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_{Cock sucking} during P2 (corresponding to warm AMO) and increased epochal WHD_Blowjob during P1 (corresponding to cold AMO) allow us to speculate that AMO could play a relatively minor role in modulating WHD_Bj 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

We are thankful so you’re able to Zhiwei Zhu and you may Jian Cao out of Nanjing University of information Science and you may Technology getting helpful discussion and you may technical guidelines into the running the numerical design. I give thanks to brand new anonymous writers because of their positive statements and you will pointers. That it functions try backed by this new Atmospheric Contaminants Control of the fresh Best Minister Finance (Grant No. DQGG0104), brand new Federal Absolute Science First step toward China (Offer No.41790471), the newest National Preliminary research Innovation (973) program off China (Give No. 2012CB417205), therefore the Strategic Consideration Look Program off Chinese Academy out-of Sciences (Offer Zero.

XDA20100304)

Data S1 Shape S1. December–March (DJF) substance differences away from ocean surface heat (SST) (shady, °C) for the several months anywhere between (a) pre-P1 (1961–1971) and you will P1 (1972–1996) (pre-P1 without P1) and (b) P2 (1997–2012) and you may article-P2 (2013–2018) (P2 minus article-P2) just after removing this new linear pattern. The brand new red traces inside the (a) and you may (b) tell you the fresh new western Pacific K-profile and east Pacific triangle-contour places, that blackfling are implemented within the identifying the fresh super-ENSO index predicated on 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_Blowjob is defined with a detrended WHD_Bj value >0.8 (

Profile S3. The newest climatological-suggest (1981–2010) DJF five-hundred-hPa geopotential peak (lines, gpm) and 850-hPa snap (vectors, m·s ?step 1 ). The brand new pentagram spells out the location out of Beijing, additionally the gray shaded area denotes this new Tibetan Plateau.

Shape S4posited DJF anomalies away from (a) body relative dampness (shady, %), (b) skin sky temperatures (shady, °C), (c) body wind-speed (shady, m·s ?step one ), (d) sea-height pressure (shaded, hPa), and (e) sky temperatures anywhere between 850 and you will step one,100000 hPa (shady, °C) to own pre-P1 (1961–1971). The beds base several months is 1961–2018.

Figure S5. DJF substance distinction regarding five-hundred-hPa omega (outlines, ten ?2 Pa·s ?step one ) inside the period ranging from P1 (1972–1996) and P2 (1997–2012) (P2 minus P1) once removing the latest linear development. Philosophy which can be extreme from the ninety% trust height is shaded. The pentagram delineates the region from Beijing.

Contour S6posited DJF defects out of SST (shady, °C) to possess blog post-P2 (2013–2018). New yellow contours show the newest western Pacific K-figure as well as the eastern Pacific triangle-profile countries, being deployed in the determining the brand new mega-ENSO index according to Wang mais aussi al. (2013). The bottom several months was 1961–2018.