【摘要】 文章通过利用2013年12月和2014年10月在珠三角开展大气边界层观测试验得到的垂直温度探空资料和逐日空气质量资料,从逆温层和低空稳定能量等角度研究了珠三角干季边界层垂直温度结构对空气质量的影响。结果表明:珠三角处于冷空气前影响时,较弱的气团活动有利于低空逆温层的持续存在和贴地逆温的发展,珠三角污染日逆温层高度主要分布在0～1 000 m之间。其中贴地逆温出现频率约为35%,低空逆温层尤其是夜间频繁出现的贴地逆温使得污染物累计在近地面气层内,对珠三角空气质量有重要影响。低空稳定能量(E_w)能够较好地反映珠三角大气垂直扩散能力,珠三角AQI与500～800 m处气层稳定能量相关性较好,说明500～800 m气层是影响珠三角空气质量的关键气层,当珠三角该层稳定能量>15 J/cm~2时,大气垂直扩散能力较弱,珠三角空气质量恶化的可能性较高。更多还原

【Abstract】 Based on the sounding data and corresponding daily AQI data obtained from the boundary layer observation experiment over Pearl River Delta(PRD) region during December 2013 and October 2014, the influence of vertical temperature structure on air quality over PRD region were discussed by inversion layer and stable energy of low layer. It is found shat when PRD was controlled by pre-cold front, affected by the weak air mass activities the lower inversion layer would exist persistently and surface inversion layer would develop instantly, the inversion layer height in pollution days was about 0～1 000 m. In pollution days the frequency of surface inversion layer was about 35% over PRD, lower inversion layer especially surface inversion layer made pollutants accumulated in ground layer, and caused local air quality deteriorated rapidly. The stable energy of low layer(E_w) was a useful tool to represent the atmospheric vertical diffusion capacity, studies showed that a high correlation coefficient could be found between AQI and E_wunder 500～800 m, indicating that air layer under 500～800 m height was the key air layer to air quality over PRD. When the E_w of that layer was larger than 15 J/cm~2, the ability for atmospheric vertical diffusion was weak, resulting in fast deteriorating air quality.更多还原