Seesaw haze pollution in North China modulated by the sub-seasonal variability of atmospheric circulation [electronic resource]
Haze, El Nino, Arctic Oscillation, East Asian Winter Monsoon, Wrf/Cmaq.
Saved in:
| Online Access: |
Online Access (via OSTI) |
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| Corporate Author: | |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. Department of Energy. ; distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
2019.
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| Subjects: |
| Summary: | Haze, El Nino, Arctic Oscillation, East Asian Winter Monsoon, Wrf/Cmaq. |
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| Abstract: | Utilizing a recent observational dataset of particulate matter with diameters less than 2.5<span class="thinspace"></span><span class="inline-formula">µ</span>m (PM<span class="inline-formula"><sub>2.5</sub></span>) in North China, this study reveals adistinct seesaw feature of abnormally high and low PM<span class="inline-formula"><sub>2.5</sub></span> concentrationsin the adjacent two months of December 2015 and January 2016, accompanied bydistinct meteorological modulations. The seesaw pattern is postulated to belinked to a super El Niño and the Arctic Oscillation (AO). During themature phase of El Niño in December 2015, the weakened East Asian wintermonsoon (EAWM) and the associated low-level southerly wind anomaly reducedplanetary boundary layer (PBL) height, favoring strong haze formation. Thiscirculation pattern was completely reversed in the following month, in partdue to a sudden phase change of the AO from positive to negative and thebeginning of a decay of the El Niño, which enhanced the southward shiftof the upper tropospheric jet from December to January relative toclimatology, leading to an enhanced EAWM and substantially lower hazeformation. This sub-seasonal change in circulation is also robustly found in1982-1983 and 1997-1998, implicative of a general physical mechanismdynamically linked to El Niño and the AO. Numerical experiments using theWeather Research and Forecasting (WRF) Community Multiscale Air Quality(CMAQ) model were used to test the modulation of the meteorologicalconditions on haze formation. With the same emission, simulations for threesuper El Niño periods (1983, 1997 and 2015) robustly show higherPM<span class="inline-formula"><sub>2.5 </sub></span> concentrations under the mature phase of the super El Niño,but substantially lower PM<span class="inline-formula"><sub>2.5</sub></span> concentrations during the decay phase ofEl Niño (and the sudden AO phase change), further verifying themodulation effect of the sub-seasonal circulation anomaly on PM<span class="inline-formula"><sub>2.5</sub></span> concentrations in North China. |
| Item Description: | Published through SciTech Connect. 01/15/2019. "pnnl-sa--139097" Atmospheric Chemistry and Physics (Online) 19 1 ISSN 1680-7324 AM. Ge Zhang; Yang Gao; Wenju Cai; L. Ruby Leung; Shuxiao Wang; Bin Zhao; Minghuai Wang; Huayao Shan; Xiaohong Yao; Huiwang Gao. |
| Physical Description: | p. 565-576 : digital, PDF file. |