CERRA

Spatial domain for the CERRA mesoscale data in windPRO (we cover approx. 300km from the coastline). Image showing average wind speeds at 100m from 2012-2012 - taken from the https://www.windprospecting.com platform.

Introduction

The Copernicus Regional Reanalysis for Europe, CERRA, is a high-resolution regional reanalysis (RRA) for a pan-European domain. It is being provided by the European Copernicus programme, though a contract with the Swedish Meteorological and Hydrological Institute (SMHI) and with Meteo-France and the Norwegian Meteorological Institute as subcontractors. The model holds data at 5.5km resolution. CERRA is downscaling to is 5.5km resolution with initial conditions and boundary conditions provided from ERA5 reanalysis data.

CERRA is based on the HARMONIE-ALADIN data assimilation system, which for CERRA uses a 3D variational analysis (3D-VAR). Assimilation is run with 8 cycles per day at 00, 03, 06, 09, 12, 15, 18 and 21 UTC. While quite many of the mesoscale datasets used in wind energy industry are developed using the excellent WRF model, here the numerical weather prediction model used is HARMONIE–ALADIN. As such, the CERRA dataset provides a welcome and alternative modelling chain to what is commonly used for wind-energy modelling - providing valuable input for uncertainty modelling and second-opinion analyses. The HARMONIE-ALADIN model is developed by the ACCORD consortium - and used by many meteorological institutes in Europe.

Dataset Overview

• Content: Limited feature and spatial-domain subset of the CERRA mesoscale dataset
  (we provide about 973.000 nodes in a distance of approx. 300km from the coastlines).
• Spatial resolution: 5.5km
• Temporal resolution: Timestep 1 hour
• Coverage: See the map to the right
• Period: In windPRO: 20+ years of data from 1999-01-01 to 2021-12-31
  
• Update schedule: Unknown (but is is our expectation that data is updated with a 3-4 month of delay from current date, due to ERA5 availability and computational demands).
  We will update this dataset when more recent data becomes available.
  

Dataset Parameters

A total of 80 parameters are available from the CERRA mesoscale data-subset in windPRO.

Table: Overview of CERRA Dataset Parameters (5.5 km grid).

Parameter	Unit	Description	Type
time		UTC time stamp (YYYY-MM-DD HH:MM)
wSpeed.x	m/s	Wind speeds at different heights above ground (x). Heights (x): 15,50,75,100,150,200,300,500m	Instantaneous
wDir.x	deg	Wind directions at different heights above ground (x). Heights (x): 15,50,75,100,150,200,300,500m	Instantaneous
sqrtTKE.x	m/s	Wind speed given as standard deviation in m/s. Derived from the turbulent kinetic energy (TKE) at different heights above ground (x). Use with caution, and avoid use for site assessment and loads as variability is underestimated. Heights (x): 15,50,75,100,150,200,300,500m	Instantaneous
press.x	Pa	Pressure at different heights above ground (x). Heights (x): 15,50,75,100,150,200,300,500m	Instantaneous
temp.x	celcius	Temperature at different heights above ground (x). Heights (x): 15,50,75,100,150,200,300,500m	Instantaneous
rh.x	%	Relative humidity at different heights above ground (x). Heights (x): 15,50,75,100,150,200,300,500m	Instantaneous
cloudWater.x	mg/kg	Cloud water content at different heights above ground (x). Heights (x): 15,50,75,100,150,200,300,500m	Instantaneous
cloudIce.x	mg/kg	Cloud icing content at different heights above ground (x). Heights (x): 15,50,75,100,150,200,300,500m	Instantaneous
wSpeed.10	m/s	Wind speeds at 10m.	Instantaneous
wDir.10	deg	Wind direction at 10m.	Instantaneous
wGust.10	deg	Wind gust at 10m.	Instantaneous
temp.2	celcius	Temperatures at 2m	Instantaneous
rh.2	%	Relative humidity at 2m	Instantaneous
psfc	Pa	Pressure at site	Instantaneous
msl	Pa	Pressure at mean sea level	Instantaneous
z0	m	Rougnhess length	Instantaneous
totalCloudCover	%	Total cloud cover in atmosphere	1h Average
totPrecip	kg/m^2	Total Precipitation at surface	1h Accumulated
sensHeatFlux	w/m2	Sensible Heat Flux at surface	Instantaneous
momFluxU	N m**-2	Instantaneous northward turbulent surface stress	Instantaneous
momFluxV	N m**-2	Instantaneous eastward turbulent surface stress	Instantaneous
zust	m/s	U-star (friction velocity)	Instantaneous
ssr	w/m2	Surface net solar radiation	1h Accumulated
ssrc	w/m2	Surface net solar radiation, clear sky	1h Accumulated
ssrd	w/m2	Surface solar radiation downwards	1h Accumulated

License and Attribution

Source: 
Distribution through EMD and windPRO - EMD International A/S, 2022. License: NLOD 2.0 and CC-BY-40.

Required windPRO License and Modules

This dataset can be accessed from the most recent version of windPRO given that you hold an active service agreement and a license to the following modules:

• BASIS
• METEO

External Links and References

• CERRA Home Page - here
• CERRA Product User Guide (at ECMWF Wiki) - here
• ACCORD Consortium home-page (developers of HARMONIE-ALADIN model) - here