长江三角洲地区对流层臭氧的数值模拟研究

将NCAR的中尺度天气预报模式MM5和作者开发的化学模式相耦合,建立了一个中尺度区域空气质量模式.利用该模式选取了2个典型个例研究了长江三角洲地区的区域臭氧化学问题.本研究的目的是利用模式再现并描述长江三角洲地区的大气物理化学过程,结合地面观测资料进一步定量分析控制该地区臭氧浓度的物理和化学因子.通过个例模拟和分析表明,模式基本反应了长江三角洲地区的大气物理化学过程,进一步的因子分析解释了模拟区域内1999 06 18(个例2)臭氧浓度普遍比1999 08 07(个例1)的臭氧浓度高的原因.模拟结果表明天气条件决定的大气动力过程对区域空气质量起着至关重要的作用,这也是个例2区域臭氧浓度普遍偏高的最主要因素之一.分析表明,物理因子(平流输送,垂直湍流输送)的作用和化学因子的作用同样重要.同时还做了模式参数的敏感性实验研究,并对中尺度云雨化学模拟及其对臭氧化学的影响做了初步研究.

Numerical modeling of tropospheric ozone over Yangtze Delta region

A meso\|scale air quality model was developed by coupling our own chemistry model into NCAR's MM5. Two cases were selected to study ozone chemistry over Yangtze Delta region based on field measurements. The aims of this study were to reproduce the physical and chemical processes over Yangtze Delta region using this meso\|scale air quality model, and to quantify the contributions to ozone production of these processes. The calculations showed that the model could describe the physical and chemical processes, and further factor analyses revealed the reasons why ozone concentrations in case 2 (June 18, 1999) were higher than those in case 1 (Aug. 7, 1999). Modeling results indicated that synoptic scale dynamical processes were crucial in regional air quality modeling. Synoptic processes resulted in high ozone concentrations in case 2. Factor analyses results showed that physical factors (advection and vertical diffusion) were important to ozone concentrations as well as chemical factors. Sensitivity studies were carried out to investigate the impacts of cloud chemistry on regional ozone process.