The purpose of this special issue is to document the current state of the art regarding our understanding of the impact of a major meteor shower on the structure, composition and dynamics of the middle atmosphere and lower ionosphere. The corner stones for this collection of papers are results from a recent international sounding rocket campaign, i.e. the ECOMA 2010 Geminids campaign. This campaign was conducted in December 2010 from the North-Norwegian Andoya Rocket Range (69°N, 16°E). In the course of this sounding rocket campaign a total of three instrumented payloads were launched: One just before the onset of the shower, one at the peak of shower activity on 13 December, and one after shower activity had ceased. All scientific payloads included instruments to probe the neutral atmosphere (density, temperature, turbulence, trace species like meteor smoke, NO, O) and the lower ionosphere (electrons, positive ions, charged aerosols). In addition, a large number of accompanying ground-based measurements was carried out. Among these are the novel Middle Atmosphere ALOMAR Radar System (MAARSY), the ALOMAR RMR and Na-lidars, several specular meteor radars, photographic observations of the meteors, the EISCAT VHF-radar, the PFISR, RISR and Arecibo incoherent scatter radars, and finally the Japanese MU-radar. In addition, publicly available satellite data sets (e.g., from SABER/TIMED, MLS/AURA, and possibly also SOFIE/AIM) will also be considered to put the more local observations into a global perspective. This unique combination of in-situ, ground-based, and satellite-based observations is expected to give us unprecedented insight into the effect of a major meteor shower like the Geminids on the middle atmosphere and lower ionosphere.

In addition to contributions from scientists who have been directly involved in the activities mentioned above, the Special Issue editors will consider including relevant papers from other research groups in this issue.