Detection of meteor smoke particles in the middle atmosphere
Every day, the Earth’s atmosphere is hit by about 50 metric tons of meteoric material, which evaporates (ablates) in the altitude range between 70 – 120 km. This evaporated material is the source of the well known metal layers such as the sodium and potassium layer. In addition, it has long been speculated that this iron oxide- and silica-rich material should recondense into small nanometer-sized meteor smoke particles. Such speculations are as old as 20 years, however, until only recently the existence of these particles could not be experimentally verified owing to the very small dimensions and concentrations of these particles (typical radii 1-5 nm, typical number densities ~1000 cm-3). Nevertheless, these particles have been proposed to be major players in a variety of atmospheric processes such as the nucleation of mesospheric ice clouds, the nucleation of stratospheric NAT particles (which play an important role in the formation of the ozone hole), and heterogeneous chemical reactions.
At IAP these particles are studied using rocket borne in situ techniques as well as powerful incoherent scatter radars. With the latter approach, in 2006 IAP has succeeded to present the first ground based measurements of these particles and determining their number densities and radii.
Methods and instruments
- Prof. Ulf-Peter Hoppe & Dr. Alvin Brattli, FFI Kjeller, Norwegen
- Prof. Martin Friedrich, TU Graz, Österreich
- Dr. Jörg Gumbel, Meteorologisches Institut, Universität Stockholm, Schweden
- Prof. Scott Robertson, Department of Physics, University of Colorado, USA
- Dr. Zoltan Sternovsky, Laboratory for Atmospheric and Space Physics, University of Colorado, USA
- Dr. Shikha Raizada & Dr. Mike Sulzer, Arecibo Observatory, Puerto Rico