Wind Rose
Wind speed and wind direction are deterministically reconstructed from the ERA5 10u and 10v components.
Wind direction is grouped into angular sectors.
Available sector resolutions are:
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12 sectors
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16 sectors
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24 sectors
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36 sectors
Wind speed is grouped into classification schemes defined as:
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Calm + 5 classes + open maximum
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Calm + 6 classes + open maximum
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Calm + 7 classes + open maximum
The active configuration is selected in the Analyze GRIB tab.
Default values may be defined in Settings → Defaults.
All frequencies are computed dynamically on-the-fly using the validated annual dataset.
Interpretation
Each sector represents a directional interval.
Within each sector:
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The radial extent represents the total frequency of wind from that direction.
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The stacked colored segments represent the contribution of each wind speed class.
Values are expressed as percentages of valid hourly observations within the main analysis year.
Calm conditions (wind speed below the defined threshold) are handled as a separate class and are not assigned to any directional sector.
Data Scope
The Wind Rose:
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Uses only the complete main analysis year.
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Excludes any extra records outside the annual boundaries.
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Is based exclusively on reconstructed wind speed and direction.
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Does not apply spatial or temporal interpolation.
Relation to Other Outputs
The Wind Rose is numerically equivalent to the Direction × Speed Frequency Table, which provides the same information in tabular form.