Development of Fourier transform spectrometry for UV-visible differential optical absorption spectroscopy measurements of tropospheric minor constituents.

Concentration measurements of trace gases in the atmosphere require the use of highly sensitive and precise techniques. The UV-visible differential optical absorption spectroscopy technique is one that is heavily used for tropospheric measurements. To assess the advantages and drawbacks of using a Fourier transform spectrometer, we built a differential optical absorption spectroscopy optical setup based on a Bruker IFS 120M spectrometer. The characteristics and the capabilities of this setup have been studied and compared with those of the more conventional grating-based instruments. Two of the main advantages of the Fourier transform spectrometer are (1) the existence of a reproducible and precise wave-number scale, which greatly simplifies the algorithms used to analyze the atmospheric spectra, and (2) the possibility of recording large spectral regions at relatively high resolution, enabling the simultaneous detection of numerous chemical species with better discriminating properties. The main drawback, on the other hand, is due to the fact that a Fourier transform spectrometer is a scanning device for which the scanning time is small compared with the total measurement time. It does not have the signal integration capabilities of the CCD or photodiode array-based grating spectrographs. The Fourier transform spectrometer therefore needs fairly large amounts of light and is limited to short to medium absorption path lengths when working in the UV.

[1]  M. Sigrist.  Air monitoring by spectroscopic techniques , 1994 .

[2]  U. Platt,et al.  Simultaneous measurement of atmospheric CH2O, O3, and NO2 by differential optical absorption , 1979 .

[3]  Ulrich Schurath,et al.  Near-UV absorption cross sections and trans/cis equilibrium of nitrous acid , 1991 .

[4]  Ulrich Platt,et al.  Detection of NO3 in the polluted troposphere by differential optical absorption , 1980 .

[5]  Ann Carine Vandaele,et al.  Measurements of the NO2 absorption cross-section from 42 000 cm−1 to 10 000 cm−1 (238–1000 nm) at 220 K and 294 K , 1998 .

[6]  M. V. Roozendael,et al.  Fourier transform measurement of NO2 absorption cross-section in the visible range at room temperature , 1996 .

[7]  Stanley C. Solomon,et al.  On the interpretation of zenith sky absorption measurements , 1987 .

[8]  M. Gil,et al.  Ground‐based stratospheric NO2 monitoring at Keflavik (Iceland) during EASOE , 1994 .

[9]  M. Molina,et al.  Chemical kinetics and photochemical data for use in stratospheric modeling , 1985 .

[10]  Ulrich Platt,et al.  Correction of the oxygen interference with UV spectroscopic (DOAS) measurements of monocyclic aromatic hydrocarbons in the atmosphere , 1998 .

[11]  R. Jakoubek,et al.  Measurement of tropospheric trace gases by long‐path differential absorption spectroscopy during the 1993 OH Photochemistry Experiment , 1997 .

[12]  A. Vandaele,et al.  SO2 Absorption Cross-section Measurement in the UV using a Fourier Transform Spectrometer , 1994 .

[13]  Kevin J. Madders,et al.  EUROPEAN SPACE AGENCY , 1983 .

[14]  J. Brion,et al.  Ozone UV spectroscopy I: Absorption cross-sections at room temperature , 1992 .

[15]  John M. C. Plane,et al.  Differential optical absorption spectrometer for measuring atmospheric trace gases , 1992 .

[16]  Ulrich Platt,et al.  Differential optical absorption spectroscopy (DOAS) , 1994 .

[17]  C. Clerbaux,et al.  Intercomparison of instruments for tropospheric measurements using differential optical absorption spectroscopy , 2019 .

[18]  Ulrich Platt,et al.  Measurements of Atmospheric Trace Gases by Long Path Differential UV/Visible Absorption Spectroscopy , 1983 .