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ANDRAS: I thought the non-European domains will use the same set of variables, is that a wrong assumption? Jose, would you check this, please?

The CDS subset of CORDEX data have been through a metadata quality control procedure which ensures a high standard of reliability of the data. It may be for example that similar data can be found in the main CORDEX archive at the ESGF (Earth System Grid Federation) however these data come with no quality assurance and may have metadata errors or omissions. The quality-control process means that the CDS subset of CORDEX data is further reduced to exclude data that have metadata errors or inconsistencies. It is important to note that passing of the quality control should not be confused with validity: for example, it will be possible for a file to have fully compliant metadata but contain gross errors in the data that have not been noted. In other words, it means that the quality control is purely technical and does not contain any scientific evaluation (for instance consistency check).

ANDRAS: I think, here we have to mention that we also publish data, which had not been available so far in the ESGF. GL : Is there any dataset in this case? Euro-CORDEX comes from the ESGF, even the new simulations from PRINCIPLES that are published on the ESGF first. Med-CORDEX will be published on the ESGF in a second step after the 34b Lot 1. And for 34d data, non-ESGF data will be published on the ESGF and ESGF data have been just Qc-ed for CDS. So I don't see any dataset that exist on the CDS which is/will be not on the ESGF. ANDRAS: OK, maybe some text as proposed below would be sufficient.

We can mention the additional effort (of 34d) to find the additional data for non-European domains. Maybe the link to the IPCC Atlas should be also mentioned. GL: I agree. Jose, would you provide some additional text about the IPCC Atlas, a link, possibly?

Additional efforts (and funding) was devoted to make new simulations for the EURO-CORDEX domains, which significantly enhances the EURO-CORDEX regional climate model matrix in terms of emission scenarios, global model forcing and regional climate models. For the non-European domains resources were put into finding simulations, which were not available before (and not published in the ESGF earlier).

In addition, CORDEX data for CDS includes Persistent IDentifiers (PID) in their metadata which allows CDS users to report any error during the scientific analysis. The error will be at least documented on the ESGF Errata Service (http://errata.es-doc.org)but also planned to be documented in the CDS. The CDS aims to publish only the latest versions of the datasets.

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Regional Climate Model (RCM) simulations needs lateral boundary conditions from Global Climate Models (GCMs). At the moment the CDS-CORDEX subset boundary conditions are extracted from CMIP5 global projections. In general the CORDEX framework requires each RCM downscale a minimum of 3 GCMs for 2 scenarios (at least RCP8.5 and RCP2.6). ANDRAS: please check this, if this is still valid for the non-European domains. Jose, would you check this, please?

The C3S-EURO-CORDEX subset aims to fill the gaps in this matrix between GCMs (aka "driving models), RCMs and RCPs. This will ensure better representation of uncertainties coming from GCMs, RCMs and RCP scenarios and make possible to study the regional climate change signals in a more comprehensive fashion. 

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GL: I let Manuel for the additional paragraph. I will update the table of simulations once we agreed on the different decisions to take (cf. our mail thread about this).

Jose, would you propose an additional paragraph, here?



Driving Global Coupled Models


HadGEM2-ESEC-EARTHCNRM-CM5NorESM1-MMPI-ESM-LRIPSL-CM5A-MRCanESM2MIROC5

Regional Climate Models

RCA4 (SMHI)111113
11111113
11





CCLM-8-17 (ETH)
11111
11



11





1

crCLIM-v1-1-1 (ETH)




1




1

2








REMO2009 (GERICS)











222







1
REMO2015 (GERICS)11
11



111

11




1
1
RACMO22E (KNMI)1111231111
11
1

1





HIRHAM5 (DMI)
12224

1
22

1








WRF361H (UHOH)













1








WRF381P (IPSL)

1

1

1

1



11





ALADIN53 (CNRM)





111














ALADIN63 (CNRM)

1


111




1








RegCM4.6.1 (ICTP)























HadGEM3-GA7-05 (MOHC)

1

1












































RCP26RCP45RCP85
[0-9] = Number of simulations

The 13 Regional Climate Models that ran simulations over European domain will be documented through the Earth-System Documentation (ES-DOC) which provides a standardised and easy way to document climate models.

Dataset numbers (simulation version)

ANDRAS: I think, this can be a bit confusing, since above we mention that we publish only the latest version. So somehow we have to explain clearly what is the difference between model version and dataset number.

GL: As said in my email, this could be delegate to the Errata Service and we can remove this paragraph. What do you think? I will create an issue on the Errata test instance to show how it looks like.

On a general level in the CDS form for the RCM simulations “v” enumerates runs and NOT model versions. For the DMI, KNMI and SMHI runs numbers different from “v1” means new simulations relative to the first “v1” one. It might not mean a new version. Hereafter we describe the meaning of the different dataset numbers for those models, which have some.

  • DMI
    • For the EC-EARTH r3i1p1 forced HIRHAM simulation “v2” is a new simulation where proper GHG concentrations changing with time are used as a contrast to “v1” that erroneously used the constant control level throughout the simulation. Therefore users should use v2.
    • As it is for the previous point “v2” is used for the HIRHAM simulation forced by MOHC-HadGEM2-ES.
    • As for the previous two points but here “v3” is used for the NorESM driven simulation. A previous “v2” version including also an error in the vertical interpolation when preparing the boundary files also exists.
  • KNMI
    • For the MOHC-HadGEM2-ES forced RACMO simulation v2 is a new simulation where a big error in SST-remapping from the HadGEM-grid to the RCM-grid in v1 was corrected. The erroneous v1-simulation has been unpublished from the ESGF.
    • For the CNRM-CM5 simulation v2 is a new simulation replacing the old now with input data taken from pressure levels instead of model levels. The originally provided model level fields from CNRM were wrong.
  • SMHI
    • Two MPI-driven scenario runs were rerun in 2016 as there had been problems with a restart file and as there was an error in the snow diagnostics in the original run. The reruns were labelled v1a.
  • CNRM
    • For the CNRM-CM5 simulation v2 is a new simulation replacing the old now with input data taken from pressure levels instead of model levels. The original provided model level fields from CNRM were wrong.

Ensembles

The boundary conditions used to run a RCM are also identified by the model member if the CMIP5 simulation used. Each modeling centre typically run the same experiment using the same GCM several times to confirm the robustness of results and inform sensitivity studies through the generation of statistical information. A model and its collection of runs is referred to as an ensemble. Within these ensembles, three different categories of sensitivity studies are done, and the resulting individual model runs are labelled by three integers indexing the experiments in each category. 

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NameShort nameUnitsDescription
2m temperaturetasKThe temperature of the air near the surface (or ambient temperature). The data represents the mean over the aggregation period at 2m above the surface.
200hPa temperatureta200KThe temperature of the air at 200hPa. The data represents the mean over the aggregation period at 200hPa pressure level.
Minimum 2m temperature in the last 24 hourstasminKThe minimum temperature of the air near the surface. The data represents the daily minimum over the aggregation period at 2m above the surface. ANDRAS: I guess this variable is available only for daily data, is that correct? Please check!
Maximum 2m temperature in the last 24 hourstasmaxKThe maximum temperature of the air near the surface. The data represents the daily maximum over the aggregation period at 2m above the surface. ANDRAS: I guess this variable is available only for daily data, is that correct? Please check!
Mean precipitation fluxprkg.m-2.s-1The deposition of water to the Earth's surface in the form of rain, snow, ice or hail. The precipitation flux is the mass of water per unit area and time. The data represents the mean over the aggregation period.
2m surface relative humidityhurs%

The relative humidity is the percentage ratio of the water vapour mass to the water vapour mass at the saturation point given the temperature at that location. The data represents the mean over the aggregation period at 2m above the surface.

2m surface specific humidityhussDimensionlessThe amount of moisture in the air at 2m above the surface divided by the amount of air plus moisture at that location. The data represents the mean over the aggregation period at 2m above the surface.
Surface pressurepsPa

The air pressure at the lower boundary of the atmosphere. The data represents the mean over the aggregation period.

Mean sea level pressurepslPaThe air pressure at sea level. In regions where the Earth's surface is above sea level the surface pressure is used to compute the air pressure that would exist at sea level directly below given a constant air temperature from the surface to the sea level point. The data represents the mean over the aggregation period.
10m Wind SpeedsfcWindm.s-1The magnitude of the two-dimensional horizontal air velocity. The data represents the mean over the aggregation period at 10m above the surface.
Surface solar radiation downwardsrsdsW.m-2The downward shortwave radiative flux of energy per unit area. The data represents the mean over the aggregation period at the surface.
Surface thermal radiation downwardrldsW.m-2

The downward longwave radiative flux of energy inciding on the surface from the above per unit area. The data represents the mean over the aggregation period.

Surface upwelling shortwave radiationrsusW.m-2

The upward shortwave radiative flux of energy from the surface per unit area. The data represents the mean over the aggregation period at the surface.

Total cloud covercltDimensionlessTotal refers to the whole atmosphere column, as seen from the surface or the top of the atmosphere. Cloud cover refers to fraction of horizontal area occupied by clouds. The data represents the mean over the aggregation period.
500hPa geopotentialzg500mThe gravitational potential energy per unit mass normalized by the standard gravity at 500hPa at the same latitude. The data represents the mean over the aggregation period at 500hPa pressure level.
10m u-component of winduasm.s-1The magnitude of the eastward component of the wind. The data represents the mean over the aggregation period at 10m above the surface.
10m v-component of windvasm.s-1The magnitude of the northward component of the wind. The data represents the mean over the aggregation period at 10m above the surface.
200hPa u-component of the windua200m.s-1

The magnitude of the eastward component of the wind. The data represents the mean over the aggregation period at 200hPa above the surface.

200hPa v-component of the windva200m.s-1The magnitude of the northward component of the wind. The data represents the mean over the aggregation period at 200hPa pressure level.
850hPa U-component of the windua850m.s-1The magnitude of the eastward component of the wind. The data represents the mean over the aggregation period at 850hPa pressure level.
850hPa V-component of the windva850m.s-1The magnitude of the northward component of the wind. The data represents the mean over the aggregation period at 850hPa pressure level.
Total run-off fluxmrrokg.m-2.s-1

The mass of surface and sub-surface liquid water per unit area and time, which drains from land. The data represents the mean over the aggregation period.

Mean evaporation fluxevspsblkg.m-2.s-1

The mass of surface and sub-surface liquid water per unit area ant time, which evaporates from land. The data includes conversion to vapour phase from both the liquid and solid phase, i.e., includes sublimation, and represents the mean over the aggregation period.

Land area fractionsftlf%The percentage of the surface occupied by land, aka land/sea mask. The data  is time-independent.
OrographyorogmThe surface altitude in the model. The data is time-independent.

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The metadata provided in NetCDF files adhere to the Climate and Forecast (CF) conventions. The rules within the CF-conventions ensure consistency across data files, for example ensuring that the naming of variables is consistent and that the use of variable units is consistent.

File naming conventions ANDRAS: please check, if this convention is also held for the non-European domains. I also think that there might be some amendment needed, because of the domain name and the resolution. Jose, would you check this, please?

When you download a CORDEX file from the CDS it will have a naming convention that is as follows:

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Quality control of the CDS-CORDEX subset ANDRAS: any additional information for QC of the non-European domains, particularly those, who were not in the ESGF? GL: 34d has a beautiful diagram on the differnet QC steps that could be interesting to copy-paste here. Jose, would you add this here, please?

The CDS subset of the CORDEX data have been through a set of quality control checks before being made available through the CDS. The objective of the quality control process is to ensure that all files in the CDS meet a minimum standard. Data files were required to pass all stages of the quality control process before being made available through the CDS. Data files that fail the quality control process are excluded from the CDS-CORDEX subset or if possible the error is corrected and a note made in the history attribute of the file. The quality control of the CDS-CORDEX subset checks for metadata errors or inconsistencies against the Climate and Forecast (CF) Conventions and a set of CORDEX specific file naming and file global metadata conventions. 

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