Enabling Monthly Averaged HISTORY Output

Basic info

The time averaging is activated by adding a keyword monthly to the collections you want to be time averaged. Also the mode for these collections should be set to time-averaged. The averaging begins at midnight of each month, continues to accumulate until the beginning of the next month (again at 0z). Every time step is accumulated.

So you need to make few changes to HISTORY.rc and to gcm_run.j (see below)

Changes to HISTORY.rc

To enable the feature you need to add the keyword monthly and set to non-zero value for each collection, for which you need a monthly average. Please note that collection needs to be a time-averaged collection, e.g.:

geosgcm_surf.monthly:  1,
geosgcm_surf.mode:      'time-averaged’,

Also, you do not need to make changes to the fields “frequency” and “duration”, but their values will get ignored internally (technically speaking, the frequency is set to be exactly one month, and the duration is set to one record per file). Each output file is timestamped at the beginning of the month. (The writing happens at the end of the month, but the file is labeled at the beginning for which averaging is done.)

Changes to gcm_run.j

If your run spans the entire month (or more), you do not need to do anything else. But if you start or stop in the middle of the month, you need to take care of the coupler restart/checkpoint (named <collection_name>.rst and .chk). Note the gcm_run.j needs to be modified accordingly

If your run starts in the middle of a month, and you did not supply the coupler's checkpoints, MAPL appends “partial” to the output for that collection.