Aircraft measurements of the geomagnetic latitude effect on air-earth current density

Abstract

Recent investigations of the electrode effect and the phenomenon of bubble electrification processes at the air-sea interface throw doubt on the applicability of using surface atmospheric electric observations made at sea by the Carnegie for proving the latitude effect in the columnar resistance of the atmosphere. Conduction current measurements were taken on flights during a period of decades by two instrumented aircraft in oceanic areas remote from sources of pollution. A composite of these measurements is given and confirms the notion that there is a latitude variation in air-Earth current. With the reasonable assumptions of an equal ionospheric potential and either low concentrations of Aitken nuclei or at least suitably small variations in their density with respect to latitude, the observed variation is apparently the integrated result of the Earth's magnetic field acting on cosmic ray activity throughout the troposphere.