Long-lived meteor trails

Abstract

Using vertical sounding data obtained by the Irkutsk digisonde DPS-4 from 2003 to 2016, we have studied the frequency of occurrence of the F1 layer in winter conditions. The frequency of occurrence of the F1 layer in December–January is shown to be more than twice lower than that in February at any level of magnetic activity. At moderate and low solar activity under quiet geomagnetic conditions, the appearance of F1 layer in midlatitudes of the Northern Hemisphere may be caused by active thermodynamic processes, which lead to transformation or destruction of the circumpolar vortex at heights of the middle atmosphere. Such global dynamic changes occurring in the winter strato-mesosphere are often associated with sudden stratospheric warming events, which are accompanied by increased generation of atmospheric waves of various scales. These wave disturbances can propagate upward to the heights of the lower thermosphere and ionosphere, carrying a significant vertical flow of energy and causing variations in the composition, thermodynamic parameters of the neutral atmosphere and ionosphere.

Studying a Long-Lasting Meteor Trail from Stereo Images and Radar Data

“…Unfortunately, we could not determine northward velocity reliably due to a lack of data. It should be noted that the velocities obtained from stereoscopy were similar to the velocities of ionized trail obtained in reference [21] and were close to the horizontal wind velocities obtained with the Fabry-Perot interferometer and meteor radar in our study (Figure 7).…”

“…The obtained characteristics of the long-lasting meteor trail, especially the velocities of its expansion, differ from characteristics obtained earlier for this event in [20,21]. Therefore, the mechanisms of long-lasting meteor trail formation discussed in these papers require correction.…”

“…The long-lasting meteor trail appeared on ionograms as a sporadic E layer with very short lifetime. Ionograms related to this event were discussed in [21]. The ionosonde does not adapt for registration of meteor echoes.…”

“…Positions of the instruments are given in Figure 1. Earlier, characteristics of this meteor trail were studied in references [20,21]. In reference [20], the authors determined spatial and kinematic characteristics of the long-lasting trail and revealed features of its evolution using the Astrometry software [22].…”

“…It was hypothesized that such a movement could not be explained by the wind. In [21], parameters of the long-lasting meteor trail were compared with ionosonde observations of the trail. Here, it was supposed that the neutral and ionized components of the long-lasting meteor trail moved with different velocities.…”