 |
| Titel |
Using a photochemical model for the validation of NO2 satellite measurements at different solar zenith angles |
| VerfasserIn |
A. Bracher, M. Sinnhuber, A. Rozanov, J. P. Burrows |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 5, no. 2 ; Nr. 5, no. 2 (2005-02-10), S.393-408 |
| Datensatznummer |
250002350
|
| Publikation (Nr.) |
 copernicus.org/acp-5-393-2005.pdf |
|
|
|
|
|
| Zusammenfassung |
| SCIAMACHY (Scanning Imaging Spectrometer for Atmospheric Chartography)
aboard the recently launched Environmental Satellite (ENVISAT) of ESA is
measuring solar radiance upwelling from the atmosphere and the
extraterrestrial irradiance. Appropriate inversion of the ultraviolet and
visible radiance measurements, observed from the atmospheric limb, yields
profiles of nitrogen dioxide, NO2, in the stratosphere (SCIAMACHY-IUP
NO2 profiles V1). In order to assess their accuracy, the resulting
NO2 profiles have been compared with those retrieved from the space
borne occultation instruments Halogen Occultation Experiment (HALOE, data
version v19) and Stratospheric Aerosol and Gas Experiment II (SAGE II, data
version 6.2). As the HALOE and SAGE II measurements are performed during
local sunrise or sunset and because NO2 has a significant diurnal
variability, the NO2 profiles derived from HALOE and SAGE II have been
transformed to those predicted for the solar zenith angles of the SCIAMACHY
measurement by using a 1-dimensional photochemical model. The model used to
facilitate the comparison of the NO2 profiles from the different
satellite sensors is described and a sensitivity ananlysis provided.
Comparisons between NO2 profiles from SCIAMACHY and those from HALOE
NO2 but transformed to the SCIAMACHY solar zenith angle, for
collocations from July to October 2002, show good agreement (within +/-12%)
between the altitude range from 22 to 33km. The results from the
comparison of all collocated NO2 profiles from SCIAMACHY and those from
SAGE II transformed to the SCIAMACHY solar zenith angle show a systematic
negative bias of 10 to 35% between 20km to 38km with a small standard
deviation between 5 to 14%. These results agree with those of Newchurch
and Ayoub (2004), implying that above 20km NO2 profiles from SAGE II
sunset are probably somewhat high. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|