WFDE5 over land merged with ERA5 over the ocean (W5E5 v2.0)
Cite as
Stefan Lange, Christoph Menz, Stephanie Gleixner, Marco Cucchi, Graham P. Weedon, Alessandro Amici, Nicolas Bellouin, Hannes Müller Schmied, Hans Hersbach, Carlo Buontempo, Chiara Cagnazzo (2021): WFDE5 over land merged with ERA5 over the ocean (W5E5 v2.0). ISIMIP Repository. https://doi.org/10.48364/ISIMIP.342217
Metadata
- Title:
- WFDE5 over land merged with ERA5 over the ocean (W5E5 v2.0)
- Version:
- 2.0
- Creators:
-
- Stefan Lange 0000-0003-2102-8873
- Christoph Menz 0000-0001-5127-1554
- Stephanie Gleixner 0000-0002-0032-9696
- Marco Cucchi 0000-0002-1039-5312
- Graham P. Weedon 0000-0003-1262-9984
- Alessandro Amici 0000-0002-1778-4505
- Nicolas Bellouin 0000-0003-2109-9559
- Hannes Müller Schmied 0000-0001-5330-9923
- Hans Hersbach 0000-0001-5330-7071
- Carlo Buontempo 0000-0002-1874-5380
- Chiara Cagnazzo 0000-0002-2054-0448
- Contact person:
-
- Stefan Lange 0000-0003-2102-8873
For inquiries concerning this dataset, please contact info@isimip.org.
- Abstract:
-
The W5E5 dataset was compiled to support the bias adjustment of climate input data for the impact assessments carried out in phase 3b of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3b).
Version 2.0 of the W5E5 dataset covers the entire globe at 0.5° horizontal and daily temporal resolution from 1979 to 2019. Data sources of W5E5 are version 2.0 of WATCH Forcing Data methodology applied to ERA5 data (WFDE5; Weedon et al., 2014; Cucchi et al., 2020), ERA5 reanalysis data (Hersbach et al., 2020), and precipitation data from version 2.3 of the Global Precipitation Climatology Project (GPCP; Adler et al., 2003).
Variables (with short names and units in brackets) included in the W5E5 dataset are Near Surface Relative Humidity (hurs, %), Near Surface Specific Humidity (huss, kg kg-1), Precipitation (pr, kg m-2 s-1), Snowfall Flux (prsn, kg m-2 s-1), Surface Air Pressure (ps, Pa), Sea Level Pressure (psl, Pa), Surface Downwelling Longwave Radiation (rlds, W m-2), Surface Downwelling Shortwave Radiation (rsds, W m-2), Near Surface Wind Speed (sfcWind, m s-1), Near-Surface Air Temperature (tas, K), Daily Maximum Near Surface Air Temperature (tasmax, K), Daily Minimum Near Surface Air Temperature (tasmin, K), Surface Altitude (orog, m), and WFDE5-ERA5 Mask (mask, 1).
- Methods:
-
W5E5 is a merged dataset. It combines WFDE5 data over land with ERA5 data over the ocean. The mask used for the merge is included in the dataset. The mask is equal to 1 over land and equal to 0 over the ocean.
Over land, orog is the surface altitude used for elevation corrections in WFDE5. For all other variables already included in WFDE5 (huss, prsn, ps, rlds, rsds, sfcWind, tas), W5E5 data over land are equal to the daily mean values of the corresponding hourly WFDE5 data. W5E5 hurs over land is the daily mean of hourly hurs computed from hourly WFDE5 huss, ps, and tas using the equations of Buck (1981) as described in Buck (2010). W5E5 pr over land is the daily mean of the sum of hourly WFDE5 rainfall and snowfall. Note that W5E5 pr and prsn over land are based on WFDE5 rainfall and snowfall bias-adjusted using GPCC monthly precipitation totals. W5E5 psl over land is the daily mean of hourly psl computed from hourly WFDE5 orog, ps, and tas according to psl = ps * exp((g * orog) / (r * tas)), where g is gravity, and r is the specific gas constant of dry air. Lastly, W5E5 tasmax and tasmin over land are the daily maximum and minimum, respectively, of hourly WFDE5 tas.
Over the ocean, W5E5 data are based on temporally (from hourly to daily resolution) and spatially (from 0.25° to 0.5° horizontal resolution) aggregated ERA5 data. The spatial aggregation using first-order conservative remapping was always done after the temporal aggregation. For tasmax and tasmin, hourly tas values were aggregated to daily maximum and minimum values, respectively. For all other variables, hourly values were aggregated to daily mean values. Variables unavailable in ERA5 (huss, hurs, sfcWind, orog) were first derived from available variables at hourly temporal and 0.25° horizontal resolution and then aggregated like all other variables. huss and hurs were derived from Near Surface Dewpoint Temperature, ps, and tas using the equations of Buck (1981) as described in Buck (2010). sfcWind was derived from Eastward Near-Surface Wind (uas) and Northward Near-Surface Wind (vas) according to sfcWind = sqrt(uas * uas + vas * vas). orog is equal to surface geopotential divided by gravity. Lastly, pr and prsn were bias-adjusted such that monthly W5E5 precipitation totals match GPCP version 2.3 values over the ocean. Monthly rescaling factors used for this purpose were computed following the scale-selective rescaling procedure described by Balsamo et al. (2010).
Compared to W5E5 v1.0 (Lange, 2019), W5E5 v2.0 covers three additional years (2017-2019) and is based on WFDE5 v2.0 instead of WFDE5 v1.0 over land. Differences between the two WFDE5 versions are threefold. First, more recent versions of CRU TS (v4.04 compared to v4.03) and GPCC (v2020 compared to v2018) were used for bias adjustment in v2.0. Secondly, a bug that affected the computation of rsds was fixed in v2.0. This has reduced the annual global (land) mean rsds by about 2 W m-2. Lastly, the method used for the bias adjustment of the monthly mean diurnal temperature range was changed from a purely multiplicative method to a mixed multiplicative-additive method, see the product user guide of WFDE5 v2.0 (C3S, 2021). This update has reduced the intra-monthly variability of the diurnal temperature range for months and grid cells where this range is biased low in ERA5. As a result, the excessively high daily maximum temperature values that occurred in some months and grid cells in v1.0 do no longer occur in v2.0.
- Publication date:
- May 5, 2021
- Publisher:
- ISIMIP Repository
- Contributors:
-
- Matthias Büchner 0000-0002-1382-7424
- Jochen Klar 0000-0002-5883-4273
- Iliusi Vega del Valle 0000-0001-6902-2257
- Jan Volkholz
- Jacob Schewe 0000-0001-9455-4159
- Stefan Lange 0000-0003-2102-8873
- Franziska Piontek 0000-0003-4305-7552
- Christopher Reyer 0000-0003-1067-1492
- Matthias Mengel 0000-0001-6724-9685
- María del Rocío Rivas López 0000-0002-1984-3070
- Christian Otto 0000-0001-5500-6774
- Bjoern Soergel 0000-0002-2630-7081
- Anne Gädeke 0000-0003-0514-2908
- Martin Park 0000-0002-2467-3256
- Katja Frieler 0000-0003-4869-3013
- Potsdam Institute for Climate Impact Research 03e8s1d88
Here we list the persons and organizations, who are responsible for the collection, the management, and the publication of this dataset.
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References
- Adler, R. F., Huffman, G. J., Chang, A., Ferraro, R., Xie, P., Janowiak, J., Rudolf, B., Schneider, U., Curtis, S., Bolvin, D., Gruber, A., Susskind, J., Arkin, P., & Nelkin, E. (2003). The Version-2 Global Precipitation Climatology Project (GPCP) Monthly Precipitation Analysis (1979–Present), Journal of Hydrometeorology, 4(6), 1147-1167. https://doi.org/10.1175/1525-7541(2003)004%3C1147:TVGPCP%3E2.0.CO;2
- Balsamo, G, Boussetta, S, Lopez, P, Ferranti, L. (2010). Evaluation of ERA-Interim and ERA-Interim-GPCP-rescaled precipitation over the U.S.A. Retrieved from Shinfield Park, Reading → https://www.ecmwf.int/node/7926
- Buck, A. L. (1981). New Equations for Computing Vapor Pressure and Enhancement Factor, Journal of Applied Meteorology and Climatology, 20(12), 1527-1532. https://doi.org/10.1175/1520-0450(1981)020%3C1527:NEFCVP%3E2.0.CO;2
- Buck Research Instruments, LLC (2010): Model CR-1A Hygrometer with Autofill: Operating Manual. → http://www.hygrometers.com/wp-content/uploads/CR-1A-users-manual-2009-12.pdf
- M. Cucchi, G. P. Weedon, A. Amici, N. Bellouin, S. Lange, H. Müller Schmied, H. Hersbach, and C. Buontempo (2020) WFDE5: bias adjusted ERA5 reanalysis data for impact studies, Earth System Science Data https://doi.org/10.5194/essd-12-2097-2020
- Hersbach, H, Bell, B, Berrisford, P, et al. The ERA5 global reanalysis. Q J R Meteorol Soc. 2020; 146: 1999– 2049. https://doi.org/10.1002/qj.3803
- Lange (2019): WFDE5 over land merged with ERA5 over the ocean (W5E5). V. 1.0. GFZ Data Services. https://doi.org/10.5880/pik.2019.023
- Weedon, G.P., Gomes, S., Viterbo, P., Österle, H., Adam, J.C., Bellouin, N., Boucher, O., and Best, M. (2010) Watch - Water and Global Change: Technical Report No. 22: The Watch Forcing Data 1958-2001: A Meteorological Forcing Dataset for Land Surface and Hydrological Models. → https://publications.pik-potsdam.de/pubman/item/item_16400
- Weedon, G. P., Balsamo, G., Bellouin, N., Gomes, S., Best, M. J., and Viterbo, P. (2014) The WFDEI meteorological forcing data set: WATCH Forcing Data methodology applied to ERA-Interim reanalysis data, Water Resour. Res., 50, 7505–7514 https://doi.org/10.1002/2014WR015638
Source datasets
- C3S (2021): Near surface meteorological variables from 1979 to 2019 derived from bias-corrected reanalysis, CDS https://doi.org/10.24381/cds.20d54e34
- GPCP Version 2.3 Combined Precipitation Data Set (2020) → https://psl.noaa.gov/data/gridded/data.gpcp.html
- C3S (2018): ERA5 hourly data on single levels from 1979 to present, CDS https://doi.org/10.24381/cds.adbb2d47
Additional documentation
- ISIMIP3 simulation protocol → https://protocol.isimip.org
GCMD Keywords
- EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WATER VAPOR > WATER VAPOR INDICATORS > HUMIDITY
- EARTH SCIENCE > ATMOSPHERE > PRECIPITATION
- EARTH SCIENCE > ATMOSPHERE > PRECIPITATION > SOLID PRECIPITATION > SNOW
- EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC PRESSURE > SURFACE PRESSURE
- EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC RADIATION > LONGWAVE RADIATION
- EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC RADIATION > SHORTWAVE RADIATION
- EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > SURFACE WINDS
- EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC TEMPERATURE > SURFACE TEMPERATURE
- Global Change Master Directory (GCMD) Keywords are a hierarchical set of controlled vocabularies maintained by NASA (more information).
Issues and notes for datasets for this DOI
-
issue low won't fixTrend and variability artifacts in W5E5 due to observation gaps in CRU and GPCC #20
Affected datasets can still be used for simulations or research.
Stefan Lange created this issue on June 27, 2022. It was last updated on March 22, 2023.
Affected versions: all versions affected
Datasets for this DOI
-
hurs
_W5E5v2.0 9.5 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
huss
_W5E5v2.0 10.1 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
mask
_W5E5v2.0 46.6 KBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
orog
_W5E5v2.0 559.7 KBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
prsn
_W5E5v2.0 3.9 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
pr
_W5E5v2.0 9.2 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
psl
_W5E5v2.0 7.2 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
ps
_W5E5v2.0 8.0 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
rlds
_W5E5v2.0 9.3 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
rsds
_W5E5v2.0 9.5 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
sfcWind
_W5E5v2.0 10.6 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
tasmax
_W5E5v2.0 8.0 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
tasmin
_W5E5v2.0 8.0 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505 -
tas
_W5E5v2.0 7.9 GBISIMIP3a SecondaryInputData climate w5e5v2.0 historical 20210505