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 WHDBlowjob 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 WHDBlowjob 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 pleased in order to Zhiwei Zhu and you can Jian Cao off Nanjing School of information Research and you can Technology to own of use dialogue and tech direction for the running the latest numerical design. I give christian cupid reviews thanks to the brand new private writers for their constructive statements and you may suggestions. It performs is actually supported by this new Atmospheric Contamination Control over this new Perfect Minister Funds (Give No. DQGG0104), the fresh new Federal Pure Research Foundation of Asia (Grant Zero.41790471), the brand new National Research Development (973) program out of Asia (Grant Zero. 2012CB417205), and the Strategic Top priority Look Program away from Chinese Academy out of Sciences (Give No.
XDA20100304)
Analysis S1 Contour S1. December–March (DJF) compound differences out of ocean epidermis temperature (SST) (shaded, °C) into the period anywhere between (a) pre-P1 (1961–1971) and you may P1 (1972–1996) (pre-P1 minus P1) and you can (b) P2 (1997–2012) and you can article-P2 (2013–2018) (P2 minus blog post-P2) immediately following removing the latest linear pattern. This new reddish outlines into the (a) and you may (b) show this new west Pacific K-profile plus the east Pacific triangle-shape places, that are implemented from inside the determining the brand new super-ENSO list according to 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 (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 (
Figure S3. The fresh new climatological-indicate (1981–2010) DJF 500-hPa geopotential top (lines, gpm) and you can 850-hPa cinch (vectors, m·s ?step one ). The fresh new pentagram distills the location from Beijing, and the grey shaded area indicates the Tibetan Plateau.
Figure S4posited DJF defects of (a) skin relative dampness (shaded, %), (b) epidermis air temperature (shaded, °C), (c) body wind-speed (shady, m·s ?step 1 ), (d) sea-height stress (shady, hPa), and (e) heavens temperature ranging from 850 and step 1,000 hPa (shady, °C) for pre-P1 (1961–1971). The base months try 1961–2018.
Shape S5. DJF composite distinction out-of five hundred-hPa omega (contours, ten ?dos Pa·s ?step 1 ) during the several months between P1 (1972–1996) and you will P2 (1997–2012) (P2 without P1) once removing the newest linear development. Values that will be extreme within ninety% count on top try shady. The fresh new pentagram delineates the spot off Beijing.
Shape S6posited DJF defects from SST (shaded, °C) for post-P2 (2013–2018). This new purple lines tell you the new western Pacific K-profile as well as the eastern Pacific triangle-figure places, which can be implemented in determining the new mega-ENSO list according to Wang et al. (2013). The bottom months try 1961–2018.
