A case study of mesospheric planetary waves observed over a three-radar network using empirical mode decomposition

Abstract

Abstract. In this paper an attempt is made to study equatorial Kelvin waves using a network of three radars: Kototabang (0.204 • S, 100.320 • E) meteor radar, Pameungpeuk (7.646 • S, 107.688 • E) medium-frequency radar, and Pontianak (0.003 • S, 109.367 • E) medium-frequency radar. We have used the continuous data gathered from the three radars during April-May 2010. Empirical mode decomposition (EMD), Lomb-Scargle periodogram (LSP) analysis, and wavelet techniques are used to study the temporal and altitude structures of planetary waves. Here, we used a novel technique called EMD to extract the planetary waves from wind data. The planetary waves of ∼ 6.5 and ∼ 3.6 days periodicity are observed in all three radar stations with peak amplitudes of about 12 and 11 m s −1 , respectively. The 3.6-day wave has an average vertical wavelength from the three radars of about 42 km. The 3.6-and 6.5-day planetary waves are particularly strong in the zonal wind component. We find that the two waves are present at the 84-94 km height region. The observed features of the 3.6-and 6.5-day waves at the three tropical-latitude stations show some correspondence with the results reported for the equatorial-latitude stations.

Mesospheric tide comparisons at low latitudes observed by two collocated meteor radars

“…Meteor radars operate around the clock, regardless of day or night, and function effectively under geographic conditions, allowing for robust long-term observations. Consequently, meteor radars have proven to be a potent technology for researching the dynamics and climate of the middle atmospheric region, including aspects like wind fields (Yi W et al, 2019;Gu SY et al, 2021;Stober et al, 2021;Zhou BZ et al, 2022;Long C et al, 2023), neutral density (Takahashi et al, 2002;Stober et al, 2014), temperature (Hocking, 1999;Hall et al, 2012), planetary waves (Kishore et al, 2018;Wang JC et al, 2021;He MS and Forbes, 2022) and tidal waves (Jacobi et al, 2017;He MS and Chau, 2019;Spargo et al, 2019;Liu GP et al, 2022).…”