Three Hourly Data Summaries
The data set for each AWS unit for the month is scanned to pick out the
nearest observation within one hour of the UTC hours 00, 03, 06, 09, 12, 15,
18, and 21 to produce the three hourly data set. If valid data are not
available within the three hourly time interval, then the entry is left blank
to indicate missing data. The means, standard deviations, resultant wind
speed and direction, the distribution of temperature, and wind speed with wind
direction are determined from the three hourly observations and are presented
as a monthly summary at the bottom of each page. A wind direction value of
zero indicates a wind speed less than 0.50 m s-1. North is indicated by a
value of 360 degrees. The maximum and minimum values are taken from the
complete data set, not the three hourly data set. The appropriate monthly
data from the three hourly data set are used for the monthly summaries
presented in 4.1. In the presence of sunlight the air temperatures are
questionable if the wind speed is less than 1 m s-1. These summaries are
available by anonymous FTP (see Section 8). If you are unable to access the
Internet, we will send the information either on diskettes or paper. Please
contact us for further information (our postal address is at end of Section 8).