School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China.
Jiangsu Provincial Academy of Environmental Science, Nanjing 210036, China.
Int J Environ Res Public Health. 2019 Apr 30;16(9):1528. doi: 10.3390/ijerph16091528.
Future climate change can impact ozone concentrations by changing regional meteorological factors related to ozone (O) pollution. To better understand the variations of meteorological factors and their effects on O formation processes under future climate conditions, we model the present and the future meteorology and air quality in summer over the Yangtze River Delta (YRD) region by using the Weather Research and Forecasting Model with Chemistry module (WRF/Chem), which is driven by the outputs of Community Climate System Model version 4 (CCSM4). The simulations predict that solar radiation, 2-m air temperature, and wind speed increase in the daytime over most of the YRD region. Absolute humidity and precipitation increase in the north and decrease in the south, while the planetary boundary layer height (PBLH) has an opposite change pattern displaying a decrease in the north and an increase in the south. The southerly wind will be strengthened in the daytime. At night, the change patterns of the meteorological factors are similar to the daytime but with small variations. Meanwhile, O and its precursors all increase in the north and decrease in the south. The increases of NO, volatile organic compounds (VOC), and CO are related with the decreases of PBLH and the input effect of stronger southerly wind, while the decreases are attributed to the output effect of the stronger southerly wind. During the daytime, the increase of surface O in the north is dominated by the chemical processes related with the increases of solar radiation, air temperature, and O precursors. The decrease of surface O in the south is mainly caused by the transport process changing with the strengthened southerly wind. At night, the surface O changing the amplitude is less than the daytime. The less O variations at night can be attributed to an O titration reaction with NO, the changes in NO concentrations, and the increases of nocturnal PBLH. With the aid of HO/HNO, O formation in the YRD region is found to be easily affected by NO in the future. The findings can help to understand the changing trend of O in the YRD region and can propose reasonable pollution control policies.
未来气候变化可能通过改变与臭氧（O）污染有关的区域气象因素来影响臭氧浓度。为了更好地了解气象因素的变化及其对未来气候条件下 O 形成过程的影响，我们使用天气研究与预报模型与化学模块（WRF/Chem）对长江三角洲（YRD）地区夏季的当前和未来气象与空气质量进行建模，该模型由第四代气候系统模式（CCSM4）的输出驱动。模拟预测，YRD 地区大部分地区的太阳辐射、2 米空气温度和风速在白天增加。绝对湿度和降水在北部增加，在南部减少，而行星边界层高度（PBLH）则呈现相反的变化模式，北部减少，南部增加。南风在白天会增强。夜间，气象因素的变化模式与白天相似，但变化较小。同时，O 和其前体在北部增加，在南部减少。NO、挥发性有机化合物（VOC）和 CO 的增加与 PBLH 的减少以及更强南风的输入效应有关，而减少则归因于更强南风的输出效应。白天，北部地表 O 的增加主要是由于与太阳辐射、空气温度和 O 前体增加相关的化学过程。南部地表 O 的减少主要是由于南风增强引起的传输过程发生变化。夜间，地表 O 的变化幅度小于白天。夜间 O 变化较小可归因于 O 与 NO 的滴定反应、NO 浓度的变化以及夜间 PBLH 的增加。在 HO/HNO 的帮助下，发现未来 YRD 地区的 O 形成很容易受到 NO 的影响。这些发现有助于了解 YRD 地区 O 的变化趋势，并提出合理的污染控制政策。
