Comparison of the influence of two types of cold surge on haze dispersion in eastern China

Abstract. Cold surge (CS) is considered a favorable weather process to improve air quality and widely recognized. However, there no detailed study on the differences in dispersion ability of different types CSs relation haze days eastern China (HDEC). This paper uses hierarchical clustering algorithm classify cool-season (November February following year) across into blocking wave-train compares their influences number HDEC from 1980 2017. Results show that can significantly visibility generally for about 2 d longer than CSs, which indicates have weaker dissipate compared with CSs. The affect by changing meteorological elements like thermal inversion potential, horizontal surface wind, sea level pressure (SLP), temperature (SAT). A period 4 after outbreak variations potential wind two tend be consistent. negative SAT anomalies positive SLP caused lasted shorter those forming conditions rapid growth HDEC. Furthermore, results recent years, especially 1990s, frequency has decreased significantly, while slightly increased, indicating overall weakened general. work may provide reference future formulation control policies East Asia.