Recent measurements of middle atmospheric electric fields and related parameters

Abstract

In 1989, two series of rocket measurements were carried out to investigate middle atmosphere electric fields. The measurements were taken both in the Northern Hemisphere on Heiss Island (80°37′N and 58°03′E) and in the Southern Hemisphere in the Indian Ocean (40–60°S and ~45°E) on board the research vessel ‘Akademik Shirshov’. Along with the vertical electric fields, aerosol content and positive ion density were also measured. Some of the rocket launches were made during the extremely strong solar proton events (SPE) of October 1989. The experiments showed the strong variability of the electric fields in the middle atmosphere at polar and high middle latitudes. In all the measurements the maximum of the vertical electric field height profile in the lower mesosphere was observed to be more than ~ 1 V/m. The electric field strength and the field direction at maximum varied considerably among the launches. A maximum value of + 12 V/m was detected at a height of about 58 km at 58°30′S on 21 October 1989 during the SPE. The simultaneous measurements of the electric field strength, positive ion density and aerosols point out both an ion -aerosol interaction and a connection between the mesospheric electric fields and aerosol content.