Surface heat ̄ux estimation with wind-pro®ler/RASS and radiosonde observations

A bulk ABL similarity approach was used to make regional estimates of the sensible heat ̄ux by combining surface temperature measurements with mixed layer temperature and wind speed pro®les. The mixed layer pro®les were measured by a 915 MHz Pro®ler/ Radio Acoustic Sounding System and by radiosondes in north-central Oklahoma at the ARM Southern Great Plains CART Central Facility. A comparison of calculated sensible heat ̄ux values with regional mean values measured at two ground stations showed good agreement with r ˆ 0:88 and r ˆ 0:76 for the 915 MHz pro®ler and the radiosonde data sets, respectively. Estimates of friction velocity u by means of radiosonde wind pro®les gave good results when compared to values measured by an surface eddy correlation system with a correlation coecient r ˆ 0:77. However, u values obtained from wind pro®les measured by the 915 MHz pro®ler were underestimated, because these velocity measurements were systematically too small. The results also show that the 915 MHz Pro®ler/Radio Acoustic Sounding System is capable of providing the needed temperature measurements to make reasonable regional estimates of sensible heat ̄ux. Ó 2000 Elsevier Science Ltd. All rights reserved.