Constructive interference of large-scale gravity waves excited by interplanetary shock on 29 October 2003: CHAMP observation

In this paper we report the detection of full constructive interference between two large-scale gravity waves in the upper thermosphere from the CHAMP accelerometer measurements. The two waves are separately excited in northern and southern auroral regions by the shock-induced auroral intensification on 29 October 2003. They propagate equatorward and encounter near the equator, where constructive interference occurs and causes nightside equatorial neutral density enhancements of similar to 60%. This result demonstrates that the constructive interference can be a potential mechanism for large density increases in the equatorial region during magnetically active periods.