Unusual optical observations of OI greenline during a geospace event on 1 February 2008

摘要: [1] We herein report the first observations of an unusual phenomenon recorded by all-sky airglow imager from low-latitude site Panhala (16.8°N, 74.1°E, geographic; 8.2°N geomagnetic), on night 1 February 2008, during main phase a moderate geomagnetic storm. The OI 557.7 nm emission reveal discrete, transient, filamentary structures referred to as “streaks.” No such features were seen in 630.0 and mesospheric sodium hydroxyl emissions. Here we speculate possible mechanisms for generation structures, though cannot conclude firmly that any one them was responsible observed features. This is puzzling observation made very low latitude recurrent storm declining solar cycle. In spite limitations identifying mechanism or this striking observation, it felt understanding processes driving rare events will substantiate our knowledge mysterious coupling occurring equatorial upper atmosphere.