Mesospheric gravity wave characteristics and identification of their sourcesaround spring equinox over Indian low latitudes

[摘要] We report OI557.7 nm night airglow observations with the help of a charged-couple device (CCD)-basedall-sky camera from a low-latitude station, Gadanki (13.5° N;79.2° E). Based on the data collected during March and April over 3years, from 2012 to 2014 (except March 2013), we characterize the small-scalegravity wave properties. During this period, 50 gravity wave eventswere detected. The horizontal wavelengths of the gravity waves are found toranging from 12to 42 km with the phase velocity 20–90 m s⁻¹. In mostcases, these waves were propagating northward with only a fewoccurrences of southward propagation. In the present novel investigationfrom the Indian sector, each of the wave events was reverse-ray-traced toits source. The outgoing longwave radiation (OLR) suggested thattropospheric convection was a possible source for generation of the observedwaves. It was found that approximately 66 % of the events were triggereddirectly by the convection.

[学科分类] 几何与拓扑