Model study of the influence of charged dust/aerosol on electrical conductivity and low latitude mesospheric echoes (LMEs)

Considerable quantities of small dust/aerosol particles of meteoric origin are present in the mesosphere at all heights and latitudes. These particles have a role to play in various aspects related to both physics and chemistry of the region. Due to electron attachment and photoionization these particles can produce electron density fluctuations that lead to an enhancement in the MST radar echo strength. Due to electron/ion-attachment the dust/aerosols can considerably alter the electrical conductivity of the mesosphere. The charge separations produced by the falling charged dust/aerosol particles can lead to the often-observed high electric fields, particularly in the lower mesosphere. In the present study, using a heterogeneous ion-chemistry model, the possibility of the influence of positively and negatively charged sub-visible particles (1-30 nm) on the electrical conductivity and MST radar echo enhancements are studied. The results are for an equatorial quiet daytime mesosphere in the height range of 60 to 90 km.