How is the CERA-20C Synoptic Monthly Means for Ensembles (edmm) organised in MARS?
In general it is organised, as a huge tree, with the indentation below, showing different levels down that tree
- stream: Synoptic monthly means for ensembles (edmm)
- Decade: 1900
- all years of a decade, months, times, types (an/fc), level types, levels, parameters and ensemble members (same tape file)
- Decade: 1910
- Decade: ...
- Decade: 2010
- Decade: 1900
What would be the natural way to group requests?
The idea is to request as much data as possible from the same tape file. In general the most efficient way to group requests would be per decade, i.e. put all years, months, times, types, level types, levels, desired parameters and ensemble members for a specific decade in one request.
- The objective of the examples below is to demonstrate how to iterate efficiently for a particular CERA-20C request.
- At this point you may wish to have a look on the CERA-20C synoptic monthly means availability and identify your desired level type, data type, time periods, parameters, etc.
- The requests below can be used as a starting point, however, you will need to adapt them to your requirements, for example change some values (the right side of the "key":"value" pairs) or add or remove some keys.
Requesting analysis (an) surface (sfc) data over multiple years
In the data tree 'decade' is highest. Getting data for the whole decade in one go might exceed data volume limitations though, so we split our request by years: we get all data we need for the first year, then move on to the next year, and so on.