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#newfcsystem

Description of upgrade

IFS Cycle 46r1 is an upgrade with many scientific contributions, including changes in data assimilation (both in the EDA and the 4DVAR), in the use of observations, and in modelling. The new cycle only includes meteorological changes; there are no technical changes, e.g. new resolutions.

The page will be updated as required. It was last changed on 05.04.2018

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

Further information and advice regarding the upgrade can be obtained from User Support.


 



News

 

  • The expected date for the operational implementation of IFS cycle 46r1 is . We will confirm this date early in May.
  • The second set of live-streamed seminars for cycle 46r1 will take place on at 09:30 BST and on  at 17:00 BST.

  • The IFS Cycle 46r1 test data is available in MARS including new model output parameters.

Cycle 46r1 live-streamed seminars

We will organise two live-streamed seminars to introduce the new IFS cycle 46r1. The first seminar has mainly covered the Scientific changes made in the new Cycle (see recording and slides below). The second seminar will focus more on the meteorological impact and scores of the new cycle, with details on how to access the Cycle 46r1 release candidate  test data. This second seminar will take place on Wednesday,  at 09:30 BST and repeated on Thursday,  at 17 :00 BST. You will have the opportunity to raise any questions during all these seminars. Please do not hesitate to contact us for additional questions.

To attend any of these seminars, please follow the link below:

https://ecmwf.adobeconnect.com/ecmwf-46r1

There is no need to pre-register.

The recording of the first cycle 46r1 seminar is available at https://ecmwf.adobeconnect.com/pgy081jw03ya/. The  presentation slides are also available separately at https://www.ecmwf.int/sites/default/files/medialibrary/2019-02/46r1_overview_AndyBrown.pdf.

Timetable for implementation

The planned timetable for the implementation of the cycle 46r1 is as follows:

DateEvent
January 2019Initial announcement
26 February and 07 March 2019Live-streamed seminar 1
May 2019Availability of test data in dissemination
15 May and 16 May 2019Live-streamed seminar 2
 11 June 2019

Expected date of implementation

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

Meteorological content of the new cycle

 Assimilation

  • Continuous data assimilation. Number of 4D-Var outer loops increased from 3 to 4. Early delivery assimilation window length increased from 6 to 8 hours. Observation cut off time extended.
  • Ensemble of Data Assimilations (EDA) increased from 25 members to 50 members.
  • Use of the EDA spread to compute the Simplified Extended Kalman Filter (SEKF) soil analysis Jacobians.
  • Weakly coupled data assimilation introduced for sea-surface temperature in the tropics only.
  • Consistent spatial interpolation of the model to observation locations in trajectories and minimisations. Interpolation in nonlinear trajectories changed from bicubic to bilinear interpolation.
  • RTTOV upgraded from v12.1 to v12.2.

Observations

  • Assimilation of SMOS neural network soil moisture product.
  • Assimilation of SSMIS-F17 150h GHz and GMI 166 v/h GHz.
  • Improved use of land sea mask in the field of view for microwave imagers.
  • Introduction of interchannel observation error correlations for ATMS.
  • Introduction of interchannel observation error correlations for geostationary water vapour channels.
  • Slant path calculations for geostationary radiances.
  • Extend usage of geostationary radiances to higher zenith angles.
  • Consistent infrared aerosol detection

For further details, read Main Contributions in data assimilation and observations.

Model

  • Improvements in convection scheme (entrainment, CAPE closure, shallow convection).
  • Activate LW scattering in radiation scheme.
  • 3D aerosol climatology replaces 2D climatology.
  • Correct scaling of dry mass flux in diffusion scheme.
  • Improvement of the TL/AD of the semi-Lagrangian departure point scheme in the polar cap area.
  • Fix instability in 2m temperature diagnostic related to wet tile.
  • Bug fix in the computation of rain amount that could freeze when intercepted by the snow-pack.
  • New parametrisations for wind input and deep water dissipation for for the wave model.
  • Limit on wave spectrum for very shallow water and minimum depth set to 3m.
  • ENS makes use of 50 EDA-members and initial perturbations are made exchangeable.
  • ENS radiation time-step is reduced from 3 hours to 1 hour, to be consistent with HRES.

For further details, read Main Contributions in modelling

Re-forecasts

The new IFS cycle 46r1 will use the ERA5 data to initialize the re-forecasts and also use ERA5 EDA to perturb the re-forecasts initial conditions.

Technical details of the new cycle

Changes to GRIB encoding

Model identifiers

The GRIB model identifiers (generating process identification number) for cycle 46r1 will be changed as follows:

GRIB 1
Section 1
Octets
GRIB 2
Section 4
Octets
eccodes key ComponentModel ID
OldNew
6 14  generatingProcessIdentifierAtmospheric model149150
Ocean wave model114115
HRES-SAW ( HRES stand alone ocean wave model)214215


New model output parameters

Extended output have been added in cycle 46r1, including a subset of ocean fields on the atmospheric grid.


paramIdshortNamenameDescriptionunitsGRIB editionComponentsTest data availableDisseminationecChartsAdded to the Catalogue

Near-surface wind output

228239200u200 metre U wind componenteastward component of the 200m wind.m s-11HRES / ENS(tick)TBCTBCTBC
228240200v200 metre V wind componentnorthward component of the 200m wind.m s-11HRES / ENS(tick)TBCTBCTBC
Wave model parameters
140098wetaWave induced mean sea level correction

Wave induced mean sea level correction

m1

HRES-WAM / HRES-SAW / ENS-WAM

(tick)TBCTBCTBC
140099wrafRatio of wave angular and frequency width
Ratio of wave angular and frequency widthdimensionless1
HRES-WAM / HRES-SAW / ENS-WAM(tick)TBCTBCTBC
140100wnslcNumber of events in freak waves statisticsNumber of events in freak waves statisticsdimensionless1HRES-WAM / HRES-SAW / ENS-WAM(tick)TBCTBCTBC
140101utauaU-component of atmospheric surface momentum fluxU-component of atmospheric surface momentum fluxN m-21HRES-WAM / HRES-SAW / ENS-WAM(tick)TBCTBCTBC
140102vtauaV-component of atmospheric surface momentum fluxV-component of atmospheric surface momentum fluxN m-21HRES-WAM / HRES-SAW / ENS-WAM(tick)TBCTBCTBC
140103utauoU-component of surface momentum flux into oceanU-component of surface momentum flux into oceanN m-21HRES-WAM / HRES-SAW / ENS-WAM(tick)TBCTBCTBC
140104vtauoV-component of surface momentum flux into oceanV-component of surface momentum flux into oceanN m-21HRES-WAM / HRES-SAW / ENS-WAM(tick)TBCTBCTBC
140105wphioWave turbulent energy flux into oceanWave turbulent energy flux into oceanW m-21HRES-WAM / HRES-SAW / ENS-WAM(tick)TBCTBCTBC
Ocean parameters available at the surface, produced by the NEMO model.
174098sithickSea-ice thickness *

Sea-ice thickness

m1

HRES / ENS

(tick)TBCTBCTBC
151148mldMixed layer depth *Mixed layer depthm1HRES / ENS(tick)TBCTBCTBC
151145zosSea surface height *Sea surface heightm1HRES / ENS(tick)TBCTBCTBC
151163t20dDepth of 20C isotherm *Depth of 20C isothermm1HRES / ENS(tick)TBCTBCTBC
151130soSea water practical salinity *Sea water practical salinitypsu1HRES / ENS(tick)TBCTBCTBC
151164tav300Average potential temperature in the upper 300m *Average potential temperature in the upper 300mdegrees C1HRES / ENS(tick)TBCTBCTBC
151175sav300Average salinity in the upper 300m *Average salinity in the upper 300mpsu1HRES / ENS(tick)TBCTBCTBC
* All fields are masked on land and lake points. tav300 and sav300 are masked on ocean points with depth < 300m.
Parameters on Potential Vorticity levels (1.5 and 2 PVU)
129zGeopotential

This parameter is the gravitational potential energy of a unit mass, at a particular location, relative to mean sea level.

m2 s-21

HRES / ENS *

(tick)TBCTBCTBC
203o3Ozone mass mixing ratio

This parameter is the mass of ozone per kilogram of air.


kg kg-11

HRES / ENS *

(tick)TBCTBCTBC
3ptPotential Temperature

Potential Temperature

K1

HRES / ENS *

(tick)TBCTBCTBC
54presPressure

Pressure

Pa1

HRES / ENS *

(tick)TBCTBCTBC
133qSpecific humidity

This parameter is the mass of water vapour per kilogram of moist air.

kg kg-11

HRES / ENS *

(tick)TBCTBCTBC
131uU component of wind

This parameter is the eastward component of the wind. It is the horizontal speed of air moving towards the east, in metres per second. A negative sign thus indicates air movement towards the west.

m s-11

HRES / ENS *

(tick)TBCTBCTBC
132vV component of wind

This parameter is the northward component of the wind. It is the horizontal speed of air moving towards the north, in metres per second. A negative sign thus indicates air movement towards the south.

m s-11

HRES / ENS *

(tick)TBCTBCTBC

* The perturbed forecasts for the ENS only contain the parameters pt, u and v.

Ensemble probabilities
131098tpg25

Total precipitation of at least 25 mm

Total precipitation of at least 25 mm

dimensionless2

ENS

(tick)TBCTBCTBC
131099tpg50

Total precipitation of at least 50 mm

Total precipitation of at least 50 mm

dimensionless2

ENS

(tick)TBCTBCTBC
131085tpg100

Total precipitation of at least 100 mm

Total precipitation of at least 100 mm

dimensionless2

ENS

(tick)TBCTBCTBC
13110010fgg10

10 metre wind gust of at least 10 m/s

10 metre wind gust of at least 10 m/s

dimensionless2

ENS

(tick)TBCTBCTBC
133093ptsa_gt_1stdevProbability of 850hPa temperature standardized anomaly greater than 1 standard deviationProbability of temperature anomaly greater than 1 standard deviation of the climatology.dimensionless2ENS(error)TBCTBCTBC
133094ptsa_gt_1p5stdevProbability of 850hPa temperature standardized anomaly greater than 1.5 standard deviationProbability of temperature anomaly greater than 1.5 standard deviation of the climatology.dimensionless2ENS(error)TBCTBCTBC
133095ptsa_gt_2stdevProbability of 850hPa temperature standardized anomaly greater than 2 standard deviationProbability of temperature anomaly greater than 2 standard deviation of the climatology.dimensionless2ENS(error)TBCTBCTBC
133096ptsa_lt_1stdevProbability of 850hPa temperature standardized anomaly less than -1 standard deviationProbability of temperature anomaly less than -1 standard deviation of the climatology.dimensionless2ENS(error)TBCTBCTBC
133097ptsa_lt_1p5stdevProbability of 850hPa temperature standardized anomaly less than -1.5 standard deviationProbability of temperature anomaly less than -1.5 standard deviation of the climatology.dimensionless2ENS(error)TBCTBCTBC
133098ptsa_lt_2stdevProbability of 850hPa temperature standardized anomaly less than -2 standard deviationProbability of temperature anomaly less than -2 standard deviation of the climatology.dimensionless2ENS(error)TBCTBCTBC
Ensemble mean / Ensemble standard deviation
10ws *

The speed of horizontal air movement in metres per second.

The speed of horizontal air movement in metres per second.

m s-11

ENS

(tick)TBCTBCTBC
130t *

This parameter is the temperature in the atmosphere.

This parameter is the temperature in the atmosphere.

K1

ENS

(tick)TBCTBCTBC
* These parameters have been added at 250 hPa.
Extreme Forecast Index (EFI) & Shift Of Tails (SOT)
132045wvfi

Water vapour flux index

EFI and SOT for water vapour flux

dimensionless1

ENS

(error)TBCTBCTBC
1321672ti2 metre temperature indexEFI and SOT for weekly mean temperaturedimensionless1ENS-EXTENDED(error)TBCTBCTBC
132228tpiTotal precipitation indexEFI and SOT for 1 week total precipitationdimensionless1ENS-EXTENDED(error)TBCTBCTBC

Software

ecCodes

ecCodes version 2.12.0 provides full support for the new model output parameters introduced in IFS Cycle 46r1.

Availability of test data from the IFS cycle 46R1 test suites

Test data in MARS

Test data from the IFS Cycle 46r1 test suites are available in MARS. The data are available with experiment version 0073 (MARS keyword EXPVER=0073) starting from 00 UTC on 29 January 2019.

The data can be accessed in MARS from:

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

We recommend users to use the MARS keyword "PARAMETER=paramId", as the shorName or full name may be ambiguous. E.g. for the new Wave model output, use "PARAMETER=140098" and not "PARAMETER=weta" or "PARAMETER=Wave induced mean sea level correction".


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 Service Desk.

Test data in dissemination

IFS Cycle 46r1 test data will become available through the test dissemination system when we will have reached the release candidate stage.

Further reading

Document versions

 

DateReason for update

 

Initial version

 

  • test data in MARS
  • recording and presentation slides for fist seminar
  • further reading

 

  • expected date for implementation announced
  • announcement of dates for second live-streamed seminar.
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2 Comments

  1. The first seminar  ... will take place on Tuesday, 26 Feb. 2019 at 09:30 

    Which time zone?

  2. UTC. Added this to the document. Thanks.