126 results on '"Dowell, Mark"'
Search Results
2. An Ocean-Colour Time Series for Use in Climate Studies: The Experience of the Ocean-Colour Climate Change Initiative (OC-CCI)
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Sathyendranath, Shubha, Brewin, Robert JW, Brockmann, Carsten, Brotas, Vanda, Calton, Ben, Chuprin, Andrei, Cipollini, Paolo, Couto, André B, Dingle, James, Doerffer, Roland, Donlon, Craig, Dowell, Mark, Farman, Alex, Grant, Mike, Groom, Steve, Horseman, Andrew, Jackson, Thomas, Krasemann, Hajo, Lavender, Samantha, Martinez-Vicente, Victor, Mazeran, Constant, Mélin, Frédéric, Moore, Timothy S, Müller, Dagmar, Regner, Peter, Roy, Shovonlal, Steele, Chris J, Steinmetz, François, Swinton, John, Taberner, Malcolm, Thompson, Adam, Valente, André, Zühlke, Marco, Brando, Vittorio E, Feng, Hui, Feldman, Gene, Franz, Bryan A, Frouin, Robert, Gould, Richard W, Hooker, Stanford B, Kahru, Mati, Kratzer, Susanne, Mitchell, B Greg, Muller-Karger, Frank E, Sosik, Heidi M, Voss, Kenneth J, Werdell, Jeremy, and Platt, Trevor
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Climate Action ,ocean colour ,water-leaving radiance ,remote-sensing reflectance ,phytoplankton ,chlorophyll-a ,inherent optical properties ,Climate Change Initiative ,optical water classes ,Essential Climate Variable ,uncertainty characterisation ,Analytical Chemistry ,Environmental Science and Management ,Ecology ,Distributed Computing ,Electrical and Electronic Engineering - Abstract
Ocean colour is recognised as an Essential Climate Variable (ECV) by the Global Climate Observing System (GCOS); and spectrally-resolved water-leaving radiances (or remote-sensing reflectances) in the visible domain, and chlorophyll-a concentration are identified as required ECV products. Time series of the products at the global scale and at high spatial resolution, derived from ocean-colour data, are key to studying the dynamics of phytoplankton at seasonal and inter-annual scales; their role in marine biogeochemistry; the global carbon cycle; the modulation of how phytoplankton distribute solar-induced heat in the upper layers of the ocean; and the response of the marine ecosystem to climate variability and change. However, generating a long time series of these products from ocean-colour data is not a trivial task: algorithms that are best suited for climate studies have to be selected from a number that are available for atmospheric correction of the satellite signal and for retrieval of chlorophyll-a concentration; since satellites have a finite life span, data from multiple sensors have to be merged to create a single time series, and any uncorrected inter-sensor biases could introduce artefacts in the series, e.g., different sensors monitor radiances at different wavebands such that producing a consistent time series of reflectances is not straightforward. Another requirement is that the products have to be validated against in situ observations. Furthermore, the uncertainties in the products have to be quantified, ideally on a pixel-by-pixel basis, to facilitate applications and interpretations that are consistent with the quality of the data. This paper outlines an approach that was adopted for generating an ocean-colour time series for climate studies, using data from the MERIS (MEdium spectral Resolution Imaging Spectrometer) sensor of the European Space Agency; the SeaWiFS (Sea-viewing Wide-Field-of-view Sensor) and MODIS-Aqua (Moderate-resolution Imaging Spectroradiometer-Aqua) sensors from the National Aeronautics and Space Administration (USA); and VIIRS (Visible and Infrared Imaging Radiometer Suite) from the National Oceanic and Atmospheric Administration (USA). The time series now covers the period from late 1997 to end of 2018. To ensure that the products meet, as well as possible, the requirements of the user community, marine-ecosystem modellers, and remote-sensing scientists were consulted at the outset on their immediate and longer-term requirements as well as on their expectations of ocean-colour data for use in climate research. Taking the user requirements into account, a series of objective criteria were established, against which available algorithms for processing ocean-colour data were evaluated and ranked. The algorithms that performed best with respect to the climate user requirements were selected to process data from the satellite sensors. Remote-sensing reflectance data from MODIS-Aqua, MERIS, and VIIRS were band-shifted to match the wavebands of SeaWiFS. Overlapping data were used to correct for mean biases between sensors at every pixel. The remote-sensing reflectance data derived from the sensors were merged, and the selected in-water algorithm was applied to the merged data to generate maps of chlorophyll concentration, inherent optical properties at SeaWiFS wavelengths, and the diffuse attenuation coefficient at 490 nm. The merged products were validated against in situ observations. The uncertainties established on the basis of comparisons with in situ data were combined with an optical classification of the remote-sensing reflectance data using a fuzzy-logic approach, and were used to generate uncertainties (root mean square difference and bias) for each product at each pixel.
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- 2019
3. CoCO2-MOSAIC 1.0: a global mosaic of regional, gridded, fossil, and biofuel CO2 emission inventories
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Universitat Politècnica de Catalunya. Departament d'Enginyeria de Projectes i de la Construcció, Barcelona Supercomputing Center, Urraca Valle, Rubén, Janssens Maenhout, Greet, Álamos, Nicolás, Berna Peña, Lucas, Crippa, Monica, Darras, Sabine, Dellaert, Stijn, Denier Van der Gon, Hugo, Dowell, Mark, Guevara Vilardell, Marc, Universitat Politècnica de Catalunya. Departament d'Enginyeria de Projectes i de la Construcció, Barcelona Supercomputing Center, Urraca Valle, Rubén, Janssens Maenhout, Greet, Álamos, Nicolás, Berna Peña, Lucas, Crippa, Monica, Darras, Sabine, Dellaert, Stijn, Denier Van der Gon, Hugo, Dowell, Mark, and Guevara Vilardell, Marc
- Abstract
Gridded bottom-up inventories of CO2 emissions are needed in global CO2 inversion schemes as priors to initialize transport models and as a complement to top-down estimates to identify the anthropogenic sources. Global inversions require gridded datasets almost in near-real time that are spatially and methodologically consistent at a global scale. This may result in a loss of more detailed information that can be assessed by using regional inventories because they are built with a greater level of detail including country-specific information and finer resolution data. With this aim, a global mosaic of regional, gridded CO2 emission inventories, hereafter referred to as CoCO2-MOSAIC 1.0, has been built in the framework of the CoCO2 project. CoCO2-MOSAIC 1.0 provides gridded (0.1∘ × 0.1∘) monthly emissions fluxes of CO2 fossil fuel (CO2ff, long cycle) and CO2 biofuel (CO2bf, short cycle) for the years 2015–2018 disaggregated in seven sectors. The regional inventories integrated are CAMS-REG-GHG 5.1 (Europe), DACCIWA 2.0 (Africa), GEAA-AEI 3.0 (Argentina), INEMA 1.0 (Chile), REAS 3.2.1 (East, Southeast, and South Asia), and VULCAN 3.0 (USA). EDGAR 6.0, CAMS-GLOB-SHIP 3.1 and CAMS-GLOB-TEMPO 3.1 are used for gap-filling. CoCO2-MOSAIC 1.0 can be recommended as a global baseline emission inventory for 2015 which is regionally accepted as a reference, and as such we use the mosaic to inter-compare the most widely used global emission inventories: CAMS-GLOB-ANT 5.3, EDGAR 6.0, ODIAC v2020b, and CEDS v2020_04_24. CoCO2-MOSAIC 1.0 has the highest CO2ff (36.7 Gt) and CO2bf (5.9 Gt) emissions globally, particularly in the USA and Africa. Regional emissions generally have a higher seasonality representing better the local monthly profiles and are generally distributed over a higher number of pixels, due to the more detailed information available. All super-emitting pixels from regional inventories contain a power station (CoCO2 database), whereas several super-emitters from glo, This research has been supported by the European Commission Prototype system for a Copernicus CO2 service (CoCO2), which received funding from the European Union's Horizon 2020 Research and Innovation Programme (grant no. 958927). Nicolás Huneeus was partially funded by the Science, Technology, Knowledge and Innovation Ministry of Chile through the FONDECYT program (grant no. 1231717) and by the AQ-WATCH project, which received funding from the European Union’s Horizon 2020 Research and Innovation Programme (grant no. 870301)., Peer Reviewed, Article signat per 24 autors/es: Ruben Urraca 1; Greet Janssens-Maenhout 1,12; Nicolás Álamos 2; Lucas Berna-Peña 3; Monica Crippa 4; Sabine Darras 5; Stijn Dellaert 6; Hugo Denier van der Gon 6; Mark Dowell 1; Nadine Gobron 1; Claire Granier 7,8; Giacomo Grassi 1; Marc Guevara 9; Diego Guizzardi 1; Kevin Gurney 10; Nicolás Huneeus 2; Sekou Keita 7; Jeroen Kuenen 6; Ana Lopez-Noreña 3; Enrique Puliafito 3; Geoffrey Roest 10; Simone Rossi 11; Antonin Soulie 7; and Antoon Visschedijk 6 / 1 European Commission, Joint Research Centre, Via Enrico Fermi 2749, 21027 Ispra, Italy; 2 Center for Climate and Resilience Research, Universidad de Chile, 8320000 Santiago, Chile; 3 Research Group for Atmospheric and Environmental Studies (GEAA), Mendoza Regional Faculty, Mendoza, M5500, Argentina; 4 Uni Systems Italy, Via Michelangelo Buonarroti 39, 20145 Milano, Italy; 5 Observatoire Midi-Pyrénées, 31400 Toulouse, France; 6 TNO, Department of Climate, Air and Sustainability, Princetonlaan 6, 3584 CB Utrecht, the Netherlands; 7 Laboratoire d’Aeìrologie, CNRS-Université de Toulouse, 31400 Toulouse, France; 8 NOAAChemical Sciences Laboratory, CIRES, University of Colorado Boulder, 80309 Boulder, CO, USA; 9 Barcelona Supercomputing Center, 08034 Barcelona, Spain; 10 School of Informatics, Computing, and Cyber Systems, Northern Arizona University, 86011 Flagstaff, AZ, USA; 11 Arcadia SIT, Via Pessano, 20151 Milano, Italy; 12 Ghent University, Faculty of Engineering and Architecture, Technology Park, 9052 Zwijnaarde, Ghent, Belgium, Postprint (published version)
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- 2024
4. CoCO2-MOSAIC 1.0: a global mosaic of regional, gridded, fossil, and biofuel CO2 emission inventories
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Urraca, Ruben, primary, Janssens-Maenhout, Greet, additional, Álamos, Nicolás, additional, Berna-Peña, Lucas, additional, Crippa, Monica, additional, Darras, Sabine, additional, Dellaert, Stijn, additional, Denier van der Gon, Hugo, additional, Dowell, Mark, additional, Gobron, Nadine, additional, Granier, Claire, additional, Grassi, Giacomo, additional, Guevara, Marc, additional, Guizzardi, Diego, additional, Gurney, Kevin, additional, Huneeus, Nicolás, additional, Keita, Sekou, additional, Kuenen, Jeroen, additional, Lopez-Noreña, Ana, additional, Puliafito, Enrique, additional, Roest, Geoffrey, additional, Rossi, Simone, additional, Soulie, Antonin, additional, and Visschedijk, Antoon, additional
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- 2024
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5. Systematic Earth Observations Supporting the Global Stocktake
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Ward, Stephen, Briggs, Stephen, Ochiai, Osamu, Seifert, Frank Martin, Dowell, Mark, and Crisp, David
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- 2021
6. Systematic Earth Observations Supporting the Global Stocktake
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Crisp, David, Dowell, Mark, Seifert, Frank Martin, Ochiai, Osamu, Briggs, Stephen, and Ward, Stephen
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- 2021
7. Top-Down Atmospheric Inventories of CO2 and CH4 to Support the Global Stocktakes
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Crisp, David and Dowell, Mark
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- 2021
8. Top-Down Atmospheric Inventories of CO2 and CH4 to Support the Global Stocktakes
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Dowell, Mark and Crisp, David
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- 2021
9. Top-down Atmospheric Inventories of CO2 and CH4 to Support the Global Stocktakes
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Tanimoto, Hiroshi, Stephens, Britton, Schuh, Andrew, Poulter, Benjamin, Palmer, Paul, O’Dell, Christopher, Oda, Tomohiro, Miller, John, Meijer, Yasjka, Maksyutov, Shamil, Lang, Ruediger, Dowell, Mark, Deniel, Carole, Chevallier, Frederic, Chatterjee, Abhishek, Bowman, Kevin, Basu, Souish, Baker, David, Byrne, Brendan, and Crisp, David
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- 2021
10. GHG Roadmap Update
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Crisp, David and Dowell, Mark
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- 2021
11. GHG Roadmap Update
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Dowell, Mark and Crisp, David
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- 2021
12. Challenges of modeling depth-integrated marine primary productivity over multiple decades: A case study at BATS and HOT
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Saba, Vincent S, Friedrichs, Marjorie A. M, Carr, Mary-Elena, Antoine, David, Armstrong, Robert A, Asanuma, Ichio, Aumont, Olivier, Bates, Nicholas R, Behrenfeld, Michael J, Bennington, Val, Bopp, Laurent, Bruggeman, Jorn, Buitenhuis, Erik T, Church, Matthew J, Ciotti, Aurea M, Doney, Scott C, Dowell, Mark, Dunne, John, Dutkiewicz, Stephanie, Gregg, Watson, Hoepffner, Nicolas, Hyde, Kimberly J. W, Ishizaka, Joji, Kameda, Takahiko, Karl, David M, Lima, Ivan, Lomas, Michael W, Marra, John, McKinley, Galen A, Melin, Frederic, Moore, J. Keith, Morel, Andre, O'Reilly, John, Salihoglu, Baris, Scardi, Michele, Smyth, Tim J, Tang, Shilin, Tjiputra, Jerry, Uitz, Julia, Vichi, Marcello, Waters, Kirk, Westberry, Toby K, and Yool, Andrew
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10.1029/2009GB003655 - Abstract
The performance of 36 models (22 ocean color models and 14 biogeochemical ocean circulation models (BOGCMs)) that estimate depth-integrated marine net primary productivity (NPP) was assessed by comparing their output to in situ 14C data at the Bermuda Atlantic Time series Study (BATS) and the Hawaii Ocean Time series (HOT) over nearly two decades. Specifically, skill was assessed based on the models' ability to estimate the observed mean, variability, and trends of NPP. At both sites, more than 90% of the models underestimated mean NPP, with the average bias of the BOGCMs being nearly twice that of the ocean color models. However, the difference in overall skill between the best BOGCM and the best ocean color model at each site was not significant. Between 1989 and 2007, in situ NPP at BATS and HOT increased by an average of nearly 2% per year and was positively correlated to the North Pacific Gyre Oscillation index. The majority of ocean color models produced in situ NPP trends that were closer to the observed trends when chlorophyll-a was derived from high-performance liquid chromatography (HPLC), rather than fluorometric or SeaWiFS data. However, this was a function of time such that average trend magnitude was more accurately estimated over longer time periods. Among BOGCMs, only two individual models successfully produced an increasing NPP trend (one model at each site). We caution against the use of models to assess multiannual changes in NPP over short time periods. Ocean color model estimates of NPP trends could improve if more high quality HPLC chlorophyll-a time series were available.
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- 2010
13. Supplementary material to "CoCO2-MOSAIC 1.0: a global mosaic of regional, gridded, fossil and biofuel CO2 emission inventories"
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Urraca, Ruben, primary, Janssens-Maenhout, Greet, additional, Álamos, Nicolás, additional, Berna-Peña, Lucas, additional, Crippa, Monica, additional, Darras, Sabine, additional, Dellaert, Sitjn, additional, Denier van der Gon, Hugo, additional, Dowell, Mark, additional, Gobron, Nadine, additional, Granier, Claire, additional, Grassi, Giacomo, additional, Guevara, Marc, additional, Guizzardi, Diego, additional, Gurney, Kevin, additional, Huneeus, Nicolás, additional, Keita, Sekou, additional, Kuenen, Jeoren, additional, Lopez-Noreña, Ana, additional, Puliafito, Enrique, additional, Roest, Geoffrey, additional, Rossi, Simone, additional, Soulie, Antonin, additional, and Visschedijk, Antoon, additional
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- 2023
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14. CoCO2-MOSAIC 1.0: a global mosaic of regional, gridded, fossil and biofuel CO2 emission inventories
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Urraca, Ruben, primary, Janssens-Maenhout, Greet, additional, Álamos, Nicolás, additional, Berna-Peña, Lucas, additional, Crippa, Monica, additional, Darras, Sabine, additional, Dellaert, Sitjn, additional, Denier van der Gon, Hugo, additional, Dowell, Mark, additional, Gobron, Nadine, additional, Granier, Claire, additional, Grassi, Giacomo, additional, Guevara, Marc, additional, Guizzardi, Diego, additional, Gurney, Kevin, additional, Huneeus, Nicolás, additional, Keita, Sekou, additional, Kuenen, Jeoren, additional, Lopez-Noreña, Ana, additional, Puliafito, Enrique, additional, Roest, Geoffrey, additional, Rossi, Simone, additional, Soulie, Antonin, additional, and Visschedijk, Antoon, additional
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- 2023
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15. Assessing the uncertainties of model estimates of primary productivity in the tropical Pacific Ocean
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Friedrichs, Marjorie AM, Carr, Mary-Elena, Barber, Richard T, Scardi, Michele, Antoine, David, Armstrong, Robert A, Asanuma, Ichio, Behrenfeld, Michael J, Buitenhuis, Erik T, Chai, Fei, Christian, James R, Ciotti, Aurea M, Doney, Scott C, Dowell, Mark, Dunne, John, Gentili, Bernard, Gregg, Watson, Hoepffner, Nicolas, Ishizaka, Joji, Kameda, Takahiko, Lima, Ivan, Marra, John, Mélin, Frédéric, Moore, J Keith, Morel, André, O'Malley, Robert T, O'Reilly, Jay, Saba, Vincent S, Schmeltz, Marjorie, Smyth, Tim J, Tjiputra, Jerry, Waters, Kirk, Westberry, Toby K, and Winguth, Arne
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Life Below Water ,Primary production ,Modeling ,Remote sensing ,Satellite ocean color ,Statistical analysis ,Tropical Pacific Ocean (15 degrees N to 15 degrees S and 125 degrees E ,to 95 degrees W) ,Oceanography - Abstract
Depth-integrated primary productivity (PP) estimates obtained from satellite ocean color-based models (SatPPMs) and those generated from biogeochemical ocean general circulation models (BOGCMs) represent a key resource for biogeochemical and ecological studies at global as well as regional scales. Calibration and validation of these PP models are not straightforward, however, and comparative studies show large differences between model estimates. The goal of this paper is to compare PP estimates obtained from 30 different models (21 SatPPMs and 9 BOGCMs) to a tropical Pacific PP database consisting of ∼ 1000 14C measurements spanning more than a decade (1983-1996). Primary findings include: skill varied significantly between models, but performance was not a function of model complexity or type (i.e. SatPPM vs. BOGCM); nearly all models underestimated the observed variance of PP, specifically yielding too few low PP (< 0.2 g C m- 2 d- 1) values; more than half of the total root-mean-squared model-data differences associated with the satellite-based PP models might be accounted for by uncertainties in the input variables and/or the PP data; and the tropical Pacific database captures a broad scale shift from low biomass-normalized productivity in the 1980s to higher biomass-normalized productivity in the 1990s, which was not successfully captured by any of the models. This latter result suggests that interdecadal and global changes will be a significant challenge for both SatPPMs and BOGCMs. Finally, average root-mean-squared differences between in situ PP data on the equator at 140°W and PP estimates from the satellite-based productivity models were 58% lower than analogous values computed in a previous PP model comparison 6 years ago. The success of these types of comparison exercises is illustrated by the continual modification and improvement of the participating models and the resulting increase in model skill. © 2008 Elsevier B.V.
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- 2009
16. A comparison of global estimates of marine primary production from ocean color
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Carr, Mary-Elena, Friedrichs, Marjorie AM, Schmeltz, Marjorie, Aita, Maki Noguchi, Antoine, David, Arrigo, Kevin R, Asanuma, Ichio, Aumont, Olivier, Barber, Richard, Behrenfeld, Michael, Bidigare, Robert, Buitenhuis, Erik T, Campbell, Janet, Ciotti, Aurea, Dierssen, Heidi, Dowell, Mark, Dunne, John, Esaias, Wayne, Gentili, Bernard, Gregg, Watson, Groom, Steve, Hoepffner, Nicolas, Ishizaka, Joji, Kameda, Takahiko, Le Quéré, Corinne, Lohrenz, Steven, Marra, John, Mélin, Frédéric, Moore, Keith, Morel, André, Reddy, Tasha E, Ryan, John, Scardi, Michele, Smyth, Tim, Turpie, Kevin, Tilstone, Gavin, Waters, Kirk, and Yamanaka, Yasuhiro
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Life Below Water ,Geochemistry ,Oceanography ,Ecology - Published
- 2006
17. Optical characterisation and reflectance modelling in Case II waters : quantitative tools for investigations of coastal environments
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Dowell, Mark David
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551.46 ,Remote sensing ,Coastal oceanography - Abstract
A methodology is proposed here to satisfy a community requirement for a regional solution to developing algorithms in coastal waters. A three component model, which allows maximum variability of the non-chlorophyllous components, was developed. This model was then systematically applied to a range of input values of the forward model defined using lognormal distributions, yielding a dataset of reflectances for the studied area. A principal component analysis was then performed on the simulated dataset. A multiple regression was carried out on the resulting eigenvectors and the input values of the optically active components to define the algorithms for the chosen region for the retrieval of chlorophyll, total suspended matter and yellow substance. A case study was made applying the method to the South Baltic and a validation dataset from the same region showed the capacity of this method to retrieve the concentrations of the individual optically active components to within the accuracy defined by NASA for Case I water chlorophyll retrieval. The sensitivity of the method, to inelastic processes and bottom reflectance, was considered. The study was made through the influence on the absolute signal as well as the influence on the shape of the characteristic vectors that are retrieved from the simulated reflectance in an attempt to assess the impact on the algorithm development procedure. In both cases the influence is shown to be minimum for wavelengths below 650nm. An alternative methodology is also presented (Direct Inversion Algorithm) which is based on the inversion of absolute reflectances for the retrieval of total absorption. This method was validated for an in-situ dataset and shown to retrieve chlorophyll "a" to within 30% accuracy. The applications of such a technique were considered in the context of primary production in coastal waters and chemotaxonomy.
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- 1998
18. COASTLOOC (COAstal Surveillance Through Observation of Ocean Colour) final report
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Aiken, James, Antoine, David, Babin, Marcel, Barth, Hans, Bricaud, Annick, Chauton, Mathilde, Claustre, Hervé, Doerffer, Roland, Dowell, Mark, Fell, Frank, Ferrari, Massimo, Fischer, Jürgen, Fournier-Sicre, Vincent, Hakvoort, Hans, Hoepffner, Nicolas, Johnsen, Geir, Montagner, François, Moore, Gerald, Morel, André, Obolensky, Grigor, Olbert, Carsten, Pinkerton, Matthew, Reuter, Rainer, Sakshaug, Egil, and Wernand, Marcel
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Marine optics ,Coastal monitoring ,Apparent optical properties ,Radiometry ,Inherent optical properties ,Absorption - Abstract
Final report of the Coastal Surveillance Through Observation of Ocean Color (COASTlOOC) oceanographic expeditions conducted in 1997 and 1998.
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- 2022
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19. CLIMATE SYMPOSIUM 2014 : Findings and Recommendations
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Asrar, Ghassem, Bony, Sandrine, Boucher, Olivier, Busalacchi, Antonio, Cazenave, Anny, Dowell, Mark, Flato, Greg, Hegerl, Gabi, Källén, Erland, Nakajima, Teruyuki, Ratier, Alain, Saunders, Roger, Slingo, Julia, Sohn, Byung-Ju, Schmetz, Johannes, Stevens, Bjorn, Zhang, Peiqun, and Zwiers, Francis
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- 2015
20. The Group on Earth Observations Carbon and Greenhouse Gas Initiative
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Dolman, Han, primary, Kutsch, Werner, additional, Muraoka, Hiroyuki, additional, Bombelli, Antonio, additional, Saigusa, Nobuko, additional, Schultz, Joerg, additional, Crisp, David, additional, Facchini, Mauro, additional, Dowell, Mark, additional, Richter, Carolin, additional, DeCola, Phil, additional, Canadell, Pep, additional, Scholes, Robert J., additional, Tarasova, Oksana, additional, Obregón, André, additional, Post, Joanna, additional, and Heiskanen, Jouni, additional
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- 2022
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21. An optical water type framework for selecting and blending retrievals from bio-optical algorithms in lakes and coastal waters
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Moore, Timothy S., Dowell, Mark D., Bradt, Shane, and Ruiz Verdu, Antonio
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- 2014
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22. The group on earth observations carbon and greenhouse gas initiative
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Dolman, Han, Kutsch, Werner, Muraoka, Hiroyuki, Bombelli, Antonio, Saigusa, Nobuko, Schultz, Joerg, Crisp, David, Facchini, Mauro, Dowell, Mark, Richter, Carolin, DeCola, Phil, Canadell, Pep, Scholes, Robert J., Tarasova, Oksana, Obregón, André, Post, Joanna, Heiskanen, Jouni, Kavvada, Argyro, Cripe, Douglas, Friedl, Lawrence, Kavvada, Argyro, Cripe, Douglas, Friedl, Lawrence, and Earth Sciences
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Greenhouse gasses ,Stakeholders ,Climate mitigation ,Observations and modelling ,SDG 13 - Climate Action ,Paris agreement ,Carbon cycle - Abstract
An improved understanding of the global carbon cycle is important to the success of efforts to mitigate climate change, such as agreed in the Paris meeting of the UN Conference of the Parties in 2016. Climate change mitigation and adaptation requires action by individual countries, municipalities, cities, and their citizens. These actions require a diverse range of information. Current efforts responding to the need for these carbon observations are, however, fragmented. There is a need to coordinate observations on carbon, GHG measurements, and ecosystem processes related to carbon cycle dynamics. The GEO Carbon and Greenhouse Gas Initiative (GEO-C) was launched to further support continuity and coherence of the ongoing efforts and facilitate their cooperation and interoperability. The GEO-C Initiative (1) supports the development of a holistic cross-domain, global carbon cycle and GHG monitoring system that provides long-term, high quality, and open access; (2) engages with users and policy makers and ensures the fitness for purpose of the observation and reporting system; and (3) aims to establish a common terminology (including scientists and decision makers) involved in addressing GHG emissions. This chapter describes the background of the GEO-GHG initiative and describes the main aims of the initiative and first steps toward implementation.
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- 2022
23. Primary production in the Yellow Sea determined by ocean color remote sensing
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Son, SeungHyun, Campbell, Janet, Dowell, Mark, Yoo, Sinjae, and Noh, Jaehoon
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- 2005
24. Ocean Climate and Satellite Optical Radiometry
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Yoder, James A., primary, Casey, Kenneth S., additional, and Dowell, Mark D., additional
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- 2014
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25. The relationship between the standing stock of deep-sea macrobenthos and surface production in the western North Atlantic
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Johnson, Nicholas A., Campbell, Janet W., Moore, Timothy S., Rex, Michael A., Etter, Ron J., McClain, Craig R., and Dowell, Mark D.
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Algorithms -- Analysis ,Algorithm ,Earth sciences - Abstract
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.dsr.2007.04.011 Byline: Nicholas A. Johnson (a), Janet W. Campbell (b), Timothy S. Moore (b), Michael A. Rex (c), Ron J. Etter (c), Craig R. McClain (d), Mark D. Dowell (e) Abstract: The relationship between surface production and benthic standing stock is fundamental to understanding biogeography in the deep sea. While much has been learned about the complex oceanographic processes involved in energy transfer to the benthos on local scales, the correspondence of overhead production to benthic community structure on regional scales remains poorly characterized. We compiled a database on the biomass and abundance of deep-sea macrobenthos in the western North Atlantic collected from 1961 to 1985. Using SeaWiFS satellite color imagery, we calculated POC from surface chlorophyll a concentrations (from 1997 to 2001), and estimated POC flux to the seafloor by using the empirically derived Pace et al. [1987. Primary production, new production and vertical flux in the eastern Pacific Ocean. Nature 325, 803-804] algorithm. The standing stock and surface production data are not concurrent, but their basic geographic trends at these very large spatial scales appear to be relatively stable over the time scales of measurement. Estimated POC flux at depth accounts for 62-67% of the variance (P Author Affiliation: (a) Committee on Evolutionary Biology, University of Chicago, Chicago, IL 60637, USA (b) Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH 03824, USA (c) Department of Biology, University of Massachusetts, Boston, MA 02125, USA (d) Monterey Bay, Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA (e) Institute for Environment and Sustainability, Commission of the European Communities, Joint Research Center, TP 272 I-21020 Ispra, Italy Article History: Received 16 August 2006; Revised 3 April 2007; Accepted 5 April 2007
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- 2007
26. Copernicus and Earth observation in support of EU policies
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KUCERA JAN, JANSSENS-MAENHOUT GREET, BRINK ANDREAS, VAN WIMERSMA GREIDANUS HERMAN, ROGGERI PAOLO, STROBL PETER, TARTAGLIA GIACINTO, BELWARD ALAN, and DOWELL MARK
- Abstract
The Copernicus programme for Earth observation represents a big investment by the EU, justified by expected returns in public governance and private business. Copernicus is user and policy driven, and provides cross-domain products and services with a full free and open data policy and where possible taking up new technologies and research. This study has made a survey of the extent that Copernicus is used to support policy making in the European Commission, also assessing the perspectives for increased uptake. Also other Earth observation data and information has been looked at. An extensive use of the services is observed for policies monitoring landuse, climatic and environmental conditions, and this is expected to increase further with e.g. the new Common Agricultural Policy and the Land Use, Land-Use Change and Forestry Regulation. Information of the Climate Change Service on optimal land-use targeting specific human activities, harnessing the beneficial opportunities of climate change, provides policy makers with a new set of adaptation measures. While air quality measures can be monitored by the atmosphere service, the marine service provides input to the information system for marine knowledge. The emergency service supports disaster risk reduction measures and a resilient build-up of society. Security is of increasing importance where land and water resources are at the origin of conflict and migration. Several lines of action have been identified to improve uptake: Increasing engagement within the policy Directorates-General, fostering feedback loops between the end-users and Copernicus services, Increasing communication, information and training, setting standards and guaranteeing quality controls, enabling full integration of different datasets. The Copernicus programme brings a unique opportunity to the EU for being a global player, addressing SDGs and International Conventions because of its a long-term sustained commitment and strong international dimension. No such space programme is currently available elsewhere., JRC.D.6-Knowledge for Sustainable Development and Food Security
- Published
- 2019
27. Generalized Ocean Color Inversion Model for Retrieving Marine Inherent Optical Properties
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Werdell, P. Jeremy, Franz, Bryan A, Bailey, Sean W, Feldman, Gene C, Boss, Emmanuel, Brando, Vittorio E, Dowell, Mark, Hirata, Takafumi, Lavender, Samantha J, Lee, ZhongPing, Loisel, Hubert, Maritorena, Stephane, Melin, Frederic, Moore, Timothy S, Smyth, TImothy J, Antoine, David, Devred, Emmanuel, Fantond'Andon, Odile Hembise, and Mangin, Antoine
- Subjects
Earth Resources And Remote Sensing - Abstract
Ocean color measured from satellites provides daily, global estimates of marine inherent optical properties (IOPs). Semi-analytical algorithms (SAAs) provide one mechanism for inverting the color of the water observed by the satellite into IOPs. While numerous SAAs exist, most are similarly constructed and few are appropriately parameterized for all water masses for all seasons. To initiate community-wide discussion of these limitations, NASA organized two workshops that deconstructed SAAs to identify similarities and uniqueness and to progress toward consensus on a unified SAA. This effort resulted in the development of the generalized IOP (GIOP) model software that allows for the construction of different SAAs at runtime by selection from an assortment of model parameterizations. As such, GIOP permits isolation and evaluation of specific modeling assumptions, construction of SAAs, development of regionally tuned SAAs, and execution of ensemble inversion modeling. Working groups associated with the workshops proposed a preliminary default configuration for GIOP (GIOP-DC), with alternative model parameterizations and features defined for subsequent evaluation. In this paper, we: (1) describe the theoretical basis of GIOP; (2) present GIOP-DC and verify its comparable performance to other popular SAAs using both in situ and synthetic data sets; and, (3) quantify the sensitivities of their output to their parameterization. We use the latter to develop a hierarchical sensitivity of SAAs to various model parameterizations, to identify components of SAAs that merit focus in future research, and to provide material for discussion on algorithm uncertainties and future ensemble applications.
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- 2013
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28. Detection of Coccolithophore Blooms in Ocean Color Satellite Imagery: a Generalized Approach for Use with Multiple Sensors
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Moore, Timothy, Dowell, Mark, and Franz, Bryan A
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Oceanography ,Earth Resources And Remote Sensing - Abstract
A generalized coccolithophore bloom classifier has been developed for use with ocean color imagery. The bloom classifier was developed using extracted satellite reflectance data from SeaWiFS images screened by the default bloom detection mask. In the current application, we extend the optical water type (OWT) classification scheme by adding a new coccolithophore bloom class formed from these extracted reflectances. Based on an in situ coccolithophore data set from the North Atlantic, the detection levels with the new scheme were between 1,500 and 1,800 coccolithophore cellsmL and 43,000 and 78,000 lithsmL. The detected bloom area using the OWT method was an average of 1.75 times greater than the default bloom detector based on a collection of SeaWiFS 1 km imagery. The versatility of the scheme is shown with SeaWiFS, MODIS Aqua, CZCS and MERIS imagery at the 1 km scale. The OWT scheme was applied to the daily global SeaWiFS imagery mission data set (years 19972010). Based on our results, average annual coccolithophore bloom area was more than two times greater in the southern hemisphere compared to the northern hemi- sphere with values of 2.00 106 km2 and 0.75 106 km2, respectively. The new algorithm detects larger bloom areas in the Southern Ocean compared to the default algorithm, and our revised global annual average of 2.75106 km2 is dominated by contributions from the Southern Ocean.
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- 2012
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29. CO2: An operational anthropogenic CO2 emissions monitoring & verification support capacity
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PINTY BERNARD, CIAIS PHILIPPE, DEE DICK, DOLMAN A. JOHANNES, DOWELL MARK, ENGELEN R., HOLMLUND KENNETH, JANSSENS-MAENHOUT GREET, MEIJER Y, PALMER PAUL, SCHOLZE MARKO, DENIER VAN DER GON HUGO, HEIMANN MARTIN, JUVYNS OLIVIER, KENTARCHOS A, and ZUNKER HUGO
- Abstract
This is the third report form the CO2 Monitoring Task Force on the multiple input streams of in-situ observations that are requirement for the Copernicus CO2 Monitoring and Verification Support capacity to: (i) calibrated and validate the space component, (ii) assimilate data in the models and integrate information in the core of the system, and (iii) evaluate the output generated by the system for its end users. The availability of sustained in situ networks is currently a significant factor of risk that needs to be mitigated to establish a European CO 2 support capacity which is fit-for-purpose. The current status of existing networks may be the source of large uncertainties in anthropogenic CO2 emission estimates as well as limited capability in meeting the requirements for country, large city and point source scale assessments. This conclusion results from a risk analysis formulated for four scenarios: 1) maintaining the status quo, 2) assuring sustained funding for the status quo, 3) enhancing network capabilities at European scale with sustained funding and 4) with a significantly improved in situ infrastructure in Europe and beyond. This report substantiates the multifaceted needs and requirements of the European CO2 support capacity with respect to in situ observations. The analysis concerns all core elements of the envisaged integrated system with a particular attention on the impact of such observations in achieving the proposed objectives. The specific needs for the validation of products delivered by the space component that is, the Copernicus Sentinels CO2 monitoring constellation, are addressed as another prerequisite for the success of the CO2 support capacity. This European asset will represent a significant contribution to the virtual constellation proposed by the Committee on Earth Observation Satellites (CEOS) and, accordingly, complementary requirements are elaborated in that international frame. The report highlights that although high measurement standards are present within existing networks such as ICOS, in the context of the needs for targeted in situ data for the realization of the operational system, these data are not fully fit-for-purpose. A fundamental prerequisite is to have a good geographical coverage over Europe for evaluating the data assimilation and modeling system over a large variety of environmental conditions such as, for instance, urban areas, agricultural regions, forested zones and industrial complexes. The in situ observations need to be extended under a coordinated European lead with sustained infrastructure and targeted additional and maintained long-term funding. It has been clearly understood from the onset that the international dimension of the European CO2 support capacity would be critical and that these aspects should be developed in parallel to, and in synergy with the definition and implementation of a European contributing system. It was also understood that this international dimension had both strategic, policy relevant and technical dimensions and the Commission and the relevant European institutional partners have started since several years to engage both bilaterally and multilaterally with the relevant stakeholders and counterparts to develop these relations. Specifically, CEOS will undertake, over the next few years, dedicated preparatory work in a coordinated international context, to provide cumulative added value to the specific programmatic activities of their member agencies. Concerted efforts have already begun in the context of the European Commission's Chairmanship of CEOS in 2018. It is recognized in the context of the European efforts, and increasingly by our international counterparts that a broad and holistic system approach is required to address the requirements which are represented by the climate policy, of which the satellite component, whilst important, cannot effectively be developed in isolation. This system indeed includes the satellite observing capability but in addition, the required modelling component and data integration elements, prior information, ancillary data and in situ observations delivered by essential networks. Acknowledging the need for an efficient coordination at international level for instance via the Global Atmosphere Watch programme of the World Meteorological Organisation is a key towards a successful implementation of appropriate actions to ensure the sustainability of essential networks, to enhance current network capabilities with new observations and to propose adequate governance schemes. Such actions to mitigate current network limitations are deemed critical to implementing the Copernicus CO 2 Monitoring & Verification Support capacity in its full strength., JRC.D.6-Knowledge for Sustainable Development and Food Security
- Published
- 2019
30. A comparison of global estimates of marine primary production from ocean color
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Yamanaka, Yasuhiro, Watersa, Kirk, Tilstone, Gavin, Turpie, Kevin, Smyth, Tim, Scardi, Michele, Ryan, John, Reddy, Tasha E, Andre´ Morel, Moore, Keith, Melino, Frederic, Marra, John, Lohrenz, Steven, Le Quere, Corinne, Kameda, Takahiko, Ishizakas, Joji, Hoepffner, Nicolas, Groom, Steve, Gregg, Watson, Gentili, Bernard, Esaias, Wayne, Dunne, John, Dowell, Mark, Dierssen, Heidi, Ciotti, Aurea, Campbell, Janet, Buitenhuis, Erik T, Bidigare, Robert, Behrenfeld, Michael, Barber, Richard, Aumont, Olivier, Asanuma, Ichio, Arrigo, Kevin R, Antoine, David, Aita, Maki Noguchi, Schmeltz, Marjorie, Friedrichs, Marjorie A.M, and Carra, Mary-Elena
- Abstract
The third primary production algorithm round robin (PPARR3) compares output from 24 models that estimate depth-integrated primary production from satellite measurements of ocean color, as well as seven general circulation models (GCMs) coupled with ecosystem or biogeochemical models. Here we compare the global primary production fields corresponding to eight months of 1998 and 1999 as estimated from common input fields of photosynthetically-available radiation (PAR), sea-surface temperature (SST), mixed-layer depth, and chlorophyll concentration. We also quantify the sensitivity of the ocean-color-based models to perturbations in their input variables. The pair-wise correlation between ocean-color models was used to cluster them into groups or related output, which reflect the regions and environmental conditions under which they respond differently. The groups do not follow model complexity with regards to wavelength or depth dependence, though they are related to the manner in which temperature is used to parameterize photosynthesis. Global average PP varies by a factor of two between models. The models diverged the most for the Southern Ocean, SST under 10 C, and chlorophyll concentration exceeding 1mg Chlm-3. Based on the conditions under which the model results diverge most, we conclude that current ocean-color-based models are challenged by high-nutrient low-chlorophyll conditions, and extreme temperatures or chlorophyll concentrations. The GCM-based models predict comparable primary production to those based on ocean color: they estimate higher values in the Southern Ocean, at low SST, and in the equatorial band, while they estimate lower values in eutrophic regions (probably because the area of high chlorophyll concentrations is smaller in the GCMs). Further progress in primary production modeling requires improved understanding of the effect of temperature on photosynthesis and better parameterization of the maximum photosynthetic rate.
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- 2006
31. Emergence of Macrolide Resistance during Treatment of Pneumococcal Pneumonia
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Musher, Daniel M., Dowell, Mark E., Shortridge, Virginia D., Flamm, Robert K., Jorgensen, James H., Le Magueres, Pierre, and Krause, Kurt L.
- Published
- 2002
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32. Response of latent syphilis or neurosyphilis to ceftriaxone therapy in persons infected with human immunodeficiency virus
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Dowell, Mark E., Ross, Paul G., Musher, Daniel M., Cate, Thomas R., and Baughn, Robert E.
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Syphilis -- Drug therapy ,Ceftriaxone -- Physiological aspects ,HIV infection -- Complications ,Health ,Health care industry - Abstract
OBJECTIVE: To evaluate the effect of ceftriaxone in treating latent syphilis or asymptomatic neurosyphilis in patients infected with the human immunodeficiency virus (HIV). DESIGN: Follow-up study of patients treated at two HIV-based clinics during 16 months from 1989 to 1991. PATIENTS: Patients were those in whom a clinical diagnosis of latent syphilis or asymptomatic neurosyphilis was made, who received all recommended doses of antimicrobial therapy, and who returned for follow-up visits for 6 or more months. RESULTS: Forty-three patients were treated with ceftriaxone, 1 to 2 g daily for 10 to 14 days. Thirteen underwent lumbar puncture before treatment; 7 (58%) had documented neurosyphilis (pleocytosis in 5, elevated protein levels in 6, VDRL reactive in cerebrospinal fluid [CSF] in 7), and 6 had documented latent syphilis (entirely normal CSF). The remaining 30 were said to have presumed latent syphilis. There was no relation between the diagnosis and the selected dosage of ceftriaxone. Response rates were similar in those who had documented neurosyphilis and documented or presumed latent syphilis. Overall, 28 patients (65%) responded to therapy, 5 (12%) were serofast, 9 (21%) had a serologic relapse, and 1 (2%) who experienced progression to symptomatic neurosyphilis was a therapeutic failure. Thirteen patients received benzathine penicillin for presumed latent syphilis; results were similar to those observed after ceftriaxone therapy, with 8 (62%) responders, 1 (8%) serofast, 2 (15%) relapses, and 2 (15%) failures. CD4 cell counts in responders were not different from those who failed to respond. CONCLUSIONS: Even in the absence of neurologic symptoms, half of the HIV-infected persons who have serologic evidence of syphilis may have neurosyphilis. Although ceftriaxone achieves high serum and CSF levels, 10 to 14 days of treatment with this drug were associated with a 23% failure rate in HIV-infected patients who had latent syphilis or asymptomatic neurosyphilis. Three doses of benzathine penicillin did not have a significantly higher relapse rate and may provide appropriate therapy, at least for documented latent syphilis in persons co-infected with HIV. Studies comparing ceftriaxone with 10 to 14 doses of procaine penicillin are needed to determine the most cost-effective treatment for asymptomatic neurosyphilis or presumed latent syphilis in this group of patients.
- Published
- 1992
33. Marine sustainability in an age of changing oceans and seas
- Author
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THIEDE JOERN, BETTI MARIA, DOWELL MARK, MARTINSOHN JANN, AKSENS DAG, BATHMANN ULRICH, BOERO FERDINANDO, BOXSHALL GEOFF, CURY PHILIPPE, EMMERSON RICHARD, ESTRADA MARTA, FINE MAOZ, GRIGELIS ALGIMANTAS, HERMAN PETER, HENDL GERHARD, KUPARINEN JORMA, PRASIL JORMA, SERRAO SANTOS RICARDO, SOOMERE TARMO, SYNOLAKIS COSTAS, BIDOGLIO Giovanni, and BIDOGLIO GIOVANNI
- Abstract
The report is the result of fruitful collaboration between EASAC and the JRC. It has been prepared by a working group of experts drawn from the European National Science Academies, which was supported by the JRC. It is hoped that the report will prove useful in the further development and implementation of European Union marine and maritime policy as well as the organisation of supporting science needed to inform and guide these policies. The last ten years have seen a growth in marine and maritime policymaking within the European Union with a key feature being the concept of the ecosystem approach to guide sustainable use of the seas. In view of this increasing focus on coherent marine and maritime policy and governance within the EU, as well as globally, the EASAC Council decided in December 2013 to conduct a study on the issue of marine sustainability. This decision particularly acknowledged the need to provide advice from the point of view of the European science academies on this new direction of marine policy and to highlight the particular challenges that this poses to the organisation of science. The report has the aim of contributing to the governance challenge of how to integrate the various aspects of marine policy (fisheries management, biodiversity conservation and marine environmental protection) as part of a coherent ecosystem approach. It considers how current science knowledge on marine ecosystems and the organisation of science can support an integrated approach to management of the seas. The report looks at a number of key aspects for sustainable development in changing oceans and seas, and particularly highlights the key scientific challenges in addressing these issues. The report presents both recommendations from science for policy development, and recommendations on policy for science. The health of the oceans and coastal seas is vital for the future well-being of all of Europe, indeed of entire mankind, and sustainable management of this sensitive and fast changing component of the global ecosystem is essential., JRC.A.3-Inter-institutional, International Relations and Outreach
- Published
- 2015
34. The JRC and the Arctic - How JRC science can underpin the successful implementation of an EU Arctic Policy
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WILSON Julian, VIGNATI Elisabetta, DOBRICIC SRDAN, STILIANAKIS Nikolaos, DOWELL Mark, WESTRA VAN HOLTHE MARION, ZAMPIERI Alessandra, MARTINSOHN Jann, and VESPE MICHELE
- Abstract
The Arctic is experiencing unprecedented and disproportionately high rates of environmental change due to effects of climate change. These changing conditions are making it easier to exploit the natural wealth of the Arctic (mineral, fisheries, land) while putting the existence of Arctic ecosystems and the indigenous population that rely on them under threat. EU institutions have recognised these opportunities for, and threats to, the Arctic. The EU Commission and the EEAS (European External Action Service) are due to “present proposals for the further development of an integrated and coherent Arctic Policy” in the first quarter of 2016. A cornerstone of EU efforts is engagement with the Arctic Council, the high-level intergovernmental forum of States bordering the Arctic, representatives of indigenous peoples, and permanent observers (including seven EU Member States). The Arctic Council has not yet pronounced on the EU’s longstanding application for observer status, and will not do so before 2017. By virtue of its scientific excellence, JRC engagement with the Arctic Council and its subsidiary bodies is therefore currently one of the few channels for direct engagement of the EU with the Arctic Council. This report presents JRC activities in support of the Arctic Council and its bodies, and possibilities for their further development, identifying three alternative paths for future engagement in support of EU Arctic policy making., JRC.H.2-Air and Climate
- Published
- 2015
35. Chapter 1.1 - Ocean Climate and Satellite Optical Radiometry
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Yoder, James A., Casey, Kenneth S., and Dowell, Mark D.
- Published
- 2014
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36. A post-Paris look at climate observations
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Dolman, A. Johannes, Belward, Alan, Briggs, Stephen, Dowell, Mark, Eggleston, Simon, Hill, Katherine, Richter, Carolin, Simmons, Adrian, Dolman, A. Johannes, Belward, Alan, Briggs, Stephen, Dowell, Mark, Eggleston, Simon, Hill, Katherine, Richter, Carolin, and Simmons, Adrian
- Abstract
The Paris Agreement1 of the United Nations Framework Convention on Climate Change in December 2015 was a landmark event. Stakeholders such as cities, companies and citizens that endure the impacts of a changing climate, as well as policymakers, now need to know what impact their future choices will have on the environment. Systematic observations of the climate system and of greenhouse gas (GHG) emissions are needed to track progress and identify where additional goals may be needed. We suggest that, although the targets agreed in Paris — to hold global warming to well below 2 °C and avert loss and damage — are formulated around temperature, monitoring and meeting these targets requires a broader range of climate indicators2. Global mean surface temperature alone has proved problematic for communicating the impacts and evolution of climate change. The warming of the oceans, sea-level rise, increasing ocean acidity, melting glaciers and decreasing snow cover, and changes in Arctic sea ice also need to be taken into account.
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- 2016
37. Postoperative respiratory failure secondary to Pneumocystis carinii pneumonia
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Klepper, Mark S., Guntupalli, Kalpalatha K., Interiano, Ben, Dowell, Mark, and Greenberg, Stephen B.
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Respiratory insufficiency -- Causes of ,Pneumocystis carinii pneumonia -- Complications ,HIV seropositivity -- Complications ,Health - Published
- 1992
38. A post-Paris look at climate observations
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Dolman, A. Johannes, primary, Belward, Alan, additional, Briggs, Stephen, additional, Dowell, Mark, additional, Eggleston, Simon, additional, Hill, Katherine, additional, Richter, Carolin, additional, and Simmons, Adrian, additional
- Published
- 2016
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39. Challenges of modeling depth-integrated marine primary productivity over multiple decades : a case study at BATS and HOT
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Saba, Vincent S., Friedrichs, Marjorie A. M., Carr, Mary-Elena, Antoine, David, Armstrong, Robert A., Asanuma, Ichio, Aumont, Olivier, Bates, Nicholas R., Behrenfeld, Michael J., Bennington, Val, Bopp, Laurent, Bruggeman, Jorn, Buitenhuis, Erik T., Church, Matthew J., Ciotti, Aurea M., Doney, Scott C., Dowell, Mark, Dunne, John P., Dutkiewicz, Stephanie, Gregg, Watson, Hoepffner, Nicolas, Hyde, Kimberly J. W., Ishizaka, Joji, Kameda, Takahiko, Karl, David M., Lima, Ivan, Lomas, Michael W., Marra, John, Mckinley, Galen A., Melin, Frédéric, Moore, J. Keith, Morel, André, O'Reilly, John, Salihoglu, Baris, Scardi, Michele, Smyth, Tim J., Tang, Shilin L., Tjiputra, Jerry, Uitz, Julia, Vichi, Marcello, Waters, Kirk, Westberry, Toby K., Yool, Andrew, Laboratoire d'océanographie de Villefranche (LOV), Observatoire océanologique de Villefranche-sur-mer (OOVM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Plymouth Marine Laboratory (PML), Plymouth Marine Laboratory, Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California, National Oceanography Centre [Southampton] (NOC), University of Southampton, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Scripps Institution of Oceanography (SIO - UC San Diego), and University of California (UC)-University of California (UC)
- Subjects
Settore BIO/07 ,interannual variability ,time-series ,sargasso sea ,oceanographic conditions ,generalized-model ,multidecadal climate forcing ,ocean primary production ,satellite chlorophyll ,marine primary productivity models ,BATS HOT trends ,skill assessment ,north pacific-ocean ,Physical Sciences and Mathematics ,10.1029/2009GB003655 ,[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography ,atlantic subtropical gyre - Abstract
The performance of 36 models (22 ocean color models and 14 biogeochemical ocean circulation models (BOGCMs)) that estimate depth-integrated marine net primary productivity (NPP) was assessed by comparing their output to in situ 14C data at the Bermuda Atlantic Time series Study (BATS) and the Hawaii Ocean Time series (HOT) over nearly two decades. Specifically, skill was assessed based on the models' ability to estimate the observed mean, variability, and trends of NPP. At both sites, more than 90% of the models underestimated mean NPP, with the average bias of the BOGCMs being nearly twice that of the ocean color models. However, the difference in overall skill between the best BOGCM and the best ocean color model at each site was not significant. Between 1989 and 2007, in situ NPP at BATS and HOT increased by an average of nearly 2% per year and was positively correlated to the North Pacific Gyre Oscillation index. The majority of ocean color models produced in situ NPP trends that were closer to the observed trends when chlorophyll-a was derived from high-performance liquid chromatography (HPLC), rather than fluorometric or SeaWiFS data. However, this was a function of time such that average trend magnitude was more accurately estimated over longer time periods. Among BOGCMs, only two individual models successfully produced an increasing NPP trend (one model at each site). We caution against the use of models to assess multiannual changes in NPP over short time periods. Ocean color model estimates of NPP trends could improve if more high quality HPLC chlorophyll-a time series were available. © 2010 by the American Geophysical Union.
- Published
- 2010
40. ChloroGIN: use of satellite and in situ data in support of ecosystem-based management of marine resources
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Hall, J., Harrison, D.E., Stammer, D., Sathyedranath, Shubha, Ahanhanzo, Justin, Bernard, Stewart, Byfield, Valborg, Delaney, Lisa, Dowell, Mark, Field, John, Groom, Steve, Hardman-Mountford, Nick, Hoepffner, Nicolas, Jacobs, Tim, Kampel, Milton, Kumar, Srinivas, Lutz, Vivian, Platt, Trevor, Hall, J., Harrison, D.E., Stammer, D., Sathyedranath, Shubha, Ahanhanzo, Justin, Bernard, Stewart, Byfield, Valborg, Delaney, Lisa, Dowell, Mark, Field, John, Groom, Steve, Hardman-Mountford, Nick, Hoepffner, Nicolas, Jacobs, Tim, Kampel, Milton, Kumar, Srinivas, Lutz, Vivian, and Platt, Trevor
- Published
- 2010
41. Assessing the uncertainties of model estimates of primary productivity in the tropical Pacific Ocean
- Author
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Friedrichs, Marjorie A. M., Carr, Mary-Elena, Barber, Richard T., Scardi, Michele, Antoine, David, Armstrong, Robert A., Asanuma, Ichio, Behrenfeld, Michael J., Buitenhuis, Erik T., Chai, Fei, Christian, James R., Ciotti, Aurea M., Doney, Scott C., Dowell, Mark, Dunne, John P., Gentili, Bernard, Gregg, Watson, Hoepffner, Nicolas, Ishizaka, Joji, Kameda, Takahiko, Lima, Ivan D., Marra, John F., Melin, Frederic, Moore, J. Keith, Morel, Andre, O'Malley, Robert T., O'Reilly, Jay, Saba, Vincent S., Schmeltz, Marjorie, Smyth, Tim J., Tjiputra, Jerry, Waters, Kirk, Westberry, Toby K., Winguth, Arne, Friedrichs, Marjorie A. M., Carr, Mary-Elena, Barber, Richard T., Scardi, Michele, Antoine, David, Armstrong, Robert A., Asanuma, Ichio, Behrenfeld, Michael J., Buitenhuis, Erik T., Chai, Fei, Christian, James R., Ciotti, Aurea M., Doney, Scott C., Dowell, Mark, Dunne, John P., Gentili, Bernard, Gregg, Watson, Hoepffner, Nicolas, Ishizaka, Joji, Kameda, Takahiko, Lima, Ivan D., Marra, John F., Melin, Frederic, Moore, J. Keith, Morel, Andre, O'Malley, Robert T., O'Reilly, Jay, Saba, Vincent S., Schmeltz, Marjorie, Smyth, Tim J., Tjiputra, Jerry, Waters, Kirk, Westberry, Toby K., and Winguth, Arne
- Abstract
Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Marine Systems 76 (2009): 113-133, doi:10.1016/j.jmarsys.2008.05.010., Depth-integrated primary productivity (PP) estimates obtained from satellite ocean color based models (SatPPMs) and those generated from biogeochemical ocean general circulation models (BOGCMs) represent a key resource for biogeochemical and ecological studies at global as well as regional scales. Calibration and validation of these PP models are not straightforward, however, and comparative studies show large differences between model estimates. The goal of this paper is to compare PP estimates obtained from 30 different models (21 SatPPMs and 9 BOGCMs) to a tropical Pacific PP database consisting of ~1000 14C measurements spanning more than a decade (1983- 1996). Primary findings include: skill varied significantly between models, but performance was not a function of model complexity or type (i.e. SatPPM vs. BOGCM); nearly all models underestimated the observed variance of PP, specifically yielding too few low PP (< 0.2 gC m-2d-2) values; more than half of the total root-mean-squared model-data differences associated with the satellite-based PP models might be accounted for by uncertainties in the input variables and/or the PP data; and the tropical Pacific database captures a broad scale shift from low biomass-normalized productivity in the 1980s to higher biomass-normalized productivity in the 1990s, which was not successfully captured by any of the models. This latter result suggests that interdecadal and global changes will be a significant challenge for both SatPPMs and BOGCMs. Finally, average root-mean-squared differences between in situ PP data on the equator at 140°W and PP estimates from the satellite-based productivity models were 58% lower than analogous values computed in a previous PP model comparison six years ago. The success of these types of comparison exercises is illustrated by the continual modification and improvement of the participating models and the resulting increase in model skill., This research was supported by a grant from the National Aeronautics and Space Agency Ocean Biology and Biogeochemistry program (NNG06GA03G), as well as by numerous other grants to the various participating investigators
- Published
- 2009
42. Generalized ocean color inversion model for retrieving marine inherent optical properties
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Werdell, P. Jeremy, primary, Franz, Bryan A., additional, Bailey, Sean W., additional, Feldman, Gene C., additional, Boss, Emmanuel, additional, Brando, Vittorio E., additional, Dowell, Mark, additional, Hirata, Takafumi, additional, Lavender, Samantha J., additional, Lee, ZhongPing, additional, Loisel, Hubert, additional, Maritorena, Stéphane, additional, Mélin, Fréderic, additional, Moore, Timothy S., additional, Smyth, Timothy J., additional, Antoine, David, additional, Devred, Emmanuel, additional, d’Andon, Odile Hembise Fanton, additional, and Mangin, Antoine, additional
- Published
- 2013
- Full Text
- View/download PDF
43. A class-based approach to characterizing and mapping the uncertainty of the MODIS ocean chlorophyll product
- Author
-
Moore, Timothy S., primary, Campbell, Janet W., additional, and Dowell, Mark D., additional
- Published
- 2009
- Full Text
- View/download PDF
44. Parameterization of a spectral solar irradiance model for the global ocean using multiple satellite sensors
- Author
-
Bouvet, Marc, primary, Hoepffner, Nicolas, additional, and Dowell, Mark D., additional
- Published
- 2002
- Full Text
- View/download PDF
45. The epidemiology of tick-borne relapsing fever in the United States.
- Author
-
Dworkin, Mark S, primary, Shoemaker, Phyllis C, additional, Anderson, Donald E, additional, Dowell, Mark E, additional, and Fritz, Curtis L, additional
- Published
- 2002
- Full Text
- View/download PDF
46. Absorption modeling in case II waters: the need to distinguish colored dissolved organic matter from nonchlorophyllous particulates
- Author
-
Dowell, Mark, primary, Berthon, Jean-Francois, additional, Hoepffner, Nicolas, additional, and Grossi, Stefania, additional
- Published
- 1997
- Full Text
- View/download PDF
47. Retrieving chlorophyll and nonchlorophyll matter from ocean color satellite data in Baltic case 2Y waters
- Author
-
Berthon, Jean-Francois, primary, Dowell, Mark, additional, Hoepffner, Nicolas, additional, and Grossi, Stefania, additional
- Published
- 1997
- Full Text
- View/download PDF
48. Relationship between the optical properties of chromophoric dissolved organic matter and total concentration of dissolved organic carbon in the southern Baltic Sea region
- Author
-
Ferrari, Giovanni M., primary, Dowell, Mark D., additional, Grossi, Stefania, additional, and Targa, Cristina, additional
- Published
- 1996
- Full Text
- View/download PDF
49. Absorption modeling in case II waters: the need to distinguish colored dissolved organic matter from nonchlorophyllous particulates.
- Author
-
Dowell, Mark, Berthon, Jean-Francois, Hoepffner, Nicolas, and Grossi, Stefania
- Published
- 1997
- Full Text
- View/download PDF
50. An Unusual Cause of Fever in a Newborn Infant
- Author
-
Dowell, Mark, primary and Musher, Daniel M., additional
- Published
- 1991
- Full Text
- View/download PDF
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