Extended Abstract (392K)P3.8
Turbulence in a shear-driven nocturnal surface layer during the CASES'99 experiment
Philippe Drobinski, Univ. Pierre et Marie Curie, Paris, France; and R. K. Newsom, R. M. Banta, P. Carlotti, R. C. Foster, P. Naveau, and J. L. Redelsperger
Recent observational data suggesting streamwise linear organization in the surface layer were obtained at night during the Cooperative Surface-Atmosphere Exchange Study field campaign in October 1999 (CASES'99), that took place at the ARM site. A -1 power law range was measured in spectra for the velocity in the surface layer on 25 October 1999. This spectral behaviour is a signature of the presence of streaky structures as shown by Carlotti (2002). Wavelet analysis of these data allowed us to divide the time series into two parts according to the change in variability and strongly indicated peaks at different time scales. This multi-resolution of these two time series in the time domain might allow a more objective way to estimate the timing and magnitude of cycle or the detection of coherent structure as initiated by Foster (1997) and Drobinski and Foster (2002) using linear theory and large-eddy simulations, respectively.
Poster Session 3, Fundamental Studies
Tuesday, 16 July 2002, 2:00 PM-2:00 PM
Previous paper Next paper