Meteor‐induced transient sporadic E as inferred from rapid‐run ionosonde observations at midlatitudes

Abstract

[1] Observations were made with a rapid-run ionosonde during a 1-month period from the end of July to the end of August 2002 that included the Perseid meteor shower. Ionograms were obtained at 1-minute intervals. All the echo traces below a virtual height of 200 km were hand-scaled for detecting weak and broken traces as well as well-determined sporadic E. Among the scaled E-region traces, a distinct meteor echo persisting for 40 min was observed. This long-duration meteor event was similar to that observed during the Leonid meteor shower in 2001. However the apparent height of the echo traces in the current event first decreased and then increased after equaling the height of a persistent sporadic E layer, while the apparent height of the long-duration meteor echo trace observed in Leonids 2001 remained nearly constant. The descending rate of the meteor echo was approximately 22 m/s, which was considerably greater than that of the tidal ion layer trapped in a downward-moving wind shear node. We ascribe the long-duration meteor echo to a transient and horizontally drifting sporadic E patch generated from meteor trail plasma.Citation: Maruyama, T., H. Kato, and M. Nakamura (2008), Meteor-induced transient sporadic E as inferred from rapid-run ionosonde observations at midlatitudes,

Ionospheric scintillations at Guilin detected by GPS ground-based and radio occultation observations

“…The Es layers associated with the Leonid meteor shower event of November 1998 has been reported on the basis of observations of rapid radio soundings in India (Chandra et al, 2001). During the Leonid meteor shower in 2001, long-duration Es echoes persisting for approximately 40 min were recorded on ionograms in Japan, which were attributed to the transient formation of a Es layer caused by a meteor ablation immediately overhead (Maruyama et al, 2003). Similarly, Es echoes related to the Perseid meteor shower in August 2002 were detected by a rapidrun ionosonde at Yamagawa, Japan, which lasted for more than 40 min (Maruyama et al, 2008).…”

“…During the Leonid meteor shower in 2001, long-duration Es echoes persisting for approximately 40 min were recorded on ionograms in Japan, which were attributed to the transient formation of a Es layer caused by a meteor ablation immediately overhead (Maruyama et al, 2003). Similarly, Es echoes related to the Perseid meteor shower in August 2002 were detected by a rapidrun ionosonde at Yamagawa, Japan, which lasted for more than 40 min (Maruyama et al, 2008). Recently, Malhotra et al (2008) Note that there have been many arguments about the correlation between the meteor shower activity and Es occurrence over the years.…”

“…Recently, Malhotra et al (2008) Note that there have been many arguments about the correlation between the meteor shower activity and Es occurrence over the years. Some researchers have concluded that an increase in Es immediately follows the occurrence of meteor shower and others have inferred a delay in the increase, while some authors have found no correlation between meteor shower activity and the occurrence of Es (Malhotra et al, 2008;Maruyama et al, 2008). One possible reason for the confusion on the effects of meteor showers on Es activity is due to the difficulty in distinguishing between intense meteor echoes and the usual Es layers echoes on ionograms during meteor shower periods, which can be overcome to a certain extent by using rapidrun ionosondes and tracking echoes from every ionograms frame as done in recent years (Chandra et al, 2001;Maruyama et al, 2008).…”

High‐latitude E and F region coupling signature: A case study results from rapid‐run ionosonde

“…Possible answer is that it comes from ablated meteor observed at 07:20 UT. However, according to observations [ Maruyama et al ., , ] the cause‐and‐effect relation is absent in general, and even if it were so, it would be difficult to explain the appearance of two separated blobs of plasma. The same reasoning can be applied to the solar flare effect started just after 08:00 UT during E s density minimum as can be seen in the magnetogram (Figure d) as a jump of the diurnal variation by 10–20 nT.…”

“…Also, there are short-lived (one to a few minutes) sporadic E layers like, e.g., at 0250, 0330, 0720, and 1320 UT. Maruyama et al [2008] suggested meteors as the most probable reason for such kind of layers.…”