In situ investigations of dusty plasma in the polar E- and D-region

This work presents results of rocket-borne measurements of dusty plasma parameters conducted in winter in high northern latitude ionosphere. It demonstrates that also smaller MSPs, i.e. with radii in sub-nanometer size range can be effectively charged and, thereby significantly influence plasma properties. Parameters of a charged MSP size distribution function were derived. The modelling results show that largest fraction of the charged MSPs reveal radii smaller than 1 nm and their density can exceed the density of electrons by up to an order of magnitude.Diese Arbeit präsentiert Ergebnisse von raketengestützten Messungen staubiger Plasmaparameter, die im Winter in der Ionosphäre in hohen nördlichen Breiten durchgeführt wurden. Es zeigt sich, dass auch kleinere MSPs (r < 1 nm), effektiv geladen werden können und damit die Plasmaeigenschaften wesentlich beeinflussen. Es wurden Parameter einer Größenverteilung von geladenen MSPs abgeleitet. Modellierungsergebnisse zeigen, dass der größte Teil der geladenen MSPs Radien kleiner als 1 nm aufweisen und ihre Dichte die Elektronendichte um bis zu einer Größenordnung überschreiten kann

Estimate of size distribution of charged MSPs measured in situ in winter during the WADIS-2 sounding rocket campaign

We present results of in situ measurements of mesosphere–lower thermosphere dusty-plasma densities including electrons, positive ions and charged aerosols conducted during the WADIS-2 sounding rocket campaign. The neutral air density was also measured, allowing for robust derivation of turbulence energy dissipation rates. A unique feature of these measurements is that they were done in a true common volume and with high spatial resolution. This allows for a reliable derivation of mean sizes and a size distribution function for the charged meteor smoke particles (MSPs). The mean particle radius derived from Schmidt numbers obtained from electron density fluctuations was ∼ 0.56 nm. We assumed a lognormal size distribution of the charged meteor smoke particles and derived the distribution width of 1.66 based on in situ-measured densities of different plasma constituents. We found that layers of enhanced meteor smoke particles' density measured by the particle detector coincide with enhanced Schmidt numbers obtained from the electron and neutral density fluctuations. Thus, we found that large particles with sizes  > 1 nm were stratified in layers of  ∼ 1 km thickness and lying some kilometers apart from each other

Simultaneous in Situ Measurements of Small-Scale Structures in Neutral, Plasma, and Atomic Oxygen Densities During the WADIS Sounding Rocket Project

In this paper we present an overview of measurements conducted during the WADIS-2 rocket campaign. We investigate the effect of small-scale processes like gravity waves and turbulence on the distribution of atomic oxygen and other species in the mesosphere–lower thermosphere (MLT) region. Our analysis suggests that density fluctuations of atomic oxygen are coupled to fluctuations of other constituents, i.e., plasma and neutrals. Our measurements show that all measured quantities, including winds, densities, and temperatures, reveal signatures of both waves and turbulence. We show observations of gravity wave saturation and breakdown together with simultaneous measurements of generated turbulence. Atomic oxygen inside turbulence layers shows two different spectral behaviors, which might imply a change in its diffusion properties