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Alpena Met Data Archive

Air temperature (C), Wind Speed (m/s), Wind Direction (degrees from; 0=from N, 90=from E, etc.)

Averaging Methods:
Average air temperatures were calculated by arithmetic mean. The average wind speed is the simple scalar average of the raw 5-minute wind speed observations. Note, this technique will produce greater wind speeds than if a true vector average was used, but may be more representative over longer time scales with widely varying wind directions. A "unit-vector" average was used to calculate the average wind direction. In this technique, unity serves as the length of the vector, and the wind direction observations serve as the orientation of the vector. The u and v components are then calculated for each observation. Next, the average u and v components are computed and the average wind direction is derived from "arctan(u/v)".

Metadata file

See also NDBC Archive

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