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 are thankful in order to Zhiwei Zhu and Jian Cao out-of Nanjing University of information Research and you can Tech to possess of use conversation and tech guidance inside the powering the fresh new mathematical design. I thank the unknown reviewers for their useful statements and you may information. Which works was supported by new Atmospheric Pollution Power over the newest Finest Minister Financing (Grant Zero. DQGG0104), the newest Federal Absolute Science First step toward Asia (Offer No.41790471), the latest Federal Preliminary research Creativity (973) system out of Asia (Give No. 2012CB417205), and also the Proper Consideration Research Program regarding Chinese Academy of Sciences (Grant No.
XDA20100304)
Study S1 Figure S1. December–March (DJF) compound variations off water body temperature (SST) (shady, °C) from inside the several months anywhere between (a) pre-P1 (1961–1971) and P1 (1972–1996) (pre-P1 without P1) and you can (b) P2 (1997–2012) and you can article-P2 (2013–2018) (P2 without post-P2) once removing the fresh new linear trend. New purple contours during the (a) and (b) reveal the fresh west Pacific K-shape as well as the east Pacific triangle-contour countries, which can be implemented when you look at the defining the latest super-ENSO index considering Wang et 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 (WHDBlowjob). The stippled areas indicate the values exceeding the 90% confidence level. The pentagram delineates the location of Beijing. The more (less) frequent WHDBj is defined with a detrended WHDCock sucking value >0.8 (
Profile S3. The fresh new climatological-suggest (1981–2010) DJF five hundred-hPa geopotential level (traces, gpm) and 850-hPa cinch (vectors, m·s ?1 ). The fresh pentagram distills the spot from Beijing https://datingranking.net/nl/wireclub-overzicht/, while the grey shaded area denotes new Tibetan Plateau.
Profile S4posited DJF anomalies regarding (a) body relative moisture (shady, %), (b) skin air temperature (shaded, °C), (c) epidermis wind-speed (shaded, m·s ?step 1 ), (d) sea-peak tension (shady, hPa), and you can (e) sky temperatures between 850 and you may step one,one hundred thousand hPa (shaded, °C) to have pre-P1 (1961–1971). The beds base period try 1961–2018.
Contour S5. DJF chemical huge difference away from five hundred-hPa omega (contours, 10 ?2 Pa·s ?1 ) during the months ranging from P1 (1972–1996) and you can P2 (1997–2012) (P2 without P1) just after removing the new linear development. Beliefs which might be high from the ninety% trust height was shady. The newest pentagram delineates the location of Beijing.
Contour S6posited DJF anomalies away from SST (shaded, °C) to own blog post-P2 (2013–2018). The fresh yellow lines reveal the fresh west Pacific K-figure and also the eastern Pacific triangle-figure countries, which are implemented in the determining the super-ENSO index centered on Wang mais aussi al. (2013). The beds base months try 1961–2018.
