Turbulent gas flux measurements below the air-water interface of a grid-stirred tank

1992 ◽  
Vol 35 (8) ◽  
pp. 1957-1968 ◽  
Author(s):  
Chia Ren Chu ◽  
Gerhard H. Jirka
Keyword(s):  
Stirred Tank ◽  
Water Interface ◽  
Gas Flux ◽  
Air Water Interface ◽  
Flux Measurements

Uncertainty analysis of gas flux measurements at air–water interface using floating chambers

2019 ◽  
Vol 19 (4) ◽  
pp. 475-486
Author(s):  
Michael Mannich ◽  
Cristovão Vicente Scapulatempo Fernandes ◽  
Tobias Bernward Bleninger
Keyword(s):  
Uncertainty Analysis ◽  
Water Interface ◽  
Gas Flux ◽  
Air Water Interface ◽  
Flux Measurements

scholarly journals Numerical tools to estimate the flux of a gas across the air–water interface and assess the heterogeneity of its forcing functions

Ocean Science ◽  
2013 ◽  
Vol 9 (2) ◽  
pp. 355-375 ◽  
Author(s):  
V. M. N. C. S. Vieira ◽  
F. Martins ◽  
J. Silva ◽  
R. Santos
Keyword(s):  
Atmospheric Stability ◽  
Water Interface ◽  
Co2 Fluxes ◽  
Gas Flux ◽  
Ria Formosa ◽  
Custom Made ◽  
Air Water Interface ◽  
Forcing Functions ◽  
Flux Model ◽  
The Difference

Abstract. A numerical tool was developed for the estimation of gas fluxes across the air–water interface. The primary objective is to use it to estimate CO2 fluxes. Nevertheless application to other gases is easily accomplished by changing the values of the parameters related to the physical properties of the gases. A user-friendly software was developed allowing to build upon a standard kernel a custom-made gas flux model with the preferred parameterizations. These include single or double layer models; several numerical schemes for the effects of wind in the air-side and water-side transfer velocities; the effects of atmospheric stability, surface roughness and turbulence from current drag with the bottom; and the effects on solubility of water temperature, salinity, air temperature and pressure. An analysis was also developed which decomposes the difference between the fluxes in a reference situation and in alternative situations into its several forcing functions. This analysis relies on the Taylor expansion of the gas flux model, requiring the numerical estimation of partial derivatives by a multivariate version of the collocation polynomial. Both the flux model and the difference decomposition analysis were tested with data taken from surveys done in the lagoon system of Ria Formosa, south Portugal, in which the CO2 fluxes were estimated using the infrared gas analyzer (IRGA) and floating chamber method, whereas the CO2 concentrations were estimated using the IRGA and degasification chamber. Observations and estimations show a remarkable fit.

scholarly journals Numerical tools to estimate the flux of a gas across the air-water interface and assess the heterogeny of its forcing functions

2012 ◽  
Vol 9 (2) ◽  
pp. 909-975
Author(s):  
Keyword(s):  
Decomposition Analysis ◽  
Water Interface ◽  
Co2 Fluxes ◽  
Gas Flux ◽  
Ria Formosa ◽  
Custom Made ◽  
Air Water Interface ◽  
Forcing Functions ◽  
Flux Model ◽  
The Difference

Abstract. A numerical tool was developed for the estimation of gas fluxes across the air water interface. The primary objective is to use it to estimate CO2 fluxes. Nevertheless application to other gases is easily accomplished by changing the values of the parameters related to the physical properties of the gases. A user friendly software was developed allowing to build upon a standard kernel a custom made gas flux model with the preferred parametrizations. These include single or double layer models; several numerical schemes for the effects of wind in the air-side and water-side transfer velocities; the effect of turbulence from current drag with the bottom; and the effects on solubility of water temperature, salinity, air temperature and pressure. It was also developed an analysis which decomposes the difference between the fluxes in a reference situation and in alternative situations into its several forcing functions. This analysis relies on the Taylor expansion of the gas flux model, requiring the numerical estimation of partial derivatives by a multivariate version of the collocation polynomial. Both the flux model and the difference decomposition analysis were tested with data taken from surveys done in the lagoonary system of Ria Formosa, south Portugal, in which the CO2 fluxes were estimated using the IRGA and floating chamber method whereas the CO2 concentrations were estimated using the IRGA and degasification chamber. Observations and estimations show a remarkable fit.

Modelling of gas flux through bubbles at the air-water interface

Tellus B ◽  
1985 ◽  
Vol 37B (4-5) ◽  
pp. 272-285 ◽  
Author(s):  
LAURENT MEMERY ◽  
LILIANE MERLIVAT
Keyword(s):  
Water Interface ◽  
Gas Flux ◽  
Air Water Interface

Modelling of gas flux through bubbles at the air-water interface

Tellus B ◽  
1985 ◽  
Vol 37 (4-5) ◽  
pp. 272-285 ◽  
Author(s):  
Laurent Memery ◽  
Liliane Merlivat
Keyword(s):  
Water Interface ◽  
Gas Flux ◽  
Air Water Interface

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

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