This study analyzes the impact of circulation types(CTs)on ozone(O_(3))pollution in Beijing.The easterly high-pressure(SWW)circulation occurred most frequently(30%;276 day),followed by northwesterly high-pressure(AN)c...This study analyzes the impact of circulation types(CTs)on ozone(O_(3))pollution in Beijing.The easterly high-pressure(SWW)circulation occurred most frequently(30%;276 day),followed by northwesterly high-pressure(AN)circulation(24.3%;224 day).The SWW type had the highest O_(3) anomaly of+17.28μg/m^(3),which was caused by excellent photochemical reactions,poor diffusion ability and regional transport.Due to the higher humidity and precipitation in the low-pressure type(C),the O_(3) increase(+8.02μg/m^(3))was less than that in the SWW type.Good diffusion/wet deposition and weak formation ability contributed to O_(3) decrease in AN(-12.54μg/m^(3))and northerly high-pressure(ESN)CTs(-12.26μg/m^(3)).The intra-area transport of O_(3) was significant in polluted circulations(SWW-and C-CTs).In addition,higher temperature,radiation and less rainfall also contributed to higher O_(3) in northern Beijing under the SWW type.For the clean CTs(AN and ESN CTs),precursor amount and intra-area transport played a dominant role in O_(3) distribution.Under the northeasterly low-pressure CT,better formation conditions and higher precursor amount combined with the intra-area southerly transport to cause higher O_(3) values in the south than in the north.The higher O_(3) in the northwestern area under the northeasterly high-pressure type was influenced by weaker titration loss and high O_(3) concentration in previous day.Annual variation in the CTs contributed up to 86.1%of the annual variation in O_(3).About 78%-83%of the diurnal variation in O_(3) resulted from local meteorological factors.展开更多
基金supported by the Beijing Municipal Natural Science Foundation(No.8204075)the National Key Research and Development Program of China(No.2016YFC0203302)+2 种基金the National Natural Science Foundation of China(Nos.4147513591744206)the Beijing Nova Program(No.xx2017079).
文摘This study analyzes the impact of circulation types(CTs)on ozone(O_(3))pollution in Beijing.The easterly high-pressure(SWW)circulation occurred most frequently(30%;276 day),followed by northwesterly high-pressure(AN)circulation(24.3%;224 day).The SWW type had the highest O_(3) anomaly of+17.28μg/m^(3),which was caused by excellent photochemical reactions,poor diffusion ability and regional transport.Due to the higher humidity and precipitation in the low-pressure type(C),the O_(3) increase(+8.02μg/m^(3))was less than that in the SWW type.Good diffusion/wet deposition and weak formation ability contributed to O_(3) decrease in AN(-12.54μg/m^(3))and northerly high-pressure(ESN)CTs(-12.26μg/m^(3)).The intra-area transport of O_(3) was significant in polluted circulations(SWW-and C-CTs).In addition,higher temperature,radiation and less rainfall also contributed to higher O_(3) in northern Beijing under the SWW type.For the clean CTs(AN and ESN CTs),precursor amount and intra-area transport played a dominant role in O_(3) distribution.Under the northeasterly low-pressure CT,better formation conditions and higher precursor amount combined with the intra-area southerly transport to cause higher O_(3) values in the south than in the north.The higher O_(3) in the northwestern area under the northeasterly high-pressure type was influenced by weaker titration loss and high O_(3) concentration in previous day.Annual variation in the CTs contributed up to 86.1%of the annual variation in O_(3).About 78%-83%of the diurnal variation in O_(3) resulted from local meteorological factors.
