Impact of the Scandinavian pattern on long-lived cold surges over the South China Sea

Abstract

Abstract This study investigates the influence of the Scandinavian (SCA) pattern on long-lived cold surges over the South China Sea (SCS). The results show that, different from the short-lived ones, the majority of long-lived cold surges over the SCS are preceded by a negative phase of quasi-stationary SCA pattern in the extratropics, which is characterized as a primary cyclonic center over the Scandinavian Peninsula and two anticyclonic ones over North Atlantic and central Siberia. This connection is mainly conducted through a continuous amplification of the high pressure anomalies over East Asia. On the other hand, the SCA-related anomalies also reveal identical responses as an increase in sea level pressure over East Asia and northerly flows over the SCS. Besides, the SCA pattern may influence the long-lived cold surges over the SCS by facilitating blocking occurrence through the extensive and quasi-stationary anticyclone over central Siberia. The present results have an implication for the extended weather forecast: The long-lasting circulation anomalies, such as the SCA pattern, can affect long-lasting weather phenomena in the regions which are located remotely in both the zonal and meridional directions, such as long-lived cold surges over the SCS.