Purpose
- To quantify improvements in actual predictability by initialising and resolving the stratosphere in seasonal forecast systems
- To compare with existing seasonal to interannual forecast skill and to provide a hindcast data set that may be used to:
- Demonstrate improvements in currently achievable season forecast skill for a range of variables and lead times
- Understand improvements under particular scenarios such as El Nino and years with an active stratosphere
- Justify changes in operational seasonal forecast approaches and methods as a subproject of the WGSIP Climate Historical Forecast Project
Proposal and Data outpu requirements
To download the proposal, click here.
Participants
Institute | Model | Resolution | Model Top | Reference | Contact |
UK Met Office Hadley Centre | HadGEM | N96L85 N96L38 |
85km 40km |
Martin et al 2006, J. Clim., 19, 1217-1301 | |
Meteo France | Arpege 4.4 + OPA | L91 L31 |
0.01hPa 10hPa |
Gueremy et al, 2005, Tellus, 57A, p308-319 | |
ECMWF | IFS | L91 L62 |
0.01hPa 5hPa |
||
CCCma | CMAM | T63L71 T63L41 |
~100km ~31km |
Scinocca et al 2008, ACP, 8, 7055-7074 | |
NCEP | CFS v1 | L64 ? |
? | Saha et al, J.Clim., vol.19, no.15, p3483-3517 | |
CPTEC | CPTEC | ? | ? | ||
IFM-GEOMAR | ECHAM5 | T63L31 T63L47 |
10hPa 0.01hPa |
Roeckner et al 2003, MPI report No. 349, 127pp Manzini et al 2006, J. Clim., 19, 3863-3881. |
Hindcasts
A set of parallel hindcasts are requested from stratosphere resolving and stratosphere non-resolving models. A stratosphere resolving model is defined here to have:
- A domain extending to 1hPa (~50km) or higher
- At least 15 model levels between the tropopause and 1hPa/50km
The use of existing HFP data as the non-stratosphere resolving hindcasts is welcomed. Either coupled ocean-atmosphere model or two-tier forecasts are welcome.
Atmospheric initial conditions are at the choice of the participant but must not include any information from the future.
Land initial conditions are at the choice of the participant but must not include any information from the future.
- Option 1: use "reanalysis" land surface data modified to your model (recommended)
- Option 2: use model climatologies from an AMIP run.
SST and sea-ice initial conditions - SST must not contain information from the future with respect to the forecast
- Option 1: persist the observed SSTA anomaly from the month preceding the forecast period (i.e., this anomaly is added to the climatological seasonal cycle of SST's)
- Option 2: statistical or other objective forecast of SSTA which is not developed with nor makes use of future information (e.g. climatology, relaxation of anomalies toward zero with some time scale, other statistical forecast, anomalies from an ocean model initialized and run separately, etc.)
Sea ice initial conditions: based on the associated sea ice data but containing no future information.