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71 results for “CO2 concentration”
The response of the ozone layer to quadrupled CO2 concentrations: implications for climate
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Dissolved CO2 and CH4 concentrations in the Connecticut River Watershed
This dataset supports the paper accepted to Limnology and Oceanography: Distinct concentration-discharge dynamics in temperate streams and rivers: CO2 exhibits chemostasis while CH4 exhibits source limitation due to temperature control Authored by Kelly S. Aho, Jennifer H. Fair, Jacob D. Hosen, Ethan D. Kyzivat, Laura A. Logozzo, Gerard Rocher-Ros, Lisa C. Weber, Bryan Yoon, and Peter A. Raymond
SGS-LTER CO2 Elevation Study: Gas exchange of the major species measured at chamber CO2 concentrations in Open Top Chambers on the Central Plains Experimental Range, Nunn, Colorado, USA 1997 - 2001
This data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Digital Collections of Colorado (http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection. Additional information and referenced materials can be found: http://hdl.handle.net/10217/82454. Single leaf gas exchange (CO2 & H2O) was measured several times per season on important grass species in the shortgrass steppe open-top-chamber experiment, to investigate physiological adaptations to elevated CO2. C3 grass displayed photosynthetic acclimation, while C4 grass did not. Leaf water-use-efficiency was improved under ECO2. Absolute assimilation rates were more dependent on soil and plant water status than on CO2. This research was conducted at the Central Plains Experimental Range, near Nunn, CO; lat.40degrees 40 minutes N; long. 104 degrees 45 minutes W in the shortgrass steppe region of NE Colorado, USA and as a collaboration between SGS-LTER and USDA-ARS researchers.
Data from: Rising atmospheric CO2 is reducing the protein concentration of a floral pollen source essential for North American bees
At present, there is substantive evidence that the nutritional content of agriculturally important food crops will decrease in response to rising levels of atmospheric carbon dioxide, Ca. However, whether Ca-induced declines in nutritional quality are also occurring for pollinator food sources is unknown. Flowering late in the season, goldenrod (Solidago spp.) pollen is a widely available autumnal food source commonly acknowledged by apiarists to be essential to native bee (e.g. Bombus spp.) and honeybee (Apis mellifera) health and winter survival. Using floral collections obtained from the Smithsonian Natural History Museum, we quantified Ca-induced temporal changes in pollen protein concentration of Canada goldenrod (Solidago canadensis), the most widespread Solidago taxon, from hundreds of samples collected throughout the USA and southern Canada over the period 1842–2014 (i.e. a Ca from approx. 280 to 398 ppm). In addition, we conducted a 2 year in situ trial of S. canadensis populations grown along a continuous Ca gradient from approximately 280 to 500 ppm. The historical data indicated a strong significant correlation between recent increases in Ca and reductions in pollen protein concentration (r2 = 0.81). Experimental data confirmed this decrease in pollen protein concentration, and indicated that it would be ongoing as Ca continues to rise in the near term, i.e. to 500 ppm (r2 = 0.88). While additional data are needed to quantify the subsequent effects of reduced protein concentration for Canada goldenrod on bee health and population stability, these results are the first to indicate that increasing Ca can reduce protein content of a floral pollen source widely used by North American bees.
Data from: Seasonally varying contributions to urban CO2 in the Chicago, IL, USA region: insights from a high-resolution CO2 concentration and δ13C record
Understanding urban carbon cycling is essential given that cities sustain 54% of the global population and contribute 70% of anthropogenic CO2 emissions. When combined with CO2 concentration measurements ([CO2]), stable carbon isotope analyses (δ13C) can differentiate sources of CO2, including ecosystem respiration and combustion of fossil fuels, such as petroleum and natural gas. In this study, we used a wavelength scanned-cavity ringdown spectrometer to collect ~2x106 paired measurements for [CO2] and δ13C values in Evanston, IL for August 2011 through February 2012. Evanston is located immediately north of Chicago, IL, the third largest city in the United States. The measurements represent one of the longest records of urban [CO2] and δ13C values thus far reported. We also compiled local meteorological information, as well as complementary [CO2] and δ13C data for background sites in Park Falls, WI and Mauna Loa, HI. We use the dataset to examine how ecosystem processes, fossil fuel usage, wind speed, and wind direction control local atmospheric [CO2] and δ13C in a midcontinent urban setting on a seasonal to daily basis. On average, [CO2] and δ13C values in Evanston were 16–23 ppm higher and 0.97–1.13‰ lower than the background sites. While seasonal [CO2] and δ13C values generally followed broader northern hemisphere trends, the difference between Evanston and the background sites was larger in winter versus summer. Mixing calculations suggest that ecosystem respiration and petroleum combustion equally contributed CO2 in excess of background during the summer and that natural gas combustion contributed 80%–94% of the excess CO2 in winter. Wind speed and direction strongly influenced [CO2] and δ13C values on an hourly time scale. The highest [CO2] and lowest δ13C values occurred at wind speeds <3 m s−1 and when winds blew from the northwest, west, and south over densely populated neighborhoods.
Data-set of CO2, CH4, N2O dissolved concentrations and ancillary data in surface waters of 24 African lakes.
<p>Geo-referenced and timestamped data-set of water temperature, Specific conductivity (SpCond), oxygen saturation level (%O<sub>2</sub>), dissolved methane (CH<sub>4</sub>) concentration, dissolved nitrous oxide (N<sub>2</sub>O) concentration, partial pressure of carbon dioxide (pCO<sub>2</sub>), carbon stable isotope composition of dissolved inorganic carbon (δ<sup>13</sup>C-DIC), dissolved organic carbon (DOC) concentration, chlorophyll-a (Chl-a) concentration, cyanobacteria abundance (CHEMTAX), nitrate (NO<sub>3</sub><sup>-</sup>) and ammonia concentration (NH<sub>4</sub><sup>+</sup>), coloured dissolved organic matter slope ratio (CDOM SR) in surface waters of African 24 lakes (Victoria, Tanganyika, Albert, Kivu, Edward, Mai Ndombe, Tumba, George, Kamohonjo, Alaotra, Ndalaga, Nyamusingere, Kyamwinga, Mbita, Lukulu, Yandja, Mbalukira, Nkugute, Nyamunuka, Kitagata, Mrambi, Kyashanduka, Katinda, Lac Vert).</p>
Data from: Soil CO2 and O2 concentrations illuminate the relative importance of weathering and respiration to seasonal soil gas fluctuations
[No abstract entered]
The spatiotemporal pH and carbon concentration during density-driven convection of CO2 in water
<p>The two supplementary videos showed the spatiotemporal pH and carbon concentration in the Hele-shaw cell by a new experimental technique. They are amied to facilitate the understanding of the density-driven convection of CO2 in water. More details of the research could be found on the manuscript of 'arXiv' named: 'Mapping dissolved carbon in space and time: An experimental technique for the measurement of pH and total carbon concentration in density driven convection of CO2 dissolved in water.'</p>
EMIT CO2 concentration enhancement retrievals for coincident EMIT/OCO-3 overpasses
<p>L2b EMIT CO2 concentration enhancement retrievals generated using log-normal matched filter for coincident observations from EMIT and OCO-3. Data to accompany Nelson et al. (2024)</p>
Impact of artificial activity decrease on black carbon aerosol concentration and CO2 at the Mt Waliguan WMO/GAW baseline station during the COVID-19 period
<p>This one is about the data of the article, including BC data, CO2, meteorological data, and boundary layer data. As well as the trajectory and CWT obtained from the Hysplit run. Both BC and CO2 are raw results and can be used to check or repeat the experiment.</p>
Data-set of CO2, CH4, N2O dissolved concentrations and ancillary data in 15 Ecuadorian high-altitude lakes
<p>Data-set of the dissolved concentrations of CO<sub>2</sub>, CH<sub>4</sub> and N<sub>2</sub>O and ancillary data in 15 lakes located in the northern region of Ecuadorian Andes along an elevational gradient from 2,213 to 4,361 m above sea level, as well as a gradient of lake surface area (0.003 to 6.1 km<sup>2</sup>) and depth (0.9 to 74 m) (Fig. 1). Most lakes were located in the páramos of Salve Facha and Antisana y Mojanda.</p> <p>Sampling was carried out over a period from April 2019 to March 2022, with an inflatable boat approximately in the center of the lake, during day-time only (early morning to late afternoon). Water temperature, specific conductivity, pH, and %O<sub>2</sub> were measured in surface water with a YSI multi-parameter probe (ProPlus). Water for CH<sub>4</sub> and N<sub>2</sub>O samples was collected with a sampling devise consisting of a 2L polyethylene bottle with the bottom cut and fitted with a silicone tubing at the stopper (Abril et al. 2007). Two borosilicate serum bottles (Weathon) with a volume of 40 ml were filled with the silicone tubing, poisoned with 100 µl of a saturated solution of HgCl<sub>2</sub> and sealed with a butyl stopper and crimped with an aluminium cap. Measurements were made, after over-night equilibration, on an headspace (Weiss 1981) (created by injecting 15 ml of high-purity N<sub>2</sub> into the 40 ml sample bottles), with a gas chromatograph (SRI 8610C) with a flame ionisation detector for CH<sub>4</sub> and electron capture detector for N<sub>2</sub>O calibrated with CH<sub>4</sub>:N<sub>2</sub>O:N<sub>2</sub> gas mixtures (Air Liquide Belgium) with mixing ratios of 1, 10 and 30 ppm for CH<sub>4</sub>, and 0.2, 2.0 and 6.0 ppm for N<sub>2</sub>O. The precision of measurement based on duplicate samples was ±10.9% for CH<sub>4</sub> and ±5.8% for N<sub>2</sub>O.</p> <p>The partial pressure of CO<sub>2</sub> (pCO<sub>2</sub>) was measured in the field with a Li-Cor Li-820 infra-red gas analyser based on the headspace technique with four 60 ml polypropylene syringes that were filled directly with surface water. The pCO<sub>2</sub> in the atmosphere was measured by injecting ambient air sampled with an additional polypropylene syringe. The Li-Cor Li-820 was calibrated with pure N<sub>2</sub> and CO<sub>2</sub>:N<sub>2</sub> gas mixtures (Air Liquide Belgium) of 388, 804, 3,707 and 8,146 ppm. The final pCO<sub>2</sub> value was computed taking into account the partitioning of CO<sub>2</sub> between water and the headspace, as well as equilibrium with HCO<sub>3</sub><sup>-</sup> (Dickson et al. 2007) using water temperature measured in-situ and after equilibration, and total alkalinity (TA). The precision of pCO<sub>2</sub> measurement was ±5.2%.</p> <p>The CO<sub>2</sub> concentration is expressed as partial pressure in parts per million (ppm) and as dissolved concentration for CH<sub>4</sub> (nmol L<sup>-1</sup>), in accordance with convention in existing topical literature. Variations of N<sub>2</sub>O were modest and concentrations fluctuated around atmospheric equilibrium, so data are presented as percent of saturation level (%N<sub>2</sub>O, where atmospheric equilibrium corresponds to 100%), computed from the global mean N<sub>2</sub>O air mixing ratios given by the Global Monitoring Division (GMD) of the Earth System Research Laboratory (ESRL) of the National Oceanic and Atmospheric Administration (NOAA) (https://www.esrl.noaa.gov/gmd/hats/combined/N2O.html), using the Henry’s constant (Weiss and Price 1980).</p> <p>Samples for the stable isotope composition of DIC (δ<sup>13</sup>C-DIC) were collected in 12 ml Exetainer vials (Labco) and poisoned with 50 µL of a saturated solution of HgCl<sub>2</sub>. Prior to the analysis of δ<sup>13</sup>C-DIC, a 2 ml helium headspace was created and 100 µL of phosphoric acid (H<sub>3</sub>PO<sub>4</sub>, 99%) was added in the vial in order to convert CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> to CO<sub>2</sub>. After overnight equilibration, up to 1 mL of the headspace was injected with a gastight syringe into a coupled elemental analyser - IRMS (EA-IRMS, Thermo FlashHT or Carlo Erba EA1110 with DeltaV Advantage). The obtained data were corrected for isotopic equilibration between dissolved and gaseous CO<sub>2</sub> as described by Gillikin and Bouillon (2007). Calibration was performed with certified standards (NBS-19 or IAEA-CO-1, and LSVEC). Reproducibility of measurement based on duplicate injections of samples was typically better than ±0.2 ‰.</p> <p>Water was collected in surface water with a 2L polyethylene bottle. The water filtered through 47 mm diameter GF/F Whatman glass fibber filters was collected and further filtered through polyethersulfone syringe encapsulated filters (0.2 µm porosity) for nitrate (NO<sub>3</sub><sup>-</sup>), nitrite (NO<sub>2</sub><sup>-</sup>), ammonium (NH<sub>4</sub><sup>+</sup>), TA, major elements (Na<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, K<sup>+</sup>), as well as dissolved silicate (DSi) and Fe, stable isotope composition of O and H of H<sub>2</sub>O (δ<sup>18</sup>O-H<sub>2</sub>O and δ<sup>2</sup>H-H<sub>2</sub>O) and dissolved organic carbon (DOC). An additional water filtration was made on 25 mm diameter GF/F Whatman glass fibber filters for particulate organic carbon (POC) analysis.</p> <p>Samples for NO<sub>3</sub><sup>-</sup>, NO<sub>2</sub><sup>-</sup>, and NH<sub>4</sub><sup>+</sup> were stored frozen (-20°C) in 50 ml polypropylene vials. NO<sub>3</sub><sup>-</sup> and NO<sub>2</sub><sup>-</sup> were determined with the sulfanilamide colorimetric with the vanadium reduction method (American Public Health Association, 1998), and NH<sub>4</sub><sup>+</sup> with the dichloroisocyanurate-salicylate-nitroprussiate colorimetric method (Standing committee of Analysts, 1981). Detection limits were 0.3, 0.01, and 0.15 µmol L<sup>-1</sup> for NH<sub>4</sub><sup>+</sup>, NO<sub>2</sub><sup>-</sup> and NO<sub>3</sub><sup>-</sup>, respectively. Precisions were ±0.02 µmol L<sup>-1</sup>, ±0.02 µmol L<sup>-1</sup>, and ±0.1 µmol L<sup>-1</sup> for NH<sub>4</sub><sup>+</sup>, NO<sub>2</sub><sup>-</sup> and NO<sub>3</sub><sup>-</sup>, respectively.</p> <p>Samples for TA were stored at ambient temperature in polyethylene 55 ml vials and measurements were carried out by open-cell titration with HCl 0.1 mol L<sup>-1</sup> according to Gran (1952), and data quality checked with certified reference material obtained from Andrew Dickson (Scripps Institution of Oceanography, University of California, San Diego, USA), with a typical reproducibility better than ±3 µmol kg<sup>-1</sup>.</p> <p>Samples for δ<sup>18</sup>O-H<sub>2</sub>O and were δ<sup>2</sup>H-H<sub>2</sub>O stored at ambient temperature in polypropylene 8 ml vials. δ<sup>2</sup>H-H<sub>2</sub>O was measured on H<sub>2</sub> gas derived from a high‐temperature (1,030°C) Cr‐based reactor by automated injections of water using a TriPlus autosampler on an elemental analyzer (Thermo Flash HT/EA; Thermo Finnigan) coupled to a continuous‐flow isotope‐ratio mass spectrometer (Delta V Advantage; Thermo Finnigan). δ<sup>18</sup>O-H<sub>2</sub>O values were measured on a Thermo GasBench II coupled to a Thermo Delta XP IRMS after equilibration with CO<sub>2</sub>. The long-term uncertainty for standard δ<sup>18</sup>O values was ±0.1‰.</p> <p>Samples for major elements were stored at ambient temperature in 20 ml scintillation vials and preserved with 50 μl of HNO<sub>3</sub> (65%). Major elements were measured with inductively coupled plasma MS (ICP-MS; Agilent 7700x) calibrated with the following standards: SRM1640a from National Institute of Standards and Technology, TM-27.3 (lot 0412) and TMRain-04 (lot 0913) from Environment Canada, and SPS-SW2 Batch 130 from Spectrapure Standard. Limit of quantification was 0.5 µmol L<sup>-1</sup> for Na<sup>+</sup>, Mg<sup>2+</sup> and Ca<sup>2+</sup>, 1.0 µmol L<sup>-1</sup> for K<sup>+</sup> and 8 µmol L<sup>-1</sup> for DSi.</p> <p>Samples to determine DOC were stored at ambient temperature and in the dark in 40 ml brown borosilicate vials with polytetrafluoroethylene (PTFE) coated septa and poisoned with 50 µL of H<sub>3</sub>PO<sub>4</sub> (85%), and DOC concentration was determined with a wet oxidation total organic carbon analyzer (IO Analytical Aurora 1030W), with a typical reproducibility better than ±5%.</p> <p>Filters for POC analysis were decarbonated with HCl fumes for 4h and dried before encapsulation into silver cups; POC concentration was analysed on an EA-IRMS (Thermo FlashHT with DeltaV Advantage), with a reproducibility better than ±5%. Data were calibrated with certified (IAEA-600: caffeine) and in-house standards (leucine, tuna muscle tissue) that were previously calibrated versus certified standards.</p> <p><strong>References</strong></p> <p>Abril, G., Commarieu, M.-V., Guérin, F., 2007. Enhanced methane oxidation in an estuarine turbidity maximum. Limnol. Oceanogr. 52, 470-475. https://doi.org/10.4319/lo.2007.52.1.0470</p> <p>American Public Health Association. Standard methods for the examination of water and wastewater, (APHA, 1998).</p> <p>Dickson, A.G., Sabine, C.L., Christian, J.R., 2007. Guide to best practices for ocean CO2 measurements. PICES Special Publication 3, 191 pp., https://doi.org/10.25607/OBP-1342</p> <p>Gillikin, D.P., Bouillon, S., 2007. Determination of δ18O of water and δ13C of dissolved inorganic carbon using a simple modification of an elemental analyzer – isotope ratio mass spectrometer (EA-IRMS): an evaluation, Rapid Comm. Mass Spectrom. 21, 1475-1478, https://doi.org/10.1002/rcm.2968</p> <p>Gran, G., 1952. Determination of the equivalence point in potentiometric titrations Part II, The Analyst, 77, 661-671, https://doi.org/10.1039/AN9527700661.</p> <p>Standing committee of Analysts (1981). Ammonia in waters. Methods for the examination of waters and associated materials. 16 pp (HMSO, 1981).</p> <p>Weiss, R.F., Price, B.A., 1980. Nitrous oxide solubility in water and seawater. Mar. Chem. 8, 347-359. https://doi.org/10.1016/0304-4203(80)90024-9</p> <p>Weiss, R.F., 1981. Determinations of carbon dioxide and methane by dual catalyst flame ionization chromatography and nitrous oxide by electron capture chromatography. J. Chromatogr. Sci. 19, 611-616. https://doi.org/10.1093/chromsci/19.12.611</p>
Inhalation of Low Concentration of CO2 in Preterm Infants Not Responding to Caffeine for the Treatment of Apnea
ClinicalTrials.gov study NCT01911182. IPD Sharing: Not stated. Countries: 1. Publications: 7.
Monitors to Improve Indoor Carbon Dioxide (CO2) Concentrations in the Hospital
ClinicalTrials.gov study NCT04770597. IPD Sharing: YES. Countries: 1. Publications: 1.
Data from: Flow of CO2 from soil may not correspond with CO2 concentration in soil
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Data from: Soil CO2 and O2 concentrations illuminate the relative importance of weathering and respiration to seasonal soil gas fluctuations
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Data from: Rising atmospheric CO2 is reducing the protein concentration of a floral pollen source essential for North American bees
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Data from: Seasonally varying contributions to urban CO2 in the Chicago, IL, USA region: insights from a high-resolution CO2 concentration and δ13C record
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Riparian Evapotranspiration (ET) Study (SEON) from the Middle Rio Grande River Bosque, New Mexico (1999-2011 ): CO2 Concentration and Flux data
This study originated with the objective of parameterizing riparian evapotranspiration (ET) in the water budget of the Middle Rio Grande. We hypothesized that flooding and invasions of non-native species would strongly impact ecosystem water use. Our objectives were to measure and compare water use of native (Rio Grande cottonwood, Populus deltoides ssp. wizleni) and non-native (saltcedar, Tamarix chinensis, Russian olive, Eleagnus angustifolia) vegetation and to evaluate how water use is affected by climatic variability resulting in high river flows and flooding as well as drought conditions and deep water tables. Eddy covariance flux towers to measure ET and shallow wells to monitor water tables were instrumented in 1999. Active sites in their second decade of monitoring include a xeroriparian, non-flooding salt cedar woodland within Sevilleta National Wildlife Refuge and a dense, monotypic salt cedar stand at Bosque del Apache NWR, which is subject to flood pulses associated with high river flows. These data are CO2 concentration at canopy and CO2 flux from canopy collected as part of this study.
Water availability drives fine root dynamics in a Eucalyptus woodland under elevated atmospheric CO2 concentration
<p>Fine roots are a key component of carbon and nutrient dynamics in forest ecosystems. Rising atmospheric [CO<sub>2</sub>] (eCO<sub>2</sub>) is likely to alter the production and activity of fine roots, with important consequences for forest carbon storage. Yet empirical evidence of the role of eCO<sub>2</sub> in driving root dynamics in low-nutrient forested ecosystems is limited, particularly for grassy woodlands, an ecosystem type of global importance.</p> <p>We sampled fine roots across seasons over a two-year period to examine the effects of eCO<sub>2</sub> on their biomass, production, turnover and functional traits in a native mature grassy <i>Eucalyptus</i> woodland in eastern Australia (EucFACE).</p> <p>Fine root biomass, production and turnover varied greatly through time, increasing as soil water content declined. Despite a lack of persistent effects of eCO<sub>2</sub> on fine root biomass, production or turnover across the two-year sampling period, we found enhanced production pulses under eCO<sub>2</sub> between 10-30 cm soil depth. These eCO<sub>2</sub>-driven production pulses were associated with large changes in abiotic conditions. In addition, eCO<sub>2</sub> led to greater carbon and phosphorus concentrations in fine roots and increased root diameter, but no detectable effects on other morphological traits.</p> <p>Synthesis. We found minor quantitative effects of eCO<sub>2</sub> on fine root biomass dynamics that were largely driven by temporal variations in soil water availability. Our results suggest that in this mature grassy woodland, and perhaps also in other similar forested ecosystem types characterized by low phosphorus content in the soil, eCO<sub>2</sub> effects are small and transient. This suggests limited belowground fine root productivity responses to rising atmospheric CO<sub>2</sub> concentrations and, thus, perhaps also a limited ability of these systems to mitigate climate change through belowground mechanisms.</p>
Effect of earth-air and temperature variation on the concentration of CO2 in the soil in extremely arid regions
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.