cesm1_2 Release Notes

cesm1_2_1

Release Notes

Contents

Release Notes
What's New
Answer-Changing Features
Machines
Known Problems

Release Notes

The CESM1.2.1 is the first incremental bug fix and machines update release in the CESM1.2 series.

** IMPORTANT NOTE ** Starting with CESM1.2.1, the Subversion repository path has changed. All documentation for downloading the most current version of the model has been updated in the CESM User's Guide to reflect this change and older version differences are noted.

To download the CESM1.2.1 release code, use this command:

> svn co --username guestuser --password [password] 
https://svn-ccsm-models.cgd.ucar.edu/cesm1/release_tags/cesm1_2_1 cesm1_2_1

You may be prompted up to 3 times for the username and password when checking out the code for the first time from this new Subversion path. This is because the code is distributed across a number of different Subversion repositories and each repository requires authentication.

What's New

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Answer-Changing Features

CAM

CAM-SE now uses vertically Lagrangian advection by default.
CAM5 ne30 tests have answer changes due to a new initial condition file.

CISM

Answer changes due to new default parameter values (temp_init, basal_mass_balance, and sigma; see the "What's new in CESM1.2" section of the CISM documentation for details)
New code version (glimmer-cism 1.9) results in small changes for all configurations, but should give roughly the same answers as the earlier version

CLM

Compsets using CLM4.5 are a new capability to the system that will change answers compared to similar CLM4.0 compsets for all resolutions and configurations.
hcru namelists will change because number of processors different.
Processors for I compsets on yellowstone for f09_g16 will be different.
f09 1850CLM40CRUCN changes answers because new initial conditions for RTM.
Some CLM4.0 compsets will change answers because RTM now has new initial conditions.
cesm1_2_0_n03_scripts4_130520 changes answers for I_1850_CLM45_CN_GLC_CISM1 (IG1850CLM45CN).
Compsets with CLM4.0 will change answers for f09_g16 CN for 1850 and CRUNCEP ICRU compsets change because they run over different forcing years.

RTM

Modifications to effective velocity for the default CLM4.5 compsets will change the amount of runoff in the system.

CESM Models