Eutrophication and temperature drive large variability in carbon dioxide from China's Lake Taihu

Tissue carbon dioxide concentrations were measured in rats following exposure of the intact animals to 10% or 30% Co2 in oxygen for time intervals from 5 minutes to 2.5 hours. The rats were sacrificed by decapitation. The average normal Co2 concentrations in skeletal muscle, heart and brain were 13.2, 18.6 and 15.1 mm/kg of wet tissue, respectively. The tissue Co2 increased at about the same rate, relative to normal concentration, in each of the three tissues, the concentration approximately doubling in the first 35 minutes on 30% Co2. The skeletal muscle Co2 concentration on 30% Co2 followed a single exponential curve in which the rate constant was 0.036 min.-1. Tissue Co2 capacity curves and data on the rate of Co2 loss post mortem are presented. The barium-soluble Co2 fraction of Conway and Fearon was found to increase in skeletal muscle from 9.4 to 14.6 mm/kg wet tissue when rats had been on 30% Co2 for 1 hour. Even in control rats this fraction showed a large variability and may have little physiological significance. Submitted on April 23, 1959

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Methane and carbon dioxide emissions from different ecosystems at the end of dry period in South Vietnam

Tropical Ecology ◽

10.1007/s42965-020-00118-1 ◽

2020 ◽

Author(s):

Jiří Dušek ◽

Vinh Xuan Nguyen ◽

Thuyen Xuan Le ◽

Marian Pavelka

Keyword(s):

Carbon Dioxide ◽

Carbon Dioxide Emissions ◽

Rain Forest ◽

Large Variability ◽

Aerobic Activity ◽

South Vietnam ◽

Gas Fluxes ◽

Soil Measurements ◽

Chamber Measurements

Abstract The carbon cycle includes important fluxes of methane (CH4) and carbon dioxide (CO2) between the ecosystem and the atmosphere. The fluxes may acquire either positive (release) or negative values (consumption). We calculated these fluxes based on short-campaign in situ chamber measurements from four ecosystems of South Vietnam: intact mountain rain forest, rice field, Melaleuca forest and mangroves (different sites with Avicennia or Rhizophora and a typhoon-disturbed gap). Soil measurements were supplemented by chamber measurements of gas fluxes from the tree stems. Measuring CH4 and CO2 together facilitates the assessment of the ratio between these two gases in connection with current conditions and specificity of individual ecosystems. The highest fluxes of CH4 were recorded in the Melaleuca forest, being within the range from 356.7 to 784.2 mg CH4–C m−2 day−1 accompanied by higher fluxes of CH4 release from Melaleuca tree stems (8.0–262.1 mg CH4–C m−2 day−1). Significant negative soil fluxes of CH4 were recorded in the mountain rain forest, within the range from − 0.3 to − 0.8 mg CH4–C m−2 day−1. Fluxes of CO2 indicate prevailing aerobic activity in the soils of the ecosystems investigated. Quite a large variability of CO2 fluxes was recorded in the soil of the Avicennia mangroves. The in situ measurements of different ecosystems are fundamental for follow-up measurements at different levels such as aerial and satellite gas fluxes observations.

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Simulating carbon exchange using a regional atmospheric model coupled to an advanced land-surface model

Biogeosciences ◽

10.5194/bg-7-2397-2010 ◽

2010 ◽

Vol 7 (8) ◽

pp. 2397-2417 ◽

Cited By ~ 8

Author(s):

H. W. Ter Maat ◽

R. W. A. Hutjes ◽

F. Miglietta ◽

B. Gioli ◽

F. C. Bosveld ◽

...

Keyword(s):

Carbon Dioxide ◽

Land Surface ◽

Land Surface Model ◽

Atmospheric Model ◽

Surface Fluxes ◽

Heat Fluxes ◽

Shortwave Radiation ◽

Surface Model ◽

Large Variability ◽

Regional Atmospheric Modelling System

Abstract. This paper is a case study to investigate what the main controlling factors are that determine atmospheric carbon dioxide content for a region in the centre of The Netherlands. We use the Regional Atmospheric Modelling System (RAMS), coupled with a land surface scheme simulating carbon, heat and momentum fluxes (SWAPS-C), and including also submodels for urban and marine fluxes, which in principle should include the dominant mechanisms and should be able to capture the relevant dynamics of the system. To validate the model, observations are used that were taken during an intensive observational campaign in central Netherlands in summer 2002. These include flux-tower observations and aircraft observations of vertical profiles and spatial fluxes of various variables. The simulations performed with the coupled regional model (RAMS-SWAPS-C) are in good qualitative agreement with the observations. The station validation of the model demonstrates that the incoming shortwave radiation and surface fluxes of water and CO2 are well simulated. The comparison against aircraft data shows that the regional meteorology (i.e. wind, temperature) is captured well by the model. Comparing spatially explicitly simulated fluxes with aircraft observed fluxes we conclude that in general latent heat fluxes are underestimated by the model compared to the observations but that the latter exhibit large variability within all flights. Sensitivity experiments demonstrate the relevance of the urban emissions of carbon dioxide for the carbon balance in this particular region. The same tests also show the relation between uncertainties in surface fluxes and those in atmospheric concentrations.

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Satellite Estimation of Dissolved Carbon Dioxide Concentrations in China’s Lake Taihu

Environmental Science & Technology ◽

10.1021/acs.est.0c04044 ◽

2020 ◽

Vol 54 (21) ◽

pp. 13709-13718

Author(s):

Tianci Qi ◽

Qitao Xiao ◽

Zhigang Cao ◽

Ming Shen ◽

Jinge Ma ◽

...

Keyword(s):

Carbon Dioxide ◽

Lake Taihu ◽

Dissolved Carbon ◽

Carbon Dioxide Concentrations ◽

Dissolved Carbon Dioxide

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Phytoprevention of Heavy Metal Contamination From Terrestrial Enhanced Weathering: Can Plants Save the Day?

Frontiers in Climate ◽

10.3389/fclim.2021.820204 ◽

2022 ◽

Vol 3 ◽

Author(s):

Tim Jesper Suhrhoff

Keyword(s):

Heavy Metals ◽

Carbon Dioxide ◽

Heavy Metal ◽

Heavy Metal Contamination ◽

Carbon Capture And Storage ◽

Heavy Metal Accumulation ◽

Environmental Risks ◽

Metal Concentrations ◽

Large Variability ◽

Heavy Metal Concentrations

Enhanced weathering is a promising approach to remove carbon dioxide from the atmosphere. However, it may also pose environmental risks through the release of heavy metals, in particular nickel and chromium. In this perspective article I explore the potential role of plants in modulating these heavy metal fluxes. Agricultural basaltic soils may be valuable study sites in this context. However, the effect of biomass harvesting on the accumulation of heavy metals is currently not well studied. Mostly caused by different parent rock concentrations, there is a large variability of heavy metal concentrations in basaltic and ultramafic soils. Hence, to minimize environmental risks of enhanced weathering, basalts with low heavy metal concentrations should be favored. Existing phytoremediation strategies may be used to “phytoprevent” the accumulation of nickel and chromium released from enhanced weathering in soils. As a result, elevated nickel and chromium concentrations in rocks must not preclude enhanced weathering in all settings. In particular, hyperaccumulating plants could be used as part of a crop rotation to periodically remove heavy metals from soils. Enhanced weathering could also be employed on fields or forests of (non-hyper) accumulating plants that have a high primary production of biomass. Both approaches may have additional synergies with phytomining or bioenergy carbon capture and storage, increasing the total amount of carbon dioxide drawdown and at the same time preventing heavy metal accumulation in soils.

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Electron Cytochemical Study of Carbon Dioxide Laser Effect on Rhesus Monkey Cornea

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005113x ◽

1974 ◽

Vol 32 ◽

pp. 224-225

Author(s):

K. C. Tsou ◽

J. Morris ◽

P. Shawaluk ◽

B. Stuck ◽

E. Beatrice

Keyword(s):

Carbon Dioxide ◽

Electron Microscope ◽

Rhesus Monkey ◽

Carbon Dioxide Laser ◽

Cytochemical Study ◽

Laser Effect

While much is known regarding the effect of lasers on the retina, little study has been done on the effect of lasers on cornea, because of the limitation of the size of the material. Using a combination of electron microscope and several newly developed cytochemical methods, the effect of laser can now be studied on eye for the purpose of correlating functional and morphological damage. The present paper illustrates such study with CO2 laser on Rhesus monkey.

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The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068382 ◽

1970 ◽

Vol 28 ◽

pp. 278-279

Author(s):

Charles TurnbiLL ◽

Delbert E. Philpott

Keyword(s):

Electron Microscopy ◽

Carbon Dioxide ◽

Surface Tension ◽

Critical Point ◽

Freeze Drying ◽

Attractive Alternative ◽

Crystal Formation ◽

Critical Point Drying ◽

Time Required ◽

Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

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