Ja. Harlan et Tm. Georges, AN EMPIRICAL RELATION BETWEEN OCEAN-SURFACE WIND DIRECTION AND THE BRAGG LINE RATIO OF HF RADAR SEA ECHO SPECTRA, J GEO RES-O, 99(C4), 1994, pp. 7971-7978
Twelve days of tests with six U.S. Air Force OTH-B over-the-horizon ra
dars produced a large surface wind direction data set covering much of
the North Atlantic and Pacific oceans. We compare wind directions der
ived from the sea echo Bragg line ratio with concurrent in situ measur
ements made by ships and buoys and with the National Meteorological Ce
nter (NMC) Global Data Assimilation System model. Using 1900 such comp
arisons, we derive an empirical model for the dependence of surface wi
nd direction on the Bragg line ratio of HF radar sea echoes. The rms d
ifference between the empirical model and the combined NMC and in situ
data is about 33-degrees. When only very high quality radar data are
used, the rms difference between the radar and buoy measurements alone
is 24-degrees. The pattern of surface streamlines derived from 1 day'
s radar measurements over the northeastern Pacific Ocean closely match
es that derived from the NMC model.