A new UV submersible spectroradiometer has been employed to determine the diffuse attenuation coefficient for irradiance in clearest natural waters [K(w)(lambda)] with emphasis on spectral region from 300 400 nm. K(w)(lambda) can be related inherent optical properties of pure water, particular total absorption a(w)(lambda) and molecular scattering b(m)(lambda), by means equations derived radiative transfer theory. We present an analysis showing that limiting values estimated vice versa....

A semianalytical radiance model is developed which predicts the upwelled spectral at sea surface as a function of phytoplankton pigment concentration for Morel Case 1 waters. The in good agreement with experimental measurements carried out waters were not included data base used to derive it. It suggests that observed variability due variations backscattering plankton and associated detrital material. extended include other material water, such dissolved organic material, referred yellow...

The springtime stratospheric ozone (O 3 ) layer over the Antarctic is thinning by as much 50 percent, resulting in increased midultraviolet (UVB) radiation reaching surface of Southern Ocean. There concern that phytoplankton communities confined to near-surface waters marginal ice zone will be harmed UVB irradiance penetrating ocean surface, thereby altering dynamics marine ecosystems. Results from a 6-week cruise (Icecolors) Bellingshausen Sea austral spring 1990 indicated O thinned: (i)...

Abstract— Spectral irradiance measurements. from 310 to 650 nm. have been made in low and modcrately productive ocean waters. These new data selected earlier clear water are used as a basis for extrapolating the diffuse attenuation coefficient into 280 nm region. This allows quantitative calculation of penetration UV‐B (280–340 nm) biologically (DNA) effective dose‐rates function depth various types. The model Green et al . (1974a) atmospheric ozone thicknesses has obtain input surface...

The diffuse attenuation coefficient for irradiance, K T , is a physical measure of the bio‐optical state ocean waters. From an analysis and pigment concentration, specific due to chlorophyll‐like pigments found be 0.016 ± 0.003 [m −1 (mg m −3 ) ]. waters can remotely sensed by spacecraft sensors. readily measured at sea highly correlated with dependent on C . This concentration provide fraction radiant energy attenuated phytoplankton. fraction, in turn, closely related production equations...

This paper addresses the collaborative development of information infrastructure for supporting data-rich scientific collaboration. Studying empirically not only in terms spatial issues but also, and equally importantly, temporal ones, we illustrate how long-term matters. Our case is about a metadata standard an ecological research domain. It complex example where standards are recognized as one element standard-making efforts include integration semantic work software tools development....

393 M ounting evidence suggests that the earth is experiencing a period of rapid climate change. Never before has it been so important to understand how environmental change influences earth’s biota and distinguish anthropogenic from natural variability. Long-term studies in western Antarctic Peninsula (WAP) region provide opportunity observe changes physical environment are related marine ecosystem. Analyses paleoc limate records (MosleyThompson 1992, Peel Domack et al. 1993, Thompson 1994,...

A technique has been developed that leads to an optical classification of natural waters in terms the dissolved and suspended biogenous material present. As a first approximation, this made total chlorophyll‐like pigment concentration. relationship between spectral diffuse attenuation coefficient for irradiance concentration found with data from diverse types ocean waters. The specific due phytoplankton is shown be consistent laboratory measurements absorption various lot cultures phytoplankton.

A bio‐optical technique is presented which allows both the classification and optical modeling of natural waters. The spectral diffuse attenuation coefficient for irradiance (300–700 nm) has been related to two biological quantities: total concentration chlorophyll‐like pigments dissolved organic material (DOM). model a component augments our previous work in that it includes new data analysis, utilizes an improved analytic fit, extends into UV region spectrum, adds DOM component. Our model,...

This paper discusses the historical connections between two large-scale undertakings that became exemplars for worldwide data-driven scientific initiatives after World War II: International Geophysical Year (1957–1958) and Biological Program (1964–1974). The was seen by its planners as a means to promote Big Science in ecology. As term gained currency 1960s, Manhattan Project national space program paradigmatic examples, but provided scientists with an alternative model: synoptic collection...

Abstract— A quantitative analysis of the wavelength‐dependent influence solar irradiance on natural phytoplankton photosynthesis has been made. The effect productivity due to several different UV radiation regimes measured. In course this analysis, it shown that biological weighting function for photoinhibition chloroplasts (Jones and Kok, 1966) allows calculation a biologically effective dose which is consistent with measured in populations. ecological implications change available...

A simple yet accurate analytical formula is proposed to compute total and photosynthetically available solar irradiance at the ocean surface under clear skies. The takes into account most important processes occurring within atmosphere, namely, scattering by molecules aerosols absorption water vapor, ozone, aerosols. These are parameterized as a function of zenith angle, aerosol type, atmospheric visibility, vertically integrated vapor ozone amounts. When compared with radiative transfer...

Growth rates of late furcilia and juvenile Antarctic krill ( Euphausia superba Dana) in the spring summer were related to food quantity quality. The 4 yr covered by this study (1991–1992, 1993–1994, 1994–1995, 1995–1996) part seasonal time series Palmer Long‐Term Ecological Research program. Chlorophyll a concentrations represented quantity, accessory photosynthetic pigments phytoplank‐ton community composition or Instantaneous growth reflected situ nutritional history previous intermolt...

THE ANTARCTIC marine ecosystem--the assemblage of plants, animals, ocean, sea ice, and island components south the Antarctic Convergence-is among largest readily defined ecosystems on Earth (36 × 106 knl ~) (Hedgpeth, 1977; Petit et aI., 1991).This ecosystem is composed an interconnected system functionally distinct hydrographic biogeochemical subdivisions (Treguer Jacques, 1992) includes open frontal regions, shelf-slope waters, marginal ice zones.Oceanic, atmospheric, processes within this...

A major objective of biological oceanography today is to quantify the mean and variance phytoplankton production on a global basis. Synoptic satellite sensing world's ocean essential this effort which requires contemporaneous sea surface data provide complete water column information. Toward these objectives we present spectrally dependent bio‐optical model for computation in situ production. Using show that can be accurately estimated from measurements incident spectral irradiance pigment...

A "bloom" of near-surface phytoplankton occurs in the Atlantic Slope region western Ocean off U.S. East Coast spring. Satellite time series sea-surface temperature and pigment concentration, derived from measurements National Oceanic Atmospheric Administration NOAA-7 Advanced Very-High-Resolution Radiometer Aeronautics Space Nimbus-7 Coastal Zone Color Scanner, respectively, give information on spatial extent temporal development such a bloom for 28-day period April through May 1982. The...

A radiative transfer model is used to investigate the relationship between photosynthetically available radiation, E par (0 + ) and total incoming solar tot at ocean surface. The ratio of lies 0.42 0.50 for most clear sky conditions. simulations indicate that parameters governing variability ): are zenith angle, amount water vapor in atmosphere, aerosol optical thickness. influence ozone other gaseous constituents insignificant. Comparisons results field data show close agreement. Given...

A physiological‐based bio‐optical model is used to estimate vertical profiles of instantaneous, diurnal, and integrated daily rates in situ primary production throughout the water column at three stations across a coastal front. The makes use an empirical relationship between photosynthesis, quantum yield, photosynthetically absorbed radiation full spectral with all relevant parameters determined as function wavelength. In prior application this model, yield irradiance were...

This paper foregrounds the long-term perspective and role of information management in creating infrastructure to support collaborative ecological research. The case study research network is an ongoing collaboration that integrates ethnographic action approaches. We describe three interdependent elements science, data technology for which provides support, articulation work needed balancing their inherent tensions requirements generated by short long term timeframes. further managers'...