Gridded NORA3 data: automated and remote data extraction

Matlab script to read the NORA3 atmosphere hindcast and interpolate the mean wind speed profiles

Gridded NORA3 data: automated and remote data extraction

Summary

The NORA3 atmosphere hindcast data are remotely accessed using the OPeNDAP framework and the THREDDS Data Server of the Norwegian Meteorological Institute [1]. The data can be extracted for multiple latitudes and longitudes and stored in a gridded format. Atmospheric data are retrieved for seven different heights, from 10 m to 750 m above the surface. The mean wind speed profile can be interpolated using a non-linear scheme based on the Deaves and Harris model [2,3]. Above the ocean, sea roughness is modeled using the Charnock relation. A summary of the NORA3 data and their potential is available in [4]. This code was used to extract the data used in [5].

The getNORA3_subset function specifically accesses subsets of the NORA3 data (monthly storage), increasing data collection by a factor of x10 or more. However, these subsets do not contain profiles of temperature.

Content

The present submission contains:

• getNORA3.m: A function that imports the NORA3 hindcast from [1].
• getNORA3_subset.m: A function accessing subsets of NORA3 for enhanced data collection. Note: This subset does not include temperature profiles.
• getz0_charnock.m: A function estimating sea surface roughness using Charnock's equation and the logarithmic profile of the mean wind speed.
• interpU.m: A function interpolating the mean wind speed using The Deaves and Harris model [2,3].
• world.mat: A data file containing the coastline of countries (used for visualization purposes only).
• Documentation.mlx: A Matlab LiveScript illustrating how these functions can be used.
• Documentation2.mlx: A second Matlab LiveScript illustrating how these functions can be used.
• Documentation3-subset.mlx: A third Matlab LiveScript illustrating getNORA3_subset works. Note that the surface temperature seems a little different here.

Any comments, questions, or suggestions are welcome.

References

[1] https://thredds.met.no

[2] Harris, R. I., & Deaves, D. M. (1980, November). The structure of strong winds, wind engineering in the eighties. In Proc. CIRIA Conf.

[3] ESDU. (1985). ESDU 85020-Characteristics of atmospheric turbulence near the ground. Part II: single point data for strong winds (neutral atmosphere).

[4] Solbrekke, I. M., Sorteberg, A., & Haakenstad, H. (2021). Norwegian hindcast archive (NORA3)–A validation of offshore wind resources in the North Sea and Norwegian Sea. Wind Energy Science Discussions, 1-31.

[5] Cheynet, E., Solbrekke, I. M., Diezel, J. M., & Reuder, J. A one-year comparison of new wind atlases over the North Sea. Journal of Physics: Conference Series 2362 (1), 012009

Example