Impacts of climate anomalies on the interannual and interdecadal variability of autumn and winter haze in North China: A review

Abstract

From the perspectives of remote sensing and climatic factors like surface meteorological parameters, large‐scale atmospheric circulations, and external forcing factors (EFFs), the authors synthesize and review spatiotemporal variations of PM2.5 over North China and how climate anomalies affect autumn and winter haze variability in North China according to recent studies. This review focuses on both interannual and interdecadal timescales. It is shown that circulations play an important role in influencing haze variability. Atmospheric circulations, which would be modulated by EFFs like sea surface temperature, sea ice, and snowpack, can affect the climate variability in haze over North China via modulation of surface‐layer parameters that are closely connected with the haze phenomenon. Therefore, EFFs are deemed significant factors impacting the climate variability of haze over North China, serving as paramount precursory signals for haze prediction. Furthermore, this paper suggests potential future research directions for haze variability studies in North China on the basis of summarizing and concluding the associated processes/mechanisms on how climatic factors affect haze variability, which could provide reference for treating and forecasting in situ hazy conditions.

Interdecadal relationship between the wintertime haze frequency over Beijing and mega‐ENSO

“…Before addressing this, the anomalies of boundary layer parameters tied to the winter haze variability in Beijing should be revisited. A higher WHD BJ is associated with significantly warmer and moister surface conditions (Figure S2a,b) as well as the stable atmospheric stratification at lower levels (Figure S2f), in conjunction with decreased surface wind, sea‐level pressure (SLP), PBLH, and surface southerly wind anomalies deduced from the spatial distribution of SLP anomalies (Figure S2c–e), which is in line with previous studies (Yin et al ., 2017; Wang et al ., 2020a). In fact, these anomalous boundary conditions are indicative of conducive environmental circumstances, favoring the transportation and accumulation of in situ aerosols and water vapor over Beijing and its surroundings.…”

“…Because the haze frequency over Beijing and other subregions in central and eastern China (CEC) is highest in the boreal winter (e.g., Mao et al ., 2019), the majority of previous studies focused on in situ haze variations in winter. There is a general consensus of opinion on the haze variabilities: winter haze frequency can be significantly modulated by both external anthropogenic emissions (e.g., Yang et al ., 2016; Pei et al ., 2020) and internal climate anomalies such as atmospheric circulation and El Niño–Southern Oscillation (ENSO) (e.g., Zhang et al ., 2014; Wang and Chen, 2016; Ding et al ., 2017; Wu et al ., 2017; Cheng et al ., 2019; Mao et al ., 2019; Chang et al ., 2020; Wang et al ., 2020a, 2020b). It is especially noteworthy that, compared to studies on the interannual variability of winter haze frequency over CEC, studies examining interdecadal timescales are much fewer.…”

Intensified modulation of winter aerosol pollution in China by El Niño with short duration

“…The ENSO cycle is composed of a warm phase (i.e., El Niño) and a cool phase (i.e., La Niña) of sea surface temperatures (SSTs) over the tropical eastern Pacific Ocean, which further cause precipitation, atmospheric circulation and temperature anomalies in much of the tropics and subtropics. Such changes also affect the spatiotemporal distribution of aerosols in China (Feng et al, 2017(Feng et al, , 2020Sun et al, 2018;Yang et al, 2014;Zhao et al, 2018;Zhu et al, 2012;J. Wang et al, 2020b).…”

Linkages between the atmospheric transmission originating from the North Atlantic Oscillation and persistent winter haze over Beijing

“…High emissions of haze pollutants (e.g., black carbon and organic matter) contribute greatly to the formation of hazy weather in Beijing (Li and Han, 2016;Wu et al, 2016;Li et al, 2017). In addition, the atmospheric and meteorological conditions as well as external and remote influences, such as Arctic sea-ice concentration (SIC), snow cover across Siberia and sea surface temperatures (SSTs), also need to be taken into consideration (An et al, 2019;Wang et al, 2020;Wang, 2016, 2018). Atmospheric circulations that are favorable for hazy weather in Beijing include a weak East Asian winter monsoon (EAWM), a shallow East Asian trough and a northward shift of the East Asian jet (Chen and Wang, 2015;Zou et al, 2017;Wang et al, 2020).…”

“…In addition, the atmospheric and meteorological conditions as well as external and remote influences, such as Arctic sea-ice concentration (SIC), snow cover across Siberia and sea surface temperatures (SSTs), also need to be taken into consideration (An et al, 2019;Wang et al, 2020;Wang, 2016, 2018). Atmospheric circulations that are favorable for hazy weather in Beijing include a weak East Asian winter monsoon (EAWM), a shallow East Asian trough and a northward shift of the East Asian jet (Chen and Wang, 2015;Zou et al, 2017;Wang et al, 2020). These circulations tend to reduce the intrusion of cold air to Beijing and hence result in poor ventilation in winter (Zou et al, 2017;.…”