A Van de Graaf source mechanism for middle atmospheric vertical electric fields

It is proposed that meteoric and other debris descending through the mesosphere constitute a natural Van de Graaf generator for vertical electric fields within the mesosphere. Dust and aerosol particles falling from above 85 km are charged negatively in the upper D-region. Charge is lost in the region below 70 km. This net charge transport creates a vertical polarization electric field. Calculated fields are in the range of 10 mV/m for the average input of meteoric debris. Observed vertical electric fields are confined to a few occasions when large fields of the order of 4 V/m are observed to maximize at 65 km. Calculated fields from this model also maximize at this altitude, but a special event with increased dust density or another mechanism to increase relative vertical velocity is required to explain the large fields. Such large values are the exception rather than the rule for D-region vertical electric fields.