 |
| Titel |
SCIAMACHY formaldehyde observations: constraint for isoprene emission estimates over Europe? |
| VerfasserIn |
G. Dufour, F. Wittrock, M. Camredon, M. Beekmann, A. Richter, B. Aumont, J. P. Burrows |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 5 ; Nr. 9, no. 5 (2009-03-05), S.1647-1664 |
| Datensatznummer |
250007004
|
| Publikation (Nr.) |
 copernicus.org/acp-9-1647-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| Formaldehyde (HCHO) is an important intermediate compound in the degradation
of volatile organic compounds (VOCs) in the troposphere. Sources of HCHO are
largely dominated by its secondary production from VOC oxidation, methane
and isoprene being the main precursors in unpolluted areas. As a result of
the moderate lifetime of HCHO, its spatial distribution is determined by
reactive hydrocarbon emissions. We focus here on Europe
and investigate the influence of the different emissions on HCHO
tropospheric columns with the CHIMERE chemical transport model in order to
interpret the comparisons between SCIAMACHY and simulated HCHO columns. Europe
was never specifically studied before for these purposes using satellite observations.
The bias between measurements and model is less than 20% on average. The differences
are discussed according to the errors on the model and the observations and
remaining discrepancies are attributed to a misrepresentation of
biogenic emissions. This study requires the characterisation of: (1) the
model errors and performances concerning formaldehyde. The errors on the
HCHO columns, mainly related to chemistry and mixed emission types, are
evaluated to 2×1015 molecule/cm2 and the model performances
evaluated using surface measurements are satisfactory (~13%); (2)
the observation errors that define the needs in spatial and temporal
averaging for meaningful comparisons. Using SCIAMACHY
observations as constraint for biogenic isoprene emissions in an inverse
modelling scheme reduces their uncertainties by about a factor of two
in region of intense emissions. The retrieved correction factors for the isoprene
emissions range from a factor of 0.15 (North Africa) to a factor of 2
(Poland, the United Kingdom) depending on the regions. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|