New ISIMIP3 country masks #95

note

Jochen Klar reported on Aug. 3, 2026.
We recently published a new set of country masks for ISIMIP3, which was created together with the ISIMIP3 population and GDP data. Compared to the previous country masks (from ISIpedia), the new mask differs in ~500 pixels, making 110 of the countries slightly smaller. This can lead to different, more accurate results, in particular with smaller countries. Please refer to the DOI page linked below for the details.

The change also affects masking countries using the "Configure download" feature using the ISIMIP FIles API. By default, we are now using the ISIMIP3 countrymask, If you still need to access the old mask, you can select it in the interface.

Please note that both the new and the old binary country masks are constructed in such a way that any grid cell touched by the country is fully counted for that country. One effect of this is that grid cells may belong to more than one country. Also, the calculation of the field mean for the country will be different than when using a fractional mask.

ISIMIP3 country masks: https://doi.org/10.48364/ISIMIP.154869

ISIpedia country masks: https://doi.org/10.48364/ISIMIP.635131.2

Details

Affected datasets can still be used for simulations or research.

Severity low

Status resolved

Versions
all versions affected
Input category
Static geographic information
Input subcategory
Country masks
Simulation round
ISIMIP3a, ISIMIP3b

Affected datasets

There are 20 datasets affected by this note. You can download a complete list of all the datasets, or files affected by this note as JSON. Alternatively, can also download a list the files as a flat file suitable for Wget. You can use the search interface to further restrict your query.