资源环境科技发展态势分析平台

The time evolution of mesospheric quasi‐biennial oscillation (MQBO) in the 82‐98 km altitude region using long‐term meteor radar observations over low and equatorial latitudes and TIMED Doppler Interferometer (TIDI) observations is discussed for the first time. The wavelet spectra of monthly mean zonal winds over Serpog (6.4⁰ S, 106.7⁰ E; 1993‐1998), Koto Tabang(0.2°S, 100.3°E; 2003‐2012) and Thumba (8.5°N, 76.9°E;2006‐2015) show the transient nature of the MQBO amplitudes thus questioning its perpetuity in the mesosphere‐ lower thermosphere (MLT). The time period of the MQBO as well as its amplitude show variability with time. The latitude‐height structures of the MQBO at four time periods (24, 26, 28 and 30 months) are constructed using TIDI measurements, which show diverse latitudinal structure. The significance of the present study lies in bringing out the time evolution of the MQBO and addressing a few outstanding issues on its ephemerality and discrepancies in its amplitudes.