ERA5 reanalysis data: Difference between revisions

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Documentation of the ERA5 archive at GFI
GFI is building up an archive of ERA5 reanalysis data on the local linux system cyclone.hpc.uib.no. ERA5 supersedes the ERA-Interim reanalysis data, which ended in August 2019. More information about the ERA5 reanalysis data set is available [https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5 at ECMWF's ERA5 websites].
GFI is building up an archive of ERA5 reanalysis data on the local linux system cyclone.hpc.uib.no. ERA5 supersedes the ERA-Interim reanalysis data, which ended in August 2019. More information about the ERA5 reanalysis data set is available [https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5 at ECMWF's ERA5 websites].


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  /Data/gfi/share/era5
  /Data/gfi/share/era5


At GFI, we share the data format with the [https://iac.ethz.ch/group/atmospheric-dynamics.html Atmospheric Dynamics group at IAC, ETH Zürich, Switzerland]; the [https://www.imk-tro.kit.edu/7425.php LSDP group at Karlsruhe Institute of Technology, Germany]; and the [https://www.weizmann.ac.il/EPS/raveh-rubin/ Dynamical Meteorology Group, Weizmann Institute of Science, Rehovot, Israel]. The data are organised as follows
The data are organised as follows


  ml/        3-hourly data on a regular 0.5 deg lat-lon grid, with model-level and pressure level files (see below)
  ml/        3-hourly data on a regular 0.5 deg lat-lon grid, with model-level and pressure level files (see below)
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  sfc/        Single-level data following the format of ERA-interim.
  sfc/        Single-level data following the format of ERA-interim.
  slope/      Isentropic slope data and its tendencies following the format of ERA-interim
  slope/      Isentropic slope data and its tendencies following the format of ERA-interim
'''Data in ETH Zurich format'''


Data in the '''ml'''-folder are contained in subdirectories for each year and month:
Data in the '''ml'''-folder are contained in subdirectories for each year and month:
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  ml/yyyy/mm/[B|H|P|Z]yyyymmdd_hh
  ml/yyyy/mm/[B|H|P|Z]yyyymmdd_hh


where yyyy is the year, mm the two-digit month, dd the two-digit day, and hh the two-digit hours, and Bxxx, Hxxx, Pxxx, Zxxx are different file types, as described in the table below.
where yyyy is the year, mm the two-digit month, dd the two-digit day, and hh the two-digit hours, and Bxxx, Hxxx, Pxxx, Zxxx are different file types, as described in the table below. This format is the same used at the [https://iac.ethz.ch/group/atmospheric-dynamics.html Atmospheric Dynamics group at IAC, ETH Zürich, Switzerland]; the [https://www.imk-tro.kit.edu/7425.php LSDP group at Karlsruhe Institute of Technology, Germany]; and the [https://www.weizmann.ac.il/EPS/raveh-rubin/ Dynamical Meteorology Group, Weizmann Institute of Science, Rehovot, Israel].


Until now, the years 1999-2018 have been retrieved, the period will successively be extended back to 1979, and forward in time.
Until now, the years 1999-2018 have been retrieved. The period will successively be extended back to 1979, and forward in time.
 
Data in the '''pl_*''', '''sfc''', '''pv2''' and '''slope'''-folders is organised in one file per month, variable and level, for example:
 
pl/ea.[ans|for].YYYYMM.PLEV.VAR
 
This data is completely available for 1979-2020.


The data files contain the following variables:
The data files contain the following variables:


{| class="wikitable"
{| class="wikitable"
!colspan="6"|ERA5 data files
|+ '''ERA5 data files in ETH Zurich format format'''
|-
|-
|File name
|File name
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Note that the variables LSP, CP, SF, SSHF, SLHF, and BLH are derived as prognostic variables from the short-range forecast. Data valid at 00, 03, 06, 09 UTC are 06, 09, 12, 15 h forecast of the 18 UTC forecast of the previous day. Accordingly, data valid at 12, 15, 18, 21 UTC are 06, 09, 12, 15 h forecast of the 06 UTC forecast. The prognostic variables are accumulated over the previous 1 h.
Note that the variables LSP, CP, SF, SSHF, SLHF, and BLH are derived as prognostic variables from the short-range forecast. Data valid at 00, 03, 06, 09 UTC are 06, 09, 12, 15 h forecast of the 18 UTC forecast of the previous day. Accordingly, data valid at 12, 15, 18, 21 UTC are 06, 09, 12, 15 h forecast of the 06 UTC forecast. The prognostic variables are accumulated over the previous 1 h.


Please see [https://confluence.ecmwf.int//display/CKB/ERA5+data+documentation#ERA5datadocumentation-Parameterlistings ECMWF ERA5 data documentation] for parameter abbreviations.
Please see [https://confluence.ecmwf.int/display/CKB/ERA5%3A+data+documentation ECMWF ERA5 data documentation] for parameter abbreviations.
 
'''Data in Bergen format'''
 
Data in the '''sfc''','''slope''', '''pl''', '''pl_tendencies''' and '''pv2'''-folders is organised in one file per month, variable and level, for example:
 
pl/ea.[ans|for].yyyymm.plev.var
 
This data is completely available for 1979-2022. Specifically, we have the following data available
 
{| class="wikitable"
|+ '''ERA5 data files in Bergen format'''
|-
!colspan="1"|Folder
!colspan="1"|Data available (see [https://confluence.ecmwf.int/display/CKB/ERA5%3A+data+documentation] for parameter abbreviations)
!colspan="1"|Details
|-
| rowspan=2 | '''sfc/'''
|blh, msl, siconc, sp, sst, t2m, tcwv, u10, v10, viewvf, vinwf
|Instantaneous (ans)
|-
|cp, lsp, slhf, sshf, ssrd, ssr, strd, str, tsr, ttr
|Accumulated over previous 3 hours (for)
|-
|'''pl/'''
|t, q, z, u, v, w
|Instantaneous (ans)
|-
|'''pl_tendencies/'''
|mttlwrcs, mttlwr, mttpm, mttswrcs, mttswr
|Accumulated over previous 3 hours (for)
|-
|'''pv2/'''
|u, v, pt, pres
|Instantaneous (ans)
|}


The folder '''slope''' contains the following variables (see  [https://doi.org/10.1002/qj.2605 Papritz and Spengler, 2015], for further details on meaning of variables):
The folder '''slope/''' contains data deriving from the isentropic slope framework (see  [https://doi.org/10.1002/qj.2605 Papritz and Spengler, 2015], for more details):


{| class="wikitable"
{| class="wikitable"
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| -dz/dθ grad<sub>θ</sub>z /S · grad<sub>θ</sub> (dθ/dt)
| -dz/dθ grad<sub>θ</sub>z /S · grad<sub>θ</sub> (dθ/dt)
|m m<sup>-1</sup> s<sup>-1</sup>
|m m<sup>-1</sup> s<sup>-1</sup>
|Accumulated over 6-hour period centred on instantaneous time step
|Accumulated over 6-hour period centred on instantaneous time step (stored as instantaneous, ans)
|-
|-
|iadv
|iadv

Revision as of 09:15, 14 September 2023

GFI is building up an archive of ERA5 reanalysis data on the local linux system cyclone.hpc.uib.no. ERA5 supersedes the ERA-Interim reanalysis data, which ended in August 2019. More information about the ERA5 reanalysis data set is available at ECMWF's ERA5 websites.

The ERA5 data files are available in a CF-compatible netCDF format on cyclone.hpc.uib.no and other computers that mount the UiB linux system at 

/Data/gfi/share/era5

The data are organised as follows 

ml/        3-hourly data on a regular 0.5 deg lat-lon grid, with model-level and pressure level files (see below)
pl/        pressure level data following the format of ERA-interim.
pl_tendencies/        diabatic temperature tendencies on pressure levels, following the format of ERA-interim.
pv2/        Data on the PV2-surface following the format of ERA-interim.
sfc/        Single-level data following the format of ERA-interim.
slope/      Isentropic slope data and its tendencies following the format of ERA-interim

Data in ETH Zurich format

Data in the ml-folder are contained in subdirectories for each year and month: 

ml/yyyy/mm/[B|H|P|Z]yyyymmdd_hh

where yyyy is the year, mm the two-digit month, dd the two-digit day, and hh the two-digit hours, and Bxxx, Hxxx, Pxxx, Zxxx are different file types, as described in the table below. This format is the same used at the Atmospheric Dynamics group at IAC, ETH Zürich, Switzerland; the LSDP group at Karlsruhe Institute of Technology, Germany; and the Dynamical Meteorology Group, Weizmann Institute of Science, Rehovot, Israel.

Until now, the years 1999-2018 have been retrieved. The period will successively be extended back to 1979, and forward in time.

The data files contain the following variables:

ERA5 data files in ETH Zurich format format
File name Pyyyymmdd_hh Zyyyymmdd_hh Hyyyymmdd_hh Byyyymmdd_hh
Leveltype Model level Surface Pressure Pressure Surface
Variables T, Q, U, V, OMEGA, LWC, IWC, RWC, SWC LSP, CP, SF, SSHF, SLHF, BLH, TCC, U10M, V10M, MSL, PS, SSTK Z, T, Q, U, V Z PS, MSL, TCC, U10M, V10M, SSTK, CI, D2M, T2M, TCW, TCWV, VIWVD, E, MN2T, MX2T, SI, TTR, TTRC, WG10, LSP, CP, SF, SSHF, SLHF, BLH
Levels 40-137 - 900, 850, 800, 700, 600, 500, 400, 300, 250, 200, 100 hPa 1000, 975, 950, 925, 900, 875, 850, 825, 800, 775, 750, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 225, 200, 175, 150, 125, 100, 70, 50, 30, 20, 10, 70, 5, 3, 2, 1 hPa -
Times available 00, 03, 06, 09, 12, 15, 18, 21 UTC

Note that the variables LSP, CP, SF, SSHF, SLHF, and BLH are derived as prognostic variables from the short-range forecast. Data valid at 00, 03, 06, 09 UTC are 06, 09, 12, 15 h forecast of the 18 UTC forecast of the previous day. Accordingly, data valid at 12, 15, 18, 21 UTC are 06, 09, 12, 15 h forecast of the 06 UTC forecast. The prognostic variables are accumulated over the previous 1 h.

Please see ECMWF ERA5 data documentation for parameter abbreviations.

Data in Bergen format

Data in the sfc,slope, pl, pl_tendencies and pv2-folders is organised in one file per month, variable and level, for example: 

pl/ea.[ans|for].yyyymm.plev.var

This data is completely available for 1979-2022. Specifically, we have the following data available

ERA5 data files in Bergen format
Folder Data available (see [1] for parameter abbreviations) Details
sfc/ blh, msl, siconc, sp, sst, t2m, tcwv, u10, v10, viewvf, vinwf Instantaneous (ans)
cp, lsp, slhf, sshf, ssrd, ssr, strd, str, tsr, ttr Accumulated over previous 3 hours (for)
pl/ t, q, z, u, v, w Instantaneous (ans)
pl_tendencies/ mttlwrcs, mttlwr, mttpm, mttswrcs, mttswr Accumulated over previous 3 hours (for)
pv2/ u, v, pt, pres Instantaneous (ans)

The folder slope/ contains data deriving from the isentropic slope framework (see Papritz and Spengler, 2015, for more details):

Variable name Description Equation Units Notes
slope Slope of isentropic surface S = abs(gradθz) m m-1 Instantaneous
tilt Tendency in slope due to tilting gradθz /S · gradθ wid m m-1 s-1 Instantaneous
diab Tendency in slope due to diabatic heating -dz/dθ gradθz /S · gradθ (dθ/dt) m m-1 s-1 Accumulated over 6-hour period centred on instantaneous time step (stored as instantaneous, ans)
iadv Tendency in slope due to isentropic advection u · gradθS m m-1 s-1 Instantaneous
w_ci Cross isentropic vertical velocity w - wiu m s-1 Instantaneous
mask_slope Combination of masks from slope, diab and tilt - 0-1 Instantaneous

Conditions of use: When using the ERA5 data from this archive please make sure to reference "Copernicus Climate Change Service (C3S) (2017): ERA5: Fifth generation of ECMWF atmospheric reanalyses of the global climate. Copernicus Climate Change Service Climate Data Store (CDS), date of citation" and acknowledge "ECMWF for providing ERA-5 data“. Also, please acknowledge "Michael Sprenger (ETH Zurich)“ for the support in providing the data.

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