Wind and turbulence measurements by the Middle and Upper Atmosphere Radar (MUR): comparison of techniques

摘要

The structure-function-based method (referred to as UCAR-STARS), atechnique for estimating mean horizontal winds, variances of threeturbulent velocity components and horizontal momentum flux was appliedto the Middle and Upper atmosphere Radar (MUR) operating in spacedantenna (SA) profiling mode. The method is discussed and compared withthe Holloway and Doviak (HAD) correlation-function-based technique.Mean horizontal winds are estimated with the STARS and HAD techniques;the Doppler Beam Swinging (DBS) method is used as a reference for evaluatingthe SA techniques. Reasonable agreement between SA and DBS techniques isfound at heights from 5km to approximately 11km, where signal-to-noiseratio was rather high.The STARS and HAD produced variances of verticalturbulent velocity are found to be in fair agreement. They are affectedby beam-broadening in a different way than the DBS-produced spectralwidth, and to a much lesser degree.Variances of horizontal turbulent velocity components and horizontalmomentum flux are estimated with the STARS method, and strong anisotropyof turbulence is found. These characteristics cannot be estimated withcorrelation-function-based SA methods, which could make UCAR-STARSa useful alternative to traditional SA techniques.