A5052682958- Marine and coastal ecosystems
- Water Quality Monitoring and Analysis
- Oceanographic and Atmospheric Processes
- Coral and Marine Ecosystems Studies
- Marine Biology and Ecology Research
- Coastal and Marine Dynamics
- Marine and coastal plant biology
- Remote Sensing in Agriculture
- Oil Spill Detection and Mitigation
- Aquatic Ecosystems and Phytoplankton Dynamics
- Space exploration and regulation
- Environmental Monitoring and Data Management
- Marine and environmental studies
- Remote-Sensing Image Classification
- Coastal and Marine Management
- Water Quality Monitoring Technologies
- Underwater Acoustics Research
- Marine and fisheries research
- Coastal wetland ecosystem dynamics
- Water Quality and Resources Studies
- Remote Sensing and LiDAR Applications
- Aeolian processes and effects
- Algal biology and biofuel production
- Underwater Vehicles and Communication Systems
- Space Exploration and Technology
United States Naval Research Laboratory
2013-2023
Consortium For Ocean Leadership
2011
Office of Naval Research
1994-2008
Ocean Optics (United States)
1995
Johnson Space Center
1994
Laboratoire d'ethnologie et de sociologie comparative
1994
Bigelow Laboratory for Ocean Sciences
1987-1991
College of Marin
1980-1986
University of Delaware
1980-1986
Procedures that may be used to evaluate the operational performance of a wide spectrum geophysical models are introduced. Primarily using complementary set difference measures, both model accuracy and precision can meaningfully estimated, regardless whether predictions manifested as scalars, directions, or vectors. It is additionally suggested reliability measures determined from bootstrap estimates confidence significance. Recommended procedures illustrated with comparative evaluation two...
Ocean color measured from satellites provides daily global, synoptic views of spectral waterleaving reflectances that can be used to generate estimates marine inherent optical properties (IOPs). These reflectances, namely the ratio upwelled radiances downwelled irradiances, describe light exiting a water mass defines its color. IOPs are absorption and scattering characteristics ocean dissolved particulate constituents. Because their dependence on concentration composition constituents,...
Two coccolithophore blooms in the Gulf of Maine were studied 1988 and 1989. Each bloom was about 50,000 km 2 area confined to top 20 m water column. Maximal cell concentrations 2,000 cells ml −1 coccolith densities 3 × 10 5 observed. The : ratio highest center (region most intense reflectance) lowest at periphery, an indication varying organic vs. inorganic C production. Chlorophyll generally low within no relation could be observed between major nutrients abundance. Backscattered light...
Natural oil seepage in the Gulf of Mexico causes persistent surface slicks that are visible from space predictable locations. A photograph sun glint pattern offshore Louisiana taken shuttle Atlantis on May 5, 1989, shows at least 124 an area about 15,000 km 2 ; a thematic mapper (TM) image collected by Landsat orbiter July 31, 1991, 66 cloud‐free 8200 overlaps photograph. Samples and descriptions made ship, aircraft, submarine confirmed presence crude floating slicks. The imagery data show...
Abstract The biodiversity and high productivity of coastal terrestrial aquatic habitats are the foundation for important benefits to human societies around world. These globally distributed need frequent broad systematic assessments, but field surveys only cover a small fraction these areas. Satellite‐based sensors can repeatedly record visible near‐infrared reflectance spectra that contain absorption, scattering, fluorescence signatures functional phytoplankton groups, colored dissolved...
Intensifying pressure on global aquatic resources and services due to population growth climate change is inspiring new surveying technologies provide science-based information in support of management policy strategies. One area rapid development hyperspectral remote sensing: imaging across the full spectrum visible infrared light. Hyperspectral imagery contains more environmentally meaningful than panchromatic or multispectral poised applications relevant society, including assessments...
Flow cytometric measurements of light scatter, near-forward scatter (theta = 1.5-19 degrees ) and side 73-107 ), from individual marine particles is modeled using Mie theory. Particles are assumed to be homogeneous nearly spherical in shape. Uniform polystyrene microspheres oil suspensions used estimate model accuracy. Within the particle diameter range 1-32 microm, mean error for 16.9% 30.1%. respectively. The size refractive index several nannoplankton species results compared with...
We present results of oceanographic surveys visually turbid blooms the coccolithophore Emiliania huxleyi in Gulf Maine during summers 1988, 1989 and 1990. In each year, hydrographic stations within could be distinguished from non-bloom on a temperature-salinity diagram. 1988 were confined to surface waters central western Maine; T-S analyses showed they occurred higher salinity at characterized by well-defined upper mixed layer overriding sharp pycnocline. Nutrients (not measured 1988) near...
Abstract. Light emerging from natural water bodies and measured by radiometers contains information about the local type concentrations of phytoplankton, non-algal particles colored dissolved organic matter in underlying waters. An increase spectral resolution forthcoming satellite airborne remote sensing missions is expected to lead new or improved capabilities for characterizing aquatic ecosystems. Such upcoming include NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission; NASA...
A coupled atmosphere and ocean radiative transfer model, the Gulf of Maine (GOM) was developed to simulate water‐leaving radiance from a vertically stratified containing bloom coccolithophore Emiliania huxleyi . The model is based largely on atmospheric data representing Maine. submodel simulates direct sunlight diffuse skylight illuminating sea surface adjusted account for seasonal changes in aerosols. optical properties E. , required by submodel, are derived measurements collected blooms...
Until recently, optical processes in shallow water, where a large portion of solar photons penetrate to the ocean floor, has received little attention outside relatively small number modeling and remote sensing investigations. In open ocean, scales variability relation attenuation length often permit treatment inwater light field as one‐dimensional, depth‐dependent problem. waters hosting productive benthic ecosystems, such coral reefs or seagrasses, in‐water is three‐dimensional character....
We report observations of the structure front that surrounds plume Connecticut River in Long Island Sound (LIS). Salinity, temperature, and velocity near‐surface waters were measured by both towed ship‐mounted sensors an autonomous underwater vehicle. find extends south from mouth river, normal to direction tidal flow LIS then curves east parallel current. The layer depth at cross‐front jumps salinity all tend decrease as distance source increases. This is qualitatively consistent with...
Abstract Use of ocean color remote sensing to understand the effects environmental changes and anthropogenic activities on estuarine coastal waters requires capability measure track optically detectable complex biogeochemical processes. An important sensor design consideration is minimum spatial resolution required resolve key features physical biological significance. The scale variability in optical properties has been investigated using continuous, along‐track measurements collected...
In modeling the optical properties of and radiative transfer within ocean water, a common assumption is that various dissolved particulate constituents per unit concentration are constant. While this probably valid for non-living materials, it frequently not case with phytoplankton. Living cells dynamic in their size, shape, composition respond readily (time scale minutes to hours) changes environment. Since each these factors plays role determining light scatter absorption cell, assignment...
A series of laboratory experiments are reported that illustrate the response beam attenuation (λ = 660 nm) and single-cell light scatter 488 properties several species marine phytoplankton to intensity. When unialgal cultures were subjected an increase in intensity, particle-scattering component near-forward found rapidly response. Cell abundance increased only slightly over course experiments, leading conclusion was due irradiance-induced changes optical properties. The percent hourly...
Flow cytometry is used to measure dilution-induced changes in the optical properties of Dunaliella tertiolecta—light scatter, cell fluorescence, and refractive index. Observed are compared simultaneous measures volume count, extracted chlorophyll a concentration, 14C uptake rate. cytometric measurements reveal short-term dilution effects (within 1 h dilution) that not evident other morphological or physiological such as volume, Data presented which suggest these result real component index,...
Understanding how turbulence impacts marine floc formation and breakup is key to predicting particulate carbon transport in the ocean. While sinking rate has been studied laboratory in-situ, response attracted less attention. To address this problem, of bentonite clay particles flocculated salt water was experimentally. Flocs were grown a large aggregation tank under unmixed mixed conditions then subjected turbulent pipe flow. Particle size quantified using microscope imaging in-situ...
An autonomous surface vehicle instrumented with optical and acoustical sensors was deployed in Kane'ohe Bay, HI, U.S.A., to provide high-resolution, situ observations of coral reef reflectance minimal human presence. The data represented a wide range bottom type, water depth, illumination supported more thorough investigations remote sensing methods for identifying mapping shallow features. were used compute spectral R_(rs,λ) as function depth benthic signals distinguish between live...
A two-flow model is developed to simulate a light field composed of both collimated and diffuse irradiance within natural waters containing canopy bottom-adhering plants. To account for the effects submerging canopy, transmittance reflectance terms associated with each plant structure (leaves, stems, fruiting bodies, etc.) are expressed as functions ratio refractive index material surrounding media internal structure. Algebraic solutions shown yield plausible physical explanations...
The magnitude of beam attenuation attributed to suspended sediments, c p , and the slope log‐transformed spectrum, γ, were used investigate properties dynamic nature matter in waters western Long Island Sound (LIS) adjacent Connecticut River plume (CRP). Within LIS, γ indicate a robust relationship between sediment concentration particle size distribution (PSD). As increased, PSD shifted larger particles. highest concentrations sizes found nepheloid layer sound floor. CRP, sediments observed...