中国东部一次典型空气污染天气型的边界层特征

论文总字数：19237字

目 录

1 绪论 1

1．1研究目的和意义 1

1．2 国内外研究现状 1

1．3研究内容 3

2 研究方法 3

2．1资料来源 3

3 结果与讨论 3

3．1 污染过程 4

3．2 天气型及地面气象要素分析 5

3．2．1 开始阶段 7

3．2．2 维持阶段 8

3．2．3 消散阶段 10

3．3 边界层结构特征 11

3．3．1 开始阶段 11

3．3．2 维持阶段 12

3．3．3 消散阶段 14

4 小结 14

4．1 结论 14

4．2 讨论 15

参考文献 15

致谢 18

中国东部一次典型空气污染天气型的边界层特征

牟南南

，China

Abstract: A large-scale persistent pollution incident occurred in the eastern part of China. From January 12 to January 23, 2018. This paper discusses the change of concentration of PM_2.5 in different stages of the pollution process in combination with weather patterns and meteorological elements，and analyzes the characteristics of the boundary layer structure in different stages of pollution process. The meteorological features of this pollution process are long-term static stability in a wide range area, and the concentration of PM_2.5 from north to south has obvious lag phenomenon. Analysis of weather types suggest that the pollution is easy to occur under the control of weak high pressure, weak low pressure, and pressure equalizing field, in which the isobars on the ground are sparse, so that pollutants can remain static and accumulate for a long time. And through the analysis of the boundary layer structure during the pollution process, it is found that the occurrence, development, and maintenance of moderately-severely polluted weather generally occur in the ground or out of ground temperature inversion of the atmospheric boundary layer and generally the lower atmosphere has high humidity. The deep and high humidity layer is more conducive to the increase of pollutant concentration than the weak temperature inversion structure. However, the temperature inversion and high humidity layer may not exist during pollution weather, it perhaps due to the transmission of high concentrations of pollutants in the vicinity. It shows that the stable temperature inversion layer and high humidity are sufficient non-essential conditions for continuous pollution.

Key words:PM_2.5, weather type, the structure of boundary layer

1 绪论

1．1研究目的和意义

大气气溶胶通常是指悬浮于大气中的直径为10^-3~10²µm的固体或液体粒子。大气气溶胶在大气物理过程中起着重要的作用，如云雾降水、大气辐射和大气光、电等。它能吸收和散射太阳短波辐射，从而影响地气系统的能量平衡^[1-2]。大气气溶胶还能作为凝结核、冰核，是云雾滴产生和长大的基础，从而影响地气系统的水循环。它还是大气污染物，在一定的气象条件下造成严重的大气污染事件，直接影响空气的能见度和人的身体健康。随着城市化进展不断加快和经济的快速发展，空气污染也日益严重。近年来，我国多次遭受持续污染天气，许多城市的空气质量显著下降，尤其是特大城市，如京津冀、长三角地区，空气污染指数不断增加，空气污染形势异常严峻。

空气污染状况与气象条件密切相关，相互作用。大气中城市污染物的扩散受当地气象条件的制约，区域气象条件决定了大气输送和扩散污染物的能力。众所周知，对一个地区而言，对于一个污染物排放相对稳定的地区，污染物浓度的高低主要取决于大气的扩散能力，与地面的天气形势密切相关。地面天气形势综合反映了高低空大气稳定程度和扩散能力，因此综合分析地面天气形势及气象要素特征，有利于了解大气污染形成的外界条件，为大气污染日常预报奠定基础。

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