Cullen, John: Recent submissions
Now showing items 1-20 of 37
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Primary Production Estimates from Recordings of Solar Stimulated Fluorescence in the Equatorial Pacific at 150-Degrees-W
Biological, optical, and hydrographical data were collected on the WEC88 cruise along 150-degrees-W and during a 6-day time series station on the equator during February/March 1988. This area was characterized by a subsurface ... -
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Methyl iodide in the NW Atlantic; spatial and seasonal variation
While the global ocean is an important source of atmospheric methyl iodide (CH (sub 3) I), the major producers of CH (sub 3) I within the ocean remain unclear. During a seasonal study in the NW Atlantic, the relationship ... -
Ocean Fertilization Science, Policy, and Commerce
Over the past 20 years there has been growing interest in the concept of fertilizing the ocean with iron to abate global warming. This interest was catalyzed by basic scientific experiments showing that iron limits primary ... -
Changes in buoyancy and chemical composition during growth of a coastal marine diatom: Ecological and biogeochemical consequences
Growth and sinking of the coastal marine diatom Thalassiosira weissflogii was studied during experiments in a 2.1 m tall water column. Under nutrient-replete conditions, T. weissflogii grew rapidly in the upper layer of ... -
Inferred influence of nutrient availability on the relationship between Sun-induced chlorophyll fluorescence and incident irradiance in the Bering Sea
This study examines variability in the relationship between Sun-induced chlorophyll fluorescence and incident solar irradiance as a potential diagnostic of the nutritional status of phytoplankton. The study site is the ... -
Distributions of Pigments and Primary Production in a Gulf-Stream Meander
An investigation was made of physical effects of Gulf Stream meandering on the vertical and horizontal distributions of photosynthetic pigments and primary production. Cruises were conducted in the vicinity of a meander ... -
New production in the warm waters of the Tropical Pacific Ocean
The average depth-integrated rate of new production in the tropical Pacific Ocean was estimated from a calculation of horizontal and vertical nitrate balance over the region enclosed by the climatological 26 degree C ... -
Spectrally weighted transparency in models of water-column photosynthesis and photoinhibition by ultraviolet radiation
We present a simple method for describing the influence of variable attenuation of spectral irradiance, Kd(lambda), on water-column photosynthesis and its inhibition by ultraviolet radiation (UV). The approach is based on ... -
Vertical migration, nutrition and toxicity in the dinoflagellate Alexandrium tamarense
The effect of nitrate-N availability on paralytic shellfish toxin production by the dinoflagellate Alexandrium tamarense was studied in a vertically stratified laboratory water column (tank) where swimming behavior could ... -
Fine-Scale Vertical Resolution of Chlorophyll and Photosynthetic Parameters in Shallow-Water Benthos
The vertical distributions of chlorophyll concentration and photosynthetic parameters of sediment-associated microalgae were measured with a resolution of 1 mm. Sediment and the overlying water were sampled at 3 sandy, ... -
Primary production by suspended and benthic microalgae in a turbid estuary: Time-scales of variability in San Antonio Bay, Texas
The within-day, between-day and month-to-month variability of light attenuation and microalgal chlorophyll a (chl a) and photosynthetic response was measured in San Antonio Bay, Texas, USA. Waters were shallow (<2 m) ... -
Inhibition of marine photosynthesis by ultraviolet radiation: Variable sensitivity of phytoplankton in the Weddell-Scotia Confluence during the austral spring
To assess the potential impacts of ozone depletion on photosynthesis in the Southern Ocean, we need to know more about effects of ultraviolet radiation (UV) on phytoplankton in Antarctic waters, where, in addition to ... -
Mapping coastal optical and biogeochemical variability using an autonomous underwater vehicle and a new bio-optical inversion algorithm
Autonomous underwater vehicles (AUVs) can map water conditions at high spatial ( horizontal and vertical) and temporal resolution, including under cloudy conditions when satellite and airborne remote sensing are not feasible. ... -
Relationships between vertical mixing and photoadaptation of phytoplankton: Similarity criteria
In their natural environment phytoplankton are exposed to fluctuations in incident irradiance due to vertical displacements in the water column induced by turbulent fluid motion. A reaction-diffusion model is analyzed to ... -
Retrieval of phytoplankton biomass from simultaneous inversion of reflectance, the diffuse attenuation coefficient, and Sun-induced fluorescence in coastal waters
[1] A model has been developed to retrieve phytoplankton absorption, a proxy for phytoplankton biomass, from observations of reflectance ( R) and the diffuse attenuation coefficient (K-d) collected by moored radiometers ... -
New algorithms for MODIS sun-induced chlorophyll fluorescence and a comparison with present data products
We discuss important sources of variability in sun-induced chlorophyll fluorescence and examine difficulties in deriving fluorescence data products from satellite imagery, with a focus on the MODerate-resolution Imaging ... -
Phytoplankton Growth and Light-Absorption as Regulated by Light, Temperature, and Nutrients
Numerous studies of the growth of phytoplankton in the laboratory have demonstrated the dependence of cellular pigment concentration and growth rate upon light intensity, photoperiod, temperature, and nutrient supply. These ...
