Climatology of Quasi‐2‐Day Wave‐Induced Horizontal Momentum Flux and Heat Fluxes Over the Tropical MLT Region Using SVU Meteor Radar

Abstract The mesosphere‐lower thermosphere (MLT) region is a highly dynamic region of the atmosphere that is strongly influenced by a broad spectrum of atmospheric waves. Among these, the quasi‐two‐day wave (QTDW) plays a prominent role in modulating MLT dynamics. In this study, we utilize more than 11 years (November 2013–March 2025) of Sri Venkateswara University (SVU) meteor radar observations made at a low‐latitude site (13.63°N, 79.4°E), SVU, Tirupati, India, to investigate the characteristics and impacts of the QTDW, as well as its contribution to momentum and heat transport in the MLT region, which remains poorly understood. The horizontal momentum flux ( zonal heat flux (), and meridional heat flux were analyzed using horizontal winds and the ambipolar diffusion coefficient (derived from meteor decay time). The ambipolar diffusion coefficient, which is directly related to the background temperature, was used for the heat flux estimation. The results reveal distinct seasonal and height‐dependent variations. In general, the horizontal momentum flux and zonal heat flux exhibited opposite trends relative to the background zonal mean wind during the solstices above 90 km ‐positive flux during the winter solstice and negative flux during the summer solstice. The meridional heat flux remained positive throughout, with enhanced values during the solstices and in October. This study is the first to quantify QTDW‐induced horizontal momentum and heat fluxes using meteor radar observations over a low‐latitude MLT region, providing new insights into wave‐mean flow interactions.