atmosphere
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Geoscience Australia and CO2CRC have constructed a greenhouse gas controlled release facility to simulate surface emissions of CO2 (and other greenhouse gases) from the soil into the atmosphere under controlled conditions. The facility is located at an experimental agricultural station maintained by CSIRO Plant Industry at Ginninderra, Canberra. The design of the facility is modelled on the ZERT controlled release facility in Montana. The facility is equipped with a 2.5 tonne liquid CO2 storage vessel, vaporiser and mass flow controller unit with a capacity for 6 individual metered CO2 gas streams (up to 600 kg/d capacity in total). Injection of CO2 into the soil is via a 120m long slotted HDPE pipe installed horizontally 2m underground. This is equipped with a packer system to partition the well into six CO2 injection chambers. The site is characterised by the presence of deep red and yellow podsolic soils with the subsoil containing mainly kaolinite and subdominant illite. Injection is above the water table. The choice of well orientation based upon the effects of various factors such as topography, wind direction, soil properties and ground water depth will be discussed. An above ground release experiment was conducted from July - October 2010 leading to the development of an atmospheric tomography technique for quantifying and locating CO2 emissions1. An overview of monitoring experiments conducted during the first subsurface release (January-March 2012), including application of the atmospheric tomography technique, soil flux surveys, microbiological surveys, and tracer studies, will be presented. Additional CO2 release experiments are planned for late 2012 and 2013. Poster presented at 11th Annual Conference on Carbon Capture Utilization & Sequestration, April 30 - May 3, 2012, Pittsburgh, Pennsylvania
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A short animation of an atmospheric simulation of methane emissions from a coal mine (produced using TAPM) compared to actual methane concentrations detected by the Atmospheric Monitoring Station, Arcturus in Central Queensland. It illustrates the effectiveness of both the detection and simulation techniques in the monitoring of atmospheric methane emissions. The animation shows a moving trace of both the simulated and actual recorded emissions data, along with windspeed and direction indicators. Some data provided by CSIRO Marine and Atmospheric Research.
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11-5413 The Probabilistic Volcanic Ash - Hazard Map movie describes how you construct a probabilistic hazard map for volcanic ash, using an example scenario from GA's volcanic ash modelling work in West Java, Indonesia. The target audience is other govt. agencies both national and international, and the general public. The 3.3 minute movie uses 3D Max animations and 2D affects, has narration and production music. The narration will also be done in Bahasa Indonesian, at a later date.
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Geoscience Australia and CO2CRC have constructed a greenhouse gas controlled release reference facility to simulate surface emissions of CO2 (and other GHG gases) from an underground slotted horizontal well into the atmosphere under controlled conditions. The facility is located at an experimental agricultural station maintained by CSIRO Plant Industry at Ginninderra, Canberra. The design of the facility is modelled on the ZERT controlled release facility in Montana. The facility is equipped with a 2.5 tonne liquid CO2 storage vessel, vaporiser and mass flow controller unit with a capacity for 6 individual metered CO2 gas streams (up to 600 kg/d capacity). Injection of CO2 into soil is via a shallow (2m depth) underground 120m horizontally drilled slotted HDPE pipe. This is equipped with a packer system to partition the well into six CO2 injection chambers. The site is characterised by the presence of deep red and yellow podsolic soils with the subsoil containing mainly kaolinite and subdominant illite. Injection is above the water table. The choice of well orientation based upon the effects of various factors such as topography, wind direction, soil properties and ground water depth will be discussed. An above ground release experiment was conducted from July - October 2010 leading to the development of an atmospheric tomography technique for quantifying and locating CO2 emissions1. This technique will be applied to the first sub-surface experiment held in January-March 2012 in addition to soil flux surveys, microbiological surveys, and tracer studies. An overview of monitoring experiments conducted during the subsurface release and preliminary results will be presented. Additional CO2 releases are planned for late 2012 and 2013. Abstract for "11th Annual Conference on Carbon Capture Utilization & Sequestration" April 30 - May 3, 2012, Pittsburgh, Pennsylvania
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Nadir BRDF Adjusted Reflectance correction standardizes Landsat data to enable image intercomparison. The method accounts for within-scene sun, view and sensor geometry variations by using coupled physics-based atmospheric and BRDF models. The BRDF shape functions derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) data with the MODerate resolution atmospheric TRANsmission version 5 (MODTRAN) radiative transfer model.
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Having techniques available for the accurate quantification of potential CO2 surface leaks from geological storage sites is critical for regulators, public assurance and for underpinning carbon pricing mechanisms. Currently, there are few options available that enable accurate CO2 quantification of potential leaks at the soil-atmosphere interface. Integrated soil flux measurements can be used to quantify CO2 emission rates from the soil and atmospheric techniques such as eddy covariance or Lagrangian stochastic modelling have been used with some success to quantify CO2 emissions into the atmosphere from simulated surface leaks. The error for all of these techniques for determining the emission rate is not less than 10%. A new technique to quantify CO2 emissions was trialled at the CO2CRC Ginninderra controlled release site in Canberra. The technique, termed atmospheric tomography, used an array of sampling sites and a Bayesian inversion technique to simultaneously solve for the location and magnitude of a simulated CO2 leak. The technique requires knowledge of concentration enhancement downwind of the source and the normalized, three-dimensional distribution (shape) of concentration in the dispersion plume. Continuous measurements of turbulent wind and temperature statistics were used to model the dispersion plume.
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The aim of the NPE10 exercise is the continuation of the multi - technology approach started with NPE09. For NPE10, a simulated release of radionuclides was the trigger for the scenario in which an REB-listed seismo-acoustic event with ML between 3.0 and 4.8 was the source. Assumptions made were: A single seismo-acoustic signal-generating underground detonation event with continuous leak of noble gas, radionuclide detections only from simulated release. Using atmospheric transport modelling the IDC identified 48 candidate seismo-acoustic events from data fusion of the seismo-acoustic REBs with radionuclide detections. We were able to reduce the number of candidate seismo-acoustic point sources from 48 to 2 by firstly rejecting events that did not appear consistently in the data fusion bulletins; secondly, reducing the time-window under consideration through analysis of xenon isotope ratios; and thirdly, by clustering the remaining earthquakes and aftershocks and applying forward tracking to these (clustered) candidate events, using the Hy-split and ARGOS modelling tools. The two candidate events that were not screened by RN analysis were Wyoming REB events 6797924 (23-Oct) and 6797555 (24-Oct). Event 6797555 was identified as an earthquake on the basis of depth (identification of candidate depth phases at five teleseismic stations); regional Pn/Lg and mb:Ms - all indicating an earthquake source. Event 6797924, however, was not screened and from our analysis would constitute a candidate event for an On-Site Inspection under the Treaty.
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There is increasing recognition that minimising methane emissions from the oil and gas sector is a key step in reducing global greenhouse gas emissions in the near term. Atmospheric monitoring techniques are likely to play an important future role in measuring the extent of existing emissions and verifying emission reductions. They can be very suitable for monitoring gas fields as they are continuous and integrate emissions from a number of potential point and diffuse sources that may vary in time. Geoscience Australia and CSIRO Marine & Atmospheric Research have collected three years of continuous methane and carbon dioxide measurements at their atmospheric composition monitoring station ('Arcturus') in the Bowen Basin, Australia. Methane signals in the Bowen Basin are likely to be influenced by cattle production, landfill, coal production, and conventional and coal seam gas (CSG) production. Australian CSG is typically 'dry' and is characterised by a mixed thermogenic-biogenic methane source with an absence of C3-C6+ alkanes. The range of '13C isotopic signatures of the CSG is similar to methane from landfill gas and cattle emissions. The absence of standard in-situ tracers for CSG fugitive emissions suggests that having a comprehensive baseline will be critical for successful measurement of fugitive emissions using atmospheric techniques. In this paper we report on the sensitivity of atmospheric techniques for the detection of fugitive emissions from a simulated new CSG field against a three year baseline signal. Simulation of emissions was performed for a 1-year period using the coupled prognostic meteorological and air pollution model TAPM at different fugitive emission rates (i.e. estimates of <1% to up to 10% of production lost) and distances (i.e. 10 - 50 km) from the station. Emissions from the simulated CSG field are based on well density, production volumes, and field size typical of CSG fields in Australia. The distributions of the perturbed and baseline signals were evaluated and statistically compared to test for the presence of fugitive methane emissions. In addition, a time series model of the methane baseline was developed in order to generate alternative realizations of the baseline signal. These were used to provide measures of both the likelihood of detecting fugitive emissions at various emission levels and of the false alarm rate. Results of the statistical analysis and an indicative minimum fugitive methane emission rate that can be detected using a single monitoring station are presented. Poster presented at the American Geophysical Union meeting, December 2013, San Francisco
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Abstract for a Poster for the CO2CRC Symposium 2013: Atmospheric tomography is a CO2 quantification and localisation technique that uses an array of sampling points and a Bayesian inversion method to solve for the location and magnitude of a CO2 leak. Knowledge of a normalized three-dimensional dispersion plume is required in order to accurately model a leak using many meteorological parameters. A previous small scale (~20 m) study using a high precision Fourier Transform Infrared found that the emission rate was determined to within 3% of the actual release rate and the localisation within 1 m of the correct position. The technique was applied during the CO2CRC Otway Stage 2B residual saturation and dissolution test in August-October 2011. A network of eight independent CO2 sensors (Vaisala GMP343 CO2 probes) were positioned at distances ranging from 154 to 473 m from the well. A 3D sonic anemometer within the measurement area collected wind turbulence data. The results of the study indicate that, through careful data processing, measurements from the reasonably inexpensive (but lower accuracy and lower precision) CO2 sensor array can provide useful data for the application of atmospheric tomography. Results have found that the low precision of the sensors over time becomes a problem due to sensor drift. A reference measurement of CO2 helps to resolve this problem and improves the perturbation signal during data processing. Preliminary inversion modeling results will be shown to show the best estimation of locating a CO2 leakage source for the Otway Stage 2B residual saturation and dissolution test. CO2CRC Symposium 2013, Hobart
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Lagrangian stochastic (LS) forward modelling of CO2 plumes from above-surface release experiments conducted at the GA-CO2CRC Ginninderra GHG controlled release facility demonstrated that small surface leaks are likely to disperse rapidly and unlikely to be detected at heights greater 4 m; this was verified using a rotorcraft to map out the plume. The CO2 sensing rotorcraft unmanned aerial vehicle (RUAV) developed at the Australian National University, Canberra, is equipped with a CO2 sensor (3 ppm accuracy and 2 s response time), a GPS, lidar and a communication module. It was developed to detect, locate and quantify CO2 gas leaks. The choice of a rotorcraft UAV allows slower flight speeds compared to speeds of a fixed-wing UAV; and the electric powered motor enables flight times of 12 min. During the experiments, gaseous CO2 (100 kg per day) was released from a small diffuse source located in the middle of the paddock of the controlled release facility, and the RUAV, flying repeatedly over the CO2 source at a few metres height, recorded CO2 concentrations up to 85 ppm above background. Meteorological parameters measured continuously at the site were input in the LS model. Mapped out horizontal and vertical CO2 concentrations established the need to be close to the ground in order to detect CO2 leakage using aerial techniques. Using the rotorcraft as a mobile sensor could be an expedient mechanism to detect plumes over large areas, and would be important for early detection of CO2 leaks arising from CO2 geological storage activities.