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10/30, twh. I recalculated the offset using data from Sept 30 through 12:00 Oct 30 and set the minimum speed equal to 10 m/s. The result is Dir.10m - dir.3m = 0.2 +/- 0.8 degree, so need to subtract another 0.2 degrees or add 226.8 degrees to the 2D wind direction data.
At FLR, the 2D sonic was pointed nominally north, but must be off by 180 degrees. The median value of Dir.10m + 180 - dir.3m = 6.6 +/- 5 deg. Thus need to add 180 - 6.6 = 173.4 deg to 2D wind direction data.
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