Challenges in atmospheric monitoring of areal emission sources – an Open-path Fourier transform infrared (OP-FTIR) spectroscopic experience report

Abstract:

Reliable detection and assessment of near-surface CO₂ emissions from natural or anthropogenic sources require the application of various monitoring tools at different spatial scales. Especially, optical remote sensing tools for atmospheric monitoring have the potential to measure integrally CO₂ emissions over larger scales (> 10.000m²). Within the framework of the MONACO project (“Monitoring approach for geological CO₂ storage sites using a hierarchical observation concept”), an integrative hierarchical monitoring concept was developed and validated at different field sites with the aim to establish a modular observation strategy including investigations in the shallow subsurface, at ground surface level and the lower atmospheric boundary layer.

The main aims of the atmospheric monitoring using optical remote sensing were the observation of the gas dispersion in to the near-surface atmosphere, the determination of maximum concentration values and identification of the main challenges associated with the monitoring of extended emission sources with the proposed methodological set up under typical environmental conditions. The presentation will give an overview about several case studies using the integrative approach of Open-Path Fourier Transform Infrared spectroscopy (OP FTIR) in combination with in situ measurements. As a main result, the method was validated as possible approach for continuous monitoring of the atmospheric composition, in terms of integral determination of GHG concentrations and to identify target areas which are needed to be investigated more in detail. Especially the data interpretation should closely consider the micrometeorological conditions. Technical aspects concerning robust equipment, experimental set up and fast data processing algorithms have to be taken into account for the enhanced automation of atmospheric monitoring.