Long-term evolution and seasonal modulation of methanol above Jungfraujoch (46.5° N, 8.0° E): optimisation of the retrieval strategy, comparison with model simulations and independent observations
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Authors
Bader, W.
Stavrakou, T.
Muller, J.-F.
Reimann, S.
Boone, C.D.
Harrison, J.J.
Flock, O.
Bovy, B.
Franco, B.
Lejeune, B.
Servais, C.
Mahieu, E.
Discipline
Earth and related Environmental sciences
Subject
absorption
atmospheric chemistry
in situ measurement
long-term change
methanol
model validation
optimization
ozone
seasonal variation
stratosphere
troposphere
Bern [Switzerland]
Jungfraujoch
Switzerland
Audience
Scientific
Date
2014Metadata
Show full item recordDescription
Methanol (CH3OH) is the second most abundant organic compound in the Earth's atmosphere after methane. In this study, we present the first long-term time series of methanol total, lower tropospheric and upper tropospheric–lower stratospheric partial columns derived from the analysis of high resolution Fourier transform infrared solar spectra recorded at the Jungfraujoch station (46.5° N, 3580 m a.s.l.). The retrieval of methanol is very challenging due to strong absorptions of ozone in the region of the selected υ8 band of CH3OH. Two wide spectral intervals have been defined and adjusted in order to maximise the information content. Methanol does not exhibit a significant trend over the 1995–2012 time period, but a strong seasonal modulation characterised by maximum values and variability in June–July, minimum columns in winter and a peak-to-peak amplitude of 130%. Analysis and comparisons with in situ measurements carried out at the Jungfraujoch and ACE-FTS (Atmospheric Chemistry Experiment-Fourier transform spectrometer) occultations have been performed. The total and lower tropospheric columns are also compared with IMAGESv2 model simulations. There is no systematic bias between the observations and IMAGESv2 but the model underestimates the peak-to-peak amplitude of the seasonal modulations.
Citation
Bader, W.; Stavrakou, T.; Muller, J.-F.; Reimann, S.; Boone, C.D.; Harrison, J.J.; Flock, O.; Bovy, B.; Franco, B.; Lejeune, B.; Servais, C.; Mahieu, E. (2014). Long-term evolution and seasonal modulation of methanol above Jungfraujoch (46.5° N, 8.0° E): optimisation of the retrieval strategy, comparison with model simulations and independent observations. , Atmospheric Measurement Techniques, Vol. 7, Issue 11, 3861-3872, DOI: 10.5194/amt-7-3861-2014.Identifiers
scopus: 2-s2.0-84911944563
Type
Article
Peer-Review
Yes
Language
eng