Development of the mesospheric Na layer at 69° N during the Geminids meteor shower 2010

Abstract

Abstract. The ECOMA sounding rocket campaign in 2010 was performed to investigate the charge state and number density of meteoric smoke particles during the Geminids meteor shower in December 2010. The ALOMAR Na lidar contributed to the campaign with measurements of sodium number density, temperature and line-of-sight wind between 80 and 110 km altitude over Andøya in northern Norway. This paper investigates a possible connection between the Geminids meteor shower and the mesospheric sodium layer. We compare with data from a meteor radar and from a rocketborne in situ particle instrument on three days. Our main result is that the sodium column density is smaller during the Geminids meteor shower than the winter average at the same latitude. Moreover, during two of the three years considered, the sodium column density decreased steadily during these three weeks of the year. Both the observed decrease of Na column density by 30 % and of meteoric smoke particle column density correlate well with a corresponding decrease of sporadic meteor echoes. We found no correlation between Geminids meteor flux rates and sodium column density, nor between sporadic meteors and Na column density (R = 0.25). In general, we found the Na column density to be at very low values for winter, between 1.8 and 2.6 × 10 13 m −2 . We detected two meteor trails containing sodium, on 13 December 2010 at 87.1 km and on 19 December 2010 at 84 km. From these meteor trails, we estimate a global meteoric Na flux of 121 kg d −1 and a global total meteoric influx of 20.2 t d −1 .

Retrieval of sodium number density profiles in the mesosphere and lower thermosphere from SCIAMACHY limb emission measurements

“…In their Fig. 7, Dunker et al (2013) show VCDs between 3×10 9 and 7×10 9 cm −2 in December. Again the seasonal cycle for the two different techniques is clear.…”

In situ observations of meteor smoke particles (MSP) during the Geminids 2010: constraints on MSP size, work function and composition

“…Hence, the contribution of the Geminids to the total mass input into the middle atmosphere can be considered as almost negligible. This issue is further discussed in the companion paper by Dunker et al (2012) who also consider the time evolution of the Na layer during this period as well as the evolution of the sporadic meteor flux. They show that both the flux of sporadic meteors, the sodium column density and the column density of MSPs steadily decreased over the time of the ECOMA campaign which possibly implies that a reduced flux of sporadic meteors is the cause for the decay of the two other quantities (while apparently the additional flux of the Geminids had no obvious measurable impact; see Dunker et al (2012) for a detailed discussion).…”

Simultaneous observations of a Mesospheric Inversion Layer and turbulence during the ECOMA-2010 rocket campaign

“…She et al (2002) and Arnold and She (2003) have described this Na lidar in detail. The set-up and status of the Na Lidar during December 2010 is described in more detail by Dunker et al (2013). The Na lidar measures sodium number density, lineof-sight wind speed and temperature in the altitude range between about 80 and 110 km with uncertainties better than 10 8 m −3 , 2 m s −1 and 2 K, respectively.…”