A Review of Instrumentation and Measurement Techniques for Ground-Based and Airborne Field Studies of Gas-Phase Tropospheric Chemistry

ABSTRACT

The development, applications and intercomparisons of instrumentation and measurement techniques for ground-based and airborne field studies of gas-phase tropospheric chemistry are reviewed. Filter radiometry, chemical actinometry and scanning spectroradiometry for j-NO₂ and j-(O¹D) are described. Detection of OH using L-POAS/DOAS, MOAS, LIF/FAGE and CIMS is discussed. Observations of NO₃ using DOAS, MIESR and CRDS, and of HO₂ and RO₂ with CA, CIMS/IMR-MS, MIESR, and LIF/FAGE are also reviewed. GC-FID, GC-ECD and GC-MS analyses of NMHCs and alkyl, peroxyacyl and bi-functional organic nitrates are described, together with applications of CIMS/PTR-MS, DOAS and LIF. CO measurements utilising GFC, GC-HgO/UV, VUV-RF and TDLAS are presented. Measurements of O₃ using UV photometry, chemiluminescence, electrochemistry, LIDAR/DIAL and DOAS are discussed. Chemiluminescence and LIF detection methods for NO with photochemical and thermal convertors for NO₂ and NO_y are also discussed, as are TDLAS, MIESR, DOAS, CRDS and other approaches for NO₂. HONO measurements using DOAS, CIMS, CRDS, TDLAS, denuder systems, chemiluminescence and on-line analyses of NO₂ ⁻ are described. For HONO₂, filter packs, denuder systems, chemiluminescence methods, mist chambers, TDLAS, CIMS and LIF are presented. Direct and indirect fluorimetric, chromatographic and spectroscopic detection techniques are discussed for CH₂O and higher carbonyls. Observations of H₂O₂ and ROOH utilising colorimetry, chemiluminescence, fluorescence, HPLC and TDLAS are also described.

Keywords:

• O₃
• intercomparison exercises

ACKNOWLEDGEMENTS

Financial support from the European Union (PRIME Project; Contract ENV4-CT97-0404) and the UK Natural Environment Research Council (CHABLIS Project; Contract NER/G/S/2001/00557) is gratefully acknowledged.