NSA/METTOWER - Questionable NSA Met-tower wind data
The data analysis software for the NSA Met-tower system was upgraded at 2200 GMT on 8 SEP 1999. The upgrade included insertion of -99.99's for the wind vectors when the wind speed or direction were either missing or equal to 0. This resulted in incorrect vector averaged wind speed, wind direction, and standard deviation of wind direction. When this occurred, the vector-averaged wind speed and standard deviation of wind direction were often abnormally high and the vector-averaged wind direction was often approximately 225 deg. Starting at 2300 GMT on 25 OCT 99 missing wind data were replaced by the previous 1-min average and starting at 2200 GMT on 15 NOV 1999 the computed wind vectors were used whenever wind speeds or wind directions were 0.
All NSA Met-tower wind data taken during this period should be flagged as requiring scrutiny before acceptance.