Assessing the effects of trans-boundary aerosol transport between various city clusters on regional haze episodes in spring over East China
Assessing the effects of trans-boundary aerosol transport between various city clusters on regional haze episodes in spring over East China
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DOI：
10.3402/tellusb.v65i0.20052
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发表时间：
2013-05
期刊：
影响因子：
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通讯作者：
Jie Li;Zifa Wang;Huili Huang;Min Hu;Fan-Shuo Meng;Yele Sun;Xiquan Wang;Yuesi Wang;Qian Wang
中科院分区：
文献类型：
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作者：
Jie Li;Zifa Wang;Huili Huang;Min Hu;Fan-Shuo Meng;Yele Sun;Xiquan Wang;Yuesi Wang;Qian Wang
自2000年以来，中国东部地区频繁报道区域性灰霾事件。本研究通过带有在线示踪标记模块的三维区域化学物质传输模型（NAQPMS）进行观测和模拟，对2011年春季华东地区的两次区域性灰霾事件进行了研究。该模型准确再现了华东地区四个城市群（长三角、山东半岛、华北平原和辽宁中部）的PM2.5观测值，相关系数为0.52~0.76，均方根误差（RMSE）为20~50μg/m3。我们的研究结果表明，从长三角到辽宁中部海拔2公里以下的向北跨境输送在这些区域性PM2.5高浓度事件的形成中发挥了重要作用。外城市群区域交通贡献呈现由南向北逐渐增加的趋势。在最北端的城市群（辽宁中部），其他城市群的贡献在这两个时期达到了40-50%。相比之下，长三角地区（最南端集群）的这一比例低于10%。造成这一趋势的原因是交通运输过程中来自不同城市群的污染物的混合积累。此外，初步估计表明，在 PM2.5 高浓度时期，PM2.5 的跨境运输可能会使每日死亡率增加 0.5-3%。
Regional haze episodes have been frequently reported in east China since 2000. In the present study, two regional haze episodes over east China in the spring of 2011 were examined by observations and simulations conducted by a three-dimensional regional chemical transport model (NAQPMS) with an on-line tracer-tagged module. The model reproduced accurately the observed PM2.5 with correlation coefficient ranging from 0.52 to 0.76 and root mean square error (RMSE) of 20–50µg/m3 in four city clusters (Yangtze River Delta, Shandong Peninsula, Huabei Plain and Central Liaoning) over east China. Our results indicate that a northward cross-border transport from the Yangtze River Delta to Central Liaoning below 2 km above ground played an important role in the formation of these regional high PM2.5 episodes. Contributions of regional transport from outside city clusters presented an increasing trend from south to north. In the northernmost cluster (Central Liaoning), the contribution from other city clusters reached 40–50% during the two episodes. In contrast, it was below 10% in the Yangtze River Delta (southernmost cluster). Mixing accumulation of pollutants from various city clusters during transport was responsible for this trend. Furthermore, a preliminary estimate shows that cross-border transport of PM2.5 might increase 0.5–3% daily mortality during the high PM2.5 episodes.