Climatology

The Central Europe Refined Analysis (CER)

The Central Europe Refined Analysis version 2 (CER v2) is an atmospheric dataset based on the original CER v1 which was generated within the frameworks of the DFG-funded research unit "Urban Climate and Heat Stress in mid-latitude cities in view of climate change (UCaHS)" and the DFG-funded research project "Heat waves in Berlin, Germany - Urban climate modifications". The current version (CER v2) covers the period 1980-2022 and provides gridded two-dimensional fields of a multitude of atmospheric variables. The setup of the original CER v1 was based on a sensitivity study concerning planetary boundary layer schemes and urban canopy models by Jänicke et al. (2017). This setup was adapted using the Kain-Fritsch cumulus and the Thompson microphysics scheme.

Description

The CER v2 data set is generated by dynamical downscaling using the Weather Research and Forecasting model (WRF) version 4.3.3. This version uses ERA5 reanalysis forcing data provided by ECMWF. The domain setup for the original CER v1 (Figure 1) consisted of two-way nested domains with 30 km, 10 km, and 2 km grid spacing. These domains broadly cover Europe, Germany, and the Berlin-Brandenburg area, respectively. CER v2 uses the 10 km and 2 km domains. Results for this version are currently only available for the 2 km domain. The simulation strategy is cascaded two-way nesting with daily re-initialization, adopted from the High Asia Refined analysis (HAR, Maussion et al., 20112014). Each run starts at 12:00 UTC and contains 36 h, with the first 12 h as spin-up time. This strategy prevents the model from deviating too far from the forcing data and provides computational flexibility since daily runs are independent of each other and can be computed in parallel and any sequence.

Similar to HAR, the output of the simulations is post-processed into product files: one single file per variable and year at various temporal aggregation levels. A selection of variables is displayed in the table below. The data is currently available for the years 1980-2022.

Contacts

Office AB 3
Time Period1980 - 2022
Spatial Resolution30 km (only CER v1), 10 km (only CER v1), 2 km
Temporal Resolutionhourly (h), daily (d), monthly (m), yearly (y)
Data Formatcompressed NetCDF 4
Pressure Levels (hPa)1000, 975, 925, 900, 850, 800, 700, 650, 600, 550, 500, 450, 400, 350, 300, 250, 200, 150, 100, 75

Please refer to Jänicke et al. (2017), see Publication List at the bottom of this page, and provide a link to this webpage when using CER data.

List of Selected Variables

Examples (CER v1)

Variable NameVariable DescriptionTypeUnit
albedoAlbedo2d-
canwatCanopy water2dkg m-2
col_qliquidTotal column liquid water mixing ratio2dkg kg-1
col_qsolidTotal column solid water mixing ratio2dkg kg-1
col_qvaporTotal column vapor water mixing ratio2dkg kg-1
emissSurface emissivity2d-
etEvapotranspiration2dmm h-1
graupelGrid scale graupel2dmm h-1
grdflxGround Heat Flux2dW m-2
hailGrid scale hail (stepwise)2dmm h-1
hfxUpward Heat Flux at the Surface2dW m-2
intliquidfluxColumn integrated absolute liquid water flux2dkg m-1 s-1
intsolidfluxColumn integrated absolute solid water flux2dkg m-1 s-1
intvaporfluxColumn integrated absolute vapor water flux2dkg m-1 s-1
lhLatent Heat Flux at the Surface2dW m-2
lwdownDownward Long Wave Flux at Ground Surface2dW m-2
lwupUpward Long Wave Flux at Ground Surface2dW m-2
netradNet Radiation at Ground Surface2dW m-2
pblhPBL Height2dm
prcpTotal Precipitation2dmm h-1
prcp_cCumulus precipitation (stepwise)2dmm h-1
prcp_frFrozen precipitation (stepwise)2dmm h-1
prcp_ncGrid scale precipitation (stepwise)2dmm h-1
psfcSFC Pressure2dPa
q2Water Vapor Mixing Ratio at 2 m2dkg kg-1
qfxUpward moisture flux at the surface2dkm m-2 s-1
scldTotal column clouds2d-
scldfraSurface cloud fraction computed in a 50km radius FOV2d-
sfroffSurface runoff2dmm
slpSea Level Pressure2dhPa
snowSnow water equivalent2dkg m-2
snowfallGrid Scale Snow and Ice2dmm h-1
snowhPhysical snow depth2dm
sstSea Surface Temperature2dK
swdownDownward Short Wave Flux at Ground Surface2dW m-2
swupUpward Short Wave Flux at Ground Surface2dW m-2
t2Temperature at 2 m2dK
t2eta2 m temperature (extrapolated from the first two eta-levels)2dK
t2pbl2 m temperature (linear fit from pbl eta-levels)2dK
tskSurface Skin Temperature2dK
u10u at 10m2dm s-1
u_intliquidfluxColumn integrated zonal liquid water flux2dkg -1 s-1
u_intsolidfluxColumn integrated zonal solid water flux2dkg -1 s-1
u_intvaporfluxColumn integrated zonal water vapor flux2dkg -1 s-1
udroffUnderground runoff2dmm
ustu* in similarity theory2dm s-1
v_intliquidfluxColumn integrated meridional liquid water flux2dkg m-1 s-1
v_intsolidfluxColumn integrated meridional solid water flux2dkg m-1 s-1
v_intvaporfluxColumn integrated meridional water vapor flux2dkg m-1 s-1
v10v at 10m2dm s-1
w_intliquidfluxColumn integrated vertical liquid water flux2dkg m-1 s-1
w_intsolidfluxColumn integrated vertical solid water flux2dkg m-1 s-1
w_intvaporfluxColumn integrated vertical water vapor flux2dkg m-1 s-1
ws1010 m Wind Speed2dm s-1
3d Variables   
geopotentialFull Model Geopotential on Mass Points3d_pressm2 s-2
qliquidLiquid Water Mixing Ratio3d_presskg kg-1
qsolidSolid Water Mixing Ratio3d_presskg kg-1
qvaporWater Vapor Mixing Ratio3d_presskg kg-1
thetaPotential Temperature (theta)3d_pressK
ux-wind component3d_pressm s-1
uliquidfluxZonal liquid water flux3d_presskg m-2 s-1
usolidfluxZonal solid water flux3d_presskg m-2 s-1
uvaporfluxZonal water vapor flux3d_presskg m-2 s-1
vy-wind component3d_pressm s-1
vliquidfluxMeridional liquid water flux3d_presskg m-2 s-1
vsolidfluxMeridional solid water flux3d_presskg m-2 s-1
vvaporfluxMeridional water vapor flux3d_presskg m-2 s-1
wz-wind component3d_pressm s-1
wliquidfluxVertical liquid water flux3d_presskg m-2 s-1
wsolidfluxVertical solid water flux3d_presskg m-2 s-1
wvaporfluxVertical water vapor flux3d_presskg m-2 s-1
wsHorizontal wind speed on mass grid points3d_pressm s-1
cldfraCloud fraction3d_press-
pressureFull model pressure3d_presshpa
3d Soil variables   
smoisSoil moisture3d_soilm3 m-3
sh2oSoil liquid water3d_soilm3 m-3
smcrelRelative soil moisture3d_soil-
tslbSoil temperature3d_soilK
Static Variables   
hgtTerrain Heightstaticm
lu_indexLand Use Categorystatic-
cosalphaLocal cosine of map rotationstatic-
sinalphaLocal sine of map rotationstatic-
laiLeaf area indexstaticarea/area
eCoriolis cosine latitude termstatics-1
fCoriolis sine latitude termstatics-1
isltypDominant soil categorystatic-
ivgtypDominant vegetation categorystatic-
vegfraVegetation fractionstatic-
landmaskLand mask (1 for land, 0 for water)static-
mapfac_mMap scale factor on mass gridstatic-
mapfac_mxMap scale factor on mass grid, x directionstatic-
mapfac_myMap scale factor on mass grid, y directionstatic-

Data set Publications

2017

Jänicke, Britta; Meier, Fred; Fenner, Daniel; Fehrenbach, Ute; Holtmann, Achim; Scherer, Dieter
Urban-rural differences in near-surface air temperature as resolved by the Central Europe Refined analysis (CER): sensitivity to planetary boundary layer schemes and urban canopy models
International Journal of Climatology, 37 (4) :2063–2079
2017
ISSN: 08998418