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A dual‐beamwidth radar method for measuring atmospheric turbulent kinetic energy
Author(s) -
VanZandt T. E.,
Nastrom G. D.,
Furumoto J.,
Tsuda T.,
Clark W. L.
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2001gl014283
Subject(s) - beamwidth , zenith , kinetic energy , radar , physics , turbulence , computational physics , turbulence kinetic energy , meteorology , wind profiler , environmental science , geodesy , geology , atmospheric sciences , remote sensing , optics , aerospace engineering , antenna (radio) , telecommunications , engineering , computer science , quantum mechanics
This paper introduces a new dual‐beamwidth (2BW) radar method for inferring the velocity variance σ turb 2 due to the turbulent kinetic energy density per unit mass. The 2BW method has the advantage of being much less sensitive than the standard single‐beamwidth (1BW) method to the necessary instrumental corrections of the observed velocity variance σ obs 2 . We test and compare the 2BW and 1BW methods using σ obs 2 between 5.0 and 7.5 km MSL measured by the MU VHF radar near Shigaraki, Japan, with beams directed toward 10° zenith angle. We find that during periods of light winds the σ turb 2 profiles from the two methods agree well. But with wind speeds >30 m/s the 1BW values of σ turb 2 are about 25% larger than the 2BW values. With the 2BW method, typical values of σ turb 2 between 6.0 and 7.5 km MSL increased from ∼0.07 m 2 /s 2 with winds of ∼2 m/s to ∼0.2 m 2 /s 2 with winds between 30 and 60 m/s.