Experiments with modifed ancillary files

There are various tools that people have used to create or modify ancillary files for particular experiments, e.g. to smooth orography or apply SST anomalies. Tools include xancil or various python utilities.

In order to better support this in the future, the NRI would like to understand the sorts of changes people are making, the input data sources and the tools they’re using.

Please reply in a comment.


Hi Martin, I’ve done a bit of experimenting changing the DMS ancillary files. It has in the past been to test sensitivity of ACCESS to changes of DMS or unaccounted for sources, but more recently it has been to test a new climatology that was released last year (ESSD - Third revision of the global surface seawater dimethyl sulfide climatology (DMS-Rev3)). I did all the changes in python and then used xancil to change back to a UM supported pp file. (I found that when I made the pp files with Iris in python, I wasn’t getting all the metadata right, so easier to use xancil).

Hi Martin,

Try to share something that me and Lynn have done recently, replacing the CNP related fields in the restart dump. More details are in my git hub:

The script can also apply on the orography.