Dusty plasma conditions in meteor trails

Pellinen-Wannberg, A.1, Häggström, I.2, Rosenberg, M.3, Meyer-Vernet, N.4, Murad, E.5, Popova, O.6, Mann, I.7, Mukai, T.7 and Rapp, M.8

1 Umeå University and Swedish Institute of Space Physics, Kiruna, Sweden
2 EISCAT Scientific Association, Kiruna, Sweden
3 Department of Electrical and Computer Engineering, University of California, San Diego, USA
4 Observatoire de Paris, Meudon, France
5 retired AFRL, Newton, USA
6 Institute for Dynamics of Geospheres, Russian Academy of Science, Moscow, Russia
7 Kobe University, Japan
8 Leibniz Institute of Atmospheric Physics, University of Rostock, Kühlungsborn, Germany

Dusty plasma conditions have been studied in a variety of environments in the outer space as well as upper atmosphere. We are investigating if dusty plasma parameters are applicable even for expanding meteor trails. As a first example we have two events where a structure seems to drift through the EISCAT UHF radar beam in a size and time scale reasonable for a meteor trail. These trails, though observed in 1990, are of the recently discussed high altitude type, observed at 148 and 130-135 km. The first one appeared in the EISCAT long pulse ACF measurement scheme, and the second one even in a Barker-coded alternating code pulse scheme. The ion-acoustic spectra of these events are enhanced in one side consequently with the background plasma drift direction monitored in the tristatic point in F-region. We will discuss how typical ionised atoms and/or molecules from the ablating meteoroids can contribute the observed spectrum and suggest better dedicated observation strategy for further studies.