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Timetable for implementation
The planned timetable for the implementation of SEAS5 is as follows:
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Date of implementation
The timetable represents current expectations and may change in light of actual progress made.
We acknowledge the contribution of the Copernicus Climate Change Service (C3S) in the production of SEAS5. C3S provided the computer time for the generation of the re-forecasts for SEAS5 and for the production of the ocean reanalysis (ORAS5), used as initial conditions for the SEAS5 re-forecasts. SEAS5 will be the ECMWF contribution to the C3S multi-model seasonal forecast products, see paragraph 'SEAS5 and Copernicus services'.
Latest news
19.01.2018: Following the successful implementation of the SEAS5 system on 5 Nov. 2017 and the parallel run of the old System 4 for 3 months, we will stop this latter on 8 Feb 2018, with the run based on 1 February 2018. May we remind all users to start using the SEAS5 system before System 4 is terminated.
08.11.2017: We are pleased to confirm that the SEAS5 system was successfully implemented in operations on 5.11.2017. System 4 will keep running for a limited time.
16.10.2017: The long range forecast documentation page has been updated, to include the SEAS5 user guide.
16.10.2017: Pre-operational SEAS5 charts are available under https://www.ecmwf.int/en/forecasts/charts/seasonal_system5/
11.10.2017: We now have modified the operational dissemination requirements to request SEAS5 data. Users can update their operational requirements, as needed. Any change made will be used for the first time in the SEAS5 run of November. Changes to the dissemination requirements for System 4 are no longer possible.
04.10.2017: The re-archiving of the problematic SEAS5 pressure level derived fields has completed last night and we have validated the data this morning.
03.10.2017: We have identified a problem with some archived pressure level fields for some derived fields associated with the real-time forecasts. The fields affected are type=hcmean from stream msmm, and types fcmean and em from stream mmsa. Pressure level fields from 925 hPa up to 1 hPa are affected, for dates from January to September 2017. Surface fields and 1000hPa pressure level fields are not affected.
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Current Status
SEAS5 was successfully implemented in operations on 5.11.2017.
New release day for SEAS5 data
We are pleased to announce that the SEAS5 products (data and charts) will be released 3 days earlier, on the 5th of each month at 12UTC. System 4 products are currently released on the 8th of each month.
Summary description of SEAS5
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Technical details of SEAS5
Changes to GRIB encoding
Model identifiers
The GRIB model identifiers (generating process identification number) for SEAS5 will be changed as follows:
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GRIB 2 data
SEAS5 model level data is coded in GRIB 2, compared to GRIB 1 for System 4. The change to GRIB 2 for model level data was introduced in IFS Cycle 37r2 in 2011. See under User impact below for more information.
Use of the octahedral reduced Gaussian grid
SEAS5 introduces a new form of the reduced Gaussian grid, the octahedral grid, for the atmospheric (mostly) single level data. See Introducing the octahedral reduced Gaussian grid for further details.
New model output parameters and changes to existing parameters
Surface parameters added
Several new parameters have been added related to the lake model, 6h instantaneous stresses have been added to help user applications such as wave modelling, and top incoming solar radiation has been added with a 24 hour output frequency. Note also that surface and sub-surface runoff are now fully available (in System 4, these parameters were available for the real-time forecasts, but only a limited number of the re-forecasts).
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Surface fields output at additional timesteps
Some surface fields previously archived every 24 hours are now archived every 6 hours. As well as increased availability of synoptic data, this also changes the monthly means for the instantaneous fields such as SST and soil temperature. These are now calculated from 6 hourly data, and no longer have the diurnal cycle aliased into them. (For accumulated fields, the monthly mean rate of accumulation is independent of whether synoptic data is written at 6 or 24h intervals).
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Model level data
SEAS5 model level data are now produced to 6 months instead of 5 months for System 4.
Ocean waves parameters added
All fields are output every 24 hours
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Impact of SEAS5 on users
Software
EMOSLIB version 443, GRIB API version 1.17.0 or ecCodes version 2.0.0 are the minimum versions recommended to manipulate all SEAS5 fields.
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ecCodes has now replaced GRIB API on the ECMWF platforms. GRIBEX is no longer available and cannot decode GRB 2 data. |
Increased field sizes
The size of the fields archived have increased by a factor 2 to 4. When retrieving data via MARS or dissemination, if no spectral truncation or grid resolutions are specified, fields are provided at the model resolution.
In particular, users should be aware of the increase in memory and CPU time needed to process the increased resolution fields and adjust their programs and batch scripts appropriately.
Availability of SEAS5 Data
Re-forecast data in MARS
The SEAS5 re-forecast data can be accessed in MARS from:
Only registered users with access to MARS will be able to access the re-forecast data sets.
The re-forecast data for all 12 months in the year have been released.
Test SEAS5 Forecast data in MARS
SEAS5 technical test data are available in MARS with experiment version 9001 (MARS keyword EXPVER=9001) for the runs of May, June and July 2017 at 00UTC. The data can be accessed in MARS from:
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Release candidate SEAS5 data have been archived in MARS from January 2017 onwards with experiment version 0001:
- Atmospheric forecasts (class=od, stream=mmsf, expver=001, system=5, method=1)
- Wave forecasts (class=od, stream=wasf, expver=001, system=5, method=1)
- Atmospheric monthly means (class=od, stream=msmm, expver=001)
- Wave monthly means (class=od, stream=swmm, expver=001)
Seasonal forecast monthly anomalies (class=od, stream=mmsa, expver=001)
Only registered users with access to MARS with permission to access real-time data will be able to access these test data sets.
Test real-time SEAS5 data in dissemination
SEAS5 test data are now available in dissemination for the run of August 2017 onwards. SEAS5 test dissemination files are queued into ECPDS in delayed (standby) mode. Users can trigger the transmission of wanted test products at their convenience by logging into the test ECPDS system at https://ecpds-xmonitor.ecmwf.int/ in the usual manner. Users can find the SEAS5 by selecting all the dates in the interface. In order to receive the test products, users will have to open their firewall to the relevant ECPDS Data Movers:
Internet transfers: 193.61.196.104 (ecpds-xma.ecmwf.int) 193.61.196.105 (ecpds-xmb.ecmwf.int)
RMDCN transfers: 136.156.8.132 (mspds-dm4.ecmwf.int)
SEAS5 test dissemination file names will have EXPVER '9001' as the last part of the file name, e.g. ALL0801000010______9001, to distinguish with the operational file names ending with '1', e.g. ALL0801000010______1. Note however that the GRIB messages in the SEAS5 test dissemination data will contain the key expver=0001. GRIB headers fully reflect the generating process (systemNumber=5, methodNumber=1).
At the moment, SEAS5 test data are generated based on the current (SYSTEM=4) dissemination requirements.
SEAS5 T319/O320 products can be requested in their original representation as well as in the previously supported representations in System 4. Supported latitude/longitude resolutions in the System 5 are:
multiplies of 0.4/0.4 degrees (as the third leg of the monthly forecast)
multiplies of 0.75/0.75 degrees, to provide seamless transition from the Seasonal System 4 (current resolution)
Where possible, we would advise users to request the native (Octahedral) resolutions.
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On the day of SEAS5 implementation into ECMWF operations, due for 5 November 2017, no test requirements will be carried into the operational mainframe. Users wishing to make their modified test SEAS5 requirements operational on the implementation date can make these changes in the operational ECPDS system (https://ecaccess.ecmwf.int:9443/do/product/requirements) or will have to let ECMWF (Data Services) know two weeks prior to the announced implementation date. |
Parallel run of System 4 and SEAS5
SEAS5 has run for May, June, July 2017 in beta testing (experiment=9001). SEAS5 will run in near real-time from September onwards. SEAS5 data will then become available shortly after the System 4 data have been released.
On the switch-over date, due for 5 November, SEAS5 will become the operational system. The SEAS5 dissemination file names will then end with EXPVER '1'. System 4 will continue to be run as a near real-time system, for a limited period of time. Data from System 4 will be available from MARS and, for those interested, through dissemination in delayed mode, on request. Those interested can transfer the System 4 files through the test ECPDS system (https://ecpds-xmonitor.ecmwf.int/) or should contact Data Services at ECMWF. On the implementation date of SEAS5, users who requested to keep getting System 4 data though dissemination will receive both the SEAS5 and System 4 files via ECPDS, with the System4 file names including EXPVER '9004', e.g. ALL1101000010______9004.
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The release date of these '9004' files in ECPDS will remain the 8th of each month at 12UTC. |
We intend to stop running System 4 before March 2018. Users are advised to make sure that all their applications are switched to using SEAS5 data as soon as possible after the implementation.
Graphical display of SEAS5 test forecasts
Graphical products from the seasonal forecast system are displayed on the Forecast Charts pages of the ECMWF website. Pre-operational SEAS5 charts for Jan-Oct 2017 are available at https://www.ecmwf.int/en/forecasts/charts/seasonal_system5/.
Time-critical applications
Member State users of the "Simple time-critical jobs" framework can test that their scripts will work with the SEAS5 test data by using the new 'event' set up.
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Users are reminded to change the directive 'SYSTEM=5' in their MARS requests.
SEAS5 in EUROSIP
EUROSIP, the Multi-model seasonal forecast, will use SEAS5 data as soon as SEAS5 will have been implemented in operations.
SEAS5 and Copernicus services
The C3S is currently in a proof-of-concept phase and the data services for the Copernicus users are being developed. At the moment, for seasonal forecasts, graphical products only are available on the C3S web site (https://climate.copernicus.eu/seasonal-forecasts). In early 2018, it is expected that SEAS5 data on a 1-degree resolution grid will be freely available for download from C3S on the 10th of each month, 5 days after the SEAS5 products are available through the normal ECMWF dissemination mechanisms.
References
- Madec G (2008) NEMO ocean engine. Tech. rep., Institut Pierre-Simon Laplace (IPSL), URL https://www.nemo-ocean.eu/doc/
Good, S. A., M. J. M., and R. N. A., 2013: EN4: Quality controlled ocean temperature and salinity profiles and monthly objective analyses with uncertainty estimates. J. Phys. Oceanogr.,118, 6704–6716, doi:10.1002/2013JC009067.
Fichefet T,Maqueda MAM (1997) Sensitivity of a global sea ice model to the treatment of ice thermodynamics and dynamics. Journal of Geophysical Research 102(C6):12,609–12,646, DOI 10.1029/97JC00480,URL http://doi.wiley.com/10.1029/97JC00480
Balmaseda MA, Mogensen K, Weaver AT (2013) Evaluation of the ECMWF ocean reanalysis system ORAS4. Quarterly Journal of the Royal Meteorological Society 139(674):1132{1161
Steffen Tietsche, Magdalena a. Balmaseda, Hao Zuo, and Kristian Mogensen. Arctic sea ice in the global eddy-permitting ocean reanalysis ORAP5. Climate Dynamics, jun 2015. ISSN 0930-7575. doi: 10.1007/s00382-015-2673-3. URL http://link.springer.com/10.1007/s00382-015-2673-3.
Hao Zuo, Magdalena A Balmaseda, and Kristian Mogensen. The new eddy-permitting ORAP5 ocean reanalysis: description, evaluation and uncertainties in climate signals. Climate Dynamics, 2015. doi: 10.1007/s00382-015-2675-1. URL http://link.springer.com/article/10.1007/s00382-015-2675-1.
Zuo, H., M.A. Balmaseda, E. Boisseson and S. Hirahara, 2017: A new ensemble generation method for ocean reanalyses. ECMWF Technical Memorandum 795.
Zuo et al 2018 (in preparation)
- SEAS5 user guide. Comments and feedback on this document can be submitted using this questionnaire.
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- Initial version
- Availability of data in MARS
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- New release day for SEAS5 - 5th of each month at 12UTC
- Preliminary information about SEAS5 data in dissemination
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- Release candidate testing
- Data in MARS and dissemination
- SEAS5 in EUROSIP
- SEAS5 and Copernicus Services
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- Re-archiving of some derived SEAS5 data. See Latest news.
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- Re-archiving of some derived SEAS5 data completed.
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- SEAS5 dissemination requirements available
- SEAS5 release candidate charts available
- SEAS5 User guide available
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- Confirmation of successful implementation of SEAS5.
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