North Atlantic Oscillation and Variations of Geomagnetic Field

Abstract

The North Atlantic Oscillation is one of the most influential climatic modes in the Northern Hemisphere. However, the mechanism(s) standing behind its wide spectra of variations is still unknown despite its numerous investigations. This paper presents evidence for a synchronization between secular variations of geomagnetic field intensity and NAO long-term variability. Analysis of the connectivity between geomagnetic secular variations and the sea-level pressure – point by point, in a grid with resolution 10 [deg] in latitude and longitude – reveals that the strength of their relation is unevenly distributed over the Northern Hemisphere. Based on the machine learning analysis over the period 1900–2019, we found that there are two centres of significant geomagnetic-pressure relations – the weaker of them is placed slightly north of Iceland, and the stronger one is in a close proximity to Azores islands. The suggested mechanism for geomagnetic influence on the near surface climatic conditions includes the geomagnetic modulation of energetic particles precipitating in Earth's atmosphere, and their impact on the lower stratospheric ozone. The analysis of ozone-pressure relation shows, in addition, reasonable similarities with the spatial patterns of geomagnetic-pressure relations.

Impact of Forbush Decreases and Geomagnetic Storms on the Atmospheric Ozone Profiles

“…Our previous analyses (Kilifarska, Bakhmutov, & Melnyk, 2022) reveal that at these latitudes is detected a centennial enhancement of ozone at 70 hPa between the first decades of 20 and 21st centuries. The strongest ozone impact on the sea level pressure, within the period 1900–2019, is found exactly in the same region (Kilifarska, Velichkova, & Mokreva, 2022). This suggests that the most probable mechanism of ozone influence on the sea level pressure near 50° latitude is the direct one.…”