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Asymmetrical Linkages Between Multifrequency Atmospheric Waves and Variations in Winter PM 2.5 Concentrations in Northern China During 2013–2019
Author(s) -
Chang Wenyuan,
Zhan Jianqiong
Publication year - 2020
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2019jd031999
Subject(s) - atmospheric sciences , climatology , haze , environmental science , atmospheric wave , geology , geography , meteorology , wave propagation , physics , gravity wave , quantum mechanics
Atmospheric waves have a broad spectrum of momentum at various frequencies and link to the PM 2.5 concentrations in northern China. We show that the meaningful circulations depended on the wave frequency and the rank of the PM 2.5 concentrations. The winter 2013–2019 PM 2.5 had different correlations with the subseasonal 850 hPa height anomalies at low (>30 days), intermediate (10–30 days), and high (<10 days) frequencies. The low‐frequency waves increased PM 2.5 concentrations by lowering the height over Eurasia and raising the height over the North Atlantic. The first two singular value decomposition principal patterns at the low‐frequency were alike Wavenumber 3 and 4 circulations, respectively. The two patterns accounted for the majority of the background variations of winter PM 2.5 in China. The intermediate‐frequency waves increased PM 2.5 concentrations via an anomalous dipole pattern over East Asia with a positive polarity over Japan and a negative polarity over Mongolia. The positive polarity is indicative of persistent haze episodes. The high‐frequency waves showed a small dipole correlation pattern with PM 2.5, but they barely accounted for high PM 2.5 concentrations. The high‐frequency waves traveled quickly. They raised or lowered PM 2.5 concentrations in a short time, preventing particulate accumulations. The anomalous heights at the low‐ and intermediate‐frequency for the PM 2.5 concentrations >90th showed a few characteristics consistent with the circulation anomalies proposed in previous climate studies with monthly mean data. Synergic effects of the waves at different frequencies result in the observed PM 2.5 variations.