Contributors: A. Troccoli (WEMC), L. Sanger (WEMC), C. Goodess (WEMC), J. Ogonji (WEMC), L. Dubus (WEMC), R. Vautard F Pons (CEA), X. Jin (CEA), G. Levavasseur (CEA), R. Legrand (MF), L. Grigis (MF), S. Martinoni-Lapierre (MF), C. Viel (MF), S. Parey (EDF), B. Oueslati (EDF), Y-M. Saint-Drenan (ASSOCIATION POUR LA RECHERCHE ET LE DEVELOPPEMENT DES METHODES ET PROCESSUS INDUSTRIELS, ARMINES, FRANCE), J. Mendes (MO), J. Osborne (MO), G.Guentchev (MO)

Table of Contents

1. General

1.1. Description

Datasets of Solar Radiation (formally, Global Horizontal Irradiance, GHI) at the surface are available for three streams:

Historical: This dataset is based on the ERA5 reanalysis and retrieved from the CDS. No bias adjustment has been applied. Averages for NUTS0 (country) and NUTS2 (sub-country) areas have
been computed.

Seasonal Forecasts: This dataset is currently available for ECMWF System 5, Météo-France ARPEGE System 7 and MetOffice GloSEA5 System 14. Seasonal Forecasts are retrieved from the CDS and are subsequently bias adjusted via quantile mapping. The forecast datasets are updated monthly when the raw forecast of each system is available. Averages for NUTS0 (country) are also provided.

Projections: This dataset is available for 11 regional climate model (RCM)/global climate model (GCM) combinations for the EURO-CORDEX project (Table 1, Appendix) and for two Representative Concentration Pathways (RCP4.5 and RCP8.5), with RCP2.6 also added for two of the RCM/GCM combinations. Historical forcing is used from 1979-2005, and RCP forcing from 2006-2100. The original EURO-CORDEX simulations are retrieved from the producers (some were already available on the Earth System Grid Federation (ESGF) portal) and are subsequently bias adjusted by applying the Cumulative Distribution Function transform (CDFt) method. Further processing involved
interpolation to a standard 0.25° latitude/longitude grid, and calculation of country and regional averages.

1.2. Units

Power per unit surface (W m-2)

Historical: data on a standard 0.25° latitude/longitude grid for the C3S Energy domain, as well as NUTS0 and NUTS2 averages. These will eventually be available via the C3S Energy/CDS demonstrator.

Seasonal Forecasts: the bias adjusted hindcast and forecast data will eventually be available via the C3S Energy/CDS demonstrator.

Projections: Bias-adjusted climate projection data on a standard 0.25° latitude/longitude grid are currently available from the ESGF portal: (select CORDEX-adjust as the Project, bias-adjusted-output as the Product, EUR-25 as the domain). They will eventually be available via the C3S Energy/CDS demonstrator.

1.4. Data format

Historical: Gridded historical data are available as NetCDF files. NUTS0 and NUTS2 are available as CSV files.

Seasonal Forecasts: Gridded seasonal forecast data are available as NetCDF files. NUTS0 are available as CSV files.

Projections: Gridded projection data are available as NetCDF files. NUTS0 and NUTS2 are available as CSV files

1.5. Keywords

Global Horizontal Irradiance (GHI)
This variable represents the incoming (downwelling) solar irradiance received on a horizontal plane at ground level over a period of time.

1.6. Contact

copernicus-support@ecmwf.int

2. Dataset coverage

2.1. Geographic area

The C3S Energy domain is: 26.5° N to 72.5° N by 22.0° W to 45.5° E

2.2. Temporal resolution

Historical: 1-hour time step as accumulated value. Averages for daily, monthly, seasonal (DJF, MAM, JJA, SON) and annual are also computed for NUTS0 and NUTS2 mean values.

Seasonal Forecasts: 24-hour time step as accumulated value. Averages for monthly, seasonal (DJF, MAM, JJA, SON) and annual are also computed for NUTS0 mean values.

Projections: 3-hour time step as accumulated value. Daily NUTS0 and NUTS2 averages are also computed.

2.3. Time period

Historical: 1979 to present (ca. 1 month behind real time); updated every month based on ERA5T data availability.

Seasonal Forecasts: The hindcasts cover the period 1993-2016 for the three models used by C3S Energy: ECMWF Sys5, Météo-France Sys7 and UK Met Office Sys14. ECMWF has all the month, MTFR SY07 currently covers October to April with the rest of the months to be completed by mid- May 2020 as this is a new system. METO SY14 ranges from June to April (notice that METO SY14 is a rolling release model, hindcast have to be computed each months). The forecasts updated have

been run every month from the first month of availability in the current version on the CDS:



Forecast availability

Forecast horizon


ECMWF Sys5

From January 2017

215 days (24-hourly time steps)


MTFR Sys7

From October 2019

211 days (24-hourly time steps)


METO Sys14

From June 2019

215 days (24-hourly time steps)


Projections: 1980 to 2098 (common period), with historical forcing to 2005, then RCP forcing.

2.4. Spatial resolution

Historical: 0.25° by 0.25° latitude/longitude. Data are also available as averages for more than 30 European countries and ca. 100 NUTS2 areas.

Seasonal Forecasts: 1° by 1° latitude/longitude and at country (NUTS0) scale. The underlying forecast systems run at different resolutions. Data are also available as averages for more than 30 European countries as NUTS0 areas.

Projections: 0.25° by 0.25° latitude/longitude. Data are also available as averages for more than 30 European countries and ca. 100 NUTS2 areas.

3. Usage

3.1. Citation(s)

Historical: ERA5

Seasonal Forecasts:

  1. ECMWF seasonal forecast system 5 technical description:
  2. Météo-France seasonal forecast system 7 technical description:
  3. Met Office technical description

Projections: original data come from CORDEX simulations available via the ESGF portal.

4. Lineage statement

4.1. Original data source

Historical: original gridded data come from the ERA5 Reanalysis

Seasonal Forecasts: original data is available from the C3S Climate Data Store. See here for further details of the seasonal forecast models used.

Projections: original data come from CORDEX simulations available via the ESGF portal.

4.2. Tools used in the production of indicators

Historical: data were retrieved and post-processed using python scripts.

Seasonal Forecasts: data were processed using standard open source python libraries, including numpy, scipy, matplotlib, and the SciTools packages iris and cartopy.

Projections: data were processed using standard open source programmes, including Fortran, R and CDO.

5. Data Quality

Historical: ERA5 data have been compared to previously used ERA-Interim for consistency.

Seasonal Forecasts: forecast skill, such as measured by anomaly correlation, is performed and will be provided via the C3S Energy demonstrator. Maps representing the bias for different time-periods for each system are also provided, as well as graphs comparing hindcast dataset before and after bias-correction.

Projections: a "health check" procedure was applied on bias adjusted data to verify:

  • that the bias adjusted projections had similar seasonal means over the reference periods; by mapping the absolute differences, it was found that they are an order of magnitude smaller than the variables variations;
  • that the changes between end of current and past centuries were similar with or without bias adjustment. We found that while the general patterns were quite similar, changes amplitudes can be modified by the CDFt method.

6. Appendix

Table 1:List of the 11 EURO-CORDEX simulations and the institutes that provided the data.

Short name

Driving GCM

RCM

Contact Institute

Period

HIIC

ECEARTH

HIRAM

Danish Meteorological Institute (DMI)

1951 - 2100

RAIC

ECEARTH

RACMO

Royal Netherlands National Meteorological Institute (KNMI)

1950 - 2100

RCIC

ECEARTH

RCA

Swedish Meteorological and Hydrological Institute (SMHI)

1970 - 2100

RAMO

HADGEM

RACMO

KNMI

1951 - 2098

RCMO

HADGEM

RCA

SMHI

1970 - 2098

ReMO

HADGEM

REGCM

International Centre for Theoretical Physics (ICTP)

1971 - 2099

WRIP

IPSL

WRF 381P

Institute Pierre Simon Laplace (IPSL)

1951 - 2100

RCMP

MPI

RCA

SMHI

1970 - 2100

CCMP

MPI

CCLM

Climate Limited-area Modelling Community

1950 - 2100

HINC

NORESM

HIRAM

Danish Meteorological Institute (DMI)

1951 - 2100

ALCN

CNRM

ALADIN63

CNRM (Centre National de Recherches Meteorologiques, Toulouse 31057, France)

1952 - 2100


This document has been produced in the context of the Copernicus Climate Change Service (C3S).

The activities leading to these results have been contracted by the European Centre for Medium-Range Weather Forecasts, operator of C3S on behalf of the European Union (Delegation Agreement signed on 11/11/2014 and Contribution Agreement signed on 22/07/2021). All information in this document is provided "as is" and no guarantee or warranty is given that the information is fit for any particular purpose.

The users thereof use the information at their sole risk and liability. For the avoidance of all doubt , the European Commission and the European Centre for Medium - Range Weather Forecasts have no liability in respect of this document, which is merely representing the author's view.

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