==== ERA5 ====
^ ^ Description ^
| Short descripition | Global reanalysis based on IFS model and 4DVAR assimilation scheme developed at ECMWF.|
| Variables | 4 (out of 19) [[era5_3Dvars|3D variables]] at level (1000, 850, 700, 500, 300 hPa) and 75 + 2 (out of 83) [[era5_2Dvars|2D variables]]. \\ 79 + 2 variables out of the 102 available in DKRZ. \\ + 2: ''tasmaxx,tasminn'' do not originally appear in ECMWF|
| Spatial coverage | Global|
| Spatial resolution | 31km, provided in their original format of gaussian grid (n320, with 1280x640 points) |
| Temporal coverage | Jan.1940- Continuously* (see Updates) |
| Temporal resolution | hourly (78 vars), daily (8 vars), monthly (78 + 2 vars) \\ **daily**: max of hourly (''tasmax''), min of hourly (''tasmin''), average of hourly (rest of variables). For: ''pr,psl,rsds,ta,tas,tasmax,tasmin,ua,va,wsgsmax,zg'' \\ **monthly**: max of hourly (''tasmaxx, wsgmax10m''), min of hourly (''tasminn''), average of daily (''tasmax, tasmin''), average of hourly (rest of vars)|
| Conditions of Use |https://cds.climate.copernicus.eu/api/v2/terms/static/licence-to-use-copernicus-products.pdf |
| Documentation and \\ Evaluation | https://rmets.onlinelibrary.wiley.com/doi/10.1002/qj.3803|
|Citation and DOI | |
| Location of data in XCES |''/work/bm1159/XCES/data4xces/reanalysis/reanalysis/ECMWF/IFS/ERA5'' for all (''sf00, sf12, ml, pl'') |
| Miscellaneous | |
| Known Issues |https://confluence.ecmwf.int/display/CKB/ERA5%3A+data+documentation#ERA5:datadocumentation-Knownissues |
|Date of latest change | 29.01.2024 (ERA5 automatically updated to the current date every 2 days)|
|General information of ECMWF products at DKRZ |https://docs.dkrz.de/doc/dataservices/finding_and_accessing_data/era_data/index.html |
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== [29.01.2024] ==
ERA5 is being automatically updated every 2 days: the ERA5 cmorisation from ''/pool/data/ERA5'' at DKRZ and ingestion process to XCES is triggered every 2 days. That means that depending on the variable (forecast or analysis) there will be a delay between 3 and 5 days respect to the current date.
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=== Updates & Changes: ===
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== [19.11.2024] ==
Added potential evapotranspiration ''evspsblpot'' at ''1hr'' and ''mon'' time frequencies.
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== [17.05.2024] ==
Due to the ERA5.1 ''E1'' 2000-20006 patch, variables ''esn snm wsgsmax lspf uvb cape clwvi clivi prlsprof prcprof prsn bld hfss hfls zmla rsds rlds rss rls rst rlut tauu tauv evspsbl xgwdparam ygwdparam gwd tasmax tasmin mrro rstcs rlutcs rsscs rlscs rsdt pr prsnc prlsns'' had some missing hours in that interval:
* some had 2000-01-01 starting at 07 (instead of 00 or 01 depending on whether the variable was Instantaneous or accumulated),
* and 2006-12-31 ending at 23 instead of 2007-01-01 00 (again, depending on the type of variable).
This missing timesteps are no longer there, the gaps have been filled with ERA5 ''E5'' data, and the daily and monthly averages recalculated accordingly.
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== [22.04.2024] ==
Variables ''rsds, rlds, rss, pr, prsn'' had 1H 2024.03.22 information missing in original grb file. This has been amended and re-run.
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== [10.04.2024] ==
Back-extended 2 evapotraspiration variables ''esn'' and ''evspsbl'' (''1hr'', ''mon'') from 1940 till now
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== [23.01.2024] ==
Added two derived variables:
* ''hurs'': or ''Near-Surface Relative Humidity''. Derived from ''tdps'' and ''tas'' as the fraction of esat(tdps)/esat(tas) ''tpds'' and ''tas'' [[https://metview.readthedocs.io/en/latest/api/functions/saturation_vapour_pressure.html#saturation_vapour_pressure | saturation vapour pressures.]]
* ''sfcwind'': or ''Near-Surface Wind''. Derived from ''uas'' and ''vas'' as ''sqrt(uas**2 + vas**2)''
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== [05.01.2024] ==
* all the variables have been updated for the whole 2023 year. NOTE: be aware that from 2023.12.31 till around 2023.09.01 the data corresponds to the ''ET'' stream, as the ''E5'' has a delay of around 3 months.
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== [23.12.2023] ==
* **ERA5 rerun for 2000-2006 due to biases**: ALL currently available variables and time-frequencies have been replaced with the improved ERA5 re-run for the period 2000 to 2006 (''ERA5.1''). This measure superseeds the one taken on 21.10.2021 where only ''ta'' was replaced.
* ''cvl, cvh tvl tvh sic'' variables have been re-formatted as ''fx'' variables
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== [25.05.2023] ==
Bug in ''sf12'' variables solved: the recently processed ''sf12'' ''1hr'' variables had the first day duplicated at each file. The derived files (e.g. ''day'' and ''mon'' averages) have also been recomputed. This did not affect ''sf00'' nor ''pl00'' data. \\
**NOTES:** concerning ''sf12'' data exclusively:
- there is a problem with the source ''/pool/data/ERA5/ET/sf/fc/1H'' (hourly) grib files starting at 2023-04-18 (the files instead of going 00-23 go 07-06 next day, with a consequent gap of 7 hrs in April). Consequently 2023-04 and 2023-05 data have not been fully correctly processed. As soon as this is solved, 2023 year will be re-processed. This should not affect neither ''sf00''nor ''pl00'' data.
- there is no 1940-01-01 file, 1940 starts with 2nd of Jan. Consecuently the monthly average of 1940-01 is incomplete.
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== [14.04.2023] ==
**All** the variables have been updated to latest date: ''sf00'', ''sf12'' (including accumulated/max/min) and ''pl00''.
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== [03.04.2023] ==
All* the variables have been updated to latest date:
- All ''sf00'' and ''pl00'' have been updated until beginnining of March 2023.
- ''sf12'' variables have been updated for the whole 2022 year (until 2022.12.31 23:00). There is a problem with the time axis in the original GRIB files at the ''/pool/data'' for 2023 files, as soon as this is solved they will be updated to latest date as well.
A selected group of variables have been back-extended until 1940:
- ''pr tasmin tasmax wsgsmax tas uas vas psl tasminn tasmaxx''
- the following ''pl00'' variables are available until 1959.01.01: ''ua va zg''. But as soon as they are available at ''/pool/data'' they will also be back-extended until 1940 as well.
Additionally:
- ''wsgsmax'' is being offered at ''1hr, day, mon'' time frequencies now, instead of ''1hr, mon''.
- ''land_area_fraction'' (''sftlf'' ) variable (''time_frequency=fx'') has also beend added.
**WARNING**: due to the aforementioned problem ''sf12'' variables of ''Accumulated, Maximum, Minimum'' type, whose day is defined from 01:00 to 00:00 (of the following day) lack the first hour of 2023 (2023.01.01 00:00). Affected variables are ''bld esn evspsbl gwd hfls hfss lspf mrro pr prcprof prlsns prlsprof prsn prsnc rls rlscs rlut rlutcs rsds rsscs rss rst rstcs snm rlds tasmax tasmin tauu tauv rsdt uvb wsgsmax xgwdparam ygwdparam''.
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== [21.09.2022] ==
The attributes of 16 have been modified to be more conformant with CF/CMIP6 anotation, including variable name for 7 radiation variables. In 2 cases the sign of the variable has also been inverted.
^OLD_VAR^NEW_VAR^OLD_SNAME^NEW_SNAME^OLD_LNAME^NEW_LNAME^SIGN_CORRECTION^
|cl|cl|cloud_area_fraction_in_atmosphere_layer|cloud_area_fraction_in_atmosphere_layer|Cloud Area Fraction|Percentage Cloud Cover||
|clivi|clivi|atmosphere_cloud_ice_content|atmosphere_mass_content_of_cloud_ice|Ice Water Path|Ice Water Path||
|clt|clt|cloud_area_fraction|cloud_area_fraction|Total Cloud Fraction|Total Cloud Cover Percentage||
|clwvi|clwvi|atmosphere_cloud_condensed_water_content|atmosphere_mass_content_of_cloud_condensed_water|Condensed Water Path|Condensed Water Path||
|evspsbl|evspsbl|water_evaporation_flux|water_evaporation_flux|Evaporation|Evaporation Including Sublimation and Transpiration||
|prlsprof|prlsprof|large_scale_rainfall_flux|stratiform_rainfall_flux|Stratiform Rainfall Flux|Stratiform Rainfall Flux||
|prsn|prsn|snowfall_flux|snowfall_flux|Snowfall|Snowfall Flux||
|psl|psl|air_pressure_at_sea_level|air_pressure_at_mean_sea_level|Sea Level Pressure|Sea Level Pressure||
|rlds|rls|surface_downwelling_longwave_flux_in_air|surface_net_downward_longwave_flux|Surface Downwelling Longwave Radiation|Net Longwave Surface Radiation|-1|
|rldscs|rlscs|surface_downwelling_longwave_flux_in_air_assuming_clear_sky|surface_net_downward_longwave_flux_assuming_clear_sky|Surface Downwelling Clear-Sky Longwave Radiation|Surface Net Downward Longwave Flux Assuming Clear Sky|-1|
|rsdscs|rsscs|surface_downwelling_shortwave_flux_in_air_assuming_clear_sky|surface_net_downward_shortwave_flux_assuming_clear_sky|Surface Downwelling Clear-Sky Shortwave Radiation|Surface Net Downward Shortwave Flux Assuming Clear Sky||
|rsut|rst|toa_outgoing_shortwave_flux|toa_net_downward_shortwave_flux|TOA Outgoing Shortwave Radiation|TOA Net Downward Shortwave Flux||
|rsutcs|rstcs|toa_outgoing_shortwave_flux_assuming_clear_sky|toa_net_downward_shortwave_flux_assuming_clear_sky|TOA Outgoing Clear-Sky Shortwave Radiation|TOA Net Downward Shortwave Flux Assuming Clear Sky||
|sftlf|sftlf|land_area_fraction|land_area_fraction|Land Area Fraction|Percentage of the Grid Cell Occupied by Land (Including Lakes)||
|strd|rlds|downwelling_longwave_radiance_in_air|surface_downwelling_longwave_flux_in_air|Surface Thermal Radiation Downwards|Surface Downwelling Longwave Radiation||
|tisr|rsdt|toa_incident_solar_radiation|toa_incoming_shortwave_flux|TOA Incident Solar Radiation|TOA Incident Shortwave Radiation||
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== [11.07.2022] ==
All the variables have been updated from 1979.01.01 to 2022.02.28 (both included).
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== [21.10.2021] ==
The bias corrected data has been added: ''ta'' for years 2000-2006.
See below for more info.
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== [19.10.2021] ==
All the variables have been updated from 1979.01.01 to 2021.07.31 (both included).
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== [18.05.2021] ==
All the variables have been updated from 1979.01.01 to 2021.01.31 (both included).
All the variables have been moved under ''ERA5''. ''ERA5-FC'' no longer exists.
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== [26.04.2021] ==
The following variables were modified and reprocessed (also reflected when needed in the tables that follow the above links):
- ''var49'': ''wsgmax10m'' is now ''wsgsmax'' && ''A'' (accumulated) is now ''I'' (instantaneous).
- ''var169'': ''ssrd'' is now ''rsds'' && ''I'' is now ''A'' && ''long_name'' has been modified. That means that ''ssrd'' **no** longer exists in XCES.
- ''var176'': ''rsds'' is now ''rss'' && ''long_name'' modified.
- ''var180'' (''tauu''): ''I'' is now ''A''.
- ''var181'' (''tauv''): ''I'' is now ''A''.
- ''var195'' (''xgwdparam''): ''I'' is now ''A''.
- ''var196'' (''xgwdparam''): ''I'' is now ''A''.
- ''var201'' (''tasmax, tasmaxx''): ''A'' is now ''I''.
- ''var202'' (''tasmin, tasminn''): ''A'' is now ''I''.
Whether a variable is ''I'' or ''A'' affects the daily and monthly aggregation. The "day" is considered from 01-00 for ''A'' while from 00-23 for ''I''.
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=== Relevant info: ===
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== [Availability of 1950-1979 data] ==
ECMWF started to provide ERA5 data from earlier than 1979 (as of 2020-07-08). However, the present data (as offered by ECMWF via CDS) are preliminary, only (see [[https://confluence.ecmwf.int/pages/viewpage.action?pageId=202168048|here]]). DKRZ will copy these data as soon as they are available in a final version, which is supposed to be **around the end of 2021**. Once the data is there we will proceed to CMORize and ingest it to the system.
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== [ERA5 rerun for 2000-2006 due to biases] ==
Recently [[https://confluence.ecmwf.int/display/CUSF/ERA5.1%2C+a+re-run+of+ERA5+for+2000-2006+only%2C+now+available+through+CDS+API|the ECMWF announced a rerun of ERA5]] (referred as ERA5.1) for the 2000-2006 period to improve upon the cold bias in the lower stratosphere seen in ERA5 during this period (more info also [[https://cds.climate.copernicus.eu/cdsapp#!/dataset/derived-near-surface-meteorological-variables?tab=overview|here]]). Consequently ALL the variables having replaced by this stream.\\