| 1 | Influence of transboundary air pollution on air quality in southwestern China显示文摘Air pollution is a grand challenge of our time due to its multitude of adverse impacts on environment and society,with the scale of impacts more severe in developing countries,including China.Thus,China has initiated and implemented strict air pollution control measures over last several years to reduce impacts of air pollution.Monitoring data from Jan 2015 to Dec 2019 on six criteria air pollutants(SO_(2),NO_(2),CO,O_(3),PM_(2.5),and PM_(10))at eight sites in southwestern China were investigated to understand the situation and analyze the impacts of transboundary air pollutants in this region.In terms of seasonal variation,the maximum concentrations of air pollutants at these sites were observed in winter or spring season depending on individual site.For diurnal variation,surface ozone peaked in the afternoon while the other pollutants had a bimodal pattern with peaks in the morning and late afternoon.There was limited transport of domestic emissions of air pollutants in China to these sites.Local emissions enhanced the concentrations of air pollutants during some pollution events.Mostly,the transboundary transport of air pollution from South Asia and Southeast Asia was associated with high concentrations of most air pollutants observed in southwestern China.Since air pollutants can be transported to southwestern China over long distances from the source regions,it is necessary to conduct more research to properly attribute and quantify transboundary transport of air pollutants,which will provide more solid scientific guidance for air pollution management in southwestern China. | Xiufeng Yin Shichang Kang Maheswar Rupakheti Benjamin de Foy Ping Li Junhua Yang Kunpeng Wu Qianggong Zhang Dipesh Rupakheti | 2021 | Geoscience Frontiers2021，12，6： | 4 |
| 2 | 冬奥张家口赛区一次冷池过程的观测分析显示文摘利用冬奥张家口赛区系留汽艇探空、激光雷达和加密冬奥地面观测等新资料,以及ERA5再分析资料,对2020年1月15—16日的冷池(CAP)过程进行了场外观测,分析了冷池的温度、湿度、风场三维结构,构建了冷池建立、发展、维持、消散过程的概念模型。结果表明:此次冷池过程发生在弱高压脊控制、中层增暖、高空风速明显减小、天空少云、近地层微风的静稳天气背景下。冷池自傍晚日落开始逐渐建立,此时大气层结为中性,山谷东西两侧山坡形成较强下坡风携带冷空气在谷底堆积辐合产生上升气流,取代谷底原来的暖空气并将其抬升,逆温形成并快速向上发展,半夜前后,即日落约4~5 h后,冷池发展到300 m左右的高度,即山谷高度3/5处,其上300 m为等温层,即暖带。冷池在发展过程中,在逆温层下出现明显的东西风切变层,随着逆温层顶的不断升高,风切变层也逐渐抬高。午夜到日出前,冷池进入稳定维持期,逆温层顶高度和温度变化不大,冷池底部温度继续缓慢下降,此阶段下坡风和下谷风已不能渗透到谷底,降温主要是长波辐射降温。日出后4 h左右冷池消散,首先太阳加热山谷西坡,导致山谷中高层快速升温,之后随着太阳高度角升高,山谷东西侧山坡出现上坡风及上谷风,将谷底冷空气向东西两侧坡面及谷外输送,山谷中高层暖空气下沉,对流边界层下降,逆温自上而下消散,这和平原地区逆温自下而上消失有明显的差别。 | 陈子健 李江波 李禧亮 田志广 段宇辉 王宗敏 | 2023 | 气象2023，49，6： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员