Centre for Atmospheric Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia.
Environ Sci Technol. 2012 Feb 7;46(3):1739-46. doi: 10.1021/es202807s. Epub 2012 Jan 26.
A Bayesian inversion technique to determine the location and strength of trace gas emissions from a point source in open air is presented. It was tested using atmospheric measurements of N(2)O and CO(2) released at known rates from a source located within an array of eight evenly spaced sampling points on a 20-m radius circle. The analysis requires knowledge of concentration enhancement downwind of the source and the normalized, three-dimensional distribution (shape) of concentration in the dispersion plume. The influence of varying background concentrations of ∼1% for N(2)O and ∼10% for CO(2) was removed by subtracting upwind concentrations from those downwind of the source to yield only concentration enhancements. Continuous measurements of turbulent wind and temperature statistics were used to model the dispersion plume. The analysis localized the source to within 0.8 m of the true position and the emission rates were determined to better than 3% accuracy. This technique will be useful in assurance monitoring for geological storage of CO(2) and for applications requiring knowledge of the location and rate of fugitive emissions.
提出了一种贝叶斯反演技术，用于确定开放空气中点源痕量气体排放的位置和强度。该技术使用在一个 20 米半径的圆上均匀分布的 8 个采样点组成的阵列中，以已知速率从源释放的 N(2)O 和 CO(2)的大气测量进行了测试。分析需要了解下风处源的浓度增强以及扩散羽流中浓度的归一化、三维分布（形状）。通过从源下风处的浓度中减去上风处的浓度，消除了背景浓度约为 N(2)O 的 1%和 CO(2)的 10%的变化的影响，从而仅得到浓度增强。连续测量的湍流风和温度统计数据用于模拟扩散羽流。分析将源定位在真实位置的 0.8 米内，并且排放率的确定精度优于 3%。该技术将在 CO(2)地质储存的保证监测以及需要了解逸散排放的位置和速率的应用中非常有用。
