Protocol updates and new forcing data coming soon

Posted on Jan. 8, 2020

Dear ISIMIP community,

this is a quick update with information about the simulation protocols and forcing data for ISIMIP2a-extended and ISIMIP3.

1) The ISIMIP2a-extended simulation protocol is almost ready, we will publish it in early January. Compared to the original ISIMIP2a simulation protocol, the forcing data have been extended to cover more recent years; new atmospheric forcing datasets have been added; further sectors have been included; and many conventions and definitions have been updated. However, existing ISIMIP2a simulations will remain consistent with this extended protocol.

2) In preparation of ISIMIP3, a new bias-correction method has been developed ( and, as well as a new target dataset (, by Stefan Lange at PIK in collaboration with colleagues from B-Open, Met Office, Uni Reading, Uni Frankfurt, and ECMWF (THANKS!). We have already downloaded and bias-corrected data from a number of CMIP6 Earth System models (ESMs). As in previous ISIMIP rounds, we have tried to identify a small "core set" of ESMs for which we will ask all ISIMIP modelers to run simulations, in order to produce a large and consistent cross-sectoral ensemble. In addition, this time, we will process and provide data from as many additional ESMs or GCMs as we can. These secondary models can then be run by impact modelers who have the interest and capacity to enlarge their simulation ensemble.

The core set will most likely include the following ESMs:
CESM2 (only if the issue of missing tasmin/tasmax data with this model can be resolved)

In terms of secondary models, we have already processed:

We plan to publish these data in the first half of January on the DKRZ server. Simultaneously, we will publish an ISIMIP3 "mini-protocol" to instruct you how to run your first set of simulations for ISIMIP3a and 3b.

The ISIMIP team at PIK