Improved analysis of all-sky meteor radar measurements of gravity wave variances and momentum fluxes

Abstract

Abstract. The advantages of using a composite day analysis for all-sky interferometric meteor radars when measuring mean winds and tides are widely known. On the other hand, problems arise if this technique is applied to Hocking's (2005) gravity wave analysis for all-sky meteor radars. In this paper we describe how a simple change in the procedure makes it possible to use a composite day in Hocking's analysis. Also, we explain how a modified composite day can be constructed to test its ability to measure gravity wave momentum fluxes. Test results for specified mean, tidal, and gravity wave fields, including tidal amplitudes and gravity wave momentum fluxes varying strongly with altitude and/or time, suggest that the modified composite day allows characterization of monthly mean profiles of the gravity wave momentum fluxes, with good accuracy at least at the altitudes where the meteor counts are large (from 89 to 92.5 km). In the present work we also show that the variances measured with Hocking's method are often contaminated by the tidal fields and suggest a method of empirical correction derived from a simple simulation model. The results presented here greatly increase our confidence because they show that our technique is able to remove the tide-induced false variances from Hocking's analysis.

Multi-year observations of gravity wave momentum fluxes at low and middle latitudes inferred by all-sky meteor radar

“…According to Andrioli et al (2013a) it is possible to infer the GW momentum fluxes and variances with a good accuracy using simple all-sky meteor radar data. We do this by using a modified composite day (MCD) method applied to the Hocking (2005) analysis.…”

“…This analysis allows us to study GWs with periods less than ∼ 3 h, vertical wavelengths less than ∼ 5-10 km, and horizontal wavelength less than ∼ 180 km. Additional details of the method can be found in Andrioli et al (2013a).…”

“…In recent years the results of a number of studies have been published using the Hocking technique, e.g., Antonita et al (2008), Fritts et al (2010Fritts et al ( , 2012a, Placke et al (2011a, b), Andrioli et al (2013a, b) and de Wit et al (2014a, b). Andrioli et al (2013a) described a method for using the technique in composite days with the purpose of maximizing the number of available meteor echoes and thus allowing the investigation of momentum fluxes using simple meteor radars with improved accuracy and with no contamination by tides and planetary waves.…”

“…Andrioli et al (2013a) described a method for using the technique in composite days with the purpose of maximizing the number of available meteor echoes and thus allowing the investigation of momentum fluxes using simple meteor radars with improved accuracy and with no contamination by tides and planetary waves. Although this method does not allow momentum fluxes with high time resolution to be inferred, we can at least investigate the monthly mean and the seasonal variation in the fluxes without tide and planetary wave contamination.…”

Mesospheric gravity wave momentum flux estimation using hybrid Doppler interferometry

“…Antonita et al, 2008;Clemesha and Batista, 2008;Mitchell, 2009, 2010;Clemesha et al, 2009;Fritts et al, 2010aFritts et al, , b, 2012aVincent et al, 2010;Placke et al, 2011aPlacke et al, , b, 2014Placke et al, , 2015Andrioli et al, 2013aAndrioli et al, , b, 2015Liu et al, 2013;de Wit et al, 2014bde Wit et al, , a, 2016Matsumoto et al, 2016;Riggin et al, 2016). This has largely arisen from a need to obtain improved spatial coverage in the parameterization of GWs and their associated momentum transport in climate models of the whole atmosphere (e.g.…”