 |
| Titel |
Evaluation of linear ozone photochemistry parametrizations in a stratosphere-troposphere data assimilation system |
| VerfasserIn |
A. J. Geer, W. A. Lahoz, D. R. Jackson, D. Cariolle, J. P. McCormack |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 7, no. 3 ; Nr. 7, no. 3 (2007-02-21), S.939-959 |
| Datensatznummer |
250004573
|
| Publikation (Nr.) |
 copernicus.org/acp-7-939-2007.pdf |
|
|
|
|
|
| Zusammenfassung |
This paper evaluates the performance of various linear ozone photochemistry
parametrizations using the stratosphere-troposphere
data assimilation system of the Met Office. A set of experiments
were run for the period 23 September 2003 to 5 November 2003 using the Cariolle
(v1.0 and v2.1), LINOZ and Chem2D-OPP (v0.1 and v2.1) parametrizations. All
operational meteorological observations were assimilated, together
with ozone retrievals from the Michelson Interferometer for
Passive Atmospheric Sounding (MIPAS). Experiments were validated against
independent data from the Halogen Occultation Experiment (HALOE)
and ozonesondes. Additionally, a simple offline method for comparing the parametrizations is introduced.
It is shown that in the upper stratosphere and mesosphere, outside the polar
night, ozone analyses are controlled by the photochemistry parametrizations
and not by the assimilated observations. The most important factor in getting
good results at these levels is to pay attention to the ozone and temperature
climatologies in the parametrizations. There should be no discrepancies
between the climatologies and the assimilated observations or the model, but
there is also a competing demand that the climatologies be objectively
accurate in themselves. Conversely, in the lower stratosphere outside regions
of heterogeneous ozone depletion, the ozone analyses are dominated by
observational increments and the photochemistry parametrizations have little
influence.
We investigate a number of known problems in LINOZ and Cariolle v1.0 in more
detail than previously, and we find discrepancies in Cariolle v2.1 and
Chem2D-OPP v2.1, which are demonstrated to have been removed in the latest
available versions (v2.8 and v2.6 respectively). In general, however, all the
parametrizations work well through much of the stratosphere, helped by the
presence of good quality assimilated MIPAS observations. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|