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The page will be updated as required. It was last changed on 3124.0305.2017.

For a record of changes made to this page please refer to  Document versions.

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The planned timetable for the implementation of the cycle 43r3 is as follows:

DateEvent
03.04.2017Initial publication on the web.
Late April
24.05.2017Initial announcement, with test data in MARS
Late May
13.06.2017Availability of test data in dissemination
20 06
11.07.2017

Expected date of implementation

The timetable represents current expectations and may change in light of actual progress made.

Current Status

The Alpha Beta testing phase of cycle 43r3 will continue and the cycle is being passed to the Forecast Department to start the Beta testinghas started, test data are available in MARS. We are running HRES and ENS to catch up with real time and have started work on the post processing of the cycle 43r3 data, including the data dissemination and graphical charts.

Meteorological content of the new cycle

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Meteorological impact of the new cycle

Comparison of scores between IFS Cycle 43r3 and IFS Cycle 43r1 for HRES can be found in the IFS Cycle 43r3 scorecard.

Results for the HRES from alpha- and beta-testing Preliminary results, based on the Alpha testing, for HRES are positive, with many of the scores over NH, SH and Europe indicating statistically significant improvements ( at the 99.7% 95% level ) up to about forecast day 5 when forecasts are verified against own analysis. When forecasts are verified against observations, the positive impact of 43r3 is also evident. Improvements are larger in summer than in winter and are to a large extent due to changes to the deep convection scheme and the aerosol climatology, which improved the temperature gradient between extra-tropics and tropics. Improvements are significant for temperature and vector wind throughout the extra-tropical troposphere. More information, including on the (extended) ENS forecasts will be given after the new cycle has passed the Beta testingIn the tropics there is some deterioration in temperature and humidity at certain vertical levels associated with the changes to the deep convection scheme. Surface parameters show partially statistically significant improvements both in the tropics and extra-tropics (2-m humidity, 10-m wind speed, total cloud cover, precipitation), except for 2-m temperature which shows neutral results.

Over the ocean, statistically significant improvements are seen for verification against own analysis for 10-m wind speed, significant wave height, and mean wave period.

Results for the ENS based on alpha-testing are mainly positive and similar to the HRES both for upper-air and surface variables for the NH, SH, and Europe when verified against analysis. In the tropics there is some deterioration in upper tropospheric wind speed and lower tropospheric temperature associated with reduced spread. There are also some slight deteriorations in tropical 2-m temperature and precipitation scores. The scorecard for the ENS will be made available when we have completed more runs.

Technical details of the new cycle

Changes to GRIB encoding

Model identifiers

The GRIB model identifiers (generating process identification number) for cycle 43R3 will be changed as follows:

GRIB 1
Section 1
Octets
GRIB 2
Section 4
Octets
grib_api key ComponentModel ID
OldNew
6 14  generatingProcessIdentifierAtmospheric model147148
Ocean wave model112113
HRES stand-alone ocean wave model212213
Note
The generatingProcessIdentifier for the Atmospheric Model is currently set to 147. We will change this as soon as possible for the new dates to be archived.

New model output parameters

There are no new parameters introduced with cycle 43r3.

Impact on users

Software

The versions of EMOSLIB and GRIB API used to decode the existing operational cycle 43r1 data are suitable to handle the cycle 43r3 data as well. Note that ecCodes has now replaced GRIB API on the ECMWF platforms.

Availability of test data from the cycle 43r3 test suites

Test data in MARS

IFS data from the cycle 43r3 suite are available in MARS with experiment version 0071 (MARS keyword EXPVER=0071) starting from 26 March 2017 at 06UTC.

The data can be accessed in MARS from:

Note
All the derived data for the ENS and extended ENS runs are not yet available in MARS.

Only registered users of ECMWF computing systems will be able to access the test data sets in MARS.

The data are intended for testing technical aspects only and should not be used for operational forecasting.  Please report any problems you find with this data to User Support.

Further Reading

  • Flemming, J., Benedetti, A., Inness, A., Engelen, R. J., Jones, L., Huijnen, V., Remy, S., Parrington, M., Suttie, M., Bozzo, A., Peuch, V.-H., Akritidis, D., and Katragkou, E.: The CAMS interim Reanalysis of Carbon Monoxide, Ozone and Aerosol for 2003–2015, Atmos. Chem. Phys., 17, 1945-1983, doi:10.5194/acp-17-1945-2017, 2017.
  • Hogan, R., and Bozzo, A., 2016: ECRAD: A new radiation scheme for the IFS. ECMWF Research Department Technical Memorandum No. 787, pp 33. Available at http://www.ecmwf.int/sites/default/files/elibrary/2016/16901-ecrad-new-radiation-scheme-ifs.pdf.

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DocumentVersions
DocumentVersions
Document versions

 

DateReason for update
31.03.2017
  • Initial version

 

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24.05.2017
  • Initial email announcement to Member and Co-operating States and to Commercial customers
    • Change of implementation date
    • Availability of test data in MARS
    • Meteorological impact and scorecard for HRES.