An OP-FTIR trace gas observatory : design, automation, and applications

Abstract

Atmospheric trace gas measurements aid in the understanding of air quality, climate change, and biogeochemical processes. Open-Path Fourier Transform Infrared (OP-FTIR) spectroscopy can be used to measure many infrared active trace gases in a lower tropospheric path. The atmospheric observatory designed as part of this project will enable long-term OP-FTIR trace gas datasets to be collected and examined by the Tropospheric Remote Sensing Laboratory (TRSL) and external users. An application of utilizing OP-FTIR data is explored in studying the detectability of biomass burning emissions from near- and far-range wildfire sources in Halifax. Atmospheric transport modeling and infrared spectrum retrievals are used to determine that transported emission detectability is likely given proper environmental conditions and sufficiently optimized retrievals. The study involved start-to-finish data analysis, from spectrum acquisition, through spectral analysis and retrieval optimization, to time series analysis of trace gas concentrations.