Maintenance Mechanism for the Teleconnection Pattern over the High Latitudes of the Eurasian Continent in Summer

Abstract

AbstractThere is a zonally oriented teleconnection pattern over the high-latitude Eurasian continent, which is maintained through baroclinic energy conversion. In this study, we investigate the unique features of the maintenance mechanism of this teleconnection. It is found that the baroclinic energy conversion is most efficient in both the midtroposphere and the lower troposphere, and that the baroclinic energy conversion in the lower troposphere is comparable to that in the midtroposphere. Further results indicate that the basic state plays a crucial role in the baroclinic energy conversion. For both the middle and lower troposphere, the atmospheric stability is low and the Coriolis parameter is large over high-latitude Eurasia, favoring strong baroclinic energy conversion. Particularly, in the lower troposphere, the atmospheric stability exhibits a clear land–sea contrast, favoring baroclinic energy conversion over the continents rather than the oceans. Furthermore, in the lower troposphere, the in-phase configuration of the meridional wind and temperature anomalies, which results from the strong meridional gradient of mean temperature around the north edge of the Eurasian continent, also significantly contributes to baroclinic energy conversion. This study highlights the role of the basic state of temperature rather than zonal wind in maintaining the high-latitude teleconnection through baroclinic energy conversion.