Influences of atmospheric intraseasonal oscillation in mid–high latitudes on winter haze pollution over the Beijing‐Tianjin‐Hebei region

Abstract

This paper analyses the intraseasonal evolution of the winter haze pollution over the Beijing‐Tianjin‐Hebei (BTH) region in China between 1979 and 2013, and the influences of the atmospheric intraseasonal oscillations (ISOs) in mid–high latitudes. Two significant ISO signals of 10–20‐day and 20–40‐day are identified from the winter haze pollution over the BTH region, and their superposition notably contributes to the occurrence of haze pollution. On the 10–20‐day timescale, the haze pollution is intimately associated with a mid–high‐level southeastward propagating wave train that originates from the North Atlantic. With the wave evolution, an anomalous anticyclone reaches the Korean Peninsula–Japan, leading to strong descents and anomalous southerly winds over the BTH region, favourable for haze pollution. On the 20–40‐day timescale, the atmospheric wave train originates from the eastern North America, propagates eastward to the northwestern Lake Baikal, and then turns southward to the northeastern China–Japan. The peak stage of the haze pollution is related to the resultant zonal dipole, with the anomalous cyclone over the northwestern Lake Baikal and the anomalous anticyclone over the northeastern China–Japan. The dominance of the mid–upper tropospheric anticyclone over the BTH region suppresses the development of convection, thus hindering the vertical diffusion and wet deposition of pollutants. Moreover, the anomalous westerly winds between the dipole weaken the incursion of cold mass from higher latitudes, thus further contributing to the peak of haze pollution.

Quasi-Biweekly Oscillation of PM2.5 in Winter over North China and Its Leading Circulation Patterns

“…In the mid-high latitude regions, there are obvious quasi-biweekly wave trains at both 850 hPa and 300 hPa. The recent research results [29][30][31][32] also indicate a close relationship between the PM 2.5 concentration and the Rossby wave train at mid-high latitudes.…”

“…In the study of Wu et al [32], it was found that the QBWO of haze events in the Beijing-Tianjin-Hebei region in the winter of 1979-2013 in China was mainly influenced by the Rossby wave spreading eastward along the Eurasian continent from the North Atlantic Ocean. The peak phase of haze pollution was related to the zonal dipole, that is, the abnormal cyclone in the northwest of Lake Baikal and the abnormal anti-cyclone in the northeast of China and Japan.…”

“…In winter, the atmosphere in East Asia shows significant quasi-biweekly oscillation (QBWO) characteristics, including wind, temperature, and humidity [27,28]. The research shows that the temporal and spatial distribution of the PM 2.5 concentration in eastern China is closely related to the wave train in Eurasia [29][30][31][32]. Under the joint action of the polar front jet and the subtropical westerly jet, the quasi-biweekly evolutions of the Eurasian teleconnection pattern and Circum-global teleconnection pattern are responsible for the propagation of the wave trains, further affecting the quasi-biweekly evolution of PM 2.5 in eastern China [29].…”

Role of the Boreal Autumn Antarctic Oscillation in Controlling the Winter Frequency of Severe Pollution Events in the Beijing–Tianjin–Hebei Region, China

“…D. Wu et al. (2023) confirmed that the correlation between the multi‐year time series of PM 2.5 concentration and the number of daily haze stations is 0.74 ( p < 0.01). The data sets were based on four times per day; that is, 06:00, 06:00, 12:00, and 18:00 local time.…”