Version guidance for COSP 1

This page outlines limitations and errors in the versions (tags) of COSP 1.4 endorsed for use in CMIP6/CFMIP3.

Version 1.4 contains an error in the treatment of mixed-phase clouds in the MODIS simulator. It is limited in that in can not produce two fields requested for CMIP6 (Optical_Thickness_vs_ReffICE, Optical_Thickness_vs_ReffLIQ, both from the MODIS simulator).

Users of version 1.4 may either submit to CMIP6/CFMIP3 with affected diagnostics omitted or upgrade to version 1.4.2. Upgrading effects roughly 500 lines of code. Upgrade can be effected through git or via a patch available here.

Version 1.4.1 also contains the error in the treatment of mixed-phase clouds in the MODIS simulator. This error impacts only columns in which mixed-phase clouds are visible from space. The two new diagnostic fields (Optical_Thickness_vs_ReffICE, Optical_Thickness_vs_ReffLIQ, both from the MODIS simulator) are also improperly initialized and provide results as fractions, rather than percent.

Users of version 1.4.1 may submit to CMIP6/CFMIP3 with affected diagnostics. Since correcting the issue requires changing only 18 lines of code we instead suggest that users upgrade to version 1.4.2, either via git or with a small patch