Mesospheric gravity waves and ionospheric plasma bubbles observed during the COPEX campaign

During the Conjugate Point Experiment (COPEX) campaign performed at Boa Vista ($2.{80}^{°}\mathrm{N};60.{70}^{°}\mathrm{W}$, dip angle $21.7^{°}\mathrm{N}$) from October to December 2002, 15 medium-scale gravity waves in the OHNIR airglow images were observed. Using a Keogram image analysis, we estimate their parameters. Most of the waves propagate to Northwest, indicating that their main sources are Southeast of Boa Vista. Quasi-simultaneous plasma bubble activities in the OI 630 nm images were observed in seven cases. The distances between the bubble depletions have a linear relationship with the wavelengths of the gravity waves observed in the mesosphere, which suggests a direct contribution of the mesospheric medium-scale gravity waves in seeding the equatorial plasma bubbles.