IL NUOVO CIMENTO Luglio-Agosto 2000 VOL. 23 C, N. 4 Sensible heat flux and boundary layer depth measurements by Doppler SODAR and sonic anemometer data (*) G. CINQUE ( 1 )( 2 ), R. ZAURI ( 2 ), P. DI CARLO ( 2 ) M. IARLORI ( 2 ) and V. RIZI ( 2 ) ( 1 ) Istituto Nazionale di Geofisica - L’Aquila, Italy ( 2 ) Dipartimento di Fisica, Università di L’Aquila - L’Aquila, Italy (ricevuto l’1 Febbraio 1999; revisionato il 16 Febbraio 2000; approvato il 21 Marzo 2000) Summary. — A validation of a simple mixed-layer similarity relationship, firstly proposed by Panofsky and McCormick (1960), is presented for wind speeds up to 7 ms 21 and over an uneven terrain. The surface heat flux and the Planetary Boundary Layer depth, z i , are retrieved from this relationship, by using SODAR measurements of the vertical velocity variance s 2 w , under the hypothesis that the heat flux linearly decreases with height. All the measurements are relative to days characterized by high-pressure conditions, during periods of well-developed convection. The values of the surface heat flux obtained from such a method are compared with those obtained by applying the eddy correlation technique to the vertical wind velocities and virtual temperatures measured by a sonic anemometer. The values of z i obtained from the same relationship are compared with the height of the lowest inversion layer estimated from the facsimile record of the echoes received by the vertical antenna of the SODAR. The spectral behavior of vertical and longitudinal wind velocity from the anemometer and the SODAR is examined, too. In such a way an independent estimate of z i is obtained from the position of the spectral maximum. PACS 92.60 – Meteorology. PACS 92.60.Fm – Boundary layer structure and processes. PACS 92.60.Ek – Convection, turbulence and diffusion. 1. – Introduction In the last few years, due to the decreasing costs and increasing performances of remote-sensing instruments able to measure the wind vector and the temperature in the first kilometer of the atmosphere, there has been a new interest in the study of this portion of the troposphere, that is usually called Planetary Boundary Layer (PBL). This name derives from the fact that the earth’s surface is a boundary on the domain of the atmosphere and that the atmospheric layers close to this boundary behave in a quite different manner than the rest of the troposphere. (*) The authors of this paper have agreed to not receive the proofs for correction. G Società Italiana di Fisica 331 brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by Scientific Open-access Literature Archive and Repository