What are continuous wind measurements?
Continuous wind measurements are six 10-minute average values of wind speed (in m/s) and direction (in degrees clockwise from North) reported each hour. These measurements provide wind data for those users who need better temporal resolution in wind data, such as for micro-scale studies of air quality and sea breeze effects. Note that NDBC uses two types of payload-dependent wind averaging methods. Not all NDBC stations report continuous winds. These measurements are usually associated with C-MAN sites along the south Atlantic and in the Gulf of Mexico and at most deep-water moored buoys of the Gulf of Mexico, the Pacific, and the northern Atlantic.
The acquisition interval of the continuous wind measurements depends on the end-of-acquisition minute. For example, let's examine a buoy reporting continuous wind speed and direction measurements reported for hour 12 which has the end-of- acquisition minute set at minute 50. The first average speed (WS1) and direction (WD1) measurements will be the average of the speed and direction data, respectively, collected from 1140 to 1150. The second average speed and direction measurements will be the average of the speed and direction data, respectively, collected from 1130 to 1140. The sixth and final average speed (WS6) and direction (WD6) measurements will be the average of the speed and direction data, respectively, collected from 1050 to 1100.
For those payloads where the end-of-acquisition minute was minute 25, the time stamping of the six measurements is as follows. The first set of average speed and direction measurements for 1200 UTC are the average of the speed and direction data, respectively, collected from 1210 to 1220. The second set is the average of the measurements collected from 1200 to 1210. The sixth and final set is the average of the measurements taken from 1120 to 1130 UTC.
Other measurements reported by stations which report continuous winds are:
- hourly peak wind (MXGT)-- maximum 5-second peak during the entire hour ending at the acquisition time
- direction of the hourly peak wind (DIRMXGT)
- the minute that the hourly peak wind occurred (MXMIN)