Information sourced from the UM user guide

Version 8.2

UM8.2 saw 94 tickets lodged on the UM trunk. Work continues to modularise the UM code, with the migration of many include files to modules. The major deliverable of UM8.2 is the rationalisation of UM output, reducing the the size of the .leave files and a tidy up of the the information present within it. Changes worth a mention from UM8.2 include:

  • rationalisation of the namelist entries as used by the RCF and UM run. Where possible they now access a shared file rather than duplicate namelists.
  • A significant UKCA upgrade consolidating many research branches.
  • Inclusion of the COSP satellite simulator code
  • Upgrade to the sea ice surface exchange scheme

Version 8.0 and UM8.1

UM8.0 saw 100 tickets lodged on the UM trunk, while UM8.1 included 78 distinct changes. Both releases saw further work on four specific initiatives: code support for multiple dynamical cores, modularisation of the UM control code, retirement of unnecessary cpp flags and code optimisations. Changes worth a mention from UM8.0 include:

  • Implementation of a fully asynchronous I/O server
  • add option to adjust I/O buffer sizes

and from UM8.1:

  • JULES was removed from the UM trunk and is now extracted from its own repository and the UM build and UI updated to support the extract and build of the atmosphere sub model from more than one repositiory.
  • The UM PP LOOKUP header now supports seconds, replacing the daynumber. Thus adding enhanced support for sub minute timestep models.

Version 7.9

UM7.9 saw 101 distinct changes (tickets) lodged on the UM trunk. The UM system development teams were busy resolving defects and extending UM capabilities. Larger changes of note include:

  • Enable the building of atmospheric execs from multiple code repositories.
  • Allow dust scheme to run with only 2 size divisions, rather than 6; switchable.
  • A new option for more scalable reproducible sums.
  • Asynchronous dumping IO Server support.

ENDGame development continues apace with a single global model configuration based upon most recent Met Office operational science now being available for the ENDGame developers to work with. The top level UM routines have been split into `dynamical core' dependent routines, a set for ENDGame and a set for New Dynamics. Thus enabling the UM to support multiple dynamical cores by utilizing compiler flags. ENDgame is not yet supported through the UI and is not ready for general use.

Version 7.8

85 distinct changes were lodged at UM7.8. A significant number were related to ENDGAME changes; collating the ENDGame code within the UM trunk in a preliminary form, to support further development. It is not ready for general use. Other changes of note included improvements to the UM model scalbility and additional science:

  • I/O server implementation, now supports asynchronous STASH IO.
  • Scalable QPOS options, improving UM model scalability.
  • Further OpenMP coverage across the UM code.
  • A new mountain drag scheme
  • SCM is now supported within the UMUI, rather than requiring external scripts.
  • UM code and UMUI capabilities extended to work with up to 250 model levels.

Version 7.7

UM 7.7 saw work begin in earnest to add future support for ENDGAME, changes to top level routines and also science sections. In total there were 88 distinct changes lodged. Those of note include:

  • I/O server implementation, to help with UM scalability.
  • A new section A39 has been added to accommodate the Cambridge nudging scheme. This is a simple form of data assimilation that adjusts dynamical variables of free running GCMs using meteorological re-analysis data to give a realistic representation of the atmosphere at a given time.
  • A new UMUI facility to allow the user to override default library paths
  • MakeBC Stashmacro, to simplify the generation of required UM fields output (rather than manually request them within the STASH window), used by MakeBC.

Version 7.6

An open science which included 94 distinct changes, bug fixes and enhancements, to UM code. For example:

  • Implementation of the TKE based higher order turbulence closure models; a new BL scheme using A03_1A.
  • Addition of Dr HOOK code to the UM routines; This is a tool which provides Call-tree information and Timings of the code.
  • Reorgansiation/rationalisation of ATM_STEP work; to shorten the length of the subroutine by 50
  • A new module introduced to support future work so to allow switching between ENDGAME and original New Dynamics grids; to set up array bounds. This is the first step in the implementation of ENDGAME dynamics, which will continue over future releases.
  • Major upgrade to IAU code; support for model error tendencies.
  • Installation modification to support asynchronous execution of prebuilds, with limit to max number at any given time.
  • STASH macros improvements; use their own UNIT numbers rather than PP streams.

Version 7.5

An open science which included 83 distinct changes, bug fixes and enhancements, to UM code. Significant items of note,

  • Introduce JULES v2.1 code as a LAND sub model. (Interim measure until the UM atmosphere component build system is upgraded to support multiple repositories.)
  • SES2 radiation scheme introduced
  • OpenMP code directives introduced: The UM compiles with OpenMP by default on the IBM-HPC.

Version 7.4

First open release after the port to the IBM saw numerous science and system changes to the UM; 71 tickets.

  • LBC functionality for tracers and UKCA, in support of AQUM.
  • Implementation of Stochastic Kinetic Energy Backscatter v2 (SKEB2)
  • New convection section/scheme 6A.
  • Variable resolution introduced to the UM.
  • Variable Resolution Turbulence Scheme
  • Improved UI support for NEMO and CICE

Version 7.3

First release of the UM ready for operational use on the IBM Power 6. This release was primarily further porting work.

  • Improved IBM signal trapping and tidy up of UM output.
  • FRAMES code incorporated within the UM code.
  • More flexible settings of 'segments' in LW,SW and convection code.
  • Many small science changes and bug fixes.
  • Addition of 3DVOM extract utility to UM small execs.