 |
| Titel |
A quasi chemistry-transport model mode for EMAC |
| VerfasserIn |
R. Deckert, P. Jöckel, V. Grewe, K.-D. Gottschaldt, P. Hoor |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1991-959X
|
| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 4, no. 1 ; Nr. 4, no. 1 (2011-03-16), S.195-206 |
| Datensatznummer |
250001561
|
| Publikation (Nr.) |
 copernicus.org/gmd-4-195-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| A quasi chemistry-transport model mode (QCTM) is presented for the numerical chemistry-climate simulation system ECHAM/MESSy
Atmospheric Chemistry (EMAC). It allows for a quantification of chemical signals through suppression of any
feedback between chemistry and dynamics. Noise would otherwise interfere too strongly. The signal is calculated from
the difference of two QCTM simulations, a reference simulation and a sensitivity simulation. In order to
avoid the feedbacks, the simulations adopt the following offline chemical fields:
(a) offline mixing ratios of radiatively active substances enter the radiation scheme,
(b) offline mixing ratios of nitric acid enter the scheme for re-partitioning and sedimentation from polar
stratospheric clouds, (c) and offline methane oxidation is the exclusive source of chemical water-vapor tendencies.
Any set of offline fields
suffices to suppress the feedbacks, though may be inconsistent with the simulation setup.
An adequate set of offline climatologies can be produced from a non-QCTM simulation using the setup of
the reference simulation.
Test simulations reveal the particular importance of adequate offline fields associated with (a).
Inconsistencies from (b) are negligible when using adequate fields of nitric acid.
Acceptably small inconsistencies come from (c), but should vanish for an adequate prescription of chemical water vapor
tendencies. Toggling between QCTM and non-QCTM is done via namelist switches and does not require a source code re-compilation. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|