Mesospheric turbulent velocity estimation using the Buckland Park MF radar

Abstract

Abstract. This paper investigates turbulent velocity estimation using the full correlation analysis (FCA) of spaced antenna (SA) data, and its application to the routine FCA observations of the Buckland Park MF (BPMF) radar. The effects of transmitter beamwidths are investigated, confirming the suggestions of previous authors that wide transmit beam widths lead to an overestimation of the turbulent velocity. The annual variation of the turbulent velocity is investigated, revealing an increase in turbulent velocity with height, and equinoctal minima and solstice maxima observed below 80 km. Investigations of the turbulent velocities about the March diurnal tide maximum reveals a diurnal variation in phase with the zonal velocity. Harmonic analysis reveals this relationship exists between February and September. Descending power layers are also observed during this period. A number of mechanisms are proposed to describe these observations.

MF and HF radar techniques for investigating the dynamics and structure of the 50 to 110 km height region: a review

“…Holdsworth et al (2001) demonstrated that wider transmit beam widths lead to an overestimation of the turbulent velocity. This confirmed the suggestions made by previous authors (e.g., Briggs 1980;Vandepeer and Hocking 1993;Hall et al 1998).…”

“…where λ is the wavelength and T 0.5 is the ground diffraction pattern lifetime in the reference frame of the pattern (e.g., Holdsworth et al 2001). Figure 16 shows the turbulent root mean square velocities obtained by for a period of 7 years using the BPMF radar.…”

“…Inspection of this figure indicates that there is a maximum extending from 93 km in summer to above 98 km in winter. attribute this to contamination from the E region total reflection because routine harmonic analysis of the turbulent velocities at these heights and times yields values which peak at mid-day when the E region contamination is expected to be most likely (e.g., Holdsworth et al 2001)…”

“…The basic theory of turbulence velocity estimation using the FCA is described by Briggs (1980), and examples of its application are provided by Holdsworth et al (2001) and . Holdsworth et al (2001) demonstrated that wider transmit beam widths lead to an overestimation of the turbulent velocity.…”

“…While the application of radars operating in the MF and HF bands to investigate the neutral upper atmosphere is one of the oldest such techniques still regularly in use, the techniques have been continuously improved, largely through the availability of better hardware (e.g., Reid et al 1995;Singer et al 2008;Li et al 2012) and readily available and economical but powerful computers, and provide a robust and reliable method of obtaining wind velocities (e.g., Stubbs 1973;Pancheva et al 2002), turbulence intensities (e.g., Hocking 1983;Holdsworth et al 2001), electron densities and collision frequencies (e.g., Thrane and Piggott 1966;von Biel 1977;Friedrich and Torkar 1983;Holdsworth et al 2002;Singer et al 2011), measurements of atmospheric structure (e.g., Gregory 1956;Hall 2000), temperatures (e.g., Tsutsumi et al 1999;Holdsworth et al 2006), and measurements of energy and momentum transfer (e.g., Reid and Vincent 1987;Murphy and Vincent 1993;Placke et al 2015) in the MLT region.…”