FT ‐ IR Measurements of Atmospheric Trace Gases and their Fluxes

Abstract

Abstract Changing atmospheric composition is the primary driving force behind most aspects global climate change. In this chapter, we focus on field‐portable FTIR measurement techniques for four of the most abundant and important trace gases – carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O) and carbon monoxide (CO). There are two themes: applications of FTIR spectrometry for high precision in situ measurements of CO 2 , CH 4 , N 2 O and CO in relatively clean air, and remote sensing of atmospheric composition by ground‐based high resolution solar FTIR spectroscopy. Portable instruments and methods suited to high precision field measurements of trace gas composition are described, followed by several approaches to the measurement of rates of emission and exchange of these trace gases with sources and sinks at the earth’s surface. Ground based remote sensing by high resolution solar absorption spectroscopy is also described.