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Observations of positively charged nanoparticles in the nighttime polar mesosphere
Author(s) -
Rapp M.,
Hedin J.,
Strelnikova I.,
Friedrich M.,
Gumbel J.,
Lübken F.J.
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl024676
Subject(s) - sounding rocket , ion , electron , range (aeronautics) , particle (ecology) , plasma , atomic physics , physics , mesosphere , altitude (triangle) , charged particle , polar , electron density , materials science , atmospheric sciences , stratosphere , geology , nuclear physics , oceanography , geometry , mathematics , quantum mechanics , astronomy , composite material
We present results of in situ measurements of charged nanoparticles, electrons, and positive ions obtained during a sounding rocket flight in October 2004 from Kiruna, Sweden, under nighttime conditions. The particle measurement reveals positive charge signatures in the altitude range between 80 and 90 km corresponding to peak charge number densities of ∼100 e /cm 3 at around 86 km. Aerodynamical analysis of the sampling efficiency of our instrument reveals that the particles must have been larger than 2 nm assuming spherical particles with a density of 3 g/cm 3 . The plasma environment of the observed particles is dominated by negative and positive ions, with only few free electrons. A calculation of the mean particle charge expected for particles in a plasma consisting of electrons and positive and negative ions shows that the presence of sufficiently heavy and numerous negative ions (i.e., m n > 300 amu and λ ≥ 50) can explain the observed positive particle charge.