 |
| Titel |
Preliminary ice shelf-ocean simulation results from idealized standalone-ocean and coupled model intercomparison projects (MIPs) |
| VerfasserIn |
Xylar Asay-Davis, Daniel Martin |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250134420
|
| Publikation (Nr.) |
 EGU/EGU2016-15144.pdf |
|
|
|
|
|
| Zusammenfassung |
| The second Ice Shelf-Ocean MIP (ISOMIP+) and the first Marine Ice Sheet-Ocean MIP
(MISOMIP1) prescribe a set of idealized experiments for ocean models with ice-shelf
cavities and coupled ice sheet-ocean models, respectively. ISOMIP+ and MISOMIP1 were
designed together with the third Marine Ice Sheet MIP (MISMIP+) with three main goals,
namely that the MIPs should provide:
a controlled forum for researchers to compare their model results with those from
other models during model development.
a path for testing components in the process of developing coupled ice
sheet-ocean models.
a basic setup from which a large variety of parameter and process studies can
usefully be performed.
The experimental design for the three MIPs is currently under review in Geoscientific Model
Development (Asay-Davis et al. 2015, doi:10.5194/gmdd-8-9859-2015).
We present preliminary results from ISOMIP+ and MISOMIP1 experiments using several
ocean-only and coupled ice sheet-ocean models. Among ocean models, we show that
differences in model behavior are significant enough that similar results can only be
achieved by tuning model parameters (e.g. boundary-layer transfer coefficients, drag
coefficients, vertical mixing parameterizations) for each models. This tuning is
constrained by a desired mean melt rate in quasi-steady state under specified forcing
conditions, akin to how models would be tuned based on observations for non-idealized
simulations.
We also present a number of parameter studies based the MIP experiments. Again, using
several models, we show that melt rates respond sub-linearly to both changes in the square
root of the drag coefficient and the heat-transfer coefficient, and that melting is relatively
insensitive to horizontal-mixing coefficients (perhaps because the resolution is sufficient to
permit eddies) but more sensitive to vertical-mixing coefficients. We show that the choice of
the equation of state (linear or nonlinear) does not have a significant impact as long as the
linearization is made around a representative value of temperature and salinity. |
|
|
|
|
|
|