Turbulence observations over a desert basin using a kite/tethered-blimp platform

Abstract

Results of the (temperature) refractive index structure parameter (C T 2 ), C n 2 , and the eddy dissipation rate ⑀ derived from the velocity structure parameter C v 2 are presented from fast response sensor observations using a kite/tethered-blimp platform in the Tularosa Basin at White Sands Missile Range, New Mexico, during the spring of 1998. Comparisons of different sensors (fine-wire probes and pitot tubes) measuring the same parameter are displayed and discussed while salient features of all sensors (standard and fast response) and the kite and tethered-blimp platforms are outlined. The nature and statistics of turbulence, including intermittency, under different stability conditions is discussed, including those found in the residual layer above the nocturnal boundary layer and the entrainment zone at the top of the daytime planetary boundary layer. In addition to displaying time series of temperature C n 2 and ⑀ results obtained at specific altitudes and times, histograms of all daytime and nighttime C n 2 and ⑀ values are compared to log-normal distributions. Examples of profiles of C n 2 and ⑀ for daytime, near sunset, and nighttime conditions are shown and discussed. The relationship of C n 2 with ⑀ is displayed for all data as well as sorted by daytime and nighttime. These results are explained in terms of potential and kinetic energy considerations under different atmospheric stability conditions.