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Detection of turbulence around jet streams using a VHF radar
Author(s) -
Pepler S. J.,
Vaughan G.,
Hooper D. A.
Publication year - 1998
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49712454605
Subject(s) - turbulence , lidar , jet stream , dissipation , radar , jet (fluid) , physics , anisotropy , remote sensing , computational physics , optics , meteorology , mechanics , geology , telecommunications , computer science , thermodynamics
Two methods for detecting turbulence near jet streams are investigated using a VHF radar‐the corrected spectral width of the vertical echo and the anisotropy of the signal returned. It is found that turbulent dissipation rates in excess of 0.2 mW kg −1 may be detected using the spectral width, but uncertainties in the derivation of this parameter preclude detection of weak turbulence. Anisotropy of the signal is capable of detecting some turbulence in regions of high static stability, but the method is not quantitative and is best employed to confirm the spectral‐width estimates when these are near the detection limit. Independent confirmation that atmospheric conditions were favourable for turbulence was provided by Richardson number profiles derived from the radar and a Raman lidar. Measurements of static stability by the lidar and spectral widths by the radar allow an estimate of the turbulent‐dissipation rate. The application of these techniques to two jet stream passages is discussed.