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Articles 1 - 9 of 9
Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology
Chlorophyll Absorption And Phytoplankton Size Information Inferred From Hyperspectral Particulate Beam Attenuation, Henry F. Houskeeper, David Draper, Raphael M. Kudela, Emmanuel Boss
Chlorophyll Absorption And Phytoplankton Size Information Inferred From Hyperspectral Particulate Beam Attenuation, Henry F. Houskeeper, David Draper, Raphael M. Kudela, Emmanuel Boss
Marine Sciences Faculty Scholarship
Electromagnetic theory predicts spectral dependencies in extinction efficiency near a narrow absorption band for a particle with an index of refraction close to that of the medium in which it is immersed. These absorption band effects are anticipated in oceanographic beam-attenuation (beam-c) spectra, primarily due to the narrow red peak in absorption produced by the phytoplankton photopigment, chlorophyll a (Chl a). Here we present a method to obtain Chl a absorption and size information by analyzing an eigendecomposition of hyperspectral beam-c residuals measured in marine surface waters by an automatic underway system. We find that three principal modes capture more …
Evaluation Of Diagnostic Pigments To Estimate Phytoplankton Size Classes, Alison P. Chase, Sasha J. Kramer, Nils Haëntjens, Emmanuel S. Boss, Lee Karp-Boss, Mimi Edmondson, Jason R. Graff
Evaluation Of Diagnostic Pigments To Estimate Phytoplankton Size Classes, Alison P. Chase, Sasha J. Kramer, Nils Haëntjens, Emmanuel S. Boss, Lee Karp-Boss, Mimi Edmondson, Jason R. Graff
Marine Sciences Faculty Scholarship
Limnology and Oceanography: Methods published by Wiley Periodicals LLC. on behalf of Association for the Sciences of Limnology and Oceanography. Phytoplankton accessory pigments are commonly used to estimate phytoplankton size classes, particularly during development and validation of biogeochemical models and satellite ocean color-based algorithms. The diagnostic pigment analysis (DPA) is based on bulk measurements of pigment concentrations and relies on assumptions regarding the presence of specific pigments in different phytoplankton taxonomic groups. Three size classes are defined by the DPA: picoplankton, nanoplankton, and microplankton. Until now, the DPA has not been evaluated against an independent approach that provides phytoplankton size …
Toward Deeper Development Of Biogeochemical-Argo Floats, Xiao Gang Xing, Hervé Claustre, Emmanuel Boss, Fei Chai
Toward Deeper Development Of Biogeochemical-Argo Floats, Xiao Gang Xing, Hervé Claustre, Emmanuel Boss, Fei Chai
Marine Sciences Faculty Scholarship
Following a series of publications reporting on successful long-term deployments of profiling floats with various biogeochemical sensors (e.g. Boss et al. 2008; Johnson, Riser, and Karl 2010; Körtzinger et al. 2004) and years of international coordination, the BGC-Argo program was officially launched in October 2016, as an extension of the Argo Program (Biogeochemical-Argo Planning Group 2016; Johnson and Claustre 2016). The objectives of the BGC-Argo Program are to establish and sustain an array with 1000 floats within five years. Similar to Argo, this is a coordinated, voluntary, distributed, and multinational network of profiling floats, but with a significant addition of …
Underway Spectrophotometry Along The Atlantic Meridional Transect Reveals High Performance In Satellite Chlorophyll Retrievals, Robert J.W. Brewin, Giorgio Dall'olmo, Silvia Pardo, Virginie Van Dongen-Vogels, Emmanuel S. Boss
Underway Spectrophotometry Along The Atlantic Meridional Transect Reveals High Performance In Satellite Chlorophyll Retrievals, Robert J.W. Brewin, Giorgio Dall'olmo, Silvia Pardo, Virginie Van Dongen-Vogels, Emmanuel S. Boss
Marine Sciences Faculty Scholarship
To evaluate the performance of ocean-colour retrievals of total chlorophyll-a concentration requires direct comparison with concomitant and co-located in situ data. For global comparisons, these in situ match-ups should be ideally representative of the distribution of total chlorophyll-a concentration in the global ocean. The oligotrophic gyres constitute the majority of oceanic water, yet are under-sampled due to their inaccessibility and under-represented in global in situ databases. The Atlantic Meridional Transect (AMT) is one of only a few programmes that consistently sample oligotrophic waters. In this paper, we used a spectrophotometer on two AMT cruises (AMT19 and AMT22) to continuously measure …
Regional Ocean-Colour Chlorophyll Algorithms For The Red Sea, Robert J.W. Brewin, Dionysios E. Raitsos, Giorgio Dall'olmo, Nikolaos Zarokanellos, Thomas Jackson, Marie Fanny Racault, Emmanuel S. Boss, Shubha Sathyendranath, Burt H. Jones, Ibrahim Hoteit
Regional Ocean-Colour Chlorophyll Algorithms For The Red Sea, Robert J.W. Brewin, Dionysios E. Raitsos, Giorgio Dall'olmo, Nikolaos Zarokanellos, Thomas Jackson, Marie Fanny Racault, Emmanuel S. Boss, Shubha Sathyendranath, Burt H. Jones, Ibrahim Hoteit
Marine Sciences Faculty Scholarship
The Red Sea is a semi-enclosed tropical marine ecosystem that stretches from the Gulf of Suez and Gulf of Aqaba in the north, to the Gulf of Aden in the south. Despite its ecological and economic importance, its biological environment is relatively unexplored. Satellite ocean-colour estimates of chlorophyll concentration (an index of phytoplankton biomass) offer an observational platform to monitor the health of the Red Sea. However, little is known about the optical properties of the region. In this paper, we investigate the optical properties of the Red Sea in the context of satellite ocean-colour estimates of chlorophyll concentration. Making …
Regional To Global Assessments Of Phytoplankton Dynamics From The Seawifs Mission, D. A. Siegel, M. J. Behrenfeld, S. Maritorena, C. R. Mcclain, D. Antoine, S. W. Bailey, P. S. Bontempi, E. S. Boss, H. M. Dierssen, S. C. Doney, R. E. Eplee, R. H. Evans, G. C. Feldman, E. Fields, B. A. Franz, N. A. Kuring, C. Mengelt, N. B. Nelson, F. S. Patt, W. D. Robinson, J. L. Sarmiento, C. M. Swan, P. J. Werdell, T. K. Westberry, J. G. Wilding, J. A. Yoder
Regional To Global Assessments Of Phytoplankton Dynamics From The Seawifs Mission, D. A. Siegel, M. J. Behrenfeld, S. Maritorena, C. R. Mcclain, D. Antoine, S. W. Bailey, P. S. Bontempi, E. S. Boss, H. M. Dierssen, S. C. Doney, R. E. Eplee, R. H. Evans, G. C. Feldman, E. Fields, B. A. Franz, N. A. Kuring, C. Mengelt, N. B. Nelson, F. S. Patt, W. D. Robinson, J. L. Sarmiento, C. M. Swan, P. J. Werdell, T. K. Westberry, J. G. Wilding, J. A. Yoder
Marine Sciences Faculty Scholarship
Photosynthetic production of organic matter by microscopic oceanic phytoplankton fuels ocean ecosystems and contributes roughly half of the Earth's net primary production. For 13. years, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission provided the first consistent, synoptic observations of global ocean ecosystems. Changes in the surface chlorophyll concentration, the primary biological property retrieved from SeaWiFS, have traditionally been used as a metric for phytoplankton abundance and its distribution largely reflects patterns in vertical nutrient transport. On regional to global scales, chlorophyll concentrations covary with sea surface temperature (SST) because SST changes reflect light and nutrient conditions. However, the ocean may …
In Situ Measurements Of Phytoplankton Fluorescence Using Low Cost Electronics, Thomas Leeuw, Emmanuel S. Boss, Dana L. Wright
In Situ Measurements Of Phytoplankton Fluorescence Using Low Cost Electronics, Thomas Leeuw, Emmanuel S. Boss, Dana L. Wright
Marine Sciences Faculty Scholarship
Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open …
Analysis Of Optical Spikes Reveals Dynamics Of Aggregates In The Twilight Zone, Nathan Briggs
Analysis Of Optical Spikes Reveals Dynamics Of Aggregates In The Twilight Zone, Nathan Briggs
Electronic Theses and Dissertations
The "biological pump," whereby phytoplankton grow in the surface ocean, aggregate, and sink, is a critical process contributing to global atmospheric CO2 drawdown and provides the vast majority of food for deep ocean and benthic ecosystems. The strength of this pump hinges on the amount of material that stick together to form larger aggregates, the sinking rates of these aggregates, and the rate at which they are consumed as they sink. However, marine aggregates, also called "marine snow," are often fragile and notoriously difficult to sample, their sinking rates are highly variable and difficult to quantify, and their concentrations can …
Sger-Exploring The Use Of Quantum Dots To Detect The Physiology Of Intact Phytoplankton Cells By Flow Cytometry, Karen Orcutt
Sger-Exploring The Use Of Quantum Dots To Detect The Physiology Of Intact Phytoplankton Cells By Flow Cytometry, Karen Orcutt
University of Maine Office of Research Administration: Grant Reports
The PIs will to apply the emerging technology of Qdots in biological oceanography, particularly in studying phytoplankton. Qdots have unique fluorescence properties with tremendous potential for probing cell structure and function. They are inorganic fluorophores that can be conjugated to biological materials such as antibodies or DNA for use in cell detection. Molecular conjugates of Qdots offer a wide spectrum of applications such as multi-labeling of proteins and fluorescent in situ hybridization of DNA. The PIs will explore a new approach to an established research topic and venture into the emerging research area of nano-materials.
The novel approach may improve …