reference period

[larsbuntemeyer]

from @gnikulin email:

I don't know if the reference period was already discussed. We are now working on a reference paper about out HCLIM43-ALADIN EUR-12 ensemble and after some discussions decided to use 1991-2020 as the current reference period defined by WMO and used by NMCs worldwide.

comment by @sam-somot via email:

The ERA-Int-driven runs during the first phase of EURO-CORDEX were limited to 1979-2008 for most of them.
Even if we want to compare the new runs with the old one in this study, I would propose to use longer period for the new ERA5-driven runs in the other sections of the paper as 20-year is really short for a good evaluation.

[jesusff]

I think we will be finally forced to re-do the analyses using the CMIP5 EURO-CORDEX runs, so we are more free to choose the periods. In this sense, @csteger also mentioned:

The warming trends of the evaluation runs (maybe compared those in the previous ensemble) should also be included, because missing/underestimated warming in GCM driven runs was criticized recently. We could at least show, that the trend is good when forced with ERA5 (for ICON-CLM this is the case).

There is a work already planned on trends, but we could use the periods to look into this observed climate change issue. If we define two analysis periods (at least for some of the analyses): 1981-2000 and 2001-2020, we could use the first one to compare with the old ensemble and the second one to evaluate recent climate change wrt the 1981-2000 in the new ensemble. Drawback: these are 20-yr periods. For extremes, we should consider the whole 40yr period. Although, extremes are tricky on a non-stationary system, anyway. Maybe we could leave extremes entirely for the dedicated work on them.

[sam-somot]

@jesusff : As there is a paper dedicated to the analysis of the past trends (nabat et al.) and another to the GCM-RCM inconsistency in the paper list, I would avoid to tackle this issue in the general paper

[sam-somot]

generally speaking, I fine with the 1991-2020 period for the reference, hoping that it will be one of the reference periods adopted by the next IPCC reports

[gnikulin]

We can use the 1991-2020 period as the main reference period to evaluate the ability of the new Euro-CORDEX-CMIP6 RCMs to simulate the recent climate and several periods for different kinds of additional analysis (trends if included, CORDEX-CMIP6 RCMs vs CORDEX-CMIP5 ones, etc.).