Introduction
Here we document the ERA5 dataset, which, eventually, will cover the period January 1950 to near real time (NRT), though the first tranche of data to be released will cover the period 2010-2016.
ERA5 was produced using 4DVar data assimilation in CY41R2 of ECMWF’s Integrated Forecast System (IFS), with 137 hybrid sigma/pressure (model) levels in the vertical, with the top level at 0.01 hPa. Atmospheric data are available on these levels and they are also interpolated to 37 pressure, 16 potential temperature and 1 potential vorticity level(s). "Surface or single level" data are also available, containing 2D parameters such as precipitation, 2m temperature, top of atmosphere radiation and vertical integrals over the entire atmosphere. The IFS is coupled to a soil model, the parameters of which are also designated as surface parameters, and an ocean wave model.
The ERA5 dataset contains one (31 km) high resolution realisation (HRES) and a reduced resolution ten member ensemble (EDA). Generally, the data are available at a sub-daily and monthly frequency and consist of analyses and short (18 hour) forecasts, initialised twice daily from analyses at 06 and 18 UTC.
The data are archived in the ECMWF data archive (MARS) and can be retrieved using the ECMWF Public Dataset service via the WebAPI (Member State users can access the data using MARS directly, in the usual manner). In the future, the data will be available from the Climate Data Store (CDS).
The IFS and data assimilation
The model documentation for CY41R2 is at https://www.ecmwf.int/search/elibrary/part?solrsort=sort_label%20asc&title=part&secondary_title=41r1&f[0]=ts_biblio_year%3A2016.
The 4DVar data assimilation uses 12 hour windows from 09 UTC to 21 UTC and 21 UTC to 09 UTC (the following day).
Data organisation
The data can be accessed using the MARS keywords class=ea and expver=0001 (or ‘dataset’ : “era5” for the ECMWF Public Dataset service via the WebAPI). Subdivisions of the data are labelled using stream, type and levtype.
Stream:
- oper: HRES sub-daily
- wave: HRES waves sub-daily
- mnth: HRES synoptic monthly means
- moda: HRES monthly means of daily means
- wamo: HRES waves synoptic monthly means
- wamd: HRES waves monthly means of daily means
- enda: EDA sub-daily
- ewda: EDA waves sub-daily
- edmm: EDA synoptic monthly means
- edmo: EDA monthly means of daily means
- ewmm: EDA waves synoptic monthly means
- ewmo: EDA waves monthly means of daily means
Type:
- an: analyses
- fc: forecasts
- em: ensemble mean
- es: ensemble standard deviation
Levtype:
- sfc: surface or single level
- pl: pressure
- pt: potential temperature
- pv: potential vorticity
- ml: model
Spatial grid
The ERA5 HRES data has a resolution of 31km, 0.28125 degrees, and the EDA has a resolution of 62km, 0.5625 degrees. The data are available either as spectral coefficients with a triangular truncation of T639 (HRES) and T319 (EDA) or on a reduced Gaussian grid with a resolution of N320 (HRES) and N160 (EDA). These grids are so called "linear grids", sometimes referred to as TL639 (HRES) and TL319 (EDA).
The wave data are archived on a reduced latitude/longitude grid with a resolution of 0.36 degrees (HRES) and 1.0 degrees (EDA).
Temporal frequency
For sub-daily data for the HRES (stream=oper/wave) the analyses (type=an) are available hourly. The short forecasts, run from 06 and 18 UTC, have hourly steps from 0 to 18 hours. For the EDA, the sub-daily non-wave data (stream=enda) are available every 3 hours but the sub-daily wave data (stream=ewda) are available hourly.
Mean rates and accumulations
The accumulations in the short forecasts (from 06 and 18 UTC) of ERA5 are treated differently compared with those in ERA-Interim (where they were from the beginning of the forecast to the forecast step). In the short forecasts of ERA5 the accumulations are since the previous post processing (archiving), so for:
- HRES: accumulations are in the hour ending at the forecast step
- EDA: accumulations are in the 3 hours ending at the forecast step
Mean rate parameters in ERA5 are similar to accumulations except that the quantities are averaged, instead of accumulated, over the period, so the units include "per second".
Monthly means
Most parameters are also available as synoptic monthly means, for each particular time and forecast step, (stream=mnth/wamo/edmm/ewmm) and monthly means of daily means, for the month as a whole (stream=moda/wamd/edmo/ewmo). For the surface and single level parameters, there are some exceptions which are listed in Table 7.
Monthly means for analyses and instantaneous forecasts are created from data with a valid time in the month, between 00 and 23 UTC, which excludes the time 00 UTC on the first day of the following month. Monthly means for accumulations and mean rates are created from data with a forecast period falling within the month. For example, monthly means of daily means for accumulations and mean rates are created from contiguous data with forecast periods spanning from 00 UTC on the first day of the month to 00 UTC on the first day of the following month.
The data values for accumulations in stream=moda/edmo (monthly means of daily means) have been scaled to give units "per day". Thus, the hydrological parameters are in units of "m of water per day" and so they should be multiplied by 1000 to convert to kgm-2day-1 or mmday-1. Energy (turbulent and radiative) and momentum fluxes should be divided by 86400 seconds (24 hours) to convert to the commonly used units of Wm-2 and Nm-2, respectively.
Ensemble means and standard deviations
For the EDA sub-daily data (stream=enda/ewda), compared with HRES sub-daily data (stream=oper/wave), there are also ensemble means and standard deviations (type=em/es). Ensemble standard deviation is often referred to as ensemble spread. These two data types contain analysed parameters when step=0, otherwise they contain forecast parameters. However, only surface and pressure level data (levtype=sfc/pl) contain forecast steps beyond 3 hours. There are no monthly means for ensemble means and standard deviations.
Data format
Model level fields are in GRIB2 format. All other fields are in GRIB1, unless otherwise indicated.
Level listings
Pressure levels: 1000/975/950/925/900/875/850/825/800/775/750/700/650/600/550/500/450/400/350/300/250/225/200/175/150/125/100/70/50/30/20/10/7/5/3/2/1
Potential temperature levels: 265/275/285/300/315/320/330/350/370/395/430/475/530/600/700/850
Potential vorticity level: 2000
Model levels: 1/to/137, which are described at https://www.ecmwf.int/en/forecasts/documentation-and-support/137-model-levels.
Parameter listings
Tables 1-5 below describe the surface and single level parameters (levtype=sfc), Table 6 describes wave parameters, Table 7 describes the monthly mean exceptions for surface and single level and wave parameters and Tables 8-12 describe upper air parameters on various levtypes.
Table 1: stream=oper/enda/mnth/moda/edmm/edmo, levtype=sfc: surface and single level parameters: invariants
count | name | units | shortName | paramId | an | fc |
1 | Lake cover | (0 - 1) | cl | 26 | x | x |
2 | Lake depth | m | dl | 228007 | x | x |
3 | Low vegetation cover | (0 - 1) | cvl | 27 | x |
|
4 | High vegetation cover | (0 - 1) | cvh | 28 | x |
|
5 | Type of low vegetation | ~ | tvl | 29 | x |
|
6 | Type of high vegetation | ~ | tvh | 30 | x |
|
7 | Soil type | ~ | slt | 43 | x |
|
8 | Standard deviation of filtered subgrid orography | m | sdfor | 74 | x |
|
9 | Geopotential | m**2 s**-2 | z | 129 | x | x |
10 | Standard deviation of orography | ~ | sdor | 160 | x |
|
11 | Anisotropy of sub-gridscale orography | ~ | isor | 161 | x |
|
12 | Angle of sub-gridscale orography | radians | anor | 162 | x |
|
13 | Slope of sub-gridscale orography | ~ | slor | 163 | x |
|
14 | Land-sea mask | (0 - 1) | lsm | 172 | x | x |
Table 2: stream=oper/enda/mnth/moda/edmm/edmo, levtype=sfc: surface and single level parameters: instantaneous
count | name | units | shortName | paramId | an | fc |
1 | Convective inhibition | J kg**-1 | cin | 228001 | x | |
2 | Friction velocity | m s**-1 | zust | 228003 | x | |
3 | Lake mix-layer temperature | K | lmlt | 228008 | x | x |
4 | Lake mix-layer depth | m | lmld | 228009 | x | x |
5 | Lake bottom temperature | K | lblt | 228010 | x | x |
6 | Lake total layer temperature | K | ltlt | 228011 | x | x |
7 | Lake shape factor | dimensionless | lshf | 228012 | x | x |
8 | Lake ice temperature | K | lict | 228013 | x | x |
9 | Lake ice depth | m | licd | 228014 | x | x |
10 | UV visible albedo for direct radiation | (0 - 1) | aluvp | 15 | x | x |
11 | Minimum vertical gradient of refractivity inside trapping layer | m**-1 | dndzn | 228015 | x | |
12 | UV visible albedo for diffuse radiation | (0 - 1) | aluvd | 16 | x | x |
13 | Mean vertical gradient of refractivity inside trapping layer | m**-1 | dndza | 228016 | x | |
14 | Near IR albedo for direct radiation | (0 - 1) | alnip | 17 | x | x |
15 | Duct base height | m | dctb | 228017 | x | |
16 | Near IR albedo for diffuse radiation | (0 - 1) | alnid | 18 | x | x |
17 | Trapping layer base height | m | tplb | 228018 | x | |
18 | Trapping layer top height | m | tplt | 228019 | x | |
19 | Cloud base height | m | cbh | 228023 | x | |
20 | Zero degree level | m | deg0l | 228024 | x | |
21 | Instantaneous 10 metre wind gust | m s**-1 | i10fg | 228029 | x | |
22 | Sea-ice cover | (0 - 1) | ci | 31 | x | x |
23 | Snow albedo | (0 - 1) | asn | 32 | x | x |
24 | Snow density | kg m**-3 | rsn | 33 | x | x |
25 | Sea surface temperature | K | sst | 34 | x | x |
26 | Ice temperature layer 1 | K | istl1 | 35 | x | x |
27 | Ice temperature layer 2 | K | istl2 | 36 | x | x |
28 | Ice temperature layer 3 | K | istl3 | 37 | x | x |
29 | Ice temperature layer 4 | K | istl4 | 38 | x | x |
30 | Volumetric soil water layer 1 | m**3 m**-3 | swvl1 | 39 | x | x |
31 | Volumetric soil water layer 2 | m**3 m**-3 | swvl2 | 40 | x | x |
32 | Volumetric soil water layer 3 | m**3 m**-3 | swvl3 | 41 | x | x |
33 | Volumetric soil water layer 4 | m**3 m**-3 | swvl4 | 42 | x | x |
34 | Convective available potential energy | J kg**-1 | cape | 59 | x | x |
35 | Leaf area index, low vegetation | m**2 m**-2 | lai_lv | 66 | x | x |
36 | Leaf area index, high vegetation | m**2 m**-2 | lai_hv | 67 | x | x |
37 | Total column cloud liquid water | kg m**-2 | tclw | 78 | x | x |
38 | Total column cloud ice water | kg m**-2 | tciw | 79 | x | x |
39 | Total column supercooled liquid water | kg m**-2 | tcslw | 228088 | x | |
40 | Total column rain water | kg m**-2 | tcrw | 228089 | x | x |
41 | Total column snow water | kg m**-2 | tcsw | 228090 | x | x |
42 | Neutral wind at 10 m u-component | m s**-1 | u10n | 228131 | x | x |
43 | Neutral wind at 10 m v-component | m s**-1 | v10n | 228132 | x | x |
44 | Surface pressure | Pa | sp | 134 | x | x |
45 | Total column water | kg m**-2 | tcw | 136 | x | x |
46 | Total column water vapour | kg m**-2 | tcwv | 137 | x | x |
47 | Soil temperature level 1 | K | stl1 | 139 | x | x |
48 | Snow depth | m of water equivalent | sd | 141 | x | x |
49 | Charnock | ~ | chnk | 148 | x | x |
50 | Mean sea level pressure | Pa | msl | 151 | x | x |
51 | Boundary layer height | m | blh | 159 | x | x |
52 | Total cloud cover | (0 - 1) | tcc | 164 | x | x |
53 | 10 metre U wind component | m s**-1 | 10u | 165 | x | x |
54 | 10 metre V wind component | m s**-1 | 10v | 166 | x | x |
55 | 2 metre temperature | K | 2t | 167 | x | x |
56 | 2 metre dewpoint temperature | K | 2d | 168 | x | x |
57 | Soil temperature level 2 | K | stl2 | 170 | x | x |
58 | Soil temperature level 3 | K | stl3 | 183 | x | x |
59 | Low cloud cover | (0 - 1) | lcc | 186 | x | x |
60 | Medium cloud cover | (0 - 1) | mcc | 187 | x | x |
61 | High cloud cover | (0 - 1) | hcc | 188 | x | x |
62 | Skin reservoir content | m of water equivalent | src | 198 | x | x |
63 | Total column ozone | kg m**-2 | tco3 | 206 | x | x |
64 | Instantaneous large-scale surface precipitation fraction | (0 - 1) | ilspf | 228217 | x | |
65 | Convective rain rate | kg m**-2 s**-1 | crr | 228218 | x | |
66 | Large scale rain rate | kg m**-2 s**-1 | lsrr | 228219 | x | |
67 | Convective snowfall rate water equivalent | kg m**-2 s**-1 | csfr | 228220 | x | |
68 | Large scale snowfall rate water equivalent | kg m**-2 s**-1 | lssfr | 228221 | x | |
69 | Instantaneous eastward turbulent surface stress | N m**-2 | iews | 229 | x | x |
70 | Instantaneous northward turbulent surface stress | N m**-2 | inss | 230 | x | x |
71 | Instantaneous surface sensible heat flux | W m**-2 | ishf | 231 | x | x |
72 | Instantaneous moisture flux | kg m**-2 s**-1 | ie | 232 | x | x |
73 | Skin temperature | K | skt | 235 | x | x |
74 | Soil temperature level 4 | K | stl4 | 236 | x | x |
75 | Temperature of snow layer | K | tsn | 238 | x | x |
76 | Forecast albedo | (0 - 1) | fal | 243 | x | x |
77 | Forecast surface roughness | m | fsr | 244 | x | x |
78 | Forecast logarithm of surface roughness for heat | ~ | flsr | 245 | x | x |
79 | 100 metre U wind component | m s**-1 | 100u | 228246 | x | x |
80 | 100 metre V wind component | m s**-1 | 100v | 228247 | x | x |
81 | Precipitation type | code table (4.201) | ptype | 260015* | x | |
82 | K index | K | kx | 260121* | x | |
83 | Total totals index | K | totalx | 260123* | x |
*GRIB2 format
Table 3: stream=oper/enda/mnth/moda/edmm/edmo, levtype=sfc: surface and single level parameters: accumulations
count | name | units | shortName | paramId | an | fc |
1 | Large-scale precipitation fraction | s | lspf | 50 | x | |
2 | Downward UV radiation at the surface | J m**-2 | uvb | 57 | x | |
3 | Boundary layer dissipation | J m**-2 | bld | 145 | x | |
4 | Surface sensible heat flux | J m**-2 | sshf | 146 | x | |
5 | Surface latent heat flux | J m**-2 | slhf | 147 | x | |
6 | Surface solar radiation downwards | J m**-2 | ssrd | 169 | x | |
7 | Surface thermal radiation downwards | J m**-2 | strd | 175 | x | |
8 | Surface net solar radiation | J m**-2 | ssr | 176 | x | |
9 | Surface net thermal radiation | J m**-2 | str | 177 | x | |
10 | Top net solar radiation | J m**-2 | tsr | 178 | x | |
11 | Top net thermal radiation | J m**-2 | ttr | 179 | x | |
12 | Eastward turbulent surface stress | N m**-2 s | ewss | 180 | x | |
13 | Northward turbulent surface stress | N m**-2 s | nsss | 181 | x | |
14 | Eastward gravity wave surface stress | N m**-2 s | lgws | 195 | x | |
15 | Northward gravity wave surface stress | N m**-2 s | mgws | 196 | x | |
16 | Gravity wave dissipation | J m**-2 | gwd | 197 | x | |
17 | Top net solar radiation, clear sky | J m**-2 | tsrc | 208 | x | |
18 | Top net thermal radiation, clear sky | J m**-2 | ttrc | 209 | x | |
19 | Surface net solar radiation, clear sky | J m**-2 | ssrc | 210 | x | |
20 | Surface net thermal radiation, clear sky | J m**-2 | strc | 211 | x | |
21 | TOA incident solar radiation | J m**-2 | tisr | 212 | x | |
22 | Vertically integrated moisture divergence | kg m**-2 | vimd | 213 | x | |
23 | Total sky direct solar radiation at surface | J m**-2 | fdir | 228021 | x | |
24 | Clear-sky direct solar radiation at surface | J m**-2 | cdir | 228022 | x | |
25 | Surface solar radiation downward clear-sky | J m**-2 | ssrdc | 228129 | x | |
26 | Surface thermal radiation downward clear-sky | J m**-2 | strdc | 228130 | x | |
27 | Surface runoff | m | sro | 8 | x | |
28 | Sub-surface runoff | m | ssro | 9 | x | |
29 | Snow evaporation | m of water equivalent | es | 44 | x | |
30 | Snowmelt | m of water equivalent | smlt | 45 | x | |
31 | Large-scale precipitation | m | lsp | 142 | x | |
32 | Convective precipitation | m | cp | 143 | x | |
33 | Snowfall | m of water equivalent | sf | 144 | x | |
34 | Evaporation | m of water equivalent | e | 182 | x | |
35 | Runoff | m | ro | 205 | x | |
36 | Total precipitation | m | tp | 228 | x | |
37 | Convective snowfall | m of water equivalent | csf | 239 | x | |
38 | Large-scale snowfall | m of water equivalent | lsf | 240 | x | |
39 | Potential evaporation | m | pev | 228251 | x |
The data values for accumulations in stream=moda/edmo (monthly means of daily means) have been scaled to give units "per day". Thus, the hydrological parameters are in units of "m of water per day" and so they should be multiplied by 1000 to convert to kgm-2day-1 or mmday-1. Energy (turbulent and radiative) and momentum fluxes should be divided by 86400 seconds (24 hours) to convert to the commonly used units of Wm-2 and Nm-2, respectively.
Table 4: stream=oper/enda, levtype=sfc: surface and single level parameters: minimum/maximum
count | name | units | shortName | paramId | an | fc |
1 | 10 metre wind gust since previous post-processing | m s**-1 | 10fg | 49 | x | |
2 | Maximum temperature at 2 metres since previous post-processing | K | mx2t | 201 | x | |
3 | Minimum temperature at 2 metres since previous post-processing | K | mn2t | 202 | x | |
4 | Maximum total precipitation rate since previous post-processing | kg m**-2 s**-1 | mxtpr | 228226 | x | |
5 | Minimum total precipitation rate since previous post-processing | kg m**-2 s**-1 | mntpr | 228227 | x |
Table 5: stream=oper/enda/mnth/moda/edmm/edmo, levtype=sfc: surface and single level parameters: vertical integrals (not available for type=em/es)
count | name | units | shortName | paramId | an | fc |
1 | Vertical integral of mass of atmosphere | kg m**-2 | vima | 162053 | x | x |
2 | Vertical integral of temperature | K kg m**-2 | vit | 162054 | x | x |
3 | Vertical integral of kinetic energy | J m**-2 | vike | 162059 | x | x |
4 | Vertical integral of thermal energy | J m**-2 | vithe | 162060 | x | x |
5 | Vertical integral of potential+internal energy | J m**-2 | vipie | 162061 | x | x |
6 | Vertical integral of potential+internal+latent energy | J m**-2 | vipile | 162062 | x | x |
7 | Vertical integral of total energy | J m**-2 | vitoe | 162063 | x | x |
8 | Vertical integral of energy conversion | W m**-2 | viec | 162064 | x | x |
9 | Vertical integral of eastward mass flux | kg m**-1 s**-1 | vimae | 162065 | x | x |
10 | Vertical integral of northward mass flux | kg m**-1 s**-1 | viman | 162066 | x | x |
11 | Vertical integral of eastward kinetic energy flux | W m**-1 | vikee | 162067 | x | x |
12 | Vertical integral of northward kinetic energy flux | W m**-1 | viken | 162068 | x | x |
13 | Vertical integral of eastward heat flux | W m**-1 | vithee | 162069 | x | x |
14 | Vertical integral of northward heat flux | W m**-1 | vithen | 162070 | x | x |
15 | Vertical integral of eastward water vapour flux | kg m**-1 s**-1 | viwve | 162071 | x | x |
16 | Vertical integral of northward water vapour flux | kg m**-1 s**-1 | viwvn | 162072 | x | x |
17 | Vertical integral of eastward geopotential flux | W m**-1 | vige | 162073 | x | x |
18 | Vertical integral of northward geopotential flux | W m**-1 | vign | 162074 | x | x |
19 | Vertical integral of eastward total energy flux | W m**-1 | vitoee | 162075 | x | x |
20 | Vertical integral of northward total energy flux | W m**-1 | vitoen | 162076 | x | x |
21 | Vertical integral of eastward ozone flux | kg m**-1 s**-1 | vioze | 162077 | x | x |
22 | Vertical integral of northward ozone flux | kg m**-1 s**-1 | viozn | 162078 | x | x |
23 | Vertical integral of divergence of cloud liquid water flux | kg m**-2 s**-1 | vilwd | 162079 | x | x |
24 | Vertical integral of divergence of cloud frozen water flux | kg m**-2 s**-1 | viiwd | 162080 | x | x |
25 | Vertical integral of divergence of mass flux | kg m**-2 s**-1 | vimad | 162081 | x | x |
26 | Vertical integral of divergence of kinetic energy flux | W m**-2 | viked | 162082 | x | x |
27 | Vertical integral of divergence of thermal energy flux | W m**-2 | vithed | 162083 | x | x |
28 | Vertical integral of divergence of moisture flux | kg m**-2 s**-1 | viwvd | 162084 | x | x |
29 | Vertical integral of divergence of geopotential flux | W m**-2 | vigd | 162085 | x | x |
30 | Vertical integral of divergence of total energy flux | W m**-2 | vitoed | 162086 | x | x |
31 | Vertical integral of divergence of ozone flux | kg m**-2 s**-1 | viozd | 162087 | x | x |
32 | Vertical integral of eastward cloud liquid water flux | kg m**-1 s**-1 | vilwe | 162088 | x | x |
33 | Vertical integral of northward cloud liquid water flux | kg m**-1 s**-1 | vilwn | 162089 | x | x |
34 | Vertical integral of eastward cloud frozen water flux | kg m**-1 s**-1 | viiwe | 162090 | x | x |
35 | Vertical integral of northward cloud frozen water flux | kg m**-1 s**-1 | viiwn | 162091 | x | x |
36 | Vertical integral of mass tendency | kg m**-2 s**-1 | vimat | 162092 | x |
Table 6: stream=wave/ewda/wamo/wamd/ewmm/ewmo: wave parameters
count | name | units | shortName | paramId | an | fc |
1 | Significant wave height of first swell partition | m | swh1 | 140121 | x | x |
2 | Mean wave direction of first swell partition | degrees | mwd1 | 140122 | x | x |
3 | Mean wave period of first swell partition | s | mwp1 | 140123 | x | x |
4 | Significant wave height of second swell partition | m | swh2 | 140124 | x | x |
5 | Mean wave direction of second swell partition | degrees | mwd2 | 140125 | x | x |
6 | Mean wave period of second swell partition | s | mwp2 | 140126 | x | x |
7 | Significant wave height of third swell partition | m | swh3 | 140127 | x | x |
8 | Mean wave direction of third swell partition | degrees | mwd3 | 140128 | x | x |
9 | Mean wave period of third swell partition | s | mwp3 | 140129 | x | x |
10 | Wave Spectral Skewness | dimensionless | wss | 140207 | x | x |
11 | Free convective velocity over the oceans | m s**-1 | wstar | 140208 | x | x |
12 | Air density over the oceans | kg m**-3 | rhoao | 140209 | x | x |
13 | Normalized energy flux into waves | dimensionless | phiaw | 140211 | x | x |
14 | Normalized energy flux into ocean | dimensionless | phioc | 140212 | x | x |
15 | Normalized stress into ocean | dimensionless | tauoc | 140214 | x | x |
16 | U-component stokes drift | m s**-1 | ust | 140215 | x | x |
17 | V-component stokes drift | m s**-1 | vst | 140216 | x | x |
18 | Period corresponding to maximum individual wave height | s | tmax | 140217 | x | x |
19 | Maximum individual wave height | m | hmax | 140218 | x | x |
20 | Model bathymetry | m | wmb | 140219 | x | x |
21 | Mean wave period based on first moment | s | mp1 | 140220 | x | x |
22 | Mean wave period based on second moment | s | mp2 | 140221 | x | x |
23 | Wave spectral directional width | dimensionless | wdw | 140222 | x | x |
24 | Mean wave period based on first moment for wind waves | s | p1ww | 140223 | x | x |
25 | Mean wave period based on second moment for wind waves | s | p2ww | 140224 | x | x |
26 | Wave spectral directional width for wind waves | dimensionless | dwww | 140225 | x | x |
27 | Mean wave period based on first moment for swell | s | p1ps | 140226 | x | x |
28 | Mean wave period based on second moment for swell | s | p2ps | 140227 | x | x |
29 | Wave spectral directional width for swell | dimensionless | dwps | 140228 | x | x |
30 | Significant height of combined wind waves and swell | m | swh | 140229 | x | x |
31 | Mean wave direction | degrees | mwd | 140230 | x | x |
32 | Peak period of 1D spectra | s | pp1d | 140231 | x | x |
33 | Mean wave period | s | mwp | 140232 | x | x |
34 | Coefficient of drag with waves | dimensionless | cdww | 140233 | x | x |
35 | Significant height of wind waves | m | shww | 140234 | x | x |
36 | Mean direction of wind waves | degrees | mdww | 140235 | x | x |
37 | Mean period of wind waves | s | mpww | 140236 | x | x |
38 | Significant height of total swell | m | shts | 140237 | x | x |
39 | Mean direction of total swell | degrees | mdts | 140238 | x | x |
40 | Mean period of total swell | s | mpts | 140239 | x | x |
41 | Mean square slope of waves | dimensionless | msqs | 140244 | x | x |
42 | 10 metre wind speed | m s**-1 | wind | 140245 | x | x |
43 | Altimeter wave height | m | awh | 140246 | x | |
44 | Altimeter corrected wave height | m | acwh | 140247 | x | |
45 | Altimeter range relative correction | ~ | arrc | 140248 | x | |
46 | 10 metre wind direction | degrees | dwi | 140249 | x | x |
47 | Wave spectral kurtosis | dimensionless | wsk | 140252 | x | x |
48 | Benjamin-Feir index | dimensionless | bfi | 140253 | x | x |
49 | Wave spectral peakedness | dimensionless | wsp | 140254 | x | x |
50 | 2D wave spectra (single) | m**2 s radian**-1 | 2dfd | 140251* | x |
|
*for 30 frequencies and 24 directions
Table 7: stream=mnth/moda/edmm/edmo, levtype=sfc or wamo/wamd/ewmm/ewmo: monthly mean surface and single level and wave parameters: exceptions from Tables 1-6
count | name | units | shortName | paramId | an | fc |
1 | UV visible albedo for direct radiation | (0 - 1) | aluvp | 15 | x | no mean |
2 | UV visible albedo for diffuse radiation | (0 - 1) | aluvd | 16 | x | no mean |
3 | Near IR albedo for direct radiation | (0 - 1) | alnip | 17 | x | no mean |
4 | Near IR albedo for diffuse radiation | (0 - 1) | alnid | 18 | x | no mean |
5 | Magnitude of turbulent surface stress | N m**-2 s | magss | 48 |
| x |
6 | 10 metre wind gust since previous post-processing | m s**-1 | 10fg | 49 | no mean | |
7 | Maximum temperature at 2 metres since previous post-processing | K | mx2t | 201 | no mean | |
8 | Minimum temperature at 2 metres since previous post-processing | K | mn2t | 202 | no mean | |
9 | 10 metre wind speed | m s**-1 | 10si | 207 | x | x |
10 | Maximum total precipitation rate since previous post-processing | kg m**-2 s**-1 | mxtpr | 228226 | no mean | |
11 | Minimum total precipitation rate since previous post-processing | kg m**-2 s**-1 | mntpr | 228227 | no mean | |
12 | Altimeter wave height | m | awh | 140246 | no mean | |
13 | Altimeter corrected wave height | m | acwh | 140247 | no mean | |
14 | Altimeter range relative correction | ~ | arrc | 140248 | no mean | |
15 | 2D wave spectra (single) | m**2 s radian**-1 | 2dfd | 140251 | no mean |
|
Table 8: stream=oper/enda/mnth/moda/edmm/edmo, levtype=pl: pressure level parameters: instantaneous
count | name | units | shortName | paramId | an | fc |
1 | Potential vorticity | K m**2 kg**-1 s**-1 | pv | 60 | x | x |
2 | Specific rain water content | kg kg**-1 | crwc | 75 | x | x |
3 | Specific snow water content | kg kg**-1 | cswc | 76 | x | x |
4 | Geopotential | m**2 s**-2 | z | 129 | x | x |
5 | Temperature | K | t | 130 | x | x |
6 | U component of wind | m s**-1 | u | 131 | x | x |
7 | V component of wind | m s**-1 | v | 132 | x | x |
8 | Specific humidity | kg kg**-1 | q | 133 | x | x |
9 | Vertical velocity | Pa s**-1 | w | 135 | x | x |
10 | Vorticity (relative) | s**-1 | vo | 138 | x | x |
11 | Divergence | s**-1 | d | 155 | x | x |
12 | Relative humidity | % | r | 157 | x | x |
13 | Ozone mass mixing ratio | kg kg**-1 | o3 | 203 | x | x |
14 | Specific cloud liquid water content | kg kg**-1 | clwc | 246 | x | x |
15 | Specific cloud ice water content | kg kg**-1 | ciwc | 247 | x | x |
16 | Fraction of cloud cover | (0 - 1) | cc | 248 | x | x |
Table 9: stream=oper/enda/mnth/moda/edmm/edmo, levtype=pt: potential temperature level parameters: instantaneous
count | name | units | shortName | paramId | an | fc |
1 | Montgomery potential | m**2 s**-2 | mont | 53 | x | |
2 | Pressure | Pa | pres | 54 | x | |
3 | Potential vorticity | K m**2 kg**-1 s**-1 | pv | 60 | x | |
4 | U component of wind | m s**-1 | u | 131 | x | |
5 | V component of wind | m s**-1 | v | 132 | x | |
6 | Specific humidity | kg kg**-1 | q | 133 | x | |
7 | Vorticity (relative) | s**-1 | vo | 138 | x | |
8 | Divergence | s**-1 | d | 155 | x | |
9 | Ozone mass mixing ratio | kg kg**-1 | o3 | 203 | x |
Table 10: stream=oper/enda/mnth/moda/edmm/edmo, levtype=pv: potential vorticity level parameters: instantaneous
count | name | units | shortName | paramId | an | fc |
1 | Potential temperature | K | pt | 3 | x | |
2 | Pressure | Pa | pres | 54 | x | |
3 | Geopotential | m**2 s**-2 | z | 129 | x | |
4 | U component of wind | m s**-1 | u | 131 | x | |
5 | V component of wind | m s**-1 | v | 132 | x | |
6 | Specific humidity | kg kg**-1 | q | 133 | x | |
7 | Ozone mass mixing ratio | kg kg**-1 | o3 | 203 | x |
Table 11: stream=oper/enda/mnth/moda/edmm/edmo, levtype=ml: model level parameters: instantaneous
count | name | units | shortName | paramId | an | fc |
1 | Specific rain water content | kg kg**-1 | crwc | 75 | x | x |
2 | Specific snow water content | kg kg**-1 | cswc | 76 | x | x |
3 | Eta-coordinate vertical velocity | s**-1 | etadot | 77 | x | x |
4 | Geopotential* | m**2 s**-2 | z | 129 | x | x |
5 | Temperature | K | t | 130 | x | x |
6 | U component of wind | m s**-1 | u | 131 | x | x |
7 | V component of wind | m s**-1 | v | 132 | x | x |
8 | Specific humidity | kg kg**-1 | q | 133 | x | x |
9 | Vertical velocity | Pa s**-1 | w | 135 | x | x |
10 | Vorticity (relative) | s**-1 | vo | 138 | x | x |
11 | Logarithm of surface pressure* | ~ | lnsp | 152 | x | x |
12 | Divergence | s**-1 | d | 155 | x | x |
13 | Ozone mass mixing ratio | kg kg**-1 | o3 | 203 | x | x |
14 | Specific cloud liquid water content | kg kg**-1 | clwc | 246 | x | x |
15 | Specific cloud ice water content | kg kg**-1 | ciwc | 247 | x | x |
16 | Fraction of cloud cover | (0 - 1) | cc | 248 | x | x |
*Only archived on level=1.
Table 12: stream=oper/enda/mnth/moda/edmm/edmo, levtype=ml: model level parameters: mean rates
count | name | units | shortName | paramId | an | fc |
---|---|---|---|---|---|---|
1 | Mean temperature tendency due to short-wave radiation | K s**-1 | mttswr | 235001 | x | |
2 | Mean temperature tendency due to long-wave radiation | K s**-1 | mttlwr | 235002 | x | |
3 | Mean temperature tendency due to short-wave radiation, clear sky | K s**-1 | mttswrcs | 235003 | x | |
4 | Mean temperature tendency due to long-wave radiation, clear sky | K s**-1 | mttlwrcs | 235004 | x | |
5 | Mean temperature tendency due to parametrisations | K s**-1 | mttpm | 235005 | x | |
6 | Mean specific humidity tendency due to parametrisations | kg kg**-1 s**-1 | mqtpm | 235006 | x | |
7 | Mean eastward wind tendency due to parametrisations | m s**-2 | mutpm | 235007 | x | |
8 | Mean northward wind tendency due to parametrisations | m s**-2 | mvtpm | 235008 | x | |
9 | Mean updraught mass flux | kg m**-2 s**-1 | mumf | 235009 | x | |
10 | Mean downdraught mass flux | kg m**-2 s**-1 | mdmf | 235010 | x | |
11 | Mean updraught detrainment rate | kg m**-3 s**-1 | mudr | 235011 | x | |
12 | Mean downdraught detrainment rate | kg m**-3 s**-1 | mddr | 235012 | x | |
13 | Mean total precipitation flux | kg m**-2 s**-1 | mtpf | 235013 | x | |
14 | Mean turbulent diffusion coefficient for heat | m**2 s**-1 | mtdch | 235014 | x |
Observations
The observations (satellite and in-situ) used as input into ERA5 are listed below.
Satellite Data
Sensor | Satellite | Satellite agency | Data provider+ | Measurement |
---|---|---|---|---|
Satellite radiances (infrared and microwave) | ||||
AIRS | AQUA | NASA | NOAA | BT |
AMSR-2 | GCOM-W1* | JAXA | BT | |
AMSRE | AQUA* | JAXA | BT | |
AMSUA | NOAA-15/16/17/18/19, AQUA, METOP-A/B | NOAA,ESA,EUMETSAT | BT | |
AMSUB | NOAA-15/16/17 | NOAA | BT | |
ATMS | NPP | NOAA | BT | |
CRIS | NPP | NOAA | BT | |
HIRS | TIROS-N, NOAA-6 /7/8/9/11/14 to 19, METOP-A/B | NOAA | BT | |
IASI | METOP-A/B | EUMETSAT/ESA | EUMETSAT | BT |
IRAS | FY-3C | NRSCC | BT | |
JMI | GPM | NASA/JAXA | BT | |
MHS | NOAA-18/19, METOP-A/B | NOAA, EUMETSAT/ESA | BT | |
MSU | TIROS-N, NOAA-6 to 12, NOAA-14 | BT | ||
MWHS | FY-3-A/B | NRSCC | BT | |
MWHS2 | FY-3-C | CMA | BT | |
MWTS | FY-3A/B | NRSCC | BT | |
MWTS2 | FY-3C | CMA | BT | |
SSM/I | DMSP-11*/13*/14*/15* | US Navy | NOAA,CMSAF* | BT |
SSMIS | DMSP-16/17/18 | US Navy | NOAA | BT |
SSU | TIROS-N, NOAA-6/7/8/9/11/14 | NOAA | BT | |
TMI | TRMM | NASA/JAXA | BT | |
MVIRI | METEOSAT 5/7 | EUMETSAT/ESA | EUMETSAT | BT |
SEVIRI | METEOSAT-8*/9*/10 | EUMETSAT/ESA | EUMETSAT | BT |
GOES IMAGER | GOES-8/9/10/11/12/13/15 | NOAA | CIMMS,NESDIS | BT |
MTSAT IMAGER | MTSAT-1R/MTSAT-2 | JMA | BT | |
AHI | Himarawi-8 | JMA | BT | |
Satellite retrievals from radiance data | ||||
MVIRI | METEOSAT-2*/3*/4*/5*/7* | EUMETSAT/ESA | EUMETSAT | wind vector |
SEVIRI | METEOSAT-8*/9*/10 | EUMETSAT/ESA | EUMETSAT | wind vector |
GOES IMAGER | GOES-4-6/8*/9*/10*/11*/12*/13*/15* | NOAA | CIMMS*,NESDIS | wind vector |
GMS IMAGER | GMS-1*/2/3*/4*/5* | JMA | wind vector | |
MTSAT IMAGER | MTSAT-1R*/MTSAT2 | JMA | wind vector | |
AHI | Himarawi-8 | JMA | JMA | wind vector |
AVHRR | NOAA-7 /9/10/11/12/14 to 18, METOP-A | NOAA | CIMMS,EUMETSAT | wind vector |
MODIS | AQUA/TERRA | NASA | NESDIS,CIMMS | wind vector |
GOME | ERS-2* | ESA | Ozone | |
GOME-2 | METOP*-A/B | ESA/EUMETSAT | Ozone | |
MIPAS | ENVISAT* | ESA | Ozone | |
MLS | EOS-AURA* | NASA | Ozone | |
OMI | EOS-AURA* | NASA | Ozone | |
SBUV,SBUV-2 | NIMBUS-7*,NOAA*9/11/14/16/17/18/19 | NOAA | NASA | Ozone |
SCIAMACHY | ENVISAT* | ESA | Ozone | |
TOMS | NIMBUS-7*,METEOS-3,ADEOS-1*,EARTH PROBE | NASA | Ozone | |
Satellite GPS-Radio Occultation data | ||||
BlackJack | CHAMP,GRACE*-A/B,SAC-C* | DLR,NASA/DLR,NASA/COMAE | GFZ,UCAR* | Bending angle |
GRAS | METOP-A/B | EUMETSAT/ESA | EUMETSAT | Bending angle |
IGOR | TerraSAR-X*, TanDEM-X, COSMIC*-1 to 6 | NSPO/NOAA | GFZ,UCAR* | Bending angle |
Satellite scatterometer data | ||||
AMI | ERS-1,ERS-2 | ESA | Backscatter sigma0 | |
ASCAT | METOP-A/B* | EUMETSAT/ESA | EUMETSAT/TU Wien | Backscatter sigma0, soil moisture index |
OSCAT | OCEANSAT-2 | ISRO | KNMI | Backscatter sigma0 |
SEAWINDS | QUIKSCAT | NASA | NASA | Backscatter sigma0 |
Satellite Altimeter data | ||||
RA | ERS-1*/2* | ESA | Wave Height | |
RA-2 | ENVISAT* | ESA | Wave Height | |
Poseidon-2 | JASON-1* | CNES/NASA | CNES | Wave Height |
Poseidon-3 | JASON-2 | CNES/NOAA/NASA/EUMETSAT | NOAA/EUMETSAT | Wave Height |
SIRAL | CRYOSAT-2 | ESA | Wave Height | |
AltiKa | SARAL | CNES/ISRO | EUMETSAT | Wave Height |
* reprocessed dataset
+ when different than the satellite agency
In-situ data, provided by WMO WIS
Dataset name | Observation type | Measurement |
---|---|---|
SYNOP | Land station | Surface Pressure, Temperature, wind, humidity |
METAR | Land station | Surface Pressure, Temperature, wind,humidity |
DRIBU/DRIBU-BATHY/DRIBU-TESAC | Drifting buoys | 10m-wind, Surface Pressure |
SHIP | ship station | Surface Pressure, Temperature, wind, humidity |
Land/ship PILOT | Radiosondes | wind profiles |
American Wind Profiler | Radar | wind profiles |
European Wind Profiler | Radar | wind profiles |
Japanese Wind Profiler | Radar | wind profiles |
TEMP SHIP | Radiosondes | Temperature, wind, humidity profiles |
DROP Sonde | Aircraft-sondes | Temperature, wind profiles |
Land/Mobile TEMP | Radiosondes | Temperature profiles |
AIREP | Aircraft data | Temperature, wind profiles |
AMDAR | Aircraft data | Temperature, wind profiles |
ACARS | Aircraft data | Temperature, wind profiles, humidity |
WIGOS AMDAR | Aircraft data | Temperature, wind profiles |
Guidelines
The following advice is intended to help users understand particular features of the ERA5 data:
- Sea surface temperature and sea-ice cover (see Table 2 above) are available at the usual times, eg hourly for the HRES, but their content is only updated once daily.
Known issues
At the time of writing (2017-07) we are aware of these issues with ERA5:
ERA5 shows too strong tropical jet in the mesosphere
ERA5 has poor fit to radiosonde temperatures in the lower stratosphere indicating some cold bias
Although small values of ensemble spread correctly mark more confident estimates than large values, numerical values are over confident
- The Potential Evapotranspiration field (pev, parameter Id 228251) is largely underestimated over deserts and high-forested areas. This is due to a bug in the code that does not allow transpiration in case no low vegetation type is present.
This list will be updated as we become aware of further issues in ERA5.
How to cite ERA5
Please acknowledge the use of ERA5 as stated in the Copernicus C3S/CAMS License agreement:
"Where the Licensee communicates to the public or distributes or publishes C3S Information, the Licensee shall inform the recipients of the source of that information by using the following or any similar notice:
Where the Licensee makes or contributes to a publication or distribution containing adapted or modified CAMS Information, the Licensee shall provide the following or any similar notice:
Any such publication or distribution shall state that "neither the European Commission nor ECMWF is responsible for any use that may be made of the information it contains."
References
ERA5 references are available from the ECMWF e-Library.
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