Response of atmospheric blocks to the arctic amplification in the idealized model experiments

Abstract

This study explores the responses of jet and atmospheric blocks to Arctic amplification (AA) in a simple atmospheric general circulation model. External heat is forced in the pole to mimic the AA. As the temperature increases in the pole, it changes the eddies, especially in midlatitudes, and the jet moves towards the equator. Meanwhile, the storm track moves equatorward along with the jet. We do not confirm that the jet gets wavier while in the midlatitudes where the jet gets stronger, whereas it is identified that the jet gets wavier at high latitudes. Though the jet gets weaker and wavier in high latitudes, no clear blocking increase is found. Rather, blocks are shown to increase in the midlatitudes, regarded as in relation to the equatorward shift of the storm track.