Passive Open-Path Fouriertransform Infrared spectroscopy (OP-FTIR) measurements in the Arctic environment of Ny Ålesund / Svalbard 2023

In the Polar MOSES campaign 2023, a ground-based remote sensing method – OP-FTIR spectroscopy- which is proven to be a flexible long-path technique for the characterization of larger areas was used. This method is able to simultaneously detect various volatile atmospheric compounds relevant for environmental assessment with a single rapid measurement. Many greenhouse gas molecules (e.g., CO₂, H₂O, CH₄) have unique signatures (absorption or emission bands) in the measured spectral IR range. IR spectroscopy allows spatial and non-invasive characterization of emissions and is a useful method to capture emissions along the coastline, both seaward and landward.

The passive technique was applied in a mobile mode to obtain IR spectra at different relevant locations. In order to investigate the near surface atmospheric composition, the mobile passive OP-FTIR spectroscopic scanning measurements was executed with Bruker RAPID devices to cover marine and terrestrial areas. The RAPID passive detection systems was deployed for 360° remote sensing of threats at distances up to 5000 m. Initially, the survey's primary objective was to qualitatively interpret spectra, enabling the identification of emission sources and the characterization of the heterogeneous emission pattern. This was achieved through the measurements in different directions to allow the direct comparisons of the various compartments under investigation and their potential interactions.