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Journal articles on the topic 'Carbon dioxide flux'

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Author: Grafiati

Published: 4 June 2021

Last updated: 28 January 2023

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1

Liang, Zhan Qi, Dan Shan, Hao Rong, and En De Xing. "The Study of Carbon Dioxide Flux on Xilamuren Grassland Based on the Eddy Covariance Technique." Applied Mechanics and Materials 209-211 (October 2012): 1162–65. http://dx.doi.org/10.4028/www.scientific.net/amm.209-211.1162.

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The eddy covariance is a micrometeorological technique to observe and investigate ecosystem flux nondestructively, as well as the main method the eddy covariance may help to research carbon dioxide exchange between global vegetations and the atmosphere. Carbon dioxide flux has been monitored on Xilamuren grassland of Wulanchabu city by Open Path Eddy Covariance System (OP-2). Carbon dioxide flux shows that carbon absorption is greater than its release, which has an evident carbon sink functions and obvious seasonal variety on the basis of experimental data from June 2009 to July 2011.

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2

Parkin, Timothy B., and Thomas C. Kaspar. "Temperature Controls on Diurnal Carbon Dioxide Flux." Soil Science Society of America Journal 67, no. 6 (November 2003): 1763–72. http://dx.doi.org/10.2136/sssaj2003.1763.

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3

Parkin, Timothy B., and Thomas C. Kaspar. "Temporal Variability of Soil Carbon Dioxide Flux." Soil Science Society of America Journal 68, no. 4 (July 2004): 1234–41. http://dx.doi.org/10.2136/sssaj2004.1234.

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4

Wuest, Stewart B., Daniel Durr, and Stephan L. Albrecht. "Carbon Dioxide Flux Measurement During Simulated Tillage." Agronomy Journal 95, no. 3 (2003): 715. http://dx.doi.org/10.2134/agronj2003.0715.

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5

Wuest, Stewart B., Daniel Durr, and Stephan L. Albrecht. "Carbon Dioxide Flux Measurement During Simulated Tillage." Agronomy Journal 95, no. 3 (May 2003): 715–18. http://dx.doi.org/10.2134/agronj2003.7150.

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6

Riederer, M., A. Serafimovich, and T. Foken. "Net ecosystem CO<sub>2</sub> exchange measurements by the closed chamber method and the eddy covariance technique and their dependence on atmospheric conditions." Atmospheric Measurement Techniques 7, no. 4 (April 25, 2014): 1057–64. http://dx.doi.org/10.5194/amt-7-1057-2014.

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Abstract. Carbon dioxide flux measurements in ecosystem sciences are mostly conducted by eddy covariance technique or the closed chamber method. But there is a lack of detailed comparisons that assess present differences and uncertainties. To determine underlying processes, a 10-day, side-by-side measurement of the net ecosystem exchange with both techniques was evaluated with regard to various atmospheric conditions during the diurnal cycle. It was found that, depending on the particular atmospheric condition, the chamber carbon dioxide flux was either (i) equal to the carbon dioxide flux measured by the reference method eddy covariance, by day with well-developed atmospheric turbulence; (ii) higher, in the afternoon in times of oasis effect; (iii) lower, predominantly at night while large coherent structure fluxes or high wind velocities prevailed; or (iv) showed less variation in the flux pattern, at night while stable stratification was present. At night – when respiration forms the net ecosystem exchange – lower chamber carbon dioxide fluxes were found. In the afternoon – when the ecosystem is still a net carbon sink – the carbon dioxide fluxes measured by the chamber prevailed. These two complementary aspects resulted in an overestimation of the ecosystem sink capacity by the chamber of 40% in this study.

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7

Riederer, M., A. Serafimovich, and T. Foken. "Net ecosystem CO<sub>2</sub> exchange measurements by the closed chamber method and the eddy covariance technique and their dependence on atmospheric conditions – a case study." Atmospheric Measurement Techniques Discussions 6, no. 5 (October 7, 2013): 8783–805. http://dx.doi.org/10.5194/amtd-6-8783-2013.

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Abstract. Carbon dioxide flux measurements in ecosystem sciences are mostly conducted by eddy covariance technique or the closed chamber method. Also some comparisons have been performed. But there is a lack of detailed assessment of present differences and uncertainties. To determine underlying processes, a ten-day, side-by-side measurement of the net ecosystem exchange with both techniques was evaluated with regard to various atmospheric conditions during the diurnal cycle. It was found that, depending on the particular atmospheric condition, the chamber carbon dioxide flux was either: (i) equal to the carbon dioxide flux measured by the reference method eddy covariance, by day with well developed atmospheric turbulence, (ii) higher, in the afternoon in times of oasis effect, (iii) lower, predominantly at night while large coherent structure fluxes or high wind velocities prevailed, or, (iv) showed less variation in the flux pattern, at night while stable stratification was present. Due to lower chamber carbon dioxide fluxes at night, when respiration forms the net ecosystem exchange, and higher chamber carbon dioxide fluxes in the afternoon, when the ecosystem is still a net carbon sink, there are two complementary aspects resulting in an overestimation of the ecosystem sink capacity by the chamber of 40% in this study.

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8

Kessler, Toby J., and Charles F. Harvey. "The global flux of carbon dioxide into groundwater." Geophysical Research Letters 28, no. 2 (January 15, 2001): 279–82. http://dx.doi.org/10.1029/2000gl011505.

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9

McGillis, Wade R., James B. Edson, Jonathan D. Ware, John W. H. Dacey, Jeffrey E. Hare, Christopher W. Fairall, and Rik Wanninkhof. "Carbon dioxide flux techniques performed during GasEx-98." Marine Chemistry 75, no. 4 (September 2001): 267–80. http://dx.doi.org/10.1016/s0304-4203(01)00042-1.

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10

Golley, Frank, Sanne Bakker, and Toshihide Hamazaki. "Carbon dioxide flux across a forest-field ecotone." Environmental Monitoring and Assessment 22, no. 2 (August 1992): 117–22. http://dx.doi.org/10.1007/bf00418010.

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11

Islam, MA, M. Mano, MS Hossen, A. Miyata, and MA Baten. "Diurnal Variation of Carbon Dioxide Flux Over Rice Paddy." Journal of Environmental Science and Natural Resources 9, no. 2 (April 14, 2017): 127–30. http://dx.doi.org/10.3329/jesnr.v9i2.32182.

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An experiment was conducted to measure carbon dioxide (CO2) flux by using the eddy covariance technique over rice paddy field at Mymensingh flux study site at Bangladesh Agricultural University, Mymensingh at three growing stage in Aman season in 2015. The variation of CO2 flux in the experimental period displayed distinct diurnal variations as influenced by rice growth and development. The diurnal pattern of CO2 flux showed broad peak at flowering stage of Aman rice at DOY 285 due to photosynthesis. The diurnal pattern of CO2 flux showed also higher broad peak at 1500 hour in DOY 272 at vegetative stage and lower broad peak at 1300 hour in DOY 330 ripening stage of Aman rice due to photosynthesis, meteorological conditions and field management activities.J. Environ. Sci. & Natural Resources, 9(2): 127-130 2016

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12

Latifah, Nurul, Sigit Febrianto, Anindya Wirasatriya, Hadi Endrawati, Muhammad Zainuri, Suryanti Suryanti, and Andreas Nur Hidayat. "AIR-SEA FLUX OF CO2 IN THE WATERS OF KARIMUNJAWA ISLAND, INDONESIA." Saintek Perikanan : Indonesian Journal of Fisheries Science and Technology 16, no. 3 (October 23, 2020): 171–78. http://dx.doi.org/10.14710/ijfst.16.3.171-178.

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The purpose of this study was to determine the distribution of CO2 flux in Karimunjawa in the east monsoon. The variables in this study were temperature; pH; salinity; DO; CO2 atm was measured using a CO2 meter; chlorophyll-a, phosphate, silicate were measured spectrophotometric method. Total Alkalinity / TA was measured using the titration method with the principle of changing pH; DIC (Dissolved Inorganic Carbon) was measured using CO2sys software. The partial pressure of seawater carbon dioxide calculated using formula: pCO2sea = 6.31T2 + 61,9 Chla2 – 365.85T – 94.41 Chl-a +5715.94, the partial pressure of atmospheric carbon dioxide calculated using formula: pCO2atm = xCO2atm (pb - pH2O). The calculation of the estimated CO2 flux using the formula: Flux CO2 = Kh x kwa x (∆pCO2) , if the CO2 flux has a positive value water acts as a CO2 source, and if it is negative, the waters act as a CO2 sink.. CO2 flux in Karimunjawa waters during east monsoon (represented by August 2018) showed that in Karimunjawa waters with normal pH 7.2-7.4 were dominated by bicarbonate ion HCO3-with an average value of DIC 1847.24 µmol/kg dan TA 1912.51 µmol/kg. The partial pressure of seawater CO2 is higher than the partial pressure of atmospheric CO2 this indicates that the role of Karimunjawa waters as a source of CO2 where there is release of carbon dioxide into the atmosphere with CO2 flux values ranging from 8.549 – 13.272 mmol m-2 day-1. The variables that affect the flux of CO2 were the pCO2sea and ΔpCO2 with a very strong and positive correlation. These two variables were influenced by sea water temperature, salinity, chlorophyll-a, phosphate and silicate.

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13

Zimmer, Martin, Peter Pilz, and Jörg Erzinger. "Long-term surface carbon dioxide flux monitoring at the Ketzin carbon dioxide storage test site." Environmental Geosciences 18, no. 2 (June 2011): 119–30. http://dx.doi.org/10.1306/eg.11181010017.

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14

Allaire, S. E., C. Dufour-L'Arrivée, J. A. Lafond, R. Lalancette, and J. Brodeur. "Carbon dioxide emissions by urban turfgrass areas." Canadian Journal of Soil Science 88, no. 4 (August 1, 2008): 529–32. http://dx.doi.org/10.4141/cjss07043.

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This research compared four turfgrass lawn management approaches on CO2 emissions: (1) fertilized and frequently mowed with clippings removal, and unfertilized with clippings left on site and mowed 2) weekly, 3) three times, or 4) once during the growing season. CO2 emissions were measured weekly with flux chambers. Mowing frequency had higher impact on CO2 flux than fertilisation and soil characteristics. Frequently mowed sites emitted CO2 at a maximum rate of 0.63 mg m-2 s-1 and annually up to 2.0 kg m-2, an emission four times higher than lawns mowed infrequently. Differences between treatments mostly occurred during warm weeks. Key words: Lawns, greenhouse gases, carbon cycle, carbon dioxide, net CO2 exchange

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15

Culf, A. D., G. Fisch, Y. Malhi, R. Carvalho Costa, A. D. Nobre, A. de O. Marques Filho, J. H. C. Gash, and J. Grace. "Carbon dioxide measurements in the nocturnal boundary layer over Amazonian forest." Hydrology and Earth System Sciences 3, no. 1 (March 31, 1999): 39–53. http://dx.doi.org/10.5194/hess-3-39-1999.

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Abstract. Measurements of carbon dioxide concentration, temperature and windspeed were made in the nocturnal boundary layer over a tropical forest near Manaus, Brazil using a tethered balloon system. The measurements were made up to a maximum height of 300 m on ten consecutive nights in November 1995. Simultaneous surface flux and in-canopy concentration measurements were made at the surface close to the site. The observation period included several different types of conditions. Generally strong windshear and relatively weak temperature gradients prevented the formation of a strong capping inversion to the nocturnal boundary layer. On some nights, however, the inversion was sufficiently strong that the CO2 concentration at 100 m above the surface exceeded 400 ppm. The concentration within the canopy was largely controlled by the presence of an inversion very close to the canopy surface. The temperature and wind profiles are contrasted with conditions in Randônia, Brazil, where the windshear was found to be weaker and higher carbon dioxide concentrations were observed in the early morning. The difference in carbon dioxide concentrations in the nocturnal boundary layer between dusk and dawn is used to estimate the regional nighttime flux of carbon dioxide. The value obtained generally exceeds the measured surface flux and sometimes exceeds the sum of the surface flux and the in-canopy storage made at the tower site. The reasons for the discrepancy are not clear; either one of the methods is in error or the regional carbon dioxide budget differs significantly from the local budget measured at the tower site.

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16

Thaysen, E. M., D. Jacques, S. Jessen, C. E. Andersen, E. Laloy, P. Ambus, D. Postma, and I. Jakobsen. "Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms." Biogeosciences Discussions 11, no. 3 (March 17, 2014): 4251–99. http://dx.doi.org/10.5194/bgd-11-4251-2014.

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Abstract. The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated. Carbon dioxide partial pressure in the soil gas (pCO2), alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley) mesocosms. The dissolved inorganic carbon (DIC) percolation flux was calculated from the pCO2, alkalinity and the water flux at the mesocosm bottom. Carbon dioxide exchange between the soil surface and the atmosphere was measured at regular intervals. The soil diffusivity was determined from soil radon-222 (222Rn) emanation rates and soil air Rn concentration profiles, and was used in conjunction with measured pCO2 gradients to calculate the soil CO2 production. Carbon dioxide fluxes were modelled using the HP1 module of the Hydrus 1-D software. The average CO2 effluxes to the atmosphere from unplanted and planted mesocosm ecosystems during 78 days of experiment were 0.1 ± 0.07 and 4.9 ± 0.07 μmol carbon (C) m−2 s−1, respectively, and largely exceeded the corresponding DIC percolation fluxes of 0.01 ± 0.004 and 0.06 ± 0.03 μmol C m−2 s−1. Post-harvest soil respiration (Rs) was only 10% of the Rs during plant growth, while the post-harvest DIC percolation flux was more than one third of the flux during growth. The Rs was controlled by production and diffusivity of CO2 in the soil. The DIC percolation flux was largely controlled by the pCO2 and the drainage flux due to low solution pH. Plant biomass and soil pCO2 were high in the mesocosms as compared to a standard field situation. Our results indicate no change of the cropland C balance under elevated atmospheric CO2 in a warmer future climate, in which plant biomass and soil pCO2 are expected to increase.

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17

Thaysen, E. M., D. Jacques, S. Jessen, C. E. Andersen, E. Laloy, P. Ambus, D. Postma, and I. Jakobsen. "Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms." Biogeosciences 11, no. 24 (December 17, 2014): 7179–92. http://dx.doi.org/10.5194/bg-11-7179-2014.

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Abstract. The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon (C) fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated to reveal controlling underlying mechanisms. Carbon dioxide partial pressure in the soil gas (pCO2), alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley) mesocosms. The dissolved inorganic carbon (DIC) percolation flux was calculated from the pCO2, alkalinity and the water flux at the mesocosm bottom. Carbon dioxide exchange between the soil surface and the atmosphere was measured at regular intervals. The soil diffusivity was determined from soil radon-222 (222Rn) emanation rates and soil air Rn concentration profiles and was used in conjunction with measured pCO2 gradients to calculate the soil CO2 production. Carbon dioxide fluxes were modeled using the HP1 module of the Hydrus 1-D software. The average CO2 effluxes to the atmosphere from unplanted and planted mesocosm ecosystems during 78 days of experiment were 0.1 ± 0.07 and 4.9 ± 0.07 μmol C m−2 s−1, respectively, and grossly exceeded the corresponding DIC percolation fluxes of 0.01 ± 0.004 and 0.06 ± 0.03 μmol C m−2 s−1. Plant biomass was high in the mesocosms as compared to a standard field situation. Post-harvest soil respiration (Rs) was only 10% of the Rs during plant growth, while the post-harvest DIC percolation flux was more than one-third of the flux during growth. The Rs was controlled by production and diffusivity of CO2 in the soil. The DIC percolation flux was largely controlled by the pCO2 and the drainage flux due to low solution pH. Modeling suggested that increasing soil alkalinity during plant growth was due to nutrient buffering during root nitrate uptake.

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18

Chen, Rui Yu, Shou Xiang Lu, Chang Hai Li, and Siu Ming Lo. "Experimental Study on Ignition and Combustion Characteristics of Fibre-Reinforced Phenolic Composite." Key Engineering Materials 707 (September 2016): 13–22. http://dx.doi.org/10.4028/www.scientific.net/kem.707.13.

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The ignition and combustion characteristics of the fibre-reinforced phenolic composite were studied experimentally employing cone calorimeter. Various parameters, including the ignition time, the mass loss and mass loss rate (MLR), the heat release rate (HRR) and the concentration of the carbon dioxide and carbon monoxide were measured and presented. Linear correlations of the transformed ignition time (1/tig)0.55 and 1/tig, the first and second peak MLR, the average MLR and the peak HRR with the heat flux were demonstrated. Based upon the correlations and theoretical analyses, flammability properties including the critical heat flux (CHF) and the minimum heat flux, the ignition temperature, the heat of gasification and the heat of combustion were calculated. The specimen with the thickness of 3 mm was prone to be thermally thin material. The peak concentration of the carbon dioxide increased with the heat flux. However, the peak concentration of the carbon monoxide declined with an increase in the applied heat flux.

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19

Habib, A., and Khaled Habib. "Modelling and Quantification of Gas Flux through an Artificial Epidermis." Journal of Biomimetics, Biomaterials and Tissue Engineering 1 (July 2008): 49–56. http://dx.doi.org/10.4028/www.scientific.net/jbbte.1.49.

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A general model of transport of gases in an artificial epidermal layer (membrane) was established. The model was developed based on Dusty Gas Model (DGM), solution diffusion and surface diffusion. As a result, solutions of the model for different transport conditions were derived. In this investigation, parameters of oxygen and carbon dioxide gases through an artificial “epidermal” membrane of varying porosity were used to calculate semi-empirical solutions of the general model. In other words, the solutions of the general model were analytically obtained for different transport conditions, using experimentally obtained parameters of oxygen and carbon dioxide gases through the artificial “epidermal” membrane of varying porosity. The obtained solutions of the general model were for the oxygen and carbon dioxide gases through the artificial “epidermal” membrane of the varying porosity.

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20

Bouche, Angie, Bernhard Beck-Winchatz, and Mark J. Potosnak. "A high-altitude balloon platform for determining exchange of carbon dioxide over agricultural landscapes." Atmospheric Measurement Techniques 9, no. 12 (November 29, 2016): 5707–19. http://dx.doi.org/10.5194/amt-9-5707-2016.

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Abstract. The exchange of carbon dioxide between the terrestrial biosphere and the atmosphere is a key process in the global carbon cycle. Given emissions from fossil fuel combustion and the appropriation of net primary productivity by human activities, understanding the carbon dioxide exchange of cropland agroecosystems is critical for evaluating future trajectories of climate change. In addition, human manipulation of agroecosystems has been proposed as a technique of removing carbon dioxide from the atmosphere via practices such as no-tillage and cover crops. We propose a novel method of measuring the exchange of carbon dioxide over croplands using a high-altitude balloon (HAB) platform. The HAB methodology measures two sequential vertical profiles of carbon dioxide mixing ratio, and the surface exchange is calculated using a fixed-mass column approach. This methodology is relatively inexpensive, does not rely on any assumptions besides spatial homogeneity (no horizontal advection) and provides data over a spatial scale between stationary flux towers and satellite-based inversion calculations. The HAB methodology was employed during the 2014 and 2015 growing seasons in central Illinois, and the results are compared to satellite-based NDVI values and a flux tower located relatively near the launch site in Bondville, Illinois. These initial favorable results demonstrate the utility of the methodology for providing carbon dioxide exchange data over a large (10–100 km) spatial area. One drawback is its relatively limited temporal coverage. While recruiting citizen scientists to perform the launches could provide a more extensive dataset, the HAB methodology is not appropriate for providing estimates of net annual carbon dioxide exchange. Instead, a HAB dataset could provide an important check for upscaling flux tower results and verifying satellite-derived exchange estimates.

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21

Dandekar, Thomas, Elena Bencurova, Özge Osmanoglu, and Muhammad Naseem. "Klimapflanzen und biologische Wege zu negativen Kohlendioxidemissionen." BIOspektrum 27, no. 7 (November 2021): 769–72. http://dx.doi.org/10.1007/s12268-021-1677-2.

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AbstractClimate plants are critical to prevent global warming as all efforts to save carbon dioxide are too slow and climate disasters on the rise. For best carbon dioxide harvesting we compare algae, trees and crop plants and use metagenomic analysis of environmental samples. We compare different pathways, carbon harvesting potentials of different plants as well as synthetic modifications including carbon dioxide flux balance analysis. For implementation, agriculture and modern forestry are important.

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22

MUSSELL, Michael John, Poul-Eric PAULEV, Yoshimi MIYAMOTO, Yoshimi NAKAZONO, and Tetsuo SUGAWARA. "A constant flux of carbon dioxide injected into the airways mimics metabolic carbon dioxide in exercise." Japanese Journal of Physiology 40, no. 6 (1990): 877–91. http://dx.doi.org/10.2170/jjphysiol.40.877.

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23

Bin Azhari, Muhamad Azwar, Nooririnah Binti Omar, Nuzaimah Binti Mustaffa, and Ahmad Fauzi Ismail. "Carbon Dioxide Permeation Characteristics in Asymmetric Polysulfone Hollow Fiber Membrane: Effect of Constant Heating and Progressive Heating." Advanced Materials Research 896 (February 2014): 37–40. http://dx.doi.org/10.4028/www.scientific.net/amr.896.37.

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This paper reports the effect of constant heating and progressive on carbon dioxide permeation characteristics in asymmetric hollow fiber polysulfone membranes. Glassy polymers are easily plasticized with the presence of plasticizing agents such as carbon dioxide. Constant heating were applied to the membranes to suppress CO2 induced plasticization. Membranes treated with constant temperature heating exhibits lower pressure-normalize flux for both carbon dioxide and methane compared to untreated membranes. This was probably due to densification of membrane skin layer during heating process. Denser skin layer increases the resistance in the membrane which resulted in decreased of pressure-normalize flux. A higher density of membrane skin layer was achieved by progressive temperature heat treatment. This further increased the resistance in the membrane resulted in a lower value of pressure normalized-flux. With the application of different feed pressure, an almost linear value of CO2 pressure-normalize flux shows that plasticization is successfully suppressed by heat treatment. From the results provided in this study, it can be concluded that plasticization of polysulfone hollow fiber membrane is successfully suppressed by heat treatment process.

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24

Törő, Ágnes, Péter Ragán, Tamás Rátonyi, Károly Kith, and Endre Harsányi. "Daily soil carbon dioxide flux under different tillage conditions." Acta Agraria Debreceniensis, no. 2 (December 15, 2019): 141–44. http://dx.doi.org/10.34101/actaagrar/2/3693.

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Over the last few years, warming of the atmospheric layer near Earth's surface is increasingly experienced and researchers have also established that concentration of numerous greenhouse gases have risen over the past two centuries value. Change is basically a legitimate process - considering atmospheric concentration as well - but the change experienced during the past centuries could not have become this critical without the contribution of human activity. Due to the nature of the greenhouse effect, the result of a very fragile, complex process is experienced currently on Earth, which can be significantly unbalanced even by a slight change. Carbon dioxide emitted from the soil is involved in the global cycle and has an impact on the greenhouse effect. The rise in soil respiration may result in the further intensification of warming. In the scope of the present study, it was examined how carbon dioxide emissions of the soil evolve over a day. The results have been established based on the comparison of the effects of different parts of the day, tillage methods and irrigation.

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25

Ohtaki, Eiji, Osamu Tsukamoto, Yoshiharu Iwatani, and Yasushi Mitsuta. "Measurements of the Carbon Dioxide Flux over the Ocean." Journal of the Meteorological Society of Japan. Ser. II 67, no. 4 (1989): 541–54. http://dx.doi.org/10.2151/jmsj1965.67.4_541.

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26

OTANI, Sosuke, and Junpei MARIKAWA. "ELUCIDATION DYNAMICS OF CARBON DIOXIDE FLUX ON SALT MARSH." Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) 73, no. 2 (2017): I_1303—I_1308. http://dx.doi.org/10.2208/kaigan.73.i_1303.

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27

Sun, Hongying, Quanwei Xin, Hailing Luo, Zhihui Ma, Liyun Xiao, Dong Liu, and Siren Lan. "Carbon dioxide flux in constructed wetland with/without plant." IOP Conference Series: Earth and Environmental Science 199 (December 19, 2018): 042014. http://dx.doi.org/10.1088/1755-1315/199/4/042014.

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28

Dong, Wei, Jian Min Shu, Ping He, and Guang Wen Ma. "The Comparison Study of Lake Carbon Flux in Summer and Autumn at Northern Grass-Type Lake-Baiyangdian." Advanced Materials Research 518-523 (May 2012): 1344–47. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.1344.

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The lake carbon circle is an important part of regional carbon circle research. The lake ecosystem is the important carbon storeroom in the earth, it absorbs a mass of carbon dioxide through photosynthesis, and transforms carbon dioxide to organically carbon, and then the lake has traits of abundant carbon reserves and heavy carbon density. As the especial geographical place and upper productivity, the lake has significant role in carbon circle. By now, there is clear acquaintanceship of greenhouse effect problem, especial we have qualitative and quantificational understanding of ocean carbon circle primary. But we have a little research of lake carbon circle and carbon flux. There are many lakes in China, so it is crucial meaning to study lake carbon circle. In this paper, the improved Static Chamber and Li8100 that used to monitor soil Carbon Flux are introduced. Through continuously monitoring from July to November 2010, in northern Grass-type Lake-Baiyangdian demonstration , a series of conclusion are concluded about lake Carbon Flux : the day-variation of Carbon Fluxes chenged significantly, and varying followed time and temperature, the highest Carbon Flux is consistent to the highest temperature; the rule of day-variation is similar to aforesaid the three months(except special days), but Carbon Fluxes are not same, August>October> November.

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29

Teng, Dexiong, Xuemin He, Jingzhe Wang, Jinlong Wang, and Guanghui Lv. "Uncertainty in gap filling and estimating the annual sum of carbon dioxide exchange for the desert Tugai forest, Ebinur Lake Basin, Northwest China." PeerJ 8 (February 10, 2020): e8530. http://dx.doi.org/10.7717/peerj.8530.

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In most eddy covariance (EC) studies, carbon flux measurements have a high defect rate for a variety of reasons. Obtaining the annual sum of carbon dioxide exchange requires imputation of data gaps with high precision and accuracy. This study used five methods to fill the gaps in carbon flux data and estimate the total annual carbon dioxide exchange of the Tugai forest in the arid desert ecosystem of Ebinur Lake Basin, Northwest China. The Monte Carlo method was used to estimate the random error and bias caused by gap filling. The results revealed that (1) there was a seasonal difference in the friction velocity threshold of nighttime flux, with values in the growing season and non-growing season of 0.12 and 0.10 m/s, respectively; (2) the five gap-filling methods explained 77–84% of the data variability in the fluxes, and the random errors estimated by these methods were characterized by non-normality and leptokurtic heavy tail features, following the Laplacian (or double-exponential) distribution; (3) estimates of the annual sum of carbon dioxide exchange using the five methods at the study site in 2015 ranged from −178.25 to −155.21 g C m−2 year−1, indicating that the Tugai forest in the Ebinur Lake Basin is a net carbon sink. The standard deviation of the total annual carbon dioxide exchange sums estimated by the five different methods ranged from 3.15 to 19.08 g C m−2 year−1, with bias errors ranging from −13.69 to 14.05 g C m−2 year−1. This study provides a theoretical basis for the carbon dioxide exchange and carbon source/sink assessment of the Tugai forest in an arid desert ecosystem. In order to explore the functioning of the Tugai forest at this site, a greater understanding of the underlying ecological mechanisms is necessary.

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30

Dariah, Ai, Fahmuddin Agus, Erni Susanti, and Jubaedah. "Relationship between Distance Sampling and Carbon Dioxide Emission under Oil Palm Plantation." JOURNAL OF TROPICAL SOILS 18, no. 2 (June 10, 2013): 125. http://dx.doi.org/10.5400/jts.2013.v18i2.125-130.

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Carbon dioxide emission on peatland under oil palm plantation were highly varied probably due to many factors involved. The objectives of the research were to evaluate the effect of distance sampling from center of oil palm tree on Carbon dioxide flux, and to study the factors that cause variability of carbon dioxide flux on peatland under oil palm plantation. The study was conducted on peatland at Arang-Arang Village, Kumpek Ulu Sub-District, Muaro Jambi District, Jambi Province, on six year old oil palm plantation. The study was conducted in the form of observational exploratory. Emission measurements performed on 5 selected oil palm trees at points within 100, 150, 200, 250, 300, 350, and 400 cm from the center of trunk. Carbon dioxide flux was measured using (IRGA), Li-COR 820. The results showed that there is significant correlation between the distance of sampling from center of oil palm tree and Carbon dioxide flux. The farther distance from the tree, Carbon dioxide flux more decreased. Before applying fertilizer, variability of soil fertility was not significantly correlated with the flux of Carbon dioxide, so the difference of Carbon dioxide flux based on distance sampling can be caused by root distribution factor. After fertilizer application, variability of Carbon dioxide flux under the oil palm tree were beside affected by differences in root distribution, was also greatly influenced by fertilization.Keywords: Carbon dioxide flux, distance sampling, oil palm, peat, root-related respiration [How to Cite: Dariah A, F Agus, E Susanti and Jubaedah. 2013.Relationship between Sampling Distance and Carbon Dioxide Emission under Oil Palm Plantation. J Trop Soils 18 (2): 125-130. Doi: 10.5400/jts.2013.18.2.125][Permalink/DOI: www.dx.doi.org/10.5400/jts.2013.18.2.125] REFERENCESAgus F, E Handayani, van M Noordwijk, K Idris and S Sabiham. 2010 Root respiration interferes with peat CO2 emission measurement. 19th World Congress of Soil Science, Soil Solutions for a Changing World. 1 - 6 August 2010, Brisbane, Australia. Published on DVD.Amador JA and RD Jones. 1993. Nutrient limitation on microbial respiration in peat soil with diffrent total phosphorus content. Soil Biol Biochem 25: 793-801.Franklin O, P Hoogberg, A Ekbled and GI Agren. 2003. Pine forest floor carbon accumulation in response to N and PK addition: Bomb C-14 modeling and respiration studies. Ecosystem 6: 644-658. Freeman C, N Ostle and H Kang. 2001. An Enzymic ‘latch’ on global carbon store-a shortage of oxigen locks up carbon in peatlands by restraining a single enzyme. Nature 409: 149-149.Hanson PJ, NT Edwards, CT Garten and JA Andrew. 2000. Separating root and soil microbial contributions to soil respiration: A review of methods and observations. Biogeochemistry 48: 115-146.Henson IE, and SH Chai. 1997. Analysis of oil palm productivity. II. Biomass, distribution, productivity and turnover of the root system. Elaeis 9: 78-92.Hergoualc’h K and LV Verchot. 2011. Stocks and fluxes of carbon associated with land use change in Southeast Asian tropical peatlands: A review. Glob Biogeochem Cycl 25. doi:10.1029/2009GB003718.Howarth RW and SG Fisher. 1976. Carbon, nitrogen, phosporus dynamic during leaf decay in nutrient-enriched stream microecosystems. Freshwater Biol 6: 221-228.Husen E and F Agus. 2011. Microbial activities as affected by peat dryness ans ameliorant. Am J Environ Sci 7: 348-353.Jauhiainen J, A Hooijer and SE Page. 2012. Carbon dioxide emissions from an Acacia plantation on peatland in Sumatra, Indonesia. Biogeosciences 9: 617–630. DOI:10.5194/bg-9-617-2012.Khalid H, ZZ Zin and JM Anderson. 1999. Quantification of oil palm biomass and nutrient value in mature planttation. II Below-ground biomass. J Oil Palm Res 11: 63-71.Knorr KH, MR Oosterwoud and C Blodau. 2008. Experimental drought alters rates of soil respiration and methanogenesis but not carbon exchange in soil of a temperate fen. Soil Biol Biochem 40: 1781-1791.Law BE, FM Kelliher, DD Baldocchi, PM Anthoni, J. Irvine, D. Moore and SV Tuyl. 2001. Spatial and temporal variation in respiration in a young ponderosa pine forest during a summer drought. Agric Forest Meteorol 110: 27-43.Laiho R, J Laine, CC Trettin and L Finner. 2004. Scot pine litter decomposition along drainage succession and soil nutrient gradient in peat land forest, and the effect of inter-annual weather variation. Soil Biol Biochem 36: 1095-1109.Madsen R, L Xu, B Claassen and D McDermit. 2009. Surface monitoring method for carbon capture and storage projects. Energy Procedia 1: 2161-2168Martoyo K. 1992. Kajian Sifat Fisik Tanah Podsolik untuk Tanaman Kelapa Sawit (Elaeis gueneensis Jacq) di Sumatera Utara. Tesis Program Pasca Sarjana, Universitas Gajah Mada. Yogyakarta (in Indonesian).Melling L, R Hatano and KJ Goh. 2007. Nitrous oxide emissions from three ecosystem in tropical peatlands of Sarawak, Malaysia. Soil Sci Plant Nutr 53: 792-805.Minkkinen K, J Laine, NJ Shurpali, P Makiranta, J Alm and T Pentilla. 2007. Heterotropic soil respiration in forestry-drained peatland. Boreal Environ Res 12: 115-126. Murdiyarso D, K Hergoualc’h K and LV Verchot. 2010 Opportunities for reducing greenhouse gas emissions in tropical peatlands. PNAS 107: 19655-19660.Olsen R, S Linden, R Giesler, and P Hogberg. 2005. Fertilization of boreal forest reduce of both autrotrophic dan heterotrophic soil respiration . Glob Change Biol 11: 1745-1753.Silvola J, J Valijoki and H Aaltonen. 1985. Effect of draining and fertilization on soil respiration at three ameliorated peatland site. Acta For Fem 191: 1-32.Silvola J, J Alm, U Aklholm, H Nykanen and PJ Martikainen. 1996a. Carbon dioxide fluxes from peat in boreal mires under varying temperature and moisture condition. J Ecol 84: 219-228.Silvola J, J Alm, U. Ahlholm, H Nykanen, and PJ Martikainen. 1996b. The contribution of plant roots to carbon dioxide fluxes from organic soils. Biol Fertil Soils 23: 126-131.Wang W, K Ohseb and J Liuc. 2005. Contribution of root respiration to soil respiration in a C3/C4 mixed grassland. J Bioscience 30: 507-514.

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Foken, Thomas, Wolfgang Babel, and Christoph Thomas. "Possible errors in flux measurements due to limited digitalization." Atmospheric Measurement Techniques 12, no. 2 (February 13, 2019): 971–76. http://dx.doi.org/10.5194/amt-12-971-2019.

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Abstract. Recently reported trends of carbon dioxide uptake pose the question of whether trends may be the result of the limited digitalization of gas analysers and sonic anemometers used in the 1990s. Modifying a 12 bit digitalization and the instrument error reported for the Gill R2 and R3 sonic anemometers found elsewhere, the influence of these deficits in comparison to the now commonly used 16 bit digitalization were quantified. Both issues have an effect only on trace gas fluxes of small magnitude, mainly for the carbon dioxide rather than for the water vapour fluxes. The influence on the annual net ecosystem exchange is negligible, because other errors resulting from gap filling routines, for example, are much larger.

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Dixon, Robert K., and Olga N. Krankina. "Forest fires in Russia: carbon dioxide emissions to the atmosphere." Canadian Journal of Forest Research 23, no. 4 (April 1, 1993): 700–705. http://dx.doi.org/10.1139/x93-091.

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Boreal forests of Russia play a prominent role in the global carbon cycle and the flux of greenhouse gases to the atmosphere. Large areas of Russian forest burn annually, and contributions to the net flux of carbon to the atmosphere may be significant. Forest fire emissions were calculated for the years 1971–1991 using fire frequency and distribution data and fuel and carbon density for different forest ecoregions of Russia. Both direct carbon release and indirect post-fire biogenic carbon flux were estimated. From 1971 to 1991 the annual total forest area burned by wildfire ranged from 1.41 × 106 to 10.0 × 106 ha. Approximately 15 000–25 000 forest fires occurred annually during this period. Mean annual direct CO2-C emissions from wildfire was approximately 0.05 Pg over this 21-year period. Total post-fire biogenic CO2-C emissions for 1971–1991 ranged from 2.5 to 5.9 Pg (0.12–0.28 Pg annually). Forest fires and other disturbances are expected to be a primary mechanism driving vegetation change associated with projected global climate change. Future forest fire scenarios in Russia based on general circulation model projections suggest that up to 30–50% of the land surface area, or 334 × 106 to 631 × 106 ha of forest, will be affected. An additional 6.7 × 106 to 12.6 × 106 ha of Russian boreal forest are projected to burn annually if general circulation model based vegetation-change scenarios are achieved within the next 50 years. The direct flux of CO2-C from future forest fires is estimated to total 6.1–10.7 Pg over a 50-year period. Indirect post-fire biogenic release of greenhouse gases in the future is expected to be two to six times greater than direct emissions. Forest management and fire-control activities may help reduce wildfire severity and mitigate the associated pulse of greenhouse gases into the atmosphere.

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Jentzsch, Katharina, Julia Boike, and Thomas Foken. "Importance of the Webb, Pearman, and Leuning (WPL) correction for the measurement of small CO<sub>2</sub> fluxes." Atmospheric Measurement Techniques 14, no. 11 (November 19, 2021): 7291–96. http://dx.doi.org/10.5194/amt-14-7291-2021.

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Abstract. The WPL (Webb, Pearman, and Leuning) correction is fully accepted to correct trace gas fluxes like CO2 for density fluctuations due to water vapour and temperature fluctuations for open-path gas analysers. It is known that this additive correction can be on the order of magnitude of the actual flux. However, this is hardly ever included in the analysis of data quality. An example from the Arctic shows the problems, because the size of the correction is a multiple of the actual flux. As a general result, we examined and tabulated the magnitude of the WPL correction for carbon dioxide flux as a function of sensible and latent heat flux. Furthermore, we propose a parameter to better estimate possible deficits in data quality and recommend integrating the quality flag derived with this parameter into the general study of small carbon dioxide fluxes.

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34

MOORE, T. R., and R. KNOWLES. "METHANE AND CARBON DIOXIDE EVOLUTION FROM SUBARCTIC FENS." Canadian Journal of Soil Science 67, no. 1 (February 1, 1987): 77–81. http://dx.doi.org/10.4141/cjss87-007.

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Rates of net methane and carbon dioxide evolution from four subarctic fens over one summer ranged from 0 to 7 mmol CH4 m−2 d−1 and from 2 to 29 mmol CO2 m2 d−1. Average molar ratios of carbon dioxide to methane ranged from 3 to 10. Partially because of the high spatial variability in evolution rates, the temperature dependence of carbon dioxide was weak, but stronger for methane, with significant (P < 0.05) positive correlations at two sites, especially with peat temperatures. Annual flux of methane is estimated to be 0.1–0.6 g C m−2 which, although low compared to other wetlands, becomes a substantial atmospheric contribution when the large area occupied by subarctic peatlands is taken into account. Key words: Methane, carbon dioxide, peatlands, fens

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35

Li, Yanli, Jinxu Lv, and Lijun Li. "Coordinated Development of Water Environment Protection and Water Ecological Carbon Sink in Baiyangdian Lake." Processes 9, no. 11 (November 18, 2021): 2066. http://dx.doi.org/10.3390/pr9112066.

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“The Hebei Xiongan New Area Planning Outline” states that the carbon sink of the water body should be improved and the quality of Baiyangdian water should be improved by cleaning the sludge, but the treatment of endogenous pollution in the water body will release a large amount of carbon dioxide, which will reduce the carbon sink of Baiyangdian, which makes the improvement of water body quality and increasing carbon sink conflicting. In order to realize the coordinated development of Baiyangdian water quality improvement and carbon sink increase, this paper establishes the calculation model of the amount of sludge to be cleared to improve the unit water quality and the amount of carbon dioxide released by clearing the silt using the release flux and diffusion flux of nitrogen and phosphorus elements in the water body, and the relationship between the content of nitrogen and phosphorus elements, the depth of Baiyangdian sludge excavation and the amount of carbon dioxide released: as the content of nitrogen and phosphorus elements in the water decreases, the depth of sludge excavated to improve the unit water body increases, and the amount of carbon dioxide released gradually increases. As the nitrogen and phosphorus content in the water decreases, the depth of dredged sludge to improve the quality of the water body increases, the carbon dioxide released gradually increases, and when the nitrogen and phosphorus concentration reaches 0.18 g/m3 and 0.6 g/m3 respectively, the carbon dioxide released will increase exponentially. Thus, we propose countermeasures to improve the water quality of Baiyangdian and increase the carbon sink capacity: we can improve the water quality by reasonable dredging before the water quality reaches poor category 3; we can achieve the dual goals of improving the water quality and increasing the carbon sink by increasing the reed planting area.

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36

Rafael, Pivotto Bortolotto, Jorge Carneiro Amado Telmo, Dalla Nora Douglas, Keller Cristiano, Roberti Debora, Ernani Fiorin Jackson, Reichardt Klaus, Paulo Batistella Pasini Mauricio, and da Silveira Nicoloso Rodrigo. "Soil carbon dioxide flux in a no-tillage winter system." African Journal of Agricultural Research 10, no. 6 (February 5, 2015): 450–57. http://dx.doi.org/10.5897/ajar2014.9399.

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Ohtaki, E. "Measurements of Carbon Dioxide Flux Over a Shallow Coastal Water." Journal of the Meteorological Society of Japan. Ser. II 64, no. 1 (1986): 161–66. http://dx.doi.org/10.2151/jmsj1965.64.1_161.

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Wang, H., D. Curtin, Y. W. Jame, B. G. McConkey, and H. F. Zhou. "Simulation of Soil Carbon Dioxide Flux During Plant Residue Decomposition." Soil Science Society of America Journal 66, no. 4 (July 2002): 1304–10. http://dx.doi.org/10.2136/sssaj2002.1304.

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Raymond, Peter A., Nina F. Caraco, and Jonathan J. Cole. "Carbon Dioxide Concentration and Atmospheric Flux in the Hudson River." Estuaries 20, no. 2 (June 1997): 381. http://dx.doi.org/10.2307/1352351.

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Houghton, R. A., R. D. Boone, J. M. Melillo, C. A. Palm, G. M. Woodwell, N. Myers, B. Moore, and D. L. Skole. "Net flux of carbon dioxide from tropical forests in 1980." Nature 316, no. 6029 (August 1985): 617–20. http://dx.doi.org/10.1038/316617a0.

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41

Roland, Fábio, Luciana O. Vidal, Felipe S. Pacheco, Nathan O. Barros, Arcilan Assireu, Jean P. H. B. Ometto, André C. P. Cimbleris, and Jonathan J. Cole. "Variability of carbon dioxide flux from tropical (Cerrado) hydroelectric reservoirs." Aquatic Sciences 72, no. 3 (March 31, 2010): 283–93. http://dx.doi.org/10.1007/s00027-010-0140-0.

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42

Bajracharya, R. M., R. Lal, and J. M. Kimble. "Erosion Effects on Carbon Dioxide Concentration and Carbon Flux from an Ohio Alfisol." Soil Science Society of America Journal 64, no. 2 (March 2000): 694–700. http://dx.doi.org/10.2136/sssaj2000.642694x.

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43

Billings, S. A., D. D. Richter, and J. Yarie. "Soil carbon dioxide fluxes and profile concentrations in two boreal forests." Canadian Journal of Forest Research 28, no. 12 (December 1, 1998): 1773–83. http://dx.doi.org/10.1139/x98-145.

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Because a large fraction of the world's carbon exists in the soil of boreal forests, understanding how soil temperature and moisture affect soil respiration is vital for predicting soil response to climate change. We measured soil respiration and CO2 concentrations within soils of floodplain and upland forests in interior Alaska from 1996 to 1997. At each site, a 0.10-ha-area shelter was constructed that prevents summer precipitation from infiltrating into the soil. Measurements of soil profile CO2, soil respiration, soil temperature, and soil moisture were made inside (treatment) and outside (control) the sheltered areas through two growing seasons and the winter of 1996-1997. Sheltered soils had decreased profile concentrations and surface flux of CO2. At the upland control site, individual flux rates ranged from 0.10 to 0.95 g·m-2·h-1 in the summer and at sites under the shelter from 0.10 to 0.53 g·m-2·h-1. Rates at the floodplain control site ranged from 0.11 to 1.45 g·m-2·h-1 and under the shelter from 0.11 to 0.55 g·m-2·h-1. Fick's Law could predict surface CO2 flux when the CO2 concentration gradient within the profile accurately represented the soil surface gradient and biological sources and sinks of the gas did not overwhelm flux calculations.

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44

McGee, Laura, and Ruoying He. "Hurricane-Induced Oceanic Carbon Changes in the Upper Ocean." Oceans 3, no. 2 (March 25, 2022): 114–24. http://dx.doi.org/10.3390/oceans3020010.

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Changes in marine carbon cycling due to hurricanes with different intensity and translation speeds have not been systematically investigated. This study uses an idealized coupled physical-biogeochemical model and a suite of model sensitivity analyses to better quantify the relationship between hurricane characteristics and marine property changes, including variations in air-sea carbon flux and partial pressure of carbon dioxide in water (pCO2w). We find that strong (category 4–5), mid-speed (5–8 m/s) storms cause the most carbon flux from the atmosphere to the ocean, and that the relationship between air-sea carbon flux and hurricane properties is non-linear. Climate models that do not consider synoptic-scale, storm-induced physical-biogeochemical coupling may underestimate regional carbon sinks.

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45

Parnell, John, Kirsty Macleod, and Malcolm J. Hole. "Carbon dioxide drawdown by Devonian lavas." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 105, no. 1 (March 2014): 1–8. http://dx.doi.org/10.1017/s1755691014000152.

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ABSTRACTLower Devonian volcanic rocks in the northern British Isles, especially Scotland, show extensive evidence for contemporaneous subaerial weathering. Basalt and andesite lavas were altered to red iron oxides, commonly accompanied by calcite. Measurement of carbonate contents in 104 samples over a region of 100,000 km2 show an average of 13% calcite. Weighted for outcrop thickness, this represents an estimated 7.3×1016 moles CO2, extracted from surface waters and ultimately the atmosphere. The time frame for this drawdown is difficult to constrain, but complete weathering of a one-metre unit over 1000 years would involve CO2 consumption comparable with the highest rates determined in modern basaltic watersheds. These data demonstrate that volcanic activity can be a major sink, as well as a source for CO2, and provide a data set for modelling of CO2 flux during episodes of volcanic activity in the geological record. The high capacity of the Devonian lavas for CO2 drawdown emphasises the potential of basalts for CO2 sequestration.

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46

Li, Chenzheng, Anatoly V. Brouchkov, Viktor G. Cheverev, Andrey V. Sokolov, and Kunyang Li. "Emission of Methane and Carbon Dioxide during Soil Freezing without Permafrost." Energies 15, no. 7 (April 6, 2022): 2693. http://dx.doi.org/10.3390/en15072693.

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Research on methane and carbon dioxide emissions mainly focuses on industrial emissions, cultivated land, and wetlands, while few studies have studied freezing-related emissions. This paper presents field experiments conducted during soil freezing to measure carbon dioxide and methane concentrations in the air, near the soil surface, and in the soil. In addition, the influence of precipitation, snowfall, air temperature, and depth of freezing on gas emissions was analyzed. We observed increased concentrations of methane and carbon dioxide in soil and air at soil freezing and snow cover growth. For the first time, an increase in gas flux during soil freezing was found in the absence of permafrost.

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47

Parkes, Ben, Alan Gadian, and John Latham. "The Effects of Marine Cloud Brightening on Seasonal Polar Temperatures and the Meridional Heat Flux." ISRN Geophysics 2012 (May 8, 2012): 1–7. http://dx.doi.org/10.5402/2012/142872.

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Marine cloud brightening (MCB) is one of several proposed solar radiation management (SRM) geoengineering schemes designed to ameliorate some of the undesirable effects of climate change, for example polar ice loss and associated increased sea levels. Satellite measurements over the last 40 years show a general reduction in polar sea ice area and thickness which is attributed to climate change. In our studies, HadGEM1, a fully coupled climate model, is used to predict changes in surface temperatures and ice cover as a result of implementing MCB in a double carbon dioxide concentration atmosphere. The meridional heat flux (MHF) is the mechanism within the earth system for the transport of energy from tropical to polar regions. This poleward transport of heat in a double carbon dioxide atmosphere amplifies the effects in polar regions, where it has a significant impact on both temperatures and ice cover. The results from this work show that MCB is capable of roughly restoring control temperatures and ice cover (where control is defined as 440 ppm carbon dioxide, a predicted 2020 level) in a double carbon dioxide atmosphere scenario. This work presents the first results on the impact of MCB on the MHF and the ability of the MCB scheme to restore the MHF to a control level.

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48

CHENITI, AICHA RIMA, HATEM BESBES, MOEZ CHAFRA, CHRISTOPHE SINTES, and MOHAMED OMRI. "TOWARD A NONINVASIVE MEASUREMENT METHOD OF CO2 ARTERIAL PRESSURE." Journal of Mechanics in Medicine and Biology 21, no. 03 (March 31, 2021): 2150028. http://dx.doi.org/10.1142/s0219519421500287.

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Until now, the measurement of carbon dioxide blood pressure is done ex vivo, using an invasive process. This paper describes a first step toward a novel noninvasive process for in vivo measurement of this pressure. As first approximation, the blood solution is modeled as a simple aqueous solution of carbon dioxide in a cylindrical rigid canalization. The drift flux model and the Young–Laplace equation are employed to describe the fluid behavior. The numerical model relates the carbon dioxide pressure through the mixture pressure and velocity. The spatial distributions of these parameters are implemented to create linear mathematical relations between the mean mixture pressure and the radial velocity variation. As long as we are interested in a noninvasive measuring of the carbon dioxide pressure, a response model is proposed to describe the ultrasound signal backscattered by the considered solution. The linear relations are applied to deduce the carbon dioxide pressure through the measured radial velocity difference, using two computing methods of ultrasound signal. A comparative study is made between them showing the more appropriate process to compute the carbon dioxide pressure.

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49

McGrath-Spangler, E. L., A. S. Denning, K. D. Corbin, and I. T. Baker. "Implementation of a boundary layer heat flux parameterization into the Regional Atmospheric Modeling System (RAMS)." Atmospheric Chemistry and Physics Discussions 8, no. 4 (July 25, 2008): 14311–46. http://dx.doi.org/10.5194/acpd-8-14311-2008.

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Abstract. The response of atmospheric carbon dioxide to a given amount of surface flux is inversely proportional to the depth of the boundary layer. Overshooting thermals that entrain free tropospheric air down into the boundary layer modify the characteristics and depth of the lower layer through the insertion of energy and mass. This alters the surface energy budget by changing the Bowen ratio and thereby altering the vegetative response and the surface boundary conditions. Although overshooting thermals are important in the physical world, their effects are unresolved in most regional models. A parameterization to include the effects of boundary layer entrainment was introduced into a coupled ecosystem-atmosphere model (SiB-RAMS). The parameterization is based on a downward heat flux at the top of the boundary layer that is proportional to the heat flux at the surface. Results with the parameterization show that the boundary layer simulated is deeper, warmer, and drier than when the parameterization is turned off. These results alter the vegetative stress factors thereby changing the carbon flux from the surface. The combination of this and the deeper boundary layer change the concentration of carbon dioxide in the boundary layer.

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50

Chavez, Luis Fernando, Telmo Jorge Carneiro Amado, Cimélio Bayer, Newton Junior La Scala, Luisa Fernanda Escobar, Jackson Ernani Fiorin, and Ben-Hur Costa de Campos. "Carbon dioxide efflux in a rhodic hapludox as affected by tillage systems in southern Brazil." Revista Brasileira de Ciência do Solo 33, no. 2 (April 2009): 325–34. http://dx.doi.org/10.1590/s0100-06832009000200010.

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Agricultural soils can act as a source or sink of atmospheric C, according to the soil management. This long-term experiment (22 years) was evaluated during 30 days in autumn, to quantify the effect of tillage systems (conventional tillage-CT and no-till-NT) on the soil CO2-C flux in a Rhodic Hapludox in Rio Grande do Sul State, Southern Brazil. A closed-dynamic system (Flux Chamber 6400-09, Licor) and a static system (alkali absorption) were used to measure soil CO2-C flux immediately after soybean harvest. Soil temperature and soil moisture were measured simultaneously with CO2-C flux, by Licor-6400 soil temperature probe and manual TDR, respectively. During the entire month, a CO2-C emission of less than 30 % of the C input through soybean crop residues was estimated. In the mean of a 30 day period, the CO2-C flux in NT soil was similar to CT, independent of the chamber type used for measurements. Differences in tillage systems with dynamic chamber were verified only in short term (daily evaluation), where NT had higher CO2-C flux than CT at the beginning of the evaluation period and lower flux at the end. The dynamic chamber was more efficient than the static chamber in capturing variations in CO2-C flux as a function of abiotic factors. In this chamber, the soil temperature and the water-filled pore space (WFPS), in the NT soil, explained 83 and 62 % of CO2-C flux, respectively. The Q10 factor, which evaluates CO2-C flux dependence on soil temperature, was estimated as 3.93, suggesting a high sensitivity of the biological activity to changes in soil temperature during fall season. The CO2-C flux measured in a closed dynamic chamber was correlated with the static alkali adsorption chamber only in the NT system, although the values were underestimated in comparison to the other, particularly in the case of high flux values. At low soil temperature and WFPS conditions, soil tillage caused a limited increase in soil CO2-C flux.

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