 |
| Titel |
The generic MESSy submodel TENDENCY (v1.0) for process-based analyses in Earth system models |
| VerfasserIn |
R. Eichinger, P. Jöckel |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1991-959X
|
| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 7, no. 4 ; Nr. 7, no. 4 (2014-07-31), S.1573-1582 |
| Datensatznummer |
250115671
|
| Publikation (Nr.) |
 copernicus.org/gmd-7-1573-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| The tendencies of prognostic variables in Earth system models are
usually only accessible, e.g. for output, as a sum over all physical,
dynamical and chemical processes at the end of one time integration
step. Information about the contribution of individual processes to
the total tendency is lost, if no special precautions are
implemented. The knowledge on individual contributions, however,
can be of importance to track down specific mechanisms in the model
system. We present the new MESSy (Modular Earth Submodel System)
infrastructure submodel TENDENCY and use it exemplarily within the
EMAC (ECHAM/MESSy Atmospheric Chemistry) model to trace
process-based tendencies of prognostic variables. The main idea is
the outsourcing of the tendency accounting for the state variables
from the process operators (submodels) to the TENDENCY submodel
itself. In this way, a record of the tendencies of all
process–prognostic variable pairs can be stored. The selection of
these pairs can be specified by the user, tailor-made for the
desired application, in order to minimise memory requirements.
Moreover, a standard interface allows the access to the individual
process tendencies by other submodels, e.g. for on-line diagnostics
or for additional parameterisations, which depend on individual
process tendencies. An optional closure test assures the correct
treatment of tendency accounting in all submodels and thus serves to
reduce the model's susceptibility. TENDENCY is independent of the
time integration scheme and therefore the concept is applicable to other model
systems as well. Test simulations with TENDENCY show an increase of
computing time for the EMAC model (in a setup without atmospheric
chemistry) of 1.8 ± 1% due to the additional subroutine calls
when using TENDENCY. Exemplary results reveal the dissolving
mechanisms of the stratospheric tape recorder signal in height over
time. The separation of the tendency of the specific humidity into
the respective processes (large-scale clouds, convective clouds,
large-scale advection, vertical diffusion and methane oxidation)
show that the upward propagating water vapour signal dissolves
mainly because of the chemical and the advective contribution. The
TENDENCY submodel is part of version 2.42 or later of MESSy. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|