Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union

Journal metrics

  • IF value: 3.089 IF 3.089
  • IF 5-year<br/> value: 3.700 IF 5-year
    3.700
  • CiteScore<br/> value: 3.59 CiteScore
    3.59
  • SNIP value: 1.273 SNIP 1.273
  • SJR value: 2.026 SJR 2.026
  • IPP value: 3.082 IPP 3.082
  • h5-index value: 45 h5-index 45
https://doi.org/10.5194/amt-2017-272
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
21 Aug 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Measurement Techniques (AMT).
Long open path measurements of greenhouse gases in air using near infrared Fourier transform spectroscopy
David W. T. Griffith1, Denis Pöhler2, Stefan Schmitt2, Samuel Hammer2, Sanam N. Vardag2,a, and Ulrich Platt2 1Centre for Atmospheric Chemistry, University of Wollongong, Wollongong, Australia
2Institute of Environmental Physics, University of Heidelberg, Heidelberg, Germany
anow at: Heidelberg Center for the Environment, University of Heidelberg, Heidelberg, Germany
Abstract. In complex and urban environments, atmospheric trace gas composition is highly variable in time and space. Point measurement techniques for trace gases with in situ instruments are well established and accurate, but do not provide spatial averaging to compare against developing high resolution atmospheric models of composition and small scale meteorology with resolutions of the order of a kilometre. Open path measurement techniques provide path average concentrations and spatial averaging which, if sufficiently accurate, may be better suited to assessment and interpretation with such models. Open path Fourier Transform Spectroscopy (FTS) in the mid infrared region, and Differential Optical Absorption Spectroscopy (DOAS) in the UV and visible, have been used for many years for open path spectroscopic measurements of selected species in both clean air and in polluted environments. Compared to the mid infrared, near infrared instrumentation allows measurements over longer paths than mid IR FTS, for species such as greenhouse gases which are not easily accessible to DOAS.

In this pilot study we present the first open path near infrared (4000–10 000 cm−1, 1.0–2.5 μm) FTS measurements of CO2, CH4, O2, H2O and HDO over a 1.5 km path in urban Heidelberg, Germany. We describe the construction of the open path FTS system, the analysis of the collected spectra, precision and accuracy of the measurements, and the results from a four-month trial measurement period in July–November 2014. The open path measurements are compared to calibrated in situ measurements made at one end of the open path. There are small but significant differences between in situ and open path measurements coincident in time which reflect local sources and sinks and the way in which they are sampled by the point and path-averaged measurements. Open path FTS may provide a valuable new tool for investigations of atmospheric trace gas composition in complex, small scale environments such as cities.


Citation: Griffith, D. W. T., Pöhler, D., Schmitt, S., Hammer, S., Vardag, S. N., and Platt, U.: Long open path measurements of greenhouse gases in air using near infrared Fourier transform spectroscopy, Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2017-272, in review, 2017.
David W. T. Griffith et al.
David W. T. Griffith et al.
David W. T. Griffith et al.

Viewed

Total article views: 250 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
178 69 3 250 1 3

Views and downloads (calculated since 21 Aug 2017)

Cumulative views and downloads (calculated since 21 Aug 2017)

Viewed (geographical distribution)

Total article views: 250 (including HTML, PDF, and XML)

Thereof 247 with geography defined and 3 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 23 Sep 2017
Publications Copernicus
Download
Short summary
Measurements of atmospheric trace gases over an open path complement in situ measurements by spatial averaging. This paper describes the first open path measurements of CO2, CH4 and other trace gases by near infrared Fourier transform spectroscopy. The measurements were made in Heidelberg, Germany for 4 months in 2014 over a 1.5 km path, and compared to in situ measurements made at one end of the path. The experiment setup and methods, and the open path – in situ comparisons, are described.
Measurements of atmospheric trace gases over an open path complement in situ measurements by...
Share