Probabilistic Inversion Modeling of Gas Emissions: A Gradient-Based MCMC Estimation of Gaussian Plume Parameters

TL;DR

This paper introduces a probabilistic inversion method using gradient-based MCMC to accurately estimate gas emission sources and dispersion parameters from concentration data, reducing bias caused by incorrect atmospheric stability assumptions.

Contribution

It presents a novel joint estimation approach for dispersion parameters and source characteristics, improving accuracy in Gaussian plume source inversion.

Findings

Joint estimation reduces bias in source localization.

Method effectively quantifies uncertainty in parameter estimates.

Application to Chilbolton data demonstrates practical utility.

Abstract

In response to global concerns regarding air quality and the environmental impact of greenhouse gas emissions, detecting and quantifying sources of emissions has become critical. To understand this impact and target mitigations effectively, methods for accurate quantification of greenhouse gas emissions are required. In this paper, we focus on the inversion of concentration measurements to estimate source location and emission rate. In practice, such methods often rely on atmospheric stability class-based Gaussian plume dispersion models. However, incorrectly identifying the atmospheric stability class can lead to significant bias in estimates of source characteristics. We present a robust approach that reduces this bias by jointly estimating the horizontal and vertical dispersion parameters of the Gaussian plume model, together with source location and emission rate, atmospheric background concentration, and sensor measurement error variance. Uncertainty in parameter estimation is quantified through probabilistic inversion using gradient-based MCMC methods. A simulation study is performed to assess the inversion methodology. We then focus on inference for the published Chilbolton dataset which contains controlled methane releases and demonstrates the practical benefits of estimating dispersion parameters in source inversion problems.