Implementation of IFS cycle 48r1

Description of upgrade

The CAMS IFS cycle 48R1 is based on ECMWF's  IFS cycle 48R1 . This is a major upgrade with various scientific contributions.

The page will be updated as required. It was last changed on 16 February 2023.

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 the Copernicus User Support.

Timetable for implementation

The planned timetable for the implementation of the cycle 47r3 is as follows:

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

Current Status

IFS cycle 48r1 is going through its final preparation phase.

Meteorological content of the new cycle

The meteorological changes can be found on the ECMWF  IFS CY48R1 page.

Atmospheric composition content of the new cycle

Assimilation

• Instrument specific bias correction for AOD
• Data assimilation for separate volcanic SO2 tracer (optional) 
• Enable modification Nitrate and Ammonium aerosols by data assimilation (bugfix)  

Observations

• Activation of assimilation of TropOMI CO retrievals 
• AOD from VIIRS (activated already in 47r3 1.2.2023) 
• Passive monitoring of IASI SO2 retrievals 

Emissions

• CAMS_GLOB_ANT v5.3 with sectoral diurnal cycles and injection heights
• CAMS_GLOB_BIO v3.1 climatology
• CAMS_GLOB_OCE v.3.1 climatology DMS
• CAMS_GLOB_AIR v3.1 CO2/NOx  (aircraft)
• Using IS4FIRES injection heights (from GFAS version 1.4)
• Sector-specific emission input to the IFS and application of sector specific injection height ranges and diurnal cycle profiles 
• Natural emissions as as used previously 

Model changes

• Activation of stratosphere chemistry using the BASCOE scheme - adding 63 reactive gas species 
• New tropospheric species: HCN, CH3CN, Glyoxal and Glycoladehyde
• Improved isoprene oxidation simulation
• Update of dry deposition formulation for reactive gases 
• Two new secondary organic aerosol tracers (anthropogenic and biogenic) and respective precursor gas tracers 
• Major update of dust emissions and removal simulation (increase in the global dust burden by factor 2)   
• Review of aerosol optical properties (dust , brown carbon) 
• Improved secondary inoraganic aerosol simulation 
• Use of COMADH advection for aerosols, reactive gases and GHG

Impact of the new cycle

For most compounds, the quality of the e-suite is ...

 A comprehensive evaluation report of the 48r1 e-suite, documenting all the changes and their impact on the forecasts, will be provided before the implementation date. 

Technical details of the new cycle

New and discontinued parameters

There are no new or discontinued parameters in the disseminated data compared to 47r3.

Change to GRIB encoding

The GRIB model identifiers (generating process identification number) for cycle 48r1 will be changed as follows:

For gridded 48r1 model output in GRIB 2 format the packing type will change as follows: 

With the introduction of the new CCSDS packing type the default behaviour in dissemination and MARS (from 14 March) will be as follows: 

This implies that by default only fields derived from gridded GRIB2 fields from 48r1 onwards will use packing type CCSDS. The default behaviour can be overridden by specifying the packing explicitly, e.g.  

  grid    = 0.1/0.1, 
  packing = CCSDS 

will deliver fields with CCSDS packing for any GRIB2 input field. It will however not be possible to get CCSDS packed fields from GRIB1 input fields. Similarly, if CCSDS compression is not desired when retrieving gridded GRIB 2 fields from MARS or dissemination, simple packing can be requested with keyword 

  packing = simple 

Using ecCodes, already retrieved CCSDS compressed fields can be converted to other packing types. This is how to convert all messages in file ccsds.grib with grid_ccsds as their packingType, and only those, to use simple packing, i.e. what we used before 48r1: 

  grib_set -r -w packingType=grid_ccsds -s packingType=grid_simple ccsds.grib grid_simple.grib

To compare the statistics of the fields before and after the conversion, the following command could be used:

  grib_ls -n statistics ccsds.grib grid_simple.grib

Software

TBC

Availability of test data from the cycle 47r3 test suites

The CAMS operational FTP server (ECPDS) will serve the most recent 3 days of test data, once the e-suite is running in near-real-time, in the directories "/DATA/CAMS_GLOBAL_TEST" and "/DATA/CAMS_EUROPE_BC_TEST" for global and regional boundary condition data, respectively. In addition, surface level fields (model level 137) will be provided as individual files in the CAMS_GLOBAL_ADDITIONAL_TEST directory and (plume model updated) GFAS hourly test data will be provided in the CAMS_GFAS_HOURLY_TEST directory . Users wanting to access the output from the current test system for a longer period can access the data from 1 September 2022 onwards directly on MARS or through our WebAPI. More details can be found here: Accessing CAMS 48r1 test data (draft).

Document versions