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 ∼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.