Relation between geomagnetic field and climate variability. Part 2: Probable mechanism

Abstract

In this study we show that correspondence of the main structures of geomagnetic field, near surface air temperature and surface pressure in the mid-latitudes, reported previously in the 1st part of the paper, has its physical foundation. The similar pattern, found in latitude-longitude distribution of the lower stratospheric ozone and specific humidity, allows us to close the chain of causal links, and to offer a mechanism through which geomagnetic field could influence on the Earth’s climate. It starts with a geomagnetic modulation of galactic cosmic rays (GCR) and ozone production in the lower stratosphere through ion-molecular reactions initiated by GCR. The alteration of the near tropopause temperature (by O3 variations at these levels) changes the amount of water vapour in the driest part of the upper troposphere/lower stratosphere (UTLS), influencing in such a way on the radiation balance of the planet. This forcing on the climatic parameters is non-uniformly distributed over the globe, due to the heterogeneous geomagnetic field controlling energetic particles entering the Earth’s atmosphere.