NORA3

Spatial domain for the NORA3 mesoscale data in windPRO (we cover approx. 300km from the coastline). Image showing average wind speeds from 2007-2021 - taken from the https://www.windprospecting.com platform.

Full domain for the NORA3 hindcast data. Image showing temperature in degrees Kelvin on 2021-12-31.

Introduction

The Norwegian Reanalysis, NORA3, is a high resolution hindcast dataset provided by the Norwegian Meteorological Institute. The model holds data at 3km resolution and covers significant on- and offshore areas around the Baltic Sea, North Sea, the Norwegian Sea and the Barents Sea. NORA3 is downscaling to the 3km resolution with initial conditions and boundary conditions provided from ERA5 reanalysis data. However, also a surface analysis is also made in order to further refine initial condition at each integration cycle. This is done by assimilating meteorological data from SYNOP and METAR stations, ships and buoys from the MARS database. While some of the mesoscale datasets used in wind energy industry is calculated using the excellent WRF model, here the numerical weather prediction model used is HARMONIE–AROME in its release "Cy 40h1.2". As such, the NORA3 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-AROME model is developed and used by many European meteorological institutes.

Dataset Overview

• Content: Limited feature and spatial-domain subset of the NORA3 mesoscale dataset
  (we provide about 760.000 nodes in a distance of approx. 300km from the coastlines).
• Spatial resolution: 3km
• 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
  (back to 1984 from Norwegian Meteorological Institute)
• Update schedule: Unknown (but expect data to be 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 from the Norwegian Meteorological Institute.
  

Usage Notes

1. I am interested in other parameters and other areas. Where can I get those? The data is freely available from the thredds server at the Norwegian Meteorological Institute (https://thredds.met.no/thredds/catalog.html).
2. How can I get turbulence intensities from the NORA3 data? This parameter is not available - but it may be possible to come up with an estimate by using the gust-value provided (we have not tried this - yet).
3. I am already using EMD-WRF Europe+ wind speed data. How does NORA3 perform in comparison? In general, the average wind speeds are higher in NORA3 than for EMD-WRF Europe+, with largest differences found over land. Initially, we have made a map with 500 random points to check on different parameters, see these maps:
   1. Difference in 100m average wind speed - here
   2. Difference (MAE) in 100m winds - here
   3. R2 in 100m instantaneous winds 2019-2020 - here
4. How do I find more on model details and model performance? See the external references below. Comprehensive model documentation and validation on offshore wind data is available.

Dataset Parameters

A total of 21 parameters are available from the NORA3 mesoscale data-subset in windPRO. Wind speeds and directions are available in 6 heights from 10m to 500m agl.

Table: Overview of NORA3 Dataset Parameters in windPRO (3km grid).

Parameter(s)	Description	Unit
time	UTC time stamp	YYYY-MM-DD HH:MM
temp.2m	Temperature in 2m height	degC
rh.2m	Relative humidity in 2m height	%
press.2m	Surface air pressure	Pa
gust.10m	Wind gust (maximum wind) in 10m agl	m/s
ws.10m, ws.20m, ws.50m, ws.100m, ws.250m, ws.500m	Wind speed in 10m, 20m, 50m, 100m, 250m and 500m agl	m/s
wdir.10m, wdir.20m, wdir.50m, wdir.100m, wdir.250m, wdir.500m	Wind direction in 10m, 20m, 50m, 100m, 250m and 500m agl	deg
precipAcc	Accumulated total precipitation	kg/m2/h
snowAcc	Total accumulated solid precipitation (snow+graupel+hail)	kg/m2/h
lwcss	Snow Water Equivivalent (SWE)	kg/m2/h
PBL	Planetary boundary layer height	m

License and Attribution

This dataset is a subset of the NORA3 mesoscale dataset - this dataset is freely available from the Norwegian Meteorological Institute, that has been released under the Norwegian License for Open Government Data (NLOD) 2.0 and the Creative Commons By Attribution 4.0 license (CC-BY-40) - https://data.norge.no/nlod/en/2.0/ and https://creativecommons.org/licenses/by/4.0/. As a part of the license conditions, the data-owner requires an attribution, such as:

Source: 
NORA3 data obtained from the Norwegian Meteorological Institute. 
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

• Norwegian Meteorological Institute - here
• NORA3 - thredds server at the Norwegian Meteorological Instutute - here
• NORA3 Model Description Publication by Haakenstad et al + in Journal of Applied Meteorology and Climatology - here
• NORA3 Validation Paper by Solbrekke, Sorteberg & Haakenstad - in Wind Energy Science - here

Acknowledgement and Credits

1. Credits and Acknowledgement: The Norwegian Meteorological Institute and the Norwegian public for the release of the NORA3 hindcast dataset as a free and open dataset.