day.tasmax : unphysical maximum values

[martinjuckes]

Max: 358.6103515625 -- 350.0
CMIP6.CMIP.MOHC.HadGEM3-GC31-LL.historical.r1i1p1f3.day.tasmax.gn.v20190624 --

MOHC_HadGEM3-GC31-MM_historical :: None
Max: 359.964599609375 -- 350.0
CMIP6.CMIP.MOHC.HadGEM3-GC31-MM.historical.r1i1p1f3.day.tasmax.gn.v20191207 --

MOHC_UKESM1-0-LL_historical :: None
Max: 366.17529296875 -- 350.0
CMIP6.CMIP.MOHC.UKESM1-0-LL.historical.r10i1p1f2.day.tasmax.gn.v20191213 --

[matthew-mizielinski]

Thanks for reporting this Martin; I'll enquire with our science teams and report back.

[martinjuckes]

There is additional information on quantiles of the data here: Overview_tasmax.md -- showing, for instance, that the 99.9th quantile of this data is withing the range of other models, so the extremes noted above are rare outliers.

[martinjuckes]

@matthew-mizielinski : any update on this?

[matthew-mizielinski]

@martinjuckes, apologies for the delay. I've now looked into this myself and I think there is indeed an issue here; looking at the first 10 years of the UKESM1 dataset you noted in this issue I can see 6 instances of tasmax >350 K, the first of which is on 1851-04-01 over central Africa.

I'll be chasing this up over the next few days to get a fuller picture and then look into documenting the issue.

[matthew-mizielinski]

@martinjuckes, I've issued an errata for this to make it clear that there is an issue; https://errata.es-doc.org/static/view.html?uid=76b3f818-d65f-c76b-bfd8-cae5bc27825c

At present I'm planning to continue to publish datasets with this issue until I can get guidance from the UK CMIP6 project team.

[martinjuckes]

@matthew-mizielinski : is there and update here? Something similar is happening in IPSL data (#65).

[martinjuckes]

PS: the IPSL values are much more extreme .. above 500K.

[matthew-mizielinski]

@matthew-mizielinski : is there and update here? Something similar is happening in IPSL data (#65).

I've poked the modelling teams here to look at this (again), and I'll keep the errata open until I get an explanation.