 |
| Titel |
Formic acid above the Jungfraujoch during 1985-2007: observed variability, seasonality, but no long-term background evolution |
| VerfasserIn |
R. Zander, P. Duchatelet, E. Mahieu, P. Demoulin, G. Roland, C. Servais, J. V. Auwera, A. Perrin, C. P. Rinsland, P. J. Crutzen  |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 20 ; Nr. 10, no. 20 (2010-10-25), S.10047-10065 |
| Datensatznummer |
250008853
|
| Publikation (Nr.) |
 copernicus.org/acp-10-10047-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
This paper reports on daytime total vertical column abundances of formic
acid (HCOOH) above the Northern mid-latitude, high altitude Jungfraujoch
station (Switzerland; 46.5° N, 8.0° E, 3580 m alt.). The columns were
derived from the analysis of infrared solar observations regularly performed
with high spectral resolution Fourier transform spectrometers during over
1500 days between September 1985 and September 2007. The investigation was
based on the spectrometric fitting of five spectral intervals, one
encompassing the HCOOH ν6 band Q branch at 1105 cm−1, and
four additional ones allowing to optimally account for critical
temperature-sensitive or time-evolving interferences by other atmospheric
gases, in particular HDO, CCl2F2 and CHClF2. The main
results derived from the 22 years long database indicate that the free
tropospheric burden of HCOOH above the Jungfraujoch undergoes important
short-term daytime variability, diurnal and seasonal modulations,
inter-annual anomalies, but no significant long-term background change.
A major progress in the remote determination of the atmospheric HCOOH
columns reported here has resulted from the adoption of new, improved
absolute spectral line intensities for the infrared ν6 band of
trans-formic acid, resulting in retrieved free tropospheric loadings being
about a factor two smaller than if derived with previous spectroscopic
parameters. Implications of this significant change with regard to earlier
remote measurements of atmospheric formic acid and comparison with relevant
Northern mid-latitude findings, both in situ and remote, will be assessed
critically. Sparse HCOOH model predictions will also be evoked and assessed
with respect to findings reported here. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|