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 WHDBj during P2 (corresponding to warm AMO) and increased epochal WHDBj during P1 (corresponding to cold AMO) allow us to speculate that AMO could play a relatively minor role in modulating WHDBj 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’re grateful to Zhiwei Zhu and you can Jian Cao off Nanjing University of information Technology and you will Technical to possess beneficial conversation and you can technology guidance inside running the fresh new mathematical model. I give thanks to new private writers because of their useful comments and you may suggestions. It works are backed by the newest Atmospheric Toxic contamination Power over the latest Primary Minister Money (Grant No. DQGG0104), the fresh new Federal Absolute Technology Foundation of China (Grant Zero.41790471), the latest Federal Research Advancement (973) system from Asia (Grant Zero. 2012CB417205), additionally the Strategic Top priority Research Program out of Chinese Academy of Sciences (Give Zero.
XDA20100304)
Study S1 Shape S1. December–March (DJF) substance distinctions of ocean epidermis temperatures (SST) (shady, °C) during the months ranging from (a) pre-P1 (1961–1971) and you may P1 (1972–1996) (pre-P1 minus P1) and you may (b) P2 (1997–2012) and post-P2 (2013–2018) (P2 without blog post-P2) after deleting the fresh new linear trend. The latest purple traces for the (a) and you may (b) inform you the brand new west Pacific K-contour additionally the eastern Pacific triangle-contour regions, which are deployed inside the determining the fresh new super-ENSO directory centered on Wang ainsi que 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 upforit telefoonnummer more and less frequent wintertime haze days in Beijing (WHDBj). The stippled areas indicate the values exceeding the 90% confidence level. The pentagram delineates the location of Beijing. The more (less) frequent WHDCock sucking is defined with a detrended WHDBj value >0.8 (
Shape S3. The new climatological-indicate (1981–2010) DJF five hundred-hPa geopotential top (traces, gpm) and you will 850-hPa piece of cake (vectors, m·s ?1 ). This new pentagram spells out the spot of Beijing, as well as the gray shaded town denotes brand new Tibetan Plateau.
Shape S4posited DJF defects regarding (a) epidermis relative humidity (shaded, %), (b) epidermis heavens temperatures (shaded, °C), (c) facial skin wind-speed (shaded, m·s ?1 ), (d) sea-peak stress (shaded, hPa), and (e) sky temperature anywhere between 850 and you can step 1,000 hPa (shaded, °C) to possess pre-P1 (1961–1971). The base months was 1961–2018.
Figure S5. DJF element change out of 500-hPa omega (lines, ten ?dos Pa·s ?step 1 ) in the months ranging from P1 (1972–1996) and P2 (1997–2012) (P2 without P1) immediately after removing the fresh new linear development. Opinions that will be significant at the 90% trust level are shady. The fresh pentagram spells out the spot off Beijing.
Shape S6posited DJF anomalies away from SST (shady, °C) getting article-P2 (2013–2018). New purple traces tell you the newest west Pacific K-contour and the east Pacific triangle-profile regions, that are implemented for the identifying the fresh new mega-ENSO list considering Wang et al. (2013). The base months are 1961–2018.