R. Crago et al., SATELLITE-DERIVED SURFACE TEMPERATURES WITH BOUNDARY-LAYER TEMPERATURES AND GEOSTROPHIC WINDS TO ESTIMATE SURFACE-ENERGY FLUXES, JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 100(D12), 1995, pp. 25447-25451
The surface sensible heat flux, H, and the latent heat flux, LE, were
determined under unstable conditions for the First ISLSCP (Internation
al Satellite Land Surface Climatology Project) Field Experiment (FIFE)
site in eastern Kansas. NOAA 9 and 11 AVHRR radiative surface tempera
tures, corrected for atmospheric effects using the split window techni
que, were used for the surface temperature in a bulk atmospheric bound
ary layer similarity formulation for H. Mean vertically integrated mix
ed layer temperatures, determined from radiosonde data, were also requ
ired in this technique. However, unlike previous applications, the pre
sent approach avoids the need for direct wind speed measurements by us
ing instead the geostrophic wind speed, V-G, as derived from the routi
ne measurements of the surface pressure field. LE was then determined
as the residual term of the surface energy balance, using H from the b
ulk similarity formulation. Under the unstable conditions considered,
results for both Hand LE were comparable to those found in previous wo
rk by means of measured wind speeds with the same FIFE data. It is sho
wn that for slight to moderate instabilities a 1% error in the frictio
n velocity generally produces less than 1% error in H.