Summary
The Mansurov effect, which for the Northern Hemisphere consists of a negative association between the By component (east-west) of the Interplanetary Magnetic Field (IMF) and the ground-level pressure for stations poleward of ~80º magnetic latitude and is asymmetric between the hemispheres has recently been confirmed for Vostok (78.5°S, 106.9°E; magnetic latitude 83.6°S) using modern data. The magnitude of the association reported at Vostok was small (0.2 hP per nT; 1.2% common covariance), but statistically significant. A more substantial association was found, with a slight delay (two to three days) and a cumulative influence, between the Vostok station pressure and the local vertical electric field (0.10 hP per Vm-1, 10.0% common covariance) supporting the contention that the sun-weather linkage mechanism operates via the atmospheric circuit, consistent with vertical current (Jz) influences on weakly electrified layer cloud lifetimes and cloud cover. We extend the modern data analysis of the Mansurov effect from 1995 to 2005, when almost complete Interplanetary Magnetic Field data are available, for a range of Northern and Southern Hemisphere sites to investigate the interhemispheric asymmetry and the expected fading with decreasing magnetic latitude of the influence implied by the atmospheric electric circuit mechanism.