Relationship between the Arctic Oscillation and Cold Surges over East Asia

Abstract

The present study reveals the changes in the characteristics of cold surges over East Asia associated with the Arctic Oscillation (AO). Based on circulation features, cold surges are grouped into two general types: wave train and blocking types. The blocking type of cold surge tends to occur during negative AO periods, that is, the AO-related polarity of the blocking type. However, the wave train type is observed during both positive and negative AO periods, although the wave train features associated with negative AO are relatively weaker. The cold surges during negative AO are stronger than those during positive AO in terms of both amplitude and duration. The cold surges during positive AO in which the extent of effect is confined to inland China passes through East Asia quickly because of weaker Siberian high and Aleutian low, leading to short duration of these cold surges. In contrast, the cold surge during negative AO, characterized by a well-organized anticyclone-cyclone couplet with high pressure over continental East Asia and low pressure over Japan, brings continuous cold air into the entire East Asian region for more than one week with long-lasting cold advection. It is also found that the tracks of the cold surges during negative AO tend to occur more frequently over Korea and Japan and less frequently over China, compared with those during positive AO. The tracks are related to a west-east dipole structure of the ratio of rain conversion to snow according to AO phase, resulting in freezing precipitation or snowfall events over inland China (Korea and Japan) are likely to occur more frequently during the positive (negative) AO periods.

A comprehensive analysis of coherent rainfall patterns in China and potential drivers. Part II: intraseasonal variability

“…We could not identify a stratospheric origin either. Studies that investigated the origin of cold surges over East Asia report antecedent large-scale wave trains over the Eurasian continent (Takaya and Nakamura 2005;Jeong et al 2006;Park et al 2008Park et al , 2011. Their wave patterns do not resemble the patterns we report here, but appear at higher latitudes.…”

Combined effect of the Arctic Oscillation and the Western Pacific pattern on East Asia winter temperature

“…2001, Jhun and Lee 2004;Jeong and Ho 2005;Park et al 2011;Li et al 2014). At the interannual time scale, Gong et al (2001) stated that the AO affects the intensity of the Siberian High and consequently the winter temperature changes in East Asia.…”

Northern Hemisphere blocking frequency and duration in the CMIP5 models

“…Both these events lead to record breaking surface air temperatures and significant increases in mortality rates [Black et al, 2004;Dole et al, 2011]. In winter, blocking highs have been identified as one of the most important causes of cold surges in the Europe and Eurasia, leading to an abrupt temperature drop with heavy precipitation [e.g., Park et al, 2011].…”