SOME ASPECTS OF TURBULENT FLUXES NEAR THE GROUND

Abstract

The observational system including sensors such as the sonic anemometer and new data processing system, HYSA T, has been proved to be used to measure turbulent fluxes and the related atmospheric characteristics. From the results of preliminary application of this system to the field measurements, the following facts are found . (i) Concerning the diurnal change of the fluxes, the phase lag of sensible heat flux to the net radiation is small compared with that of momentum flux to the net radiation. (ii) The thermal balance on the ground surface was certified to contain an error margin of 10%. (iii) The drag coefficient increases with decreasing wind speed in the wind speed lower than one or two meters per second both over land and over water.