Potential impact of atmospheric heating over East Europe on the zonal shift in the South Asian high: the role of the Silk Road teleconnection

It is well recognized that the zonal shift in the South Asian High (SAH) has pronounced influences on weather and climate anomalies over surrounding and teleconnected regions. Hence, it is of great importance to investigate the factors related to the interannual variation in the zonal location of the SAH. This study indicates that the anomalous atmospheric apparent heat source (<Q(1)>) around East Europe has a close relationship with the interannual variation in the SAH zonal shift during boreal summer. In particular, when above (below) normal <Q(1)> exists, the SAH tends to shift westward (eastward). Above-normal <Q(1)> over East Europe can trigger an eastward propagating wave train along the subtropical jet stream, resembling the negative phase of the Silk Road teleconnection pattern, with positive geopotential height anomalies around the Iranian Plateau and Northeast Asia and negative anomalies around East Europe and the Tibetan Plateau, which could lead to a westward shift in the SAH. Our model experiments confirm that anomalous <Q(1)> around East Europe can exert pronounced impacts on the zonal shift in the SAH by inducing an eastward propagating atmospheric wave train.