Trace gas concentrations and fluxes derived from open-path FTIR measurements
Abstract
Open-Path Fourier Transform Infrared Spectroscopy (OP-FTIR) is a well-established technique used to measure boundary layer trace gas concentrations, especially in fenceline monitoring. Recently, the technique has been applied to derivations of trace gas emissions using the flux-gradient approach.
We describe the deployment of a monostatic OP-FTIR spectrometer over a very long atmospheric path (550 m one-way), highlighting some challenges and technical solutions under these measurement conditions, which are representative of newest satellite footprints. We also present details of our retrievals of trace gas concentrations using an iterative non-linear least squares fitting technique, which requires auxiliary data inputs of pressure, temperature, and spectroscopic absorption strength and line broadening parameters. During the summer of 2018 and 2019 we made long-path concentration measurements at two different heights and we discuss the suitability of such measurements for emission calculations using the flux-gradient approach. Finally, we also made auxiliary in situ measurements of criteria air contaminants and greenhouse gases at both ends of the open-path and we present a study of the representativeness of both measurement geometries.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A21A..09W
- Keywords:
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- 0345 Pollution: urban and regional;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0368 Troposphere: constituent transport and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3307 Boundary layer processes;
- ATMOSPHERIC PROCESSES;
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES