APS2-development ACCESS-G N512 25km resolution global NWP medium-range assimilation-forecast suite documentation


1. Brief Description

ACCESS Global N512 suite is developed by ACCESSS Model System Team (MST), in collaboration with other ACCESS teams. Comparer with previous ACCESS-G suite, it has an increased horizontal resolution of 25 km (from 40km), and the same 70 level of vertical resolution (to 70 km?). The System were originally developed on vayu at NCI in August 2012, and it was ported to Solar at BOM in December 2012. The systems were again ported to the new HPC systems both at NCI and BOM in 2013, and they are now routinely running on raijin at NCI and on Ngamai at BOM. Some of the recent verifications are available at http://flurry-bm/~yix/aps2_n512_plots, and early ones are at http://flurry-bm/~yix/n512_plots. Charts from N512 suite can be viewed at (put link here)

2. Suite Specification

The Configuration of ACEESSS N512 suite is based on PS32 release from the UK Met Office. It runs 4 times a day. At each cycle (00Z,06Z,12Z,18Z), observations are processed by OPS (observation is handled via ODB), followed by a 4DVAR Analysis. The soil moisture content (smc) is created by SURF , and updated at each cycle. In addition, the sea surface temperature (sst, from BlueLink) and the sea ice (from NCEP) are updated at 06Z daily. At 00Z and 12Z, a 10 days forecast is produced by the Unified Model (UM).

Specific details about the N512 suite are summarised in Table below.

Components Horizontal Grid Vertical Grid Time Step Software Versions Comments
UM 1024 x 768 ( ~25km) L70 10 minutes 8.2
VAR 432 x 325 L70 20(?) minutes 29.1.2 Using V30.0 is being tested
OPS L70 30.0.0 ObsGroups : Surface, Aicraft, AMV, Scat, ATOVS,AIRS,MTSATClear,CRIS,ATMS,SSMIS
SURF 18.5 Testing SURF30.0
ODB ODB30 With ODB feedBack Enabled

Note that, the N512 suite has gone through a few updates since it started in 2012. Version of various software used may still be changed.

3. Suite Dependencies

As a complex NWP system, the N512 suite contains many tasks. Some of the tasks are associated with components mentioned in previous section, others are just simple house keeping tasks, which gets inpuns in places or sends outputs away. A scheduler controls when and how to run a task within the suite. Depending on the scheduler being used, there are two types of ACCESS N512 NWP suites, one is under SCS (Suite Control System from UKMO), the other is under cylc (from NIWA). The SCS suite is only available at the Bureau, the cylc suite is available both at NCI and atthe Bureau. Although the two types of N512 suites share most aspects, there are some differences:

  • The SCS suite is hosted on a HPC (Ngamai); The cylc suite is hosted on a none-HPC machine: accessdev at NCI, and twister at the Bureau.
  • Component tasks (see the full task list in 3.1 below for more details ) OPS/VAR/UM/SURF maybe defined differently
    • For SCS suite, OPS/VAR/UM tasks are defined using the corresponding UI (from UKMO);
      SURF tasks are defined within SCSUI itself.
    • For cylc suite, OPS/VAR/SURF tasks are defined with rose (from UKMO) through rose-app.conf files.
      UM tasks are still defined using UMUI in current APS2 N512 suite. This is due to the old version of UM (vn8.2) which does not have rose support.
  • Another noticable difference between the SCS and cylc suite is that
    • SCS suite runs one cycle at a time, such 2014040106;
    • cylc suite can run across multiple times at once, ie tasks have their own cycle times. This means that cylc suite is far more efficient, especailly in research environment with none real time running or in catch up mode in operation.

3.1 Suite Tasks

There are many tasks within the ACCESS N512 suite. Roles of these tasks are listed as below

   |  |-Prep                 send bin and app over (cylc suite only)
 | |-remote_cycling       
 |   |-get_bufr           get obs bufr files 
 |   |-get_old_bgerr      get old bgerr file ( only at cold start )
 |   |-get_ic             get external start dump file ( only at cold start )
 |   |-get_surf           get external sst and sea ice files (at 06Z only)
 |   |-ODB                ODB family
 |   | |-get_iasi         Create ODB for iasi
 |   | |-get_airs         Create ODB for airs
 |   | |-get_surface      Create ODB for surface
 |   | |-get_cris         Create ODB for CrIS
 |   | |-get_s            Create ODB for Screen OPS
 |   | |-get_atms         Create ODB for ATMS
 |   | |-get_scat         Create ODB for Acat
 |   | |-get_mtsatclear   Create ODB for MTSatClear
 |   | |-get_gpsro        Create ODB for GPSRO
 |   | |-get_atovs        Create ODB for ATOVS
 |   | |-get_as           Create ODB for Aircraft and Sonde
 |   | |-get_amv          Create ODB for SatWind
 |   | |-get_ssmis        Create ODB for SSMIS
 |   |-build_ops          Build ops executable
 |   |-GEN                GEN Family
 |     |-bgerr            Create backgrund Error
 |     |-OPS              OPS family
 |       |-Ops_iasi       Extract and process iasi
 |       |-Ops_amv        Extract and process SatWind
 |       |-Ops_airs       Extract and process airs
 |       |-Ops_surface    Extract and process Surface
 |       |-Ops_cris       Extract and process CrIS
 |       |-Ops_s          Extract and process Screen Obs
 |       |-Ops_atms       Extract and process ATMS
 |       |-Ops_mtsatclear Extract and process MTSATClear
 |       |-Ops_gpsro      Extract and process GPSRO
 |       |-Ops_atovs      Extract and process ATOVS
 |       |-Ops_as         Extract and process Aircrafe and Sonde
 |       |-Ops_scat       Extract and process ASCAT
 |       |-Ops_ssmis      Extract and process SSMIS
 |     |-VAR              VAR family
 |     | |-ConfigScreen   Configure Screen LS files
 |     | |-ConfigLS108    Configure LS for N108 files
 |     | |-ConfigLS216    Configure LS for N216 files
 |     | |-ScreenVAR      3D Screen Analysis
 |     | |-Analysis216    N216 4D AnalysisPF
 |     | |-Analysis108    N108 4D AnalysisPF
 |   |-SURF               SURF family
 |   | |-Surf_ssticesnow  produce sst/seaice/snow at targeted grid (at 06Z only)
 |   | |-Surf_smc         produce smc at targeted grid
 |   |-UM                 UM family
 |   | |-g2g              reconfigure start dump to targeted grids ( only at cold start )
 |   | |-FC_short         short step IAU Forecast
 |   | |-FC               IAU Forecast
 |   | |-InitialFC        Initial Forecast ( only at cold start )
 |   | |-ReconSST         update sst and seaice (at 06Z only)
 |   |-Archive            Archive family
 |   | |-run_archive      run time archive family
 |   |   |-a_pa           run time archive pa stream to mars/opendap
 |   |   |-a_pb           run time archive pb stream to mars/opendap
 |   |   |-a_pc           run time archive pc stream to mars/opendap
 |   |   |-arc_staging    run time staging
 |   | |-post_fc          post UM forecast family
 |   | | |-PostFinal      last time archive
 |   | | |-staging        move files to archive directory
 |   | | |-charts         produce forecast charts
 |   | | |-PostArchive    archive to sam/mdss  for previous cycle
 |   | | |-housekeeping   tidy up

Dependencies among tasks are illustrated as below, where nodes ODB and OPS are family nodes, they represent tasks within the family detailed as above.

The suite dependency graph also shows the data flow within the suite, which is useful for a user to understand the suite, especial when a manual action (outside the scheduler) is required, such as trigger a task, reset a task state in a cylc suite.

3.2 Component Definitions

As mentioned early in Section 3, tasks from components OPS/VAR/SURF/UM are defined either through UIs (User Interface), or with rose task configuration rose-app.conf . When they are defined with rose, definitions of these component tasks are a part of the cylc suite definition. When they are defined though UIs, they are referenced by the SCS suite, but are not included in the SCSUI suite definition.

Component definitions that we talked about here are only applied to tasks defined through UIs. A corresponding rose-app.conf file can be obtained directly from a UI definition. Please note that, beyond APS2, UIs will be replaced by rose, and will no longer be supported.

Note that SURF tasks are part of the suite definition, both under SCS and cylc , and they are kept with the suite database under SCSUI (on Ngamai) or rosie (on accessdev).

3.3 Suite Control Data

Within a NWP suite, tasks usually require some control data in order to be executed, such as StationList for OPS, Covariance File for VAR, Ancillary Files for UM etc. These control data are under ~access, and small ones are also under svn. Details are as below.

~access/nwpdir/share/APS2/Data : large data files for OPS
~access/nwpdir/share/APS2/other : large data files for VAR

Note that files that are under ~access/nwpdir/share/APS2/Data and ~access/nwpdir/share/APS2/other are large files, and they are not maintained svn

  • UM UM control files stay on disk.
    • version specific control files are under


  • Resolution dependent files are under ( to be decided )


3.4 Component Software

4. Running The Suite

5. Data Management

Last modified 7 years ago Last modified on Oct 10, 2014 2:29:28 PM

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