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Turbulence and waves in the optically clear planetary boundary layer resolved by dual‐Doppler radars
Author(s) -
Doviak Richard J.,
Berger Myron
Publication year - 1980
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs015i002p00297
Subject(s) - doppler effect , physics , planetary boundary layer , turbulence , radar , doppler radar , wind profile power law , boundary layer , computational physics , geology , meteorology , wind speed , optics , remote sensing , mechanics , astronomy , telecommunications , computer science
Dual Doppler radars provide a unique method to resolve the spatial structure of planetary boundary layer (PBL) air motions. Both the wave and turbulent fluctuations of air in the convectively unstable PBL are revealed from synthesis of the Doppler velocities of echoes (from the atmosphere's intrinsic scatterers) returned to two spaced (40 km) radars. The smaller turbulent scales follow closely the two‐thirds law‐of‐similarity theory, whereas the observed 4‐km wave is compared with those from theoretical models. Power spectra derived from Fourier space analysis of Doppler‐synthesized wind are compared to those obtained from time‐space conversion of Fourier time analysis applied to wind measurements on a 500‐m tower. It is shown that turbulent eddies move with the mean wind and maintain an identity for nearly 60 min. Larger wind variance is observed in the cross‐wind component than in the along‐wind component. Error variances are in agreement with estimates from theoretical studies. Comparisons of refractive index structure constants C n 2 deduced by radar and aircraft are within 1 dB.