Solar proton events and evolution of cyclones in the North Atlantic

The influence of solar proton events (SPEs) with particle energies > 90 MeV on the evolution of extratropical cyclones in the North Atlantic is studied. A substantial intensification of the regeneration (secondary deepening) of cyclones near the southeastern Greenland coast after the SPE onset is detected. It is shown that the observed deepening of cyclones is caused by intensified advection of cold when the zone of the Arctic front in the region of the Greenland coast is approached. The results allow us to assume that SPEs with the above particle energies cause substantial changes in the structure of the thermobaric field of the subpolar and high-latitude troposphere, which form more favorable conditions for the regeneration of cyclones. In this case the role of the Arctic vertical frontal zone is apparently important. Temperature field changes can be caused by the radiation effects of variations in the upper cloudiness.