Deployment of Unmanned Aerial Vehicle during surface CO2 release experiments at the Ginninderra greenhouse gas controlled release facility H. Berko (CO2CRC, Geoscience Australia), F. Poppa (The Australian National University), U. Zimmer (The Australian National University) and A. Feitz (CO2CRC, Geoscience Australia) Lagrangian stochastic (LS) forward modelling of CO2 plumes from above-surface release experiments conducted at the GA-CO2CRC Ginninderra 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, a GPS, lidar and a communication module. It was developed to detect and locate CO2 gas leaks; and estimate CO2 concentration at the emission source. The choice of a rotor-craft UAV allows slower flight speeds compared to speeds of a fixed-wing UAV; and the electric powered motor enables flight times of 12 min. In experiments conducted at the Ginninderra controlled release facility, gaseous CO2 (100 kg per day) was released from a small diffuse source located in the middle of the paddock, and the RUAV was flown repeatedly over the CO2 source at a few meters height. Meteorological parameters measured continuously at the site at the time of the flight 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 CCS activities.

In July 2010, Geoscience Australia and CSIRO Marine & Atmospheric Research jointly commissioned a new atmospheric composition monitoring station, named Arcturus, in sub-tropical Queensland, Australia. The facility is designed as a proto-type remotely operated `baseline monitoring station' that could be deployed in areas that are likely targets for commercial scale geological storage of carbon dioxide. A key question, given the ecosystem and anthropogenic sources of CO2 in the region, and the absence of a 'clean-wind' sector baseline, is how large would a CO2 leak have to be from a geological storage site before it can be detected above the background CO2 signal? To address this, CO2 leak simulation modelling was performed for 1-year period using the coupled prognostic meteorological and air pollution model TAPM at various locations, emission rates and distances (1-10 km) from the station.

Geoscience Australia and the CO2CRC have constructed a greenhouse gas controlled release facility at an experimental agricultural station maintained by CSIRO Plant Industry at Ginninderra, Canberra. The facility is designed to simulate surface emissions of CO2 from the soil into the atmosphere and is modelled on the ZERT controlled release facility in Montana. Injection of CO2 into the soil is via a 120 m long slotted HDPE pipe installed horizontally 2 m underground. An eddy covariance (EC) system was installed at Ginninderra during the first sub-surface release (March - June 2012). The EC system, which generated 15 minute averages using a 10 Hz sampling frequency, measured net radiation (as a function of upwelling and downwelling, solar and longwave radiation); wind speed and direction in 3 dimensions; CO2 and H2O concentration; and temperature and pressure. The EC system was installed to provide baseline atmospheric measurements and assess methods for quantifying CO2 leakages. The daily CO2 release rate was 100 kg/d. Here we report on the application of the CO2 emissions quantification method developed by Pan et al. (2010) for detecting and quantifying CO2 leakages using EC techniques. The approach seeks to isolate the CO2 leakage signal from the natural variation inherent in flux data, using a time-window splitting scheme, median filtering and scaling techniques. Results from application of the EC method at the Ginninderra site will be presented and modifications to the method and its limitations discussed. Pan, L.; Lewicki, J.L.; Oldenburg C.M.; and Fischer M.L., (2010). Time-window based filtering method for near-surface detection of leakage from geological carbon sequestration sites, Environmental Earth Sciences, 60, pp 359-369. Proceedings of the 2013 International Carbon Dioxide Conference - Beijing China

The CO2CRC has been leading the international development and application of atmospheric techniques for CO2 leak detection and quantification for CCS. CSIRO's atmospheric monitoring program at the CO2CRC Otway Project demonstrated world's leading practice for atmospheric monitoring at geological storage sites. The GA-CO2CRC Ginninderra controlled release facility has enabled development and testing of a new atmospheric tomography approach for accurately quantifying CO2 emissions using atmospheric techniques. A scaled-up version of the technique using an array of more cost effective (but less accurate) sensors was applied at a larger scale at the Otway Stage 2B controlled release. Additional techniques have been developed including data filtering to optimize the detection of emitted gases against the ecosystem background and Bayesian inverse modeling to locate and quantify a source. GA and CSIRO operate a joint baseline atmospheric station in the Bowen Basin and have been independently investigating the sensitivity of CO2 leak detection through coupling of measurements taken in a sub-tropical environment with simulated leakage events. An outcome from this body of work is the importance of good quality, calibrated measurements, a long baseline record and the development and application of techniques using atmospheric models for quantifying gaseous emissions from the ground to the atmosphere. These same measurement requirements and quantification techniques have direct application to fugitive methane emissions from open cut coal mines, coal seam gas, tight gas, and conventional gas emissions. Application is easier for methane: the background signal is lower, sensors are available at affordable cost, and the emissions are measureable now. The Bowen Basin site, for example, is detecting fugitive methane emitted from open cut coal mining activities tens of kilometres away. An example of the sensitivity of atmospheric techniques for the detection of fugitive emissions from a simulated methane source will be presented.

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.

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

This folder contains the work related to Climate Future Tasmania project including hazard, risk calculation, standalone tool, management and reports etc.

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.

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.

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.