Over the past months, the cross-sectoral science team, management group and sectoral coordinators have been thinking about how ISIMIP could contribute to the scientific basis for the planned Special Report from the IPCC on the impacts of 1.5°C warming. This was also a topic of intense discussions at the ISIMIP workshop in Potsdam in June, 2016.
Based on these discussions, we’ve been working hard to put together a proposal for an ISIMIP simulation scenario design to facilitate a targeted contribution from ISIMIP to the Special Report. Effectively this is a re-focusing of what was already planned for ISIMIP2.1b and ISIMIP 2.2 – we’re calling the 1.5°C-focused simulation round simply "ISIMIP2b", and is the product of many discussions between the sectoral coordinators and cross-sectoral science team.
Scenario Design Paper
The proposed scenario design has now been worked into a paper, led by Katja Frieler, describing the scientific rationale for the scenario design and a description of the selected input data sets. This manuscript has now been submitted to the discussion journal Geoscientific Model Development (GMD) and should become available for public comment shortly (we will forward a link to the discussion paper once it is online). The submitted version of the paper is attached to this email. We are particularly keen to hear your feedback on the planned simulations and input data sets.
Given the tight timeline for the IPCC 1.5°C Special Report (the publication deadline for papers to be considered in the Special Report is October, 2017), this next simulation round, ISIMIP2b, is going to be a challenge to us all, and a big effort has been made to keep the number of simulation scenarios to a minimum, whilst maximising the scientific value that can be drawn from them.
Simulation Protocol, Data & Timeline
As we speak, we are in the process of collecting and pre-processing the input data, including bias correction of the climate data using an improved version of the ISIMIP Fast Track bias-correction method. A first full climate-data set is very close to finished, covering pre-industrial through to extended future daily climate data for the global climate model IPSL-CM5A-LR, and 3 more GCMs are on the way.
The next steps on the coordination side are to condense the scenario design paper into a simulation protocol, containing only the instructions on how to run the simulations. We would very much like to integrate your feedback on the attached manuscript into both the final version of the manuscript, and the simulation protocol. For this reason, it would be greatly appreciated if you would take the time to look at the manuscript in the coming days and to provide feedback as soon as possible, and at the latest by Friday, 16 September, but the sooner the better. We hope to then publish the simulation protocol and input data by the end of September, allowing simulations to start on 1 October, 2016, one year before the submission deadline for the IPCC report. The aim would be to have first simulations finished by the end of this year, and the full set of simulations by 31 March, 2017 at the very latest.
Computing Resources
If limited computing resources might hinder you in participating in ISIMIP2b, please get in touch as soon as possible. It may be possible to make use of the new super-computer at PIK to run your model.
Thanks for reading this far - we welcome your questions and comments and very much look forward to hearing your feedback, and providing you with the finished protocol and input data.