1. Contributing Centres to S2S database
Data provider (11)
Archiving centre (3)
ECMWF
ECCC
UKMO
HMCR
KMA
IRI
NCEP
Météo
France
ISAC
CMA
JMA
BoM

2. S2S Models Time-range Resol. Ens. Size Freq. Hcsts Hcst length
Hcst Freq
Hcst Size
ECMWF
D 0-46
T639/319L91 51
2/week
On the fly
Past 20y
2/weekly 11
UKMO
D 0-60
N216L85 4
daily
4/month 3
NCEP
D 0-44
N126L64
4/daily
Fix 1
ECCC
D 0-32
0.45x0.45 L40 21
weekly
BoM
T47L17 33
6/month
JMA
D 0-34
T319L60 25
3/month 5
KMA
CMA
D 0-45
T106L40
CNRM
T255L91
2/monthly 15
CNR-ISAC
0.75x0.56 L54 40
HMCR
D 0-63
1.1x1.4 L28 20 10

3. S2S models Models Ocean coupling Active Sea Ice Planned ECMWF YES UKMO
NCEP
ECCC NO
BoM
Planned
JMA
KMA
CMA
CNRM
ISA-CNR
HMCR

4. S2S Database current status
Open access to researchers since May 2015 from ECMWF and Nov from CMA. Subset of the database also available in netcdf from IRI data library.
Currently, data from all centres except KMA (will become available soon) are available.
Total size of the database so far: 43 Tbytes
- real-time: 7 Tbytes
- re-forecasts: 36 Tbytes
Plans
End of 2016: all 11 Data Providers
Add new ocean sub-surface and sea-ice variables
Compute and archive indices such as MJO RMMs, SSW index, Weather regimes, Tropical storm tracks, Monsoon indices to be available for the research community from ECMWF and IRI servers.

5. New variables to be added
Atmosphere:
Vertical Velocity (currently archived at 500 hPa only) to be archived in all pressure levels: from 1st January 2017 in some S2S models
Ocean/sea-ice variables:
Sea surface salinity
Depth of 20 deg isoth
Mixed layer depth
Heat content at top 300m
Salinity in top 300m
U surface current
V surface current
Sea surface height
Sea ice thickness
These new variables will be archived in netcdf in MARS. Work is ongoing to archive ocean data in the MARS system (project for ERA-CLIM2).
New variables will not be ready for all the S2S models straight away. For models with fixed climatology, we may need to wait the next version of these model.

6. ECMWF S2S website: s2s.ecmwf.int CMA website: s2s.cma.cn

7. Use of the S2S database
600 registered users from 65 countries at ECMWF
140 register users mostly from China at CMA
ECMWF Server

8. BAMS article on S2S database to be published in Jan 2017

9. S2S model documentation

10. Initialization of land surface Documentation
A questionnaire has been produced by GEWEX/GLASS
The S2S Project Office has sent the questionnaire to 11 the data providers
So far 9 have replied, and the soil initialization documentation is now included in their model documentation in the ECMWF S2S website.
Have not replied yet: NCEP and HMCR

11. Questionnaire on Land ICs
 1. What is the land surface model (LSM) and version used in the forecast model, and what are the current/relevant references for the model? Are there any significant changes/deviations in the operational version of the LSM from the documentation of the LSM?
 2. How is soil moisture initialized in the forecasts? (climatology / realistic / other)
• If “climatology”, what is the source of the climatology?
• If “realistic”, does the soil moisture come from an analysis using the same LSM as is coupled to the GCM for forecasts, or another source? Please describe the process of soil moisture initialization.
• If “other”, please describe the process of soil moisture initialization.
• Is there horizontal and/or vertical interpolation of initialization data onto the forecast model grid? If so, please give original data resolution(s).
• Does the LSM differentiate between liquid and ice content of the soil? If so, how are each initialized?
• If all model soil layers are not initialized in the same way or from the same source, please describe.
3. How is snow initialized in the forecasts? (climatology / realistic / other)
• If “realistic”, does the snow come from an analysis using the same LSM as is coupled to the GCM for forecasts, or another source? Please describe the process of soil moisture initialization.
• Is there horizontal and/or vertical interpolation of data onto the forecast model grid? If so, please give original data resolution(s)
• Are snow mass, snow depth or both initialized? What about snow age, albedo, or other snow properties?
4. How is soil temperature initialized in the forecasts? (climatology / realistic / other)
• Is the soil temperature initialized consistently with soil moisture (frozen soil water where soil temperature ≤0°C) and snow cover (top layer soil temperature ≤0°C under snow)?