. However, also owing to a large number of cases of improper labelling, the Italian agro-food industry faces an ever-increasing competition. For this reason, there is a decline of consumers’ confidence towards food production systems and safety controls. To prevent erroneous classification of products and to protect consumers from false instore information, it is important to develop and validate techniques that are able to detect mislabelling at any stage of the food-chain. This paper describes some examples of genetic traceability of primary products in some important plant food chains such as durum wheat, olive and tomato, based on DNA analysis both of raw material and of processed food (pasta, olive oil, and peeled tomato.

  13. Effects of UV radiation on DNA photodamage and production in bacterioplankton in the coastal Caribbean Sea

    NARCIS (Netherlands)

    Visser, P.M; Snelder, E; Kop, A.J; Boelen, P.; Buma, A.G.J.; van Duyl, F.C

    1999-01-01

    This study focuses on the effects of ultraviolet radiation (UVR) on bacterioplankton. The effect of different parts of the sunlight spectrum on the leucine and thymidine incorporation and on the induction of DNA damage in natural bacterial populations in the coastal Caribbean Sea off Curacao were

  14. Seasonality and toxin production of Pyrodinium bahamense in a Red Sea lagoon

    KAUST Repository

    Banguera Hinestroza, Eulalia; Eikrem, W.; Mansour, H.; Solberg, Ingrid; Curdia, Joao; Holtermann, Karie Ellen; Edvardsen, B.; Kaartvedt, Stein

    2016-01-01

    Harmful algal blooms of the dinoflagellate Pyrodinium bahamense have caused human and economic losses in the last decades. This study, for the first time, documents a bloom of P. bahamense in the Red Sea. The alga was recurrently present in a semi

  15. Role of iron deficiency in production and remineralization of organic matter in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    The Arabian Sea contains the only major western-boundary upwelling system in the world's oceans During summer, strong southwesterly winds bring up subsurface waters from depths of up to 200m off Somalia, Yemen and Oman These waters, having high...

  16. Primary productivity and the prospects for biofuels in the United Kingdom

    Science.gov (United States)

    Lawson, G. J.; Callaghan, T. V.

    1983-09-01

    Estimates of land use and plant productivity are combined to predict total annual primary production in the UK as 252 million tonnes dry matter (10.5 t ha-1yr-1). Annual above ground production is predicted to be 165 Mt (6.9 t ha-1yr-1). Within these totals, intensive agriculture contributes 60%, productive woodland 8%, natural vegetation 26% and urban vegetation 5%. However, only 25% of total plant production is cropped by man and animals, and most of this is subsequently discarded as wastes and residues. 2112 PJ of organic material is available for fuel without reducing food or fibre production, but since much of this could not be economically collected, 859 PJ is calculated as a more realistic biofuel contribution by the year 2000. After deducting 50% conversion losses, this could save P1 billion (1979 prices) in oil imports. Short rotation energy plantations, forest residues, coppice woodlands, animal and crop wastes, industrial and domestic wastes, catch crops, natural vegetation and urban vegetation all have immediate or short term potential as biofuel sources. Sensitive planning is required to reduce environmental impact, but in some cases more diverse wildlife habitats may be created.

  17. Monitoring Agricultural Production in Primary Export Countries within the framework of the GEOGLAM Initiative

    Science.gov (United States)

    Becker-Reshef, I.; Justice, C. O.; Vermote, E.

    2012-12-01

    Up to date, reliable, global, information on crop production prospects is indispensible for informing and regulating grain markets and for instituting effective agricultural policies. The recent price surges in the global grain markets were in large part triggered by extreme weather events in primary grain export countries. These events raise important questions about the accuracy of current production forecasts and their role in market fluctuations, and highlight the deficiencies in the state of global agricultural monitoring. Satellite-based earth observations are increasingly utilized as a tool for monitoring agricultural production as they offer cost-effective, daily, global information on crop growth and extent and their utility for crop production forecasting has long been demonstrated. Within this context, the Group on Earth Observations developed the Global Agricultural Monitoring (GEOGLAM) initiative which was adopted by the G20 as part of the action plan on food price volatility and agriculture. The goal of GEOGLAM is to enhance agricultural production estimates through the use of Earth observations. This talk will explore the potential contribution of EO-based methods for improving the accuracy of early production estimates of main export countries within the framework of GEOGLAM.

  18. Evaluation of the Gas Production Potential of Marine HydrateDeposits in the Ulleung Basin of the Korean East Sea

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, George J.; Reagan, Matthew T.; Kim, Se-Joon; Seol,Yongkoo; Zhang, Keni

    2007-11-16

    Although significant hydrate deposits are known to exist in the Ulleung Basin of the Korean East Sea, their survey and evaluation as a possible energy resource has not yet been completed. However, it is possible to develop preliminary estimates of their production potential based on the limited data that are currently available. These include the elevation and thickness of the Hydrate-Bearing Layer (HBL), the water depth, and the water temperature at the sea floor. Based on this information, we developed estimates of the local geothermal gradient that bracket its true value. Reasonable estimates of the initial pressure distribution in the HBL can be obtained because it follows closely the hydrostatic. Other critical information needs include the hydrate saturation, and the intrinsic permeabilities of the system formations. These are treated as variables, and sensitivity analysis provides an estimate of their effect on production. Based on the geology of similar deposits, it is unlikely that Ulleung Basin accumulations belong to Class 1 (involving a HBL underlain by a mobile gas zone). If Class 4 (disperse, low saturation accumulations) deposits are involved, they are not likely to have production potential. The most likely scenarios include Class 2 (HBL underlain by a zone of mobile water) or Class 3 (involving only an HBL) accumulations. Assuming nearly impermeable confining boundaries, this numerical study indicates that large production rates (several MMSCFD) are attainable from both Class 2 and Class 3 deposits using conventional technology. The sensitivity analysis demonstrates the dependence of production on the well design, the production rate, the intrinsic permeability of the HBL, the initial pressure, temperature and hydrate saturation, as well as on the thickness of the water zone (Class 2). The study also demonstrates that the presence of confining boundaries is indispensable for the commercially viable production of gas from these deposits.

  19. Landscape level influence: aquatic primary production in the Colorado River of Glen and Grand canyons

    Science.gov (United States)

    Yard, M. D.; Kennedy, T.; Yackulic, C. B.; Bennett, G. E.

    2012-12-01

    Irregular features common to canyon-bound regions intercept solar incidence (photosynthetic photon flux density [PPFD: μmol m-2 s-1]) and can affect ecosystem energetics. The Colorado River in Grand Canyon is topographically complex, typical of most streams and rivers in the arid southwest. Dam-regulated systems like the Colorado River have reduced sediment loads, and consequently increased water transparency relative to unimpounded rivers; however, sediment supply from tributaries and flow regulation that affects erosion and subsequent sediment transport, interact to create spatial and temporal variation in optical conditions in this river network. Solar incidence and suspended sediment loads regulate the amount of underwater light available for aquatic photosynthesis in this regulated river. Since light availability is depth dependent (Beer's law), benthic algae is often exposed to varying levels of desiccation or reduced light conditions due to daily flow regulation, additional factors that further constrain aquatic primary production. Considerable evidence suggests that the Colorado River food web is now energetically dependent on autotrophic production, an unusual condition since large river foodwebs are typically supported by allochthonous carbon synthesized and transported from terrestrial environments. We developed a mechanistic model to account for these regulating factors to predict how primary production might be affected by observed and alternative flow regimes proposed as part of ongoing adaptive management experimentation. Inputs to our model include empirical data (suspended sediment and temperature), and predictive relationships: 1) solar incidence reaching the water surface (topographic complexity), 2) suspended sediment-light extinction relationships (optical properties), 3) unsteady flow routing model (stage-depth relationship), 4) channel morphology (photosynthetic area), and 5) photosynthetic-irradiant response for dominant algae (Cladophora

  20. NODC Standard Product: International ocean atlas Volume 12 - Climatic atlas of the North Pacific Seas 2009 (NODC Accession 0098576)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Atlas contains monthly climatic charts of temperature, salinity, and oxygen at the sea surface and at standard depth levels for the Bering Sea, Sea of Okhotsk,...

  1. Measurement and evaluation of radioactive corrosion product behaviour in primary sodium circuits of JOYO

    International Nuclear Information System (INIS)

    Ito, K.; Iizawa, K.; Takahashi, K.; Zulquarnain, M.A.; Suzuki, S.; Kinjo, K.

    1992-01-01

    In the experimental fast reactor JOYO, the radioactive corrosion product (CP) measurement has been conducted in the primary sodium circuits during each annual inspection. The measured data has been analyzed by the computer code 'PSYCHE', which has been developed by PNC. Main results obtained from the measurements and/or calculations are as follows; (1) The dominant CP nuclide is 54 Mn followed by 60 Co and 58 Co. (2) Average surface gamma dose rate around the primary piping system at the 8th annual inspection is 0.96 mSv/h. The increasing rate of this value is 0.25 (mSv/h)/EFPY. (3) The calculated deposition densities of 54 Mn and 60 Co agree with measured ones within factor of 0.7 ∼ 1.7. (author)

  2. Control of fluxes towards antibiotics and the role of primary metabolism in production of antibiotics

    DEFF Research Database (Denmark)

    Gunnarsson, Nina; Eliasson Lantz, Anna; Nielsen, Jacob

    2004-01-01

    Yield improvements in antibiotic-producing strains have classically been obtained through random mutagenesis and screening. An attractive alternative to this strategy is the rational design of producer strains via metabolic engineering, an approach that offers the possibility to increase yields...... in the metabolic network. Here we describe and discuss available methods for identification of these steps, both in antibiotic biosynthesis pathways and in the primary metabolism, which serves as the supplier of precursors and cofactors for the secondary metabolism. Finally, the importance of precursor...... and cofactor supply from primary metabolism in the biosynthesis of different types of antibiotics is discussed and recent developments in metabolic engineering towards increased product yields in antibiotic producing strains are reviewed....

  3. Thermodynamics and the transport of corrosion products in PWR primary circuits

    International Nuclear Information System (INIS)

    Turner, D.J.

    1992-01-01

    It is argued that practically useful models for the activation, transport and deposition of corrosion products in PWR primary circuits can only be produced on the basis of an improved understanding of the chemical processes which control them. In particular, if a model is to make reliable predictions it is essential that its thermodynamic basis be sound. This is not the case with most current models which employ the erroneous concept of a corrosion product 'solubility'. In addition to the misuse of this term, other complications are discussed. These include the need to take account of the consequences of Gibbs' phase rule and the fact that, for mixed spinels, neither the concept of a thermodynamic solubility nor of a solubility product is valid. There is no reason to believe that measured apparent solubilities of nickel ferrites or spinel mixtures containing cobalt can give any direct guidance on the direction of transport of Ni or Co in PWR primary circuits. This is more likely to be determined by the distribution of stable and unstable ferrites and chromites than by any temperature coefficient of apparent solubility. Most of the transport of Ni and Co into and out of the core probably occurs as a consequence of either chemical or mechanical transients. Most important is likely to be the oxidative destruction and subsequent re-precipitation of chromites which occurs as a consequence of the oxygenated conditions employed during plant shutdown. (author)

  4. Decreasing Net Primary Productivity in Response to Urbanization in Liaoning Province, China

    Directory of Open Access Journals (Sweden)

    Tan Chen

    2017-01-01

    Full Text Available Regional ecosystems have been greatly affected by the rapid expansion of urban areas. In order to explore the impact of land use change on net primary productivity (NPP in rapidly developing cities during the current urbanization process, we quantified land use change in Liaoning province between 2000 and 2010 using net primary productivity as an indicator of ecosystem productivity and health. The Carnegie–Ames–Stanford Approach model was used to estimate NPP by region and land use. We used a unit circle-based evaluation model to quantify local urbanization effects on NPP around eight representative cities. The dominant land use types were farmland, woodland and urban, with urban rapidly replacing farmland. Mean annual NPP and total NPP decreased faster from 2005 to 2010 than from 2000 to 2005, reflecting increasing urbanization rates. The eastern, primarily woodland part of Liaoning province had the greatest reduction in NPP, while the western part, which was primarily farmland and grassland, had the lowest reduction.

  5. Natural forcings on a transformed territory overshoot thresholds of primary productivity in the Guadalquivir estuary

    Science.gov (United States)

    Ruiz, J.; Macías, D.; Navarro, G.

    2017-09-01

    A three year-long quasi continuum sampling dataset on the Guadalquivir estuary water quality was used to assess the role of light availability on its biological production. We found that inorganic nutrients within the estuary are very high (with mean values for inorganic nitrogen and phosphorous of 285 and 2.4 μM respectively) while phytoplankton biomass remains low most of the time (with a mean value of 2.6 mg/m3). A strong relationship between phytoplankton biomass and water turbidity was found indicating that, indeed, light availability is the major constraint of primary production in this system. Most of the time this limitation of primary production is not associated to enhanced turbidity connected to fresh water inputs. Instead, our data indicate that, independently of freshwater inputs, the photosynthesis is restricted by tidal forcings enhancing turbidity in an estuary that has been highly modified. Our results match with classical theories on the functioning of well-mixed, estuarine ecosystems as well as with recent modeling exercises. We also discuss the potential impacts of this particular characteristic of some estuarine systems for their management and regulatory control.

  6. Role of the Digestive Gland in Ink Production in Four Species of Sea Hares: An Ultrastructural Comparison

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Prince

    2013-01-01

    Full Text Available The ultrastructure of the digestive gland of several sea hare species that produce different colored ink (Aplysia californica produces purple ink, A. juliana white ink, A. parvula both white and purple ink, while Dolabrifera dolabrifera produces no ink at all was compared to determine the digestive gland’s role in the diet-derived ink production process. Rhodoplast digestive cells and their digestive vacuoles, the site of digestion of red algal chloroplast (i.e., rhodoplast in A. californica, were present and had a similar ultrastructure in all four species. Rhodoplast digestive cell vacuoles either contained a whole rhodoplast or fragments of one or were empty. These results suggest that the inability to produce colored ink in some sea hare species is not due to either an absence of appropriate digestive machinery, that is, rhodoplast digestive cells, or an apparent failure of rhodoplast digestive cells to function. These results also propose that the digestive gland structure described herein occurred early in sea hare evolution, at least in the common ancestor to the genera Aplysia and Dolabrifera. Our data, however, do not support the hypothesis that the loss of purple inking is a synapomorphy of the white-ink-producing subgenus Aplysia.

  7. Estimating crop net primary production using inventory data and MODIS-derived parameters

    Energy Technology Data Exchange (ETDEWEB)

    Bandaru, Varaprasad; West, Tristram O.; Ricciuto, Daniel M.; Izaurralde, Roberto C.

    2013-06-03

    National estimates of spatially-resolved cropland net primary production (NPP) are needed for diagnostic and prognostic modeling of carbon sources, sinks, and net carbon flux. Cropland NPP estimates that correspond with existing cropland cover maps are needed to drive biogeochemical models at the local scale and over national and continental extents. Existing satellite-based NPP products tend to underestimate NPP on croplands. A new Agricultural Inventory-based Light Use Efficiency (AgI-LUE) framework was developed to estimate individual crop biophysical parameters for use in estimating crop-specific NPP. The method is documented here and evaluated for corn and soybean crops in Iowa and Illinois in years 2006 and 2007. The method includes a crop-specific enhanced vegetation index (EVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS), shortwave radiation data estimated using Mountain Climate Simulator (MTCLIM) algorithm and crop-specific LUE per county. The combined aforementioned variables were used to generate spatially-resolved, crop-specific NPP that correspond to the Cropland Data Layer (CDL) land cover product. The modeling framework represented well the gradient of NPP across Iowa and Illinois, and also well represented the difference in NPP between years 2006 and 2007. Average corn and soybean NPP from AgI-LUE was 980 g C m-2 yr-1 and 420 g C m-2 yr-1, respectively. This was 2.4 and 1.1 times higher, respectively, for corn and soybean compared to the MOD17A3 NPP product. Estimated gross primary productivity (GPP) derived from AgI-LUE were in close agreement with eddy flux tower estimates. The combination of new inputs and improved datasets enabled the development of spatially explicit and reliable NPP estimates for individual crops over large regional extents.

  8. Modeling and Monitoring Terrestrial Primary Production in a Changing Global Environment: Toward a Multiscale Synthesis of Observation and Simulation

    Directory of Open Access Journals (Sweden)

    Shufen Pan

    2014-01-01

    Full Text Available There is a critical need to monitor and predict terrestrial primary production, the key indicator of ecosystem functioning, in a changing global environment. Here we provide a brief review of three major approaches to monitoring and predicting terrestrial primary production: (1 ground-based field measurements, (2 satellite-based observations, and (3 process-based ecosystem modelling. Much uncertainty exists in the multi-approach estimations of terrestrial gross primary production (GPP and net primary production (NPP. To improve the capacity of model simulation and prediction, it is essential to evaluate ecosystem models against ground and satellite-based measurements and observations. As a case, we have shown the performance of the dynamic land ecosystem model (DLEM at various scales from site to region to global. We also discuss how terrestrial primary production might respond to climate change and increasing atmospheric CO2 and uncertainties associated with model and data. Further progress in monitoring and predicting terrestrial primary production requires a multiscale synthesis of observations and model simulations. In the Anthropocene era in which human activity has indeed changed the Earth’s biosphere, therefore, it is essential to incorporate the socioeconomic component into terrestrial ecosystem models for accurately estimating and predicting terrestrial primary production in a changing global environment.

  9. Neural computation of visual imaging based on Kronecker product in the primary visual cortex

    Directory of Open Access Journals (Sweden)

    Guozheng Yao

    2010-03-01

    Full Text Available Abstract Background What kind of neural computation is actually performed by the primary visual cortex and how is this represented mathematically at the system level? It is an important problem in the visual information processing, but has not been well answered. In this paper, according to our understanding of retinal organization and parallel multi-channel topographical mapping between retina and primary visual cortex V1, we divide an image into orthogonal and orderly array of image primitives (or patches, in which each patch will evoke activities of simple cells in V1. From viewpoint of information processing, this activated process, essentially, involves optimal detection and optimal matching of receptive fields of simple cells with features contained in image patches. For the reconstruction of the visual image in the visual cortex V1 based on the principle of minimum mean squares error, it is natural to use the inner product expression in neural computation, which then is transformed into matrix form. Results The inner product is carried out by using Kronecker product between patches and function architecture (or functional column in localized and oriented neural computing. Compared with Fourier Transform, the mathematical description of Kronecker product is simple and intuitive, so is the algorithm more suitable for neural computation of visual cortex V1. Results of computer simulation based on two-dimensional Gabor pyramid wavelets show that the theoretical analysis and the proposed model are reasonable. Conclusions Our results are: 1. The neural computation of the retinal image in cortex V1 can be expressed to Kronecker product operation and its matrix form, this algorithm is implemented by the inner operation between retinal image primitives and primary visual cortex's column. It has simple, efficient and robust features, which is, therefore, such a neural algorithm, which can be completed by biological vision. 2. It is more suitable

  10. Fire intensity impacts on post-fire temperate coniferous forest net primary productivity

    Science.gov (United States)

    Sparks, Aaron M.; Kolden, Crystal A.; Smith, Alistair M. S.; Boschetti, Luigi; Johnson, Daniel M.; Cochrane, Mark A.

    2018-02-01

    Fire is a dynamic ecological process in forests and impacts the carbon (C) cycle through direct combustion emissions, tree mortality, and by impairing the ability of surviving trees to sequester carbon. While studies on young trees have demonstrated that fire intensity is a determinant of post-fire net primary productivity, wildland fires on landscape to regional scales have largely been assumed to either cause tree mortality, or conversely, cause no physiological impact, ignoring the impacted but surviving trees. Our objective was to understand how fire intensity affects post-fire net primary productivity in conifer-dominated forested ecosystems on the spatial scale of large wildland fires. We examined the relationships between fire radiative power (FRP), its temporal integral (fire radiative energy - FRE), and net primary productivity (NPP) using 16 years of data from the MOderate Resolution Imaging Spectrometer (MODIS) for 15 large fires in western United States coniferous forests. The greatest NPP post-fire loss occurred 1 year post-fire and ranged from -67 to -312 g C m-2 yr-1 (-13 to -54 %) across all fires. Forests dominated by fire-resistant species (species that typically survive low-intensity fires) experienced the lowest relative NPP reductions compared to forests with less resistant species. Post-fire NPP in forests that were dominated by fire-susceptible species were not as sensitive to FRP or FRE, indicating that NPP in these forests may be reduced to similar levels regardless of fire intensity. Conversely, post-fire NPP in forests dominated by fire-resistant and mixed species decreased with increasing FRP or FRE. In some cases, this dose-response relationship persisted for more than a decade post-fire, highlighting a legacy effect of fire intensity on post-fire C dynamics in these forests.

  11. Cellular Microenvironment Dictates Androgen Production by Murine Fetal Leydig Cells in Primary Culture1

    Science.gov (United States)

    Carney, Colleen M.; Muszynski, Jessica L.; Strotman, Lindsay N.; Lewis, Samantha R.; O'Connell, Rachel L.; Beebe, David J.; Theberge, Ashleigh B.; Jorgensen, Joan S.

    2014-01-01

    ABSTRACT Despite the fact that fetal Leydig cells are recognized as the primary source of androgens in male embryos, the mechanisms by which steroidogenesis occurs within the developing testis remain unclear. A genetic approach was used to visualize and isolate fetal Leydig cells from remaining cells within developing mouse testes. Cyp11a1-Cre mice were bred to mT/mG dual reporter mice to target membrane-tagged enhanced green fluorescent protein (GFP) within steroidogenic cells, whereas other cells expressed membrane-tagged tandem-dimer tomato red. Fetal Leydig cell identity was validated using double-labeled immunohistochemistry against GFP and the steroidogenic enzyme 3beta-HSD, and cells were successfully isolated as indicated by qPCR results from sorted cell populations. Because fetal Leydig cells must collaborate with neighboring cells to synthesize testosterone, we hypothesized that the fetal Leydig cell microenvironment defined their capacity for androgen production. Microfluidic culture devices were used to measure androstenedione and testosterone production of fetal Leydig cells that were cultured in cell-cell contact within a mixed population, were isolated but remained in medium contact via compartmentalized co-culture with other testicular cells, or were isolated and cultured alone. Results showed that fetal Leydig cells maintained their identity and steroidogenic activity for 3–5 days in primary culture. Microenvironment dictated proficiency of testosterone production. As expected, fetal Leydig cells produced androstenedione but not testosterone when cultured in isolation. More testosterone accumulated in medium from mixed cultures than from compartmentalized co-cultures initially; however, co-cultures maintained testosterone synthesis for a longer time. These data suggest that a combination of cell-cell contact and soluble factors constitute the ideal microenvironment for fetal Leydig cell activity in primary culture. PMID:25143354

  12. Distribution and production of plankton communities in the subtropical convergence zone of the Sargasso Sea. I. Phytoplankton and bacterioplankton

    DEFF Research Database (Denmark)

    Riemann, Lasse; Nielsen, Torkel Gissel; Kragh, Theis

    2011-01-01

    Elevated levels of biomass and productivity are often associated with ocean frontal systems. The Subtropical Convergence Zone (STCZ) in the southern Sargasso Sea shows pronounced and stable thermal fronts, but little is known about the ecological consequences of these hydrographic features....... With the aim of improving the understanding of physical and lower trophic level processes in the area, we carried out field studies of physical, chemical and biological characteristics along 3 transects crossing thermal fronts associated with the STCZ in March to April 2007. Thermal and chemical stratification...

  13. Fine-Root Production in an Amazon Rain Forest: Deep Roots are an Important Component of Net Primary Productivity

    Science.gov (United States)

    Norby, R.; Cordeiro, A. L.; Oblitas, E.; Valverde-Barrantes, O.; Quesada, C. A.

    2017-12-01

    Fine-root production is a significant component of net primary production (NPP), but it is the most difficult of the major components to measure. Data on fine-root production are especially sparse from tropical forests, and therefore the estimates of tropical forest NPP may not be accurate. Many estimates of fine-root production are based on observations in the top 15 or 30 cm of soil, with the implicit assumption that this approach will capture most of the root distribution. We measured fine-root production in a 30-m tall, old-growth, terra firme rain forest near Manaus, Brazil, which is the site for a free-air CO2 enrichment (FACE) experiment. Ten minirhizotrons were installed at a 45 degree angle to a depth of 1.1 meters; the tubes were installed 2 years before any measurements were made to allow the root systems to recover from disturbance. Images were collected biweekly, and measurements of root length per area of minirhizotron window were scaled up to grams of root per unit land area. Scaling up minirhizotron measurments is problematic, but our estimate of fine-root standing crop in the top 15 cm of soil (281 ± 37 g dry matter m-2) compares well with a direct measurement of fine roots in two nearby 15-cm soil cores (290 ± 37 g m-2). Although the largest fraction of the fine-root standing crop was in the upper soil horizons, 44% of the fine-root mass was deeper than 30 cm, and 17% was deeper than 60 cm. Annual fine-root production was 934 ± 234 g dry matter m-2 (453 ± 113 g C m-2), which was 35% of estimated NPP of the forest stand (1281 g C m-2). A previous estimate of NPP of the forest at this site was smaller (1010 g m-2), but that estimate relied on fine-root production measured elsewhere and only in the top 10 or 30 cm of soil; fine roots accounted for 21% of NPP in that analysis. Extending root observations deeper into the soil will improve estimates of the contribution of fine-root production to NPP, which will in turn improve estimates of ecosystem

  14. Primary structure of the human fgr proto-oncogene product p55/sup c-fgr/

    Energy Technology Data Exchange (ETDEWEB)

    Katamine, S.; Notario, V.; Rao, C.D.; Miki, T.; Cheah, M.S.C.; Tronick, S.R.; Robbins, K.C.

    1988-01-01

    Normal human c-fgr cDNA clones were constructed by using normal peripheral blood mononuclear cell mRNA as a template. Nucleotide sequence analysis of two such clones revealed a 1,587-base-pair-long open reading frame which predicted the primary amino acid sequence of the c-fgr translational product. Homology of this protein with the v-fgr translational product stretched from codons 128 to 516, where 32 differences among 388 codons were observed. Sequence similarity with human c-src, c-yes, and fyn translations products began at amino acid position 76 of the predicted c-fgr protein and extended nearly to its C-terminus. In contrast, the stretch of 75 amino acids at the N-terminus demonstrated a greatly reduced degree of relatedness to these same proteins. To verify the deduced amino acid sequence, antibodies were prepared against peptides representing amino- and carboxy-terminal regions of the predicted c-fgr translational product. Both antibodies specifically recognized a 55-kilodalton protein expressed in COS-1 cells transfected with a c-fgr cDNA expression plasmid. Moreover, the same protein was immunoprecipitated from an Epstein-Barr virus-infected Burkitt's lymphoma cell line which expressed c-fgr mRNA but not in its uninfected fgr mRNA-negative counterpart. These findings identified the 55-kilodalton protein as the product of the human fgr proto-oncogene.

  15. Towards predicting basin-wide invertebrate organic biomass and production in marine sediments from a coastal sea.

    Directory of Open Access Journals (Sweden)

    Brenda J Burd

    Full Text Available Detailed knowledge of environmental conditions is required to understand faunal production in coastal seas with topographic and hydrographic complexity. We test the hypothesis that organic biomass and production of subtidal sediment invertebrates throughout the Strait of Georgia, west coast of Canada, can be predicted by depth, substrate type and organic flux modified to reflect lability and age of material. A basin-wide database of biological, geochemical and flux data was analysed using an empirical production/biomass (P/B model to test this hypothesis. This analysis is unique in the spatial extent and detail of P/B and concurrent environmental measurements over a temperate coastal region. Modified organic flux was the most important predictor of organic biomass and production. Depth and substrate type were secondary modifiers. Between 69-74% of variability in biomass and production could be explained by the combined environmental factors. Organisms <1 mm were important contributors to biomass and production primarily in shallow, sandy sediments, where high P/B values were found despite low organic flux. Low biomass, production, and P/B values were found in the deep, northern basin and mainland fjords, which had silty sediments, low organic flux, low biomass of organisms <1 mm, and dominance by large, slow-growing macrofauna. In the highest organic flux and biomass areas near the Fraser River discharge, production did not increase beyond moderate flux levels. Although highly productive, this area had low P/B. Clearly, food input is insufficient to explain the complex patterns in faunal production revealed here. Additional environmental factors (depth, substrate type and unmeasured factors are important modifiers of these patterns. Potential reasons for the above patterns are explored, along with a discussion of unmeasured factors possibly responsible for unexplained (30% variance in biomass and production. We now have the tools for basin

  16. Preliminary study of radionuclide corrosion products in primary cooling water at RSG-GAS

    International Nuclear Information System (INIS)

    Lestari, D.E.; Pudjojanto, M.S.; Subiharto; Budi, S.

    1998-01-01

    Analysis of radionuclides emitting gamma rays at the primary cooling water at RSG-GAS has been carried out. The water coolant samples was performed using a low level background gamma spectrometer unit, including of high resolution of gamma detector HP-Ge Tennelec and Multichannel Analyzer (MCA) ADCAM 100 ORTEC. The result indicated Na-24 and Mn-56 radionuclides that may be as corrosion product and should studied deeply in the future. The expected activity concentration radionuclide for Mn-56 is lower than those written in the Safety Analysis Report (SAR), while for Na-24 is in agreement

  17. Global land-surface primary productivity based upon Nimbus-7 37 GHz data

    Science.gov (United States)

    Choudhury, B. J.

    1988-01-01

    Accumulation and renewal of organic matter as quantified through net primary productivity (NPP) is considered a very major function of the biosphere, and its estimation is crucial in understanding the carbon cycle. A physically-based model relating NPP to the difference of vertically and horizontally polarized brightness temperatures (Delta T) observed at 37 GHz frequency of the scanning multichannel microwave radiometer on board the Nimbus-7 satellite is used for fitting areally averaged values of NPP and Delta T for five biomes. The land-surface NPP within 80 deg N to 55 deg S is then calculated using the Delta T data and compared with other estimates.

  18. Study of the formation and transport of corrosion products in PWR primary circuit simulators

    International Nuclear Information System (INIS)

    Noe, M.; Frejaville, G.; Camp, J.J.

    1983-01-01

    The formation, migration and deposition of corrosion products in PWR primary circuits are studied in out-of-reactor loops. The aim of these studies is to limit the build-up of the radiation fields impinging on out-of-flux walls and to reduce the danger of rapid corrosion of fuel cans, taking into account the tougher conditions imposed on current trends in the operation of such industrial plants. Four simulator loops and their respective possibilities and research methods are described. (author)

  19. Worldwide estimates and bibliography of net primary productivity derived from pre-1982 publications

    Energy Technology Data Exchange (ETDEWEB)

    Esser, G. [Justus-Liebig-Univ., Giessen (Germany). Inst. for Plant Ecology; Lieth, H.F.H. [Univ. of Osnabrueck (Germany). Systems Research Group; Scurlock, J.M.O.; Olson, R.J. [Oak Ridge National Lab., TN (United States)

    1997-10-01

    An extensive compilation of more than 700 field estimates of net primary productivity of natural and agricultural ecosystems worldwide was synthesized in Germany in the 1970s and early 1980s. Although the Osnabrueck data set has not been updated since the 1980s, it represents a wealth of information for use in model development and validation. This report documents the development of this data set, its contents, and its recent availability on the Internet from the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics. Caution is advised in using these data, which necessarily include assumptions and conversions that may not be universally applicable to all sites.

  20. Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species

    Directory of Open Access Journals (Sweden)

    Catherine J. Collier

    2017-08-01

    Full Text Available Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant occurs, for three seagrass species (Cymodocea serrulata, Halodule uninervis, and Zostera muelleri. To obtain whole plant net production, photosynthesis, and respiration rates of leaves and the root/rhizome complex were measured using oxygen-sensitive optodes in closed incubation chambers at temperatures ranging from 15 to 43°C. The temperature-dependence of photosynthesis and respiration was fitted to empirical models to obtain maximum metabolic rates and thermal optima. The thermal optimum (Topt for gross photosynthesis of Z. muelleri, which is more commonly distributed in sub-tropical to temperate regions, was 31°C. The Topt for photosynthesis of the tropical species, H. uninervis and C. serrulata, was considerably higher (35°C on average. This suggests that seagrass species are adapted to water temperature within their distributional range; however, when comparing among latitudes and seasons, thermal optima within a species showed limited acclimation to ambient water temperature (Topt varied by 1°C in C. serrulata and 2°C in H. uninervis, and the variation did not follow changes in ambient water temperature. The Topt for gross photosynthesis were higher than Topt calculated from plant net productivity, which includes above- and below-ground respiration for Z. muelleri (24°C and H. uninervis (33°C, but remained unchanged at 35°C in C. serrulata. Both estimated plant net productivity and Topt are sensitive to the proportion of below-ground biomass, highlighting the need for consideration of below- to above-ground biomass ratios when applying thermal optima to other meadows. The

  1. Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species.

    Science.gov (United States)

    Collier, Catherine J; Ow, Yan X; Langlois, Lucas; Uthicke, Sven; Johansson, Charlotte L; O'Brien, Katherine R; Hrebien, Victoria; Adams, Matthew P

    2017-01-01

    Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km) in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant) occurs, for three seagrass species ( Cymodocea serrulata, Halodule uninervis , and Zostera muelleri ). To obtain whole plant net production, photosynthesis, and respiration rates of leaves and the root/rhizome complex were measured using oxygen-sensitive optodes in closed incubation chambers at temperatures ranging from 15 to 43°C. The temperature-dependence of photosynthesis and respiration was fitted to empirical models to obtain maximum metabolic rates and thermal optima. The thermal optimum ( T opt ) for gross photosynthesis of Z. muelleri , which is more commonly distributed in sub-tropical to temperate regions, was 31°C. The T opt for photosynthesis of the tropical species, H. uninervis and C. serrulata , was considerably higher (35°C on average). This suggests that seagrass species are adapted to water temperature within their distributional range; however, when comparing among latitudes and seasons, thermal optima within a species showed limited acclimation to ambient water temperature ( T opt varied by 1°C in C. serrulata and 2°C in H. uninervis , and the variation did not follow changes in ambient water temperature). The T opt for gross photosynthesis were higher than T opt calculated from plant net productivity, which includes above- and below-ground respiration for Z. muelleri (24°C) and H. uninervis ( 33°C), but remained unchanged at 35°C in C. serrulata . Both estimated plant net productivity and T opt are sensitive to the proportion of below-ground biomass, highlighting the need for consideration of below- to above-ground biomass ratios when applying thermal optima to other meadows. The

  2. In silico exploration of Red Sea Bacillus genomes for natural product biosynthetic gene clusters

    KAUST Repository

    Othoum, Ghofran K

    2018-05-22

    BackgroundThe increasing spectrum of multidrug-resistant bacteria is a major global public health concern, necessitating discovery of novel antimicrobial agents. Here, members of the genus Bacillus are investigated as a potentially attractive source of novel antibiotics due to their broad spectrum of antimicrobial activities. We specifically focus on a computational analysis of the distinctive biosynthetic potential of Bacillus paralicheniformis strains isolated from the Red Sea, an ecosystem exposed to adverse, highly saline and hot conditions.ResultsWe report the complete circular and annotated genomes of two Red Sea strains, B. paralicheniformis Bac48 isolated from mangrove mud and B. paralicheniformis Bac84 isolated from microbial mat collected from Rabigh Harbor Lagoon in Saudi Arabia. Comparing the genomes of B. paralicheniformis Bac48 and B. paralicheniformis Bac84 with nine publicly available complete genomes of B. licheniformis and three genomes of B. paralicheniformis, revealed that all of the B. paralicheniformis strains in this study are more enriched in nonribosomal peptides (NRPs). We further report the first computationally identified trans-acyltransferase (trans-AT) nonribosomal peptide synthetase/polyketide synthase (PKS/ NRPS) cluster in strains of this species.ConclusionsB. paralicheniformis species have more genes associated with biosynthesis of antimicrobial bioactive compounds than other previously characterized species of B. licheniformis, which suggests that these species are better potential sources for novel antibiotics. Moreover, the genome of the Red Sea strain B. paralicheniformis Bac48 is more enriched in modular PKS genes compared to B. licheniformis strains and other B. paralicheniformis strains. This may be linked to adaptations that strains surviving in the Red Sea underwent to survive in the relatively hot and saline ecosystems.

  3. Diving behaviour and haemoglobin function: the primary structure of the alpha- and beta-chains of the sea turtle (Caretta caretta) and its functional implications.

    Science.gov (United States)

    Petruzzelli, R; Aureli, G; Lania, A; Galtieri, A; Desideri, A; Giardina, B

    1996-06-15

    The amino acid sequence of the alpha- and beta-chains of haemoglobin (Hb) from the loggerhead sea turtle (Caretta caretta) has been determined. Comparison with that of human Hb shows differences in several residues involved in both alpha 1 beta 1 and alpha 1 beta 2 packing contacts. On the whole, in spite of the mutations, the essential characteristics of both interfaces seem to be maintained. The functional properties of the sea turtle Hb have been investigated at different temperatures and as a function of proton, chloride and organic phosphate concentrations. In addition to overall similarities shared with most of the vertebrate Hbs previously described, this molecule shows significant differences which could be related to the life behaviour of the turtle. In fact, while the shape of the Bohr-effect curve is well adapted for gas exchange during prolonged dives, the very small enthalpy change for O2 binding ensures that O2 delivery becomes essentially insensitive to the temperature changes of the environment. Moreover, and similarly to the case of emperor penguin Hb, the small alkaline Bohr effect appears to be only choride-linked, since the pH dependence of the O2 affinity is abolished in the absence of this ion. These functional characteristics are discussed on the basis of the primary structure of alpha- and beta-chains.

  4. Observation and simulation of net primary productivity in Qilian Mountain, western China.

    Science.gov (United States)

    Zhou, Y; Zhu, Q; Chen, J M; Wang, Y Q; Liu, J; Sun, R; Tang, S

    2007-11-01

    We modeled net primary productivity (NPP) at high spatial resolution using an advanced spaceborne thermal emission and reflection radiometer (ASTER) image of a Qilian Mountain study area using the boreal ecosystem productivity simulator (BEPS). Two key driving variables of the model, leaf area index (LAI) and land cover type, were derived from ASTER and moderate resolution imaging spectroradiometer (MODIS) data. Other spatially explicit inputs included daily meteorological data (radiation, precipitation, temperature, humidity), available soil water holding capacity (AWC), and forest biomass. NPP was estimated for coniferous forests and other land cover types in the study area. The result showed that NPP of coniferous forests in the study area was about 4.4 tCha(-1)y(-1). The correlation coefficient between the modeled NPP and ground measurements was 0.84, with a mean relative error of about 13.9%.

  5. The whale pump: marine mammals enhance primary productivity in a coastal basin.

    Directory of Open Access Journals (Sweden)

    Joe Roman

    Full Text Available It is well known that microbes, zooplankton, and fish are important sources of recycled nitrogen in coastal waters, yet marine mammals have largely been ignored or dismissed in this cycle. Using field measurements and population data, we find that marine mammals can enhance primary productivity in their feeding areas by concentrating nitrogen near the surface through the release of flocculent fecal plumes. Whales and seals may be responsible for replenishing 2.3×10(4 metric tons of N per year in the Gulf of Maine's euphotic zone, more than the input of all rivers combined. This upward "whale pump" played a much larger role before commercial harvest, when marine mammal recycling of nitrogen was likely more than three times atmospheric N input. Even with reduced populations, marine mammals provide an important ecosystem service by sustaining productivity in regions where they occur in high densities.

  6. Seasonal rates of benthic primary production in a Greenland fjord measured by aquatic eddy correlation

    DEFF Research Database (Denmark)

    M. Attard, Karl; Glud, Ronnie; McGinnis, Daniel F.

    2014-01-01

    -quality multiple-day EC data sets document the presence of a year-round productive benthic phototrophic community. The shallow-water sites were on average autotrophic during the spring and summer months, up to 43.6 mmol O2 m22 d21, and heterotrophic or close to metabolic balance during the autumn and winter....... Substantial benthic gross primary production (GPP) was measured year-round. The highest GPP rates were measured during the spring, up to 5.7 mmol O2 m22 h21 (136.8 mmol O2 m22 d21), and even at low light levels (, 80 mmol quanta m22 s21) during late autumn and winter we measured rates of up to 1.8 mmol O2 m22...

  7. Drought-induced reduction in global terrestrial net primary production from 2000 through 2009.

    Science.gov (United States)

    Zhao, Maosheng; Running, Steven W

    2010-08-20

    Terrestrial net primary production (NPP) quantifies the amount of atmospheric carbon fixed by plants and accumulated as biomass. Previous studies have shown that climate constraints were relaxing with increasing temperature and solar radiation, allowing an upward trend in NPP from 1982 through 1999. The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP, and a drying trend in the Southern Hemisphere has decreased NPP in that area, counteracting the increased NPP over the Northern Hemisphere. A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production.

  8. Primary production of edaphic algal communities in a Mississippi salt marsh

    International Nuclear Information System (INIS)

    Sullivan, M.J.; Moncreiff, C.A.

    1988-01-01

    Primary production rates of edaphic algae associated with the sediments beneath four monospecific canopies of vascular plants were determined over an annual cycle in a Mississippi salt marsh. The edaphic algal flora was dominated by small, motile pennate diatoms. Algal production (as measured by 14 C uptake) was generally highest in spring-early summer and lowest in fall. Hourly rates ranged from a low of 1.4 mg C/m 2 in Juncus roemerianus Scheele to a high of 163 mg C/m 2 beneath the Scirpus olneyi Gray canopy. Stepwise multiple regressions identified a soil moisture index and chlorophyll a as the best environmental predictors of hourly production; light energy reaching the marsh surface and sediment and air temperature proved of little value. Adding the relative abundances of 33 diatom taxa to the set of independent variables only slightly increased R 2 ; however, virtually all variables selected were diatom taxa. R 2 was only 0.38 for the Spartina alterniflora Loisel. habitat but ranged from 0.70 to 0.87 for the remaining three vascular plant zones. Annual rates of algal production (g C/m 2 ) were estimated as follows: Juncus (28), Spartina (57), Distichlis spicata (L.) Greene (88), and Scirpus (151). The ratio of annual edaphic algal production to vascular plant net aerial production (EAP/VPP) was 10-12% for the first three habitats and 61% for Scirpus. Chlorophyll a concentrations, annual algal production rates, and EAP/VPP values were comparable to those determined in Texas, Delaware, and Massachusetts salt marshes but lower than those reported for Georgia and particularly California marshes

  9. A novel free ammonia based pretreatment technology to enhance anaerobic methane production from primary sludge.

    Science.gov (United States)

    Wei, Wei; Zhou, Xu; Xie, Guo-Jun; Duan, Haoran; Wang, Qilin

    2017-10-01

    This study proposed a novel free ammonia (FA, i.e., NH 3 ) pretreatment technology to enhance anaerobic methane production from primary sludge for the first time. The solubilization of primary sludge was substantially enhanced following 24 h FA pretreatment (250-680 mg NH 3 -N/L), by which the release of soluble chemical oxygen demand (SCOD) (i.e., 0.4 mg SCOD/mg VS added; VS: volatile solids) was approximately 10 times as much as that without pretreatment (i.e., 0.03 mg SCOD/mg VS added). Then, biochemical methane potential (BMP) tests demonstrated that FA pretreatment of 250-680 mg NH 3 -N/L was capable of enhancing anaerobic methane production while the digestion time was more than 7 days. Model based analysis indicated that the improved anaerobic methane production was due to an increased biochemical methane potential (B 0 ) of 8-17% (i.e., from 331 to 357-387 L CH 4 /kg VS added), with the highest B 0 achieved at 420 mg NH 3 -N/L pretreatment. However, FA pretreatment of 250-680 mg NH 3 -N/L decreased hydrolysis rate (k) by 24-38% compared with control (i.e., from 0.29 d -1 to 0.18-0.22 d -1 ), which explained the lower methane production over the first 7 days' digestion period. Economic analysis and environmental evaluation demonstrated that FA pretreatment technology was environmentally friendly and economically favorable. Biotechnol. Bioeng. 2017;114: 2245-2252. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  10. Metrology requirements for the serial production of ELT primary mirror segments

    Science.gov (United States)

    Rees, Paul C. T.; Gray, Caroline

    2015-08-01

    The manufacture of the next generation of large astronomical telescopes, the extremely large telescopes (ELT), requires the rapid manufacture of greater than 500 1.44m hexagonal segments for the primary mirror of each telescope. Both leading projects, the Thirty Meter Telescope (TMT) and the European Extremely Large Telescope (E-ELT), have set highly demanding technical requirements for each fabricated segment. These technical requirements, when combined with the anticipated construction schedule for each telescope, suggest that more than one optical fabricator will be involved in the delivery of the primary mirror segments in order to meet the project schedule. For one supplier, the technical specification is challenging and requires highly consistent control of metrology in close coordination with the polishing technologies used in order to optimize production rates. For production using multiple suppliers, however the supply chain is structured, consistent control of metrology along the supply chain will be required. This requires a broader pattern of independent verification than is the case of a single supplier. This paper outlines the metrology requirements for a single supplier throughout all stages of the fabrication process. We identify and outline those areas where metrology accuracy and duration have a significant impact on production efficiency. We use the challenging ESO E-ELT technical specification as an example of our treatment, including actual process data. We further develop this model for the case of a supply chain consisting of multiple suppliers. Here, we emphasize the need to control metrology throughout the supply chain in order to optimize net production efficiency.

  11. Benthic primary producers are key to sustain the Wadden Sea food web: stable carbon isotope analysis at landscape scale

    NARCIS (Netherlands)

    Christianen, M.J.A.; Middelburg, J.J.; Holthuijsen, S.J.; Jouta, J.; Compton, T.J.; van der Heide, T.; Piersma, T.; Sinninghe Damsté, J.S.; van der Veer, H.W.; Schouten, S.; Olff, H.

    2017-01-01

    Coastal food webs can be supported by local benthic or pelagic primary produc-ers and by the import of organic matter. Distinguishing between these energy sources is essen-tial for our understanding of ecosystem functioning. However, the relative contribution ofthese components to the food web at

  12. Benthic primary producers are key to sustain the Wadden Sea food web : stable carbon isotope analysis at landscape scale

    NARCIS (Netherlands)

    Christianen, M.J.A.; Middelburg, Jack J.|info:eu-repo/dai/nl/079665373; Holthuijsen, S.J.; Jouta, J.; Compton, T.J.; van der Heide, T.; Piersma, T.; Sinninghe Damsté, Jaap S.|info:eu-repo/dai/nl/07401370X; van der Veer, H.W.; Schouten, Stefan|info:eu-repo/dai/nl/137124929; Olff, H.

    Coastal food webs can be supported by local benthic or pelagic primary producers and by the import of organic matter. Distinguishing between these energy sources is essential for our understanding of ecosystem functioning. However, the relative contribution of these components to the food web at the

  13. Benthic primary producers are key to sustain the Wadden Sea food web : Stable carbon isotope analysis at landscape scale

    NARCIS (Netherlands)

    Christianen, M J A; Middelburg, J J; Holthuijsen, S J; Jouta, J; Compton, T J; van der Heide, T; Piersma, T.; Sinninghe Damsté, J S; van der Veer, H W; Schouten, S; Olff, H

    Coastal food webs can be supported by local benthic or pelagic primary producers and by the import of organic matter. Distinguishing between these energy sources is essential for our understanding of ecosystem functioning. However, the relative contribution of these components to the food web at the

  14. Nutrient content in macrophyta collected from southern Baltic Sea beaches in relation to eutrophication and biogas production

    Energy Technology Data Exchange (ETDEWEB)

    Bucholc, K.; Szymczak-Żyła, M.; Lubecki, L. [Marine Pollution Laboratory, Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot (Poland); Zamojska, A. [University of Gdańsk, Department of Econometrics, ul. Armii Krajowej 101, 81-824 Sopot (Poland); Hapter, P. [Marine Pollution Laboratory, Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot (Poland); Tjernström, E. [Environmental Department, Trelleborg Municipality, Algatan 13, 231 83 Trelleborg (Sweden); Kowalewska, G. [Marine Pollution Laboratory, Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot (Poland)

    2014-03-01

    One of the signs of eutrophication is the excessive growth of opportunistic macroalgae, a worldwide phenomenon also observed in the Baltic Sea. Mats of macroalgae may drift long distances and accumulate at the seashore, considerably decreasing the recreational value of beaches. The matter accumulating at the shore is treated usually as waste. However, it could be used, for example, as a resource for biogas production. The aim of this work was to verify the hypothesis that collecting of macrophyta accumulating on the beach and potential usage of this material for biogas production will decrease nutrient reserves in the sea to counteract eutrophication and the increase in greenhouse effects. Samples of macrophyta were collected in 2011 and 2012 and analysed for their C, N, and P contents, and degree of degradation (% Chl-a in the sum of chloropigments-a); the results were analysed statistically. The nutrient content was studied in macrophyta accumulating on the beach (Sopot, Gulf of Gdańsk, Poland) and for comparison, macrophyta collected from their habitats in less nutrient polluted area (off the Skåre coast, Trelleborg, Sweden). The nutrient content (N, P) in macrophyta depends primarily on their morphology and only secondarily on environmental nutrient pollution. Collecting the macrophyta biomass accumulating on beaches will not significantly change the eutrophication of the Baltic as a whole; any improvements in this respect are likely to be on a local scale only. Collecting macrophyta removes more nitrogen than phosphorous, so this would decrease the N/P ratio in seawater. This macrophyta biomass is a substantial reserve of renewable energy, which could be utilized with the appropriate technology for biomass collection/preservation and biofuel production as an additive to other carbon-rich biomasses. And the biofuel production should be evaluated not only from the standpoint of economic efficiency but also from the environmental point of view. - Highlights:

  15. Monthly CO2 at A4HDYD station in a productive shallow marginal sea (Yellow Sea) with a seasonal thermocline: Controlling processes

    Science.gov (United States)

    Xu, Xuemei; Zang, Kunpeng; Zhao, Huade; Zheng, Nan; Huo, Cheng; Wang, Juying

    2016-07-01

    Based upon 21 field surveys conducted from March 2011 to November 2013, monthly variation of carbon dioxide partial pressure (pCO2) and other carbon system parameters were investigated for the first time (to our knowledge) at A4HDYD station (38°40‧N, 122°10‧E) located in the North Yellow Sea, a region with a seasonal thermocline. Surface pCO2 was undersaturated from March to May and nearly in equilibrium with the atmosphere from June to August. During September and November, pCO2 declined to a lower level than that from June to August, but reached the highest level in December. In contrast, pCO2 declined to atmospheric CO2 levels in February. Overall, the study area was a net CO2 sink at a rate of 0.85 ± 0.59 mol C m- 2 yr- 1. The underlying processes governing the variation of pCO2 were also examined. In general, temperature had an important influence on the monthly variation of pCO2, but its effect was counterbalanced by biological production in spring and vertical mixing in early winter. Our study indicated that dynamic mechanism studies based on high temporal resolution observations are urgently needed to understand the complexity of the carbon cycle and detect biogeochemical changes or ecosystem responses to climate change on continental margins.

  16. Spring-summer net community production, new production, particle export and related water column biogeochemical processes in the marginal sea ice zone of the Western Antarctic Peninsula 2012-2014.

    Science.gov (United States)

    Ducklow, Hugh W; Stukel, Michael R; Eveleth, Rachel; Doney, Scott C; Jickells, Tim; Schofield, Oscar; Baker, Alex R; Brindle, John; Chance, Rosie; Cassar, Nicolas

    2018-06-28

    New production (New P, the rate of net primary production (NPP) supported by exogenously supplied limiting nutrients) and net community production (NCP, gross primary production not consumed by community respiration) are closely related but mechanistically distinct processes. They set the carbon balance in the upper ocean and define an upper limit for export from the system. The relationships, relative magnitudes and variability of New P (from 15 NO 3 - uptake), O 2  : argon-based NCP and sinking particle export (based on the 238 U :  234 Th disequilibrium) are increasingly well documented but still not clearly understood. This is especially true in remote regions such as polar marginal ice zones. Here we present a 3-year dataset of simultaneous measurements made at approximately 50 stations along the Western Antarctic Peninsula (WAP) continental shelf in midsummer (January) 2012-2014. Net seasonal-scale changes in water column inventories (0-150 m) of nitrate and iodide were also estimated at the same stations. The average daily rates based on inventory changes exceeded the shorter-term rate measurements. A major uncertainty in the relative magnitude of the inventory estimates is specifying the start of the growing season following sea-ice retreat. New P and NCP(O 2 ) did not differ significantly. New P and NCP(O 2 ) were significantly greater than sinking particle export from thorium-234. We suggest this is a persistent and systematic imbalance and that other processes such as vertical mixing and advection of suspended particles are important export pathways.This article is part of the theme issue 'The marine system of the west Antarctic Peninsula: status and strategy for progress in a region of rapid change'. © 2018 The Author(s).

  17. Effect of production quotas on economic and environmental values of growth rate and feed efficiency in sea cage fish farming.

    Science.gov (United States)

    Besson, M; de Boer, I J M; Vandeputte, M; van Arendonk, J A M; Quillet, E; Komen, H; Aubin, J

    2017-01-01

    In sea cage fish farming, production quotas aim to constrain the impact of fish farming on the surrounding ecosystem. It is unknown how these quotas affect economic profitability and environmental impact of genetic improvement. We combined bioeconomic modelling with life cycle assessment (LCA) to calculate the economic (EV) and environmental (ENV) values of thermal growth coefficient (TGC) and feed conversion ratio (FCR) of sea bass reared in sea cages, given four types of quota commonly used in Europe: annual production (Qprod), annual feed distributed (Qannual_feed), standing stock (Qstock), and daily feed distributed (Qdaily_feed). ENV were calculated for LCA impact categories climate change, eutrophication and acidification. ENV were expressed per ton of fish produced per year (ENV(fish)) and per farm per year (ENV(farm)). Results show that irrespective of quota used, EV of FCR as well as ENV(fish) and ENV(farm) were always positive, meaning that improving FCR increased profit and decreased environmental impacts. However, the EV and the ENV(fish) of TGC were positive only when quota was Qstock or Qdaily_feed. Moreover, the ENV(farm) of TGC was negative in Qstock and Qdaily_feed quotas, meaning that improving TGC increased the environmental impact of the farm. We conclude that Qstock quota and Qdaily_feed quota are economically favorable to a genetic improvement of TGC, a major trait for farmers. However, improving TGC increases the environmental impact of the farm. Improving FCR represents a good opportunity to balance out this increase but more information on its genetic background is needed to develop breeding programs improving FCR.

  18. Effect of production quotas on economic and environmental values of growth rate and feed efficiency in sea cage fish farming.

    Directory of Open Access Journals (Sweden)

    M Besson

    Full Text Available In sea cage fish farming, production quotas aim to constrain the impact of fish farming on the surrounding ecosystem. It is unknown how these quotas affect economic profitability and environmental impact of genetic improvement. We combined bioeconomic modelling with life cycle assessment (LCA to calculate the economic (EV and environmental (ENV values of thermal growth coefficient (TGC and feed conversion ratio (FCR of sea bass reared in sea cages, given four types of quota commonly used in Europe: annual production (Qprod, annual feed distributed (Qannual_feed, standing stock (Qstock, and daily feed distributed (Qdaily_feed. ENV were calculated for LCA impact categories climate change, eutrophication and acidification. ENV were expressed per ton of fish produced per year (ENV(fish and per farm per year (ENV(farm. Results show that irrespective of quota used, EV of FCR as well as ENV(fish and ENV(farm were always positive, meaning that improving FCR increased profit and decreased environmental impacts. However, the EV and the ENV(fish of TGC were positive only when quota was Qstock or Qdaily_feed. Moreover, the ENV(farm of TGC was negative in Qstock and Qdaily_feed quotas, meaning that improving TGC increased the environmental impact of the farm. We conclude that Qstock quota and Qdaily_feed quota are economically favorable to a genetic improvement of TGC, a major trait for farmers. However, improving TGC increases the environmental impact of the farm. Improving FCR represents a good opportunity to balance out this increase but more information on its genetic background is needed to develop breeding programs improving FCR.

  19. Modeling of primary production of phytoplankton in the wetland Jaboque, Bogotá D.C.

    Directory of Open Access Journals (Sweden)

    Julio Eduardo Beltrán Vargas

    2016-02-01

    Full Text Available A dynamic simulation model is presented to explain the general behavior of the  primary production of phytoplankton in the wetland Jaboque - Bogota, Colombia, in three sections with differential physical and chemical characteristics. The model takes into account the physicochemical variables, the basin area, depth, annual rainfall, water temperature, pH and concentration of chlorophyll _a. The dynamic modeling is based on differential equations and the Euler integration method is used, the modeling was developed using Stella 9.1® computer program. The model allows quantifying the primary production of phytoplankton in wetland Jaboque from chlorophyll _a monthly average concentration for each section. The results of the Ppf modeling show that Ppf concentration variations  in each section of the wetland follow a reverse pattern to the bimodal behavior of precipitation. A high degree of correspondence between the values of chlorophyll_a Ppf field and modeled in the following manner r2 = 0.86 for the first section and r2 = 0.86 and r2 = 0.79 for the remaining sections was found. Error determination was 0,57 relative to the first section and 0,35; 0,46, indicating that the results are not overstated. The model shows in general terms the functional aspects of behavior Ppf and its relation to the process of eutrophication, and it allows recommendations for the management and restoration of wetlands.

  20. Spatial extrapolation of light use efficiency model parameters to predict gross primary production

    Directory of Open Access Journals (Sweden)

    Karsten Schulz

    2011-12-01

    Full Text Available To capture the spatial and temporal variability of the gross primary production as a key component of the global carbon cycle, the light use efficiency modeling approach in combination with remote sensing data has shown to be well suited. Typically, the model parameters, such as the maximum light use efficiency, are either set to a universal constant or to land class dependent values stored in look-up tables. In this study, we employ the machine learning technique support vector regression to explicitly relate the model parameters of a light use efficiency model calibrated at several FLUXNET sites to site-specific characteristics obtained by meteorological measurements, ecological estimations and remote sensing data. A feature selection algorithm extracts the relevant site characteristics in a cross-validation, and leads to an individual set of characteristic attributes for each parameter. With this set of attributes, the model parameters can be estimated at sites where a parameter calibration is not possible due to the absence of eddy covariance flux measurement data. This will finally allow a spatially continuous model application. The performance of the spatial extrapolation scheme is evaluated with a cross-validation approach, which shows the methodology to be well suited to recapture the variability of gross primary production across the study sites.