Fourth, it was observed that DJF AMO exhibits clear interdecadal fluctuations around the early 1970s (switching from positive to negative) and mid-1990s (switching from negative to positive) (Geng et al., 2017 ), and it has a fairly similar in-phase interdecadal relationship with mega-ENSO. , 2015 ), the warm (cold) AMO might lead to an increased (decreased) epochal winter haze frequency over Beijing and its surroundings by suppressing (facilitating) occurrences of in situ cold air via a quasi-barotropic planetary-scale Rossby wavetrain emanating from the North Atlantic. However, the actual decreased epochal WHD_Blowjob during P2 (corresponding to warm AMO) and increased epochal WHD_{Cock sucking} during P1 (corresponding to cold AMO) allow us to speculate that AMO could play a relatively minor role in modulating WHD_{Cock sucking} on decadal timescales compared to mega-ENSO. Furthermore, it was found that AMO can modulate variations in PDO/IPO on decadal timescales through atmospheric bridges (Si and Ding, 2016 ; Kosaka, 2018 ; Zhang et al., 2018 ). Therefore, the existence of appreciable interactions between DJF AMO and mega-ENSO, if any, should be ascertained. These issues are deserving of further investigations in future studies.

ACKNOWLEDGEMENTS

Our company is pleased so you can Zhiwei Zhu and Jian Cao regarding Nanjing School of data Technology and you can Tech to have beneficial discussion and you may tech recommendations from inside the powering the brand new numerical design. I thank this new unknown writers for their constructive statements and you will advice. It really works are backed by the new Atmospheric Contamination Control over the Perfect Minister Funds (Give Zero. DQGG0104), brand new Federal Natural Research Foundation of China (Grant Zero.41790471), the brand new National Preliminary research Creativity (973) program regarding China (Give No. 2012CB417205), together with Strategic Concern Research System off Chinese Academy of Sciences (Give Zero.

XDA20100304)

Investigation S1 Contour S1. December–February (DJF) element distinctions out of ocean body temperature (SST) (shady, °C) within the period between (a) pre-P1 (1961–1971) and you can P1 (1972–1996) (pre-P1 without P1) and you will (b) P2 (1997–2012) and article-P2 (2013–2018) (P2 without blog post-P2) shortly after deleting the latest linear trend. The latest reddish contours within the (a) and (b) show the fresh western Pacific K-shape while the eastern Pacific triangle-shape places, which happen to be implemented for the determining brand new super-ENSO directory considering Wang mais aussi al. (2013).

Figure S2. DJF composite differences of (a) surface relative humidity (shaded, %), (b) surface air temperature (shaded, °C), (c) surface wind speed (shaded, m·s ?1 ), (d) sea-level pressure (shaded, hPa), (e) planetary boundary layer height (shaded, m), and (f) air temperature between 850 and 1,000 hPa (shaded, °C) between years of more and less frequent wintertime haze days in Beijing (WHD_{Cock sucking}). The stippled areas indicate the values exceeding the 90% confidence level. The pentagram delineates the location of Beijing. The more (less) frequent WHD_Bj is blendr coupons defined with a detrended WHD_Blowjob value >0.8 (

Profile S3. The brand new climatological-mean (1981–2010) DJF five hundred-hPa geopotential top (contours, gpm) and 850-hPa cinch (vectors, m·s ?step 1 ). The pentagram distills the location out of Beijing, therefore the grey shaded town indicates brand new Tibetan Plateau.

Profile S4posited DJF defects off (a) skin relative dampness (shaded, %), (b) epidermis air temperatures (shady, °C), (c) skin wind-speed (shady, m·s ?1 ), (d) sea-top pressure (shaded, hPa), and you will (e) heavens temperatures ranging from 850 and step one,100000 hPa (shaded, °C) for pre-P1 (1961–1971). The bottom months is actually 1961–2018.

Figure S5. DJF compound variation off five-hundred-hPa omega (outlines, 10 ?2 Pa·s ?step one ) for the several months anywhere between P1 (1972–1996) and you can P2 (1997–2012) (P2 minus P1) just after removing the new linear pattern. Beliefs which might be significant in the ninety% believe height is actually shady. The new pentagram spells out the location off Beijing.

Contour S6posited DJF anomalies of SST (shaded, °C) having article-P2 (2013–2018). The new red traces show the western Pacific K-contour together with east Pacific triangle-contour countries, which are deployed in the determining the fresh mega-ENSO directory according to Wang et al. (2013). The base several months try 1961–2018.