Optical measurements of backscatter and absorption for characterizing water column structure and spatial pattern of coastal ocean color

2005 ◽  
Author(s):  
Leon M. Delwiche ◽  
Miles G. Logsdon
Keyword(s):  
Spatial Pattern ◽  
Water Column ◽  
Ocean Color ◽  
Coastal Ocean ◽  
Optical Measurements ◽  
Column Structure

scholarly journals Differential co-occurrence relationships shaping ecotype diversification within Thaumarchaeota populations in the coastal ocean water column

2019 ◽  
Vol 13 (5) ◽  
pp. 1144-1158 ◽  
Author(s):  
Linta Reji ◽  
Bradley B. Tolar ◽  
Jason M. Smith ◽  
Francisco P. Chavez ◽  
Christopher A. Francis
Keyword(s):  
Water Column ◽  
Coastal Ocean ◽  
Ocean Water

scholarly journals Optical tools for ocean monitoring and research

Ocean Science ◽  
2009 ◽  
Vol 5 (4) ◽  
pp. 661-684 ◽  
Author(s):  
C. Moore ◽  
A. Barnard ◽  
P. Fietzek ◽  
M. R. Lewis ◽  
H. M. Sosik ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ocean Color ◽  
Analytical Techniques ◽  
Optical Measurements ◽  
Physical Parameters ◽  
Optical Tools ◽  
Wide Range ◽  
Radiance Distribution ◽  
Ocean Monitoring ◽  
Methane Carbon

Abstract. Requirements for understanding the relationships between ocean color and suspended and dissolved materials within the water column, and a rapidly emerging photonics and materials technology base for performing optical based analytical techniques have generated a diverse offering of commercial sensors and research prototypes that perform optical measurements in water. Through inversion, these tools are now being used to determine a diverse set of related biogeochemical and physical parameters. Techniques engaged include measurement of the solar radiance distribution, absorption, scattering, stimulated fluorescence, flow cytometry, and various spectroscopy methods. Selective membranes and other techniques for material isolation further enhance specificity, leading to sensors for measurement of dissolved oxygen, methane, carbon dioxide, common nutrients and a variety of other parameters. Scientists are using these measurements to infer information related to an increasing set of parameters and wide range of applications over relevant scales in space and time.

scholarly journals Water column structure and statistics of Denmark Strait Overflow Water cyclones

2014 ◽  
Vol 84 ◽  
pp. 110-126 ◽  
Author(s):  
Wilken-Jon von Appen ◽  
Robert S. Pickart ◽  
Kenneth H. Brink ◽  
Thomas W.N. Haine
Keyword(s):  
Water Column ◽  
Column Structure ◽  
Denmark Strait

scholarly journals Water Column Optical Properties of Pacific Coral Reefs Across Geomorphic Zones and in Comparison to Offshore Waters

2019 ◽  
Vol 11 (15) ◽  
pp. 1757 ◽  
Author(s):  
Russell ◽  
Dierssen ◽  
Hochberg
Keyword(s):  
Optical Properties ◽  
Coral Reefs ◽  
Water Column ◽  
Light Availability ◽  
Optical Measurements ◽  
Fringing Reefs ◽  
Tropical Conditions ◽  
Local Measurements ◽  
High Degree ◽  
Significant Underestimation

Despite the traditional view of coral reefs occurring in oligotrophic tropical conditions, water optical properties over coral reefs differ substantially from nearby clear oceanic waters. Through an extensive set of optical measurements across the tropical Pacific, our results suggest that coral reefs themselves exert a high degree of influence over water column optics, primarily through release of colored dissolved organic matter (CDOM). The relative contributions of phytoplankton, non-algal particles, and CDOM were estimated from measurements of absorption and scattering across different geomorphic shallow-water reef zones (<10 m) in Hawaii, the Great Barrier Reef, Guam, and Palau (n = 172). Absorption was dominated at the majority of stations by CDOM, with mixtures of phytoplankton and CDOM more prevalent at the protected back reef and lagoon zones. Absorption could be dominated by sediments and phytoplankton at fringing reefs and terrestrially impacted sites where particulate backscattering was significantly higher than in the other zones. Scattering at three angles in the backward direction followed recent measurements of the particulate phase function. Optical properties derived from satellite imagery indicate that offshore waters are consistently lower in absorption and backscattering than reef waters. Therefore, the use of satellite-derived offshore parameters in modeling reef optics could lead to significant underestimation of absorption and scattering, and overestimation of benthic light availability. If local measurements are not available, average optical properties based on the general reef zone could provide a more accurate means of assessing light conditions on coral reefs than using offshore water as a proxy.

scholarly journals A note on modeling mixing in the upper layers of the Bay of Bengal: Importance of water type, water column structure and precipitation

2019 ◽  
Vol 168 ◽  
pp. 104643
Author(s):  
Lakshmi Kantha ◽  
Robert A. Weller ◽  
J. Thomas Farrar ◽  
Hasibur Rahaman ◽  
Venkata Jampana
Keyword(s):  
Water Column ◽  
Bay Of Bengal ◽  
Water Type ◽  
Column Structure ◽  
Type Water

scholarly journals Large-Eddy Simulation of a Coastal Ocean under the Combined Effects of Surface Heat Fluxes and Full-Depth Langmuir Circulation

2016 ◽  
Vol 46 (8) ◽  
pp. 2411-2436 ◽  
Author(s):  
Rachel Walker ◽  
Andrés E. Tejada-Martínez ◽  
Chester E. Grosch
Keyword(s):  
Water Column ◽  
Stable Stratification ◽  
Coastal Ocean ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Surface Heating ◽  
Surface Cooling ◽  
Surface Heat Fluxes ◽  
Wide Range ◽  
Large Eddy

AbstractResults are presented from the large-eddy simulations (LES) of a wind-driven flow representative of the shallow coastal ocean under the influences of Langmuir forcing and surface heating and cooling fluxes. Langmuir (wind and surface gravity wave) forcing leads to the generation of Langmuir turbulence consisting of a wide range of Langmuir circulations (LCs) or parallel, counterrotating vortices that are aligned roughly in the direction of the wind. In unstratified, shallow coastal regions, the largest of the LCs reach the bottom of the water column. Full-depth LCs are investigated under surface waves with a significant wave height of 1.2 m and a dominant wavelength of 90 m and wave period of 8 s, for a wind speed of 7.8 m s−1 in a 15-m-deep coastal shelf region. Both unstable and stable stratification are imposed by constant surface heat fluxes and an adiabatic bottom wall. Simulations are characterized by Rayleigh and Richardson numbers representative of surface buoyancy forcing relative to wind forcing. For the particular combination of Langmuir forcing parameters studied, although surface cooling is able to augment the strength of LC, a significantly high cooling flux of 560 W m−2 (such that the Rayleigh number is Raτ = 1000) is required in order for turbulence kinetic energy generation by convection to exceed Langmuir production. Such a transition is expected at a lower heat flux for weaker wind and wave conditions and thus weaker LCs than those studied. Furthermore, a surface heating flux of approximately 281 W m−2 (such that the Richardson number is Riτ = 500) is able to inhibit vertical mixing of LC, particularly in the bottom half of the water column, allowing stable stratification to develop.

Water Column Structure and Circulation In The Main channel, Twin Cays, Belize

2005 ◽  
Vol 535 ◽  
pp. 136-156
Author(s):  
S. R. Kibler ◽  
Maria A. Faust ◽  
M. V. Vandersea ◽  
S. M. Varnam ◽  
R. Wayne Litaker ◽  
...  
Keyword(s):  
Water Column ◽  
Main Channel ◽  
Column Structure
Sign in / Sign up

Export Citation Format

Share Document