A Method for Determining Total Carbon Dioxide in Nanolitre Volumes of Liquid

1974 ◽  
Vol 61 (3) ◽  
pp. 667-675
Author(s):  
COLIN LITTLE
Keyword(s):  
Carbon Dioxide ◽  
Standard Deviation ◽  
Total Carbon

1. A microdiffusion method is described by which total carbon dioxide can be determined in 2 nl samples of liquid. The standard deviation for 0-30 mM/l HCO3- is approximately 1 mM/l. 2. The volume of sample can be reduced to o·8 nl, but the S.D. then rises to 1·6 mM/l. With volumes of 0·4 nl, the S.D. is 2·7 mM/l. It is not possible, without modification, to use volumes smaller than about 0·4 nl. 3. In samples where the HCO3- concentration is low, accuracy can be increased by using larger volumes: 10 mM/l HCO3- can be determined in 6 nl samples with a standard deviation of 0·5 mM/l.

scholarly journals Atmospheric greenhouse gases retrieved from SCIAMACHY: comparison to ground-based FTS measurements and model results

2012 ◽  
Vol 12 (3) ◽  
pp. 1527-1540 ◽  
Author(s):  
O. Schneising ◽  
P. Bergamaschi ◽  
H. Bovensmann ◽  
M. Buchwitz ◽  
J. P. Burrows ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Standard Deviation ◽  
Greenhouse Gases ◽  
Seasonal Cycle ◽  
Relative Accuracy ◽  
Total Carbon ◽  
Inverse Modelling ◽  
Data Sets ◽  
Relative Precision ◽  
Data Set

Abstract. SCIAMACHY onboard ENVISAT (launched in 2002) enables the retrieval of global long-term column-averaged dry air mole fractions of the two most important anthropogenic greenhouse gases carbon dioxide and methane (denoted XCO2 and XCH4). In order to assess the quality of the greenhouse gas data obtained with the recently introduced v2 of the scientific retrieval algorithm WFM-DOAS, we present validations with ground-based Fourier Transform Spectrometer (FTS) measurements and comparisons with model results at eight Total Carbon Column Observing Network (TCCON) sites providing realistic error estimates of the satellite data. Such validation is a prerequisite to assess the suitability of data sets for their use in inverse modelling. It is shown that there are generally no significant differences between the carbon dioxide annual increases of SCIAMACHY and the assimilation system CarbonTracker (2.00 ± 0.16 ppm yr−1 compared to 1.94 ± 0.03 ppm yr−1 on global average). The XCO2 seasonal cycle amplitudes derived from SCIAMACHY are typically larger than those from TCCON which are in turn larger than those from CarbonTracker. The absolute values of the northern hemispheric TCCON seasonal cycle amplitudes are closer to SCIAMACHY than to CarbonTracker and the corresponding differences are not significant when compared with SCIAMACHY, whereas they can be significant for a subset of the analysed TCCON sites when compared with CarbonTracker. At Darwin we find discrepancies of the seasonal cycle derived from SCIAMACHY compared to the other data sets which can probably be ascribed to occurrences of undetected thin clouds. Based on the comparison with the reference data, we conclude that the carbon dioxide data set can be characterised by a regional relative precision (mean standard deviation of the differences) of about 2.2 ppm and a relative accuracy (standard deviation of the mean differences) of 1.1–1.2 ppm for monthly average composites within a radius of 500 km. For methane, prior to November 2005, the regional relative precision amounts to 12 ppb and the relative accuracy is about 3 ppb for monthly composite averages within the same radius. The loss of some spectral detector pixels results in a degradation of performance thereafter in the spectral range currently used for the methane column retrieval. This leads to larger scatter and lower XCH4 values are retrieved in the tropics for the subsequent time period degrading the relative accuracy. As a result, the overall relative precision is estimated to be 17 ppb and the relative accuracy is in the range of about 10–20 ppb for monthly averages within a radius of 500 km. The derived estimates show that the SCIAMACHY XCH4 data set before November 2005 is suitable for regional source/sink determination and regional-scale flux uncertainty reduction via inverse modelling worldwide. In addition, the XCO2 monthly data potentially provide valuable information in continental regions, where there is sparse sampling by surface flask measurements.

scholarly journals Carbon dioxide retrieval from OCO-2 satellite observations using the RemoTeC algorithm and validation with TCCON measurements

2018 ◽  
Author(s):  
Lianghai Wu ◽  
Otto Hasekamp ◽  
Haili Hu ◽  
Jochen Landgraf ◽  
Andre Butz ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Standard Deviation ◽  
Bias Correction ◽  
Satellite Observations ◽  
Total Carbon ◽  
A Posteriori ◽  
Gas Concentration ◽  
Dry Air ◽  
Spectral Bands ◽  
A Value

Abstract. In this study we present the retrieval of the column averaged dry air mole fraction of carbon dioxide (XCO2) from the Orbiting Carbon Observatory-2 (OCO-2) satellite observations using the RemoTeC algorithm, previously successfully applied to retrieval of greenhouse gas concentration from the Greenhouse Gases Observing Satellite (GOSAT). The XCO2 product has been validated with collocated ground based measurements from the Total Carbon Column Observing Network (TCCON) for almost 2 years of OCO-2 data from September 2014 to July 2016. We found that fitting an additive radiometric offset in all three spectral bands of OCO-2 significantly improved the retrieval. Based on a small correlation of the XCO2 error over land with fit residuals, we applied an a posteriori bias correction to our OCO-2 retrievals. In daily averaged results, XCO2 retrievals have a standard deviation ~ 1.30 ppm and a station-to-station variability of ~ 0.40 ppm among collocated TCCON sites. The seasonal relative accuracy (SRA) has a value of 0.52 ppm. The validation shows relatively larger difference with TCCON over high latitude areas and some specific regions like Japan.

scholarly journals A Method for Determining Total Carbon Dioxide in Small Volumes of Liquid

1970 ◽  
Vol 52 (2) ◽  
pp. 395-400
Author(s):  
COLIN LITTLE ◽  
GARY RUSTON
Keyword(s):  
Carbon Dioxide ◽  
Standard Deviation ◽  
Freezing Point ◽  
Present Form ◽  
Total Carbon ◽  
Barium Hydroxide ◽  
Freezing Point Depression ◽  
Dissolved Carbon ◽  
Hydroxide Solution ◽  
Dissolved Carbon Dioxide

1. A microdiffusion method for estimating total dissolved carbon dioxide in volumes of approximately 1.5 µl. is described. The principle of the method is to displace the CO2 with acid, to absorb it in barium hydroxide solution and to measure the change in the freezing-point depression of this solution. 2. The range of measurement is 0-30 mM/l. HCO3 with a standard deviation of ± 0.3-0.4 mM/l. 3. In its present form the method cannot be used with smaller volumes without correcting for errors arising from the diffusion of water vapour between the sample and the barium hydroxide solution.

scholarly journals Preliminary validation of column-averaged volume mixing ratios of carbon dioxide and methane retrieved from GOSAT short-wavelength infrared spectra

2011 ◽  
Vol 4 (6) ◽  
pp. 1061-1076 ◽  
Author(s):  
I. Morino ◽  
O. Uchino ◽  
M. Inoue ◽  
Y. Yoshida ◽  
T. Yokota ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Fourier Transform ◽  
Standard Deviation ◽  
High Resolution ◽  
Infrared Spectra ◽  
Short Wavelength ◽  
Total Carbon ◽  
Infrared Observation ◽  
Mixing Ratios ◽  
Preliminary Validation

Abstract. Column-averaged volume mixing ratios of carbon dioxide and methane retrieved from the Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed observation (GOSAT SWIR XCO2 and XCH4) were compared with the reference calibrated data obtained by ground-based high-resolution Fourier Transform Spectrometers (g-b FTSs) participating in the Total Carbon Column Observing Network (TCCON). Preliminary results are as follows: the GOSAT SWIR XCO2 and XCH4 (Version 01.xx) are biased low by 8.85 ± 4.75 ppm (2.3 ± 1.2 %) and 20.4 ± 18.9 ppb (1.2 ± 1.1 %), respectively. The standard deviation of the GOSAT SWIR XCO2 and XCH4 is about 1 % (1 σ) after correcting the negative biases of XCO2 and XCH4 by 8.85 ppm and 20.4 ppb, respectively. The latitudinal distributions of zonal means of the GOSAT SWIR XCO2 and XCH4 show similar features to those of the g-b FTS data except for the negative biases in the GOSAT data.

Impact of Dursban and Abate on Microbial Numbers and Some Chemical Properties of Standing Ponds

1975 ◽  
Vol 10 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. Butcher ◽  
M. Boyer ◽  
CD. Fowle
Keyword(s):  
Carbon Dioxide ◽  
Active Ingredient ◽  
Algal Blooms ◽  
Chemical Properties ◽  
Total Carbon ◽  
Dissolved Carbon ◽  
Photosynthetic Productivity ◽  
Dissolved Carbon Dioxide ◽  
Microbial Numbers

Abstract Eleven small ponds, lined with polyethylene, were used to assess the consequences of applications of *DursbanR at 0.004, 0.030, 0.100 and 1.000 ppm and AbateR at 0.025 and 0.100 ppm active ingredient. The treated ponds showed a more pronounced long-term increase in pH and dissolved oxygen and decreasing total and dissolved carbon dioxide in comparison with untreated ponds. Algal blooms were of longer duration in treated ponds than in controls. Total photosynthetic productivity was higher in treated ponds but bacterial numbers did not change significantly. Photosynthetic productivity was estimated by following the changes in total carbon dioxide.

Coulometric total carbon dioxide analysis for marine studies: Automation and calibration

1987 ◽  
Vol 21 (2) ◽  
pp. 117-133 ◽  
Author(s):  
K.M Johnson ◽  
J.McN Sieburth ◽  
P.J.leB Williams ◽  
L Brändström
Keyword(s):  
Carbon Dioxide ◽  
Total Carbon ◽  
Carbon Dioxide Analysis

Comparative Study on BRIC Carbon Dioxide Emissions - Econometric Empirical Test Based on Cross-Century Time Series Data

2012 ◽  
Vol 616-618 ◽  
pp. 1512-1515
Author(s):  
Wei Hua Du
Keyword(s):  
Carbon Dioxide ◽  
Time Series ◽  
Carbon Dioxide Emissions ◽  
Time Series Data ◽  
Comparative Statics ◽  
Total Carbon ◽  
Series Data ◽  
Per Capita Gdp ◽  
Bric Countries ◽  
Per Capita

Take for example the BRIC economies: Brazil, Russia, India and China. We investigated the time series data on the relationship between carbon dioxide emission and economic growth in these fast-growing developing countries by both comparative statics and comparative dynamics. The results show that there is the monotonic relationship between total carbon dioxide emissions, carbon dioxide emissions per capita and per capita GDP in any one of the BRIC countries. And there is decreasing relationship between the carbon dioxide emissions per unit GDP and per capita GDP.

Electricity production and its effects on carbon dioxide emissions in the Kingdom of Saudi Arabia: إنتاج الكهرباء وآثاره في انبعاثات ثاني أكسيد الكربون في المملكة العربية السعودية

2021 ◽  
Vol 5 (3) ◽  
pp. 134-108
Author(s):  
Zakiah Radhi Alhajji, Mohamed Elsayed Hafez Ali Zakiah Radhi Alhajji, Mohamed Elsayed Hafez Ali
Keyword(s):  
Carbon Dioxide ◽  
Saudi Arabia ◽  
Carbon Dioxide Emissions ◽  
Fossil Fuels ◽  
Electric Energy ◽  
Total Carbon ◽  
Electricity Production ◽  
Energy Productivity ◽  
Gulf Region ◽  
Kingdom Of Saudi Arabia

Because of increased demand for electrical energy in the Kingdom of Saudi Arabia, which has resulted in an increase in carbon dioxide emissions, the electricity system in the Kingdom of Saudi Arabia is the largest in the Gulf region and the Arab world, with approximately 61.7 gigatons (GW) of peak demand and 89.2 gigatons (GW) of available capacity in 2018 of electricity power. It has grown rapidly over more than 20 years and has almost doubled in size since 2000. Where we observe that the total carbon dioxide emissions in the Kingdom of Saudi Arabia from 1990 to 2020; where shows rapid growth in emissions of carbon dioxide and greenhouse gases, as it was found that CO2 emissions in 1990 amounted to 151 million metric tons compared to 2011 when it reached about 435 million metric tons, and the increase continued until 2020 when it reached about 530 million metric tons. The comprehensive study relied on time series analysis to carefully analyze the electric energy productivity rate from fossil fuels and the significant amount of carbon dioxide emissions typically resulting from promptly burning fossil fuels to naturally produce electric energy. Therefore, the Kingdom of Saudi Arabia, through Vision 2030 and the Paris Agreement on Climate Change, looks to reduce the rate of carbon dioxide emissions in the field of electric power generation by diversifying the fuels used or replacing them with clean and renewable energy such as solar and wind energy.

scholarly journals Using airborne HIAPER Pole-to-Pole Observations (HIPPO) to evaluate model and remote sensing estimates of atmospheric carbon dioxide

2016 ◽  
Author(s):  
C. Frankenberg ◽  
S. S. Kulawik ◽  
S. Wofsy ◽  
F. Chevallier ◽  
B. Daube ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Correlation Coefficients ◽  
Added Value ◽  
Total Carbon ◽  
Accuracy And Precision ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Global Carbon ◽  
Comparable Quality

Abstract. In recent years, space-borne observations of atmospheric carbon-dioxide (CO2) have become increasingly used in global carbon-cycle studies. In order to obtain added value from space-borne measurements, they have to suffice stringent accuracy and precision requirements, with the latter being less crucial as it can be reduced by just enhanced sample size. Validation of CO2 column averaged dry air mole fractions (XCO2) heavily relies on measurements of the Total Carbon Column Observing Network TCCON. Owing to the sparseness of the network and the requirements imposed on space-based measurements, independent additional validation is highly valuable. Here, we use observations from the HIAPER Pole-to-Pole Observations (HIPPO) flights from January 2009 through September 2011 to validate CO2 measurements from satellites (GOSAT, TES, AIRS) and atmospheric inversion models (CarbonTracker CT2013B, MACC v13r1). We find that the atmospheric models capture the XCO2 variability observed in HIPPO flights very well, with correlation coefficients (r2) of 0.93 and 0.95 for CT2013B and MACC, respectively. Some larger discrepancies can be observed in profile comparisons at higher latitudes, esp. at 300 hPa during the peaks of either carbon uptake or release. These deviations can be up to 4 ppm and hint at misrepresentation of vertical transport. Comparisons with the GOSAT satellite are of comparable quality, with an r2 of 0.85, a mean bias μ of −0.06 ppm and a standard deviation σ of 0.45 ppm. TES exhibits an r2 of 0.75, μ of 0.34 ppm and σ of 1.13 ppm. For AIRS, we find an r2 of 0.37, μ of 1.11 ppm and σ of 1.46 ppm, with latitude-dependent biases. For these comparisons at least 6, 20 and 50 atmospheric soundings have been averaged for GOSAT, TES and AIRS, respectively. Overall, we find that GOSAT soundings over the remote pacific ocean mostly meet the stringent accuracy requirements of about 0.5 ppm for space-based CO2 observations.

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