Journal cover Journal topic
Annales Geophysicae Sun, Earth, planets, and planetary systems An interactive open-access journal of the European Geosciences Union
Ann. Geophys., 35, 1033-1049, 2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Regular paper
04 Sep 2017
Nanodust dynamics during a coronal mass ejection
Andrzej Czechowski1 and Jens Kleimann2 1Space Research Center, Polish Academy of Sciences, Bartycka 18A, 00-716 Warsaw, Poland
2Institut für Theoretische Physik IV, Ruhr-Universität Bochum, 44780 Bochum, Germany
Abstract. The dynamics of nanometer-sized grains (nanodust) is strongly affected by electromagnetic forces. High-velocity nanodust was proposed as an explanation for the voltage bursts observed by STEREO. A study of nanodust dynamics based on a simple time-stationary model has shown that in the vicinity of the Sun the nanodust is trapped or, outside the trapped region, accelerated to high velocities.

We investigate the nanodust dynamics for a time-dependent solar wind and magnetic field configuration in order to find out what happens to nanodust during a coronal mass ejection (CME).

The plasma flow and the magnetic field during a CME are obtained by numerical simulations using a 3-D magnetohydrodynamic (MHD) code. The equations of motion for the nanodust particles are solved numerically, assuming that the particles are produced from larger bodies moving in near-circular Keplerian orbits within the circumsolar dust cloud. The charge-to-mass ratios for the nanodust particles are taken to be constant in time. The simulation is restricted to the region within 0.14 AU from the Sun.

We find that about 35 % of nanodust particles escape from the computational domain during the CME, reaching very high speeds (up to 1000 km s−1). After the end of the CME the escape continues, but the particle velocities do not exceed 300 km s−1. About 30 % of all particles are trapped in bound non-Keplerian orbits with time-dependent perihelium and aphelium distances. Trapped particles are affected by plasma ion drag, which causes contraction of their orbits.

Citation: Czechowski, A. and Kleimann, J.: Nanodust dynamics during a coronal mass ejection, Ann. Geophys., 35, 1033-1049,, 2017.
Publications Copernicus
Short summary
Interplanetary dust also includes very small (nanometer-sized) particles. The dynamics of nanodust is determined by electromagnetic forces, which accelerate the dust to velocities on the order of 500 km s−1 or, in the vicinity of the Sun, trap them in bound orbits. We investigate the behavior of nanodust during a coronal mass ejection. We find a new population of extremely fast (1000 km s−1) nanodust. We also study the effect of the ion drag force.
Interplanetary dust also includes very small (nanometer-sized) particles. The dynamics of...