Relationship between Ural–Siberian Blocking and the East Asian Winter Monsoon in Relation to the Arctic Oscillation and the El Niño–Southern Oscillation

Abstract

This study attempts to assess the possible linkage between Ural–Siberian blocking and the East Asian winter monsoon (EAWM). During the boreal winter, the dominance of blocking thermally enhances cold advection downstream. The frequent occurrence of Ural–Siberian blocking potentially promotes a cold EAWM and vice versa. The seasonal blocking activity can be regarded as the combined effect of the Arctic Oscillation (AO) and the El Niño–Southern Oscillation (ENSO). Weakened (strengthened) meridional flow in the positive (negative) phase of the AO is unfavorable (favorable) for the formation of blocking highs. Because the AO shows a close relationship with the North Atlantic Oscillation (NAO), its teleconnection with Ural–Siberian blocking may exist in the form of an eastward-propagating wave train. Be that as it may, the wave train signal across East Asia may be disturbed by the external effect of a strong ENSO event, which probably enhances (weakens) the westerlies near Siberia in its warm (cold) phase. Consequently, the blocking–EAWM relationship is stronger (weaker) when the AO and ENSO are in phase (out of phase). If both AO and ENSO attain the positive (negative) phase, the Siberian high tends to be weaker (stronger) and the temperature tends to be higher (lower) in East Asia, with less (more) Ural–Siberian blocking. On the other hand, if they are out of phase, they are not strongly linked to the intensity of the Siberian high, and the blocking activity over Ural–Siberia is unclear.

The 2011 Great Flood in Thailand: Climate Diagnostics and Implications from Climate Change

“…8d; i.e., era difference between 1997-2013 and 1980-96), although around East Asia the colder SST and stronger winter monsoon northeasterlies stood apart from the global pattern as a pronounced regional feature. One possible explanation is that the well-developed La Niña during 2011 may enhance East Asian winter monsoon; this echoes the observation by Cheung et al (2012) that the cold event of ENSO (i.e., La Niña) tends to enhance the Siberian high and lower the temperatures in East Asia. This observation is also apparent in 2011 by the robust anticyclone anomaly over Siberia (Fig.…”

Impact of Arctic amplification on East Asian winter climate

“…Based on our previous results, the quasi-stationary Rossby wave train of the blocking-EAWM teleconnections has centers of action over the Euro-Atlantic region (~0°), the Urals Mountains (~60°E), and East Asia (~120°E) (Cheung et al 2012). Because the Rossby wave train propagates eastwards from the Euro-Atlantic region to East Asia, we speculate that this is related to the mean state of the mean zonal wind over the North Atlantic and Eurasia.…”

“…As demonstrated in Cheung et al (2012), the blocking-EAWM relationship is related to large-scale teleconnections (e.g. North Atlantic Oscillation (NAO) and El Niño-Southern Oscillation (ENSO)) in a statistical sense, but the underlying dynamics have not been explored.…”

“…All the cold spells are being compared with the four typical cold-air pathways mentioned in Ding and Krishnamurti (1987). The cold spells have also been matched with the blocking events obtained in our previous work (Cheung et al 2012(Cheung et al , 2013. Finally, we will investigate the evolution of extreme cold spells in East Asia in relation to blocking, as well as assess the models' abilities to capture the blocking events with different origins of cold spells and their relative contribution to EAWM variability.…”

Assessment of Climate Variability over East Asia-Korea for 2015/16 Winter

“…동아시아 겨울몬순은 시베리아 고기압, 동아시아 상층 제트 및 기압골의 강 도 등으로 표현되며 (Ding, 1990;Wang et al, 2010), 특히 시베리아 고기압 강도의 계절내 변동은 동아시 아 겨울몬순의 중요한 특징인 한파의 발생과 밀접한 관련이 있다 (Ding, 1990;Zhang et al, 1997). 동아시 아 겨울몬순의 변동성은 엘니뇨와 Madden Julian Oscillation (MJO) 등의 열대 기후변동성 (Jeong et al, 2005(Jeong et al, , 2008, 극진동 및 북대서양진동 (Gong et al, 2001;Jeong and Ho, 2005), 유라시아 저지고기압 (Cheung et al, 2012), 성층권 변동성 (Song et al, 2015;Woo et al, 2015) 등의 외부의 다양한 인자에 영향을 받는다고 알려져있다. 알려진 내외부적 영향인자 이 외에도, 장기 기후변화와 관련하여 겨울몬순의 특성 이 변화하고 있으며 (Woo et al, 2012), 북극해빙 (Honda et al, 2009;Kug et al, 2015) 및 유라시아 눈덮임 (Cohen and Jones, 2011;Jeong et al, 2011 (Fig.…”