ERA5 Gaussian Grid

Winds @ 100m

Introduction

ERA5 is a climate reanalysis dataset developed through the Copernicus Climate Change Service (C3S) and processed/delivered by ECMWF. The dataset is intended to replace the ERA-Interim dataset from ECMWF shortly after the ERA5 dataset is complete. The ERA5 dataset has several improvements compared to ERA-Interim:

1. Newer modelling system
2. More observations used in the assimilation
3. Higher spatial horizontal resolution (around 31 km compared to 79 km)
4. Higher spatial vertical resolution

More information is available in the windPRO Online Data release note from august 2017 here.

Resolution and Coverage

The model grid is a reduced gaussian grid (T620) which has a lateral resolution of 0.28125 (around 31 km).
It holds 1 hourly values.
Coverage is global for land-areas and coastal regions.
In windPRO, offshore coverage is expected up to cover and area of approximately 300 km from the coastline.

Data Availability

The release of the remaining parts of ERA5 is following the schedule from C3S and ECMWF (see the image to the right). The first batch of data covers the period of 2010-2016. It was released during summer 2017. Data from 2017+ and later with a monthly update cycle will be available from 2017-Q3/Q4. The batch of data from 1979-2009 is planned at 2018-Q2. The period dating back to 1950 will be available in 2019. EMD will release ERA5 in windPRO as soon as it is available.

Data Parameters

EMD extracts a focused subset of climate-parameters from the ERA5 datasets - this subset focuses on wind-energy modelling. When the data have been processed at EMD, then the following parameters are available from within the online-data services within windPRO.

Table: Overview of ERA5 Dataset Parameters.

Parameter	Unit	Description
time		UTC time stamp
wSpeed.10	m/s	Wind speed @ 10m
wDir.10	deg	Wind direction @ 10m
wSpeed.10n	m/s	Neutral wind speed @ 10m
wDir.10n	deg	Neutral wind direction @ 10m
wSpeed.100	m/s	Wind speed @ 100m
wDir.100	deg	Wind direction @ 100m
temperature.2	deg.celcius	Temperature @ 2m
dewPointTemp.2	deg.celcius	Dew point temperature @ 2m
rh.2	%	Relative humidity @ 2m
psfc	pa	Surface pressure
msl	pa	Mean sea-level pressure
sst	deg.celcius	Sea surface temperature
blh	m	Boundary layer height
tcc	%	Total cloud cover
fsr	m	Forecast surface roughness
tclw	kg/m2	Total column liquid water
tciw	kg/m2	Total column ice water
charnock	~	Charnock
heatFlux	w/m2	Instantaneous surface sensible heat flux
lowCc	%	Low cloud cover
medCc	%	Medium cloud cover
hiCc	%	High cloud cover
eastTss	N m**-2	Instantaneous eastward turbulent surface stress
northTss	N m**-2	Instantaneous northward turbulent surface stress
zust	m/s	Friction velocity
cbh	m	Cloud base height
uvbAcc	w/m2	Downward UV radiation at the surface
sshfAcc	w/m2	Surface sensible heat flux
ssrdAcc	w/m2	Surface solar radiation downwards
ssrAcc	w/m2	Surface net solar radiation
ssrcAcc	w/m2	Surface net solar radiation, clear sky
tisrAcc	w/m2	TOA incident solar radiation
fdirAcc	w/m2	Total sky direct solar radiation at surface
cdirAcc	w/m2	Clear-sky direct solar radiation at surface
ssrdcAcc	w/m2	Surface solar radiation downward clear-sky

External Links

• ECMWF - What is ERA5 - https://software.ecmwf.int/wiki/display/CKB/What+is+ERA5
• Copernicus Climate Change Service - ERA5 Page - https://climate.copernicus.eu/products/climate-reanalysis

Acknowledgement

Credits:

• ERA5 is being developed through the Copernicus Climate Change Service (C3S).
• Data processing and distribution for ERA5 is carried out by ECMWF.