Columns wind$x and wind$y are location, while
wind$u is the wind speed, in m/s.
source
The data are taken from Figure 5 of Koch et al. (1983).
References
S. E. Koch and M. DesJardins and P. J. Kocin, 1983. ``An
interactive Barnes objective map anlaysis scheme for use with satellite
and conventional data,'' J. Climate Appl. Met., vol 22,
p. 1487-1503.
