Abstract: Multi-time scale characteristics of ventilation quantity, mixed layer height, atmospheric stability and mean wind speed in mixed layer in Chongqing main city zone were quantitatively analyzed using the recent 30-year data observed at Shapingba meteorological station in Chonqing. The ventilation quantity in Chongqing main city zone exhibited evident decadal variations, and it lay in a high level and showed a descending trend before 2003, while it lay in a low level after 2003 and showed an ascending trend in recent 10 years. The decadal changes of ventilation quantity in four seasons were consistent with that of the annual mean. The ventilation quantity had an oscillation period from 2 to 3 years. In different seasons, the inter-annual oscillation intensity varied with the largest oscillation amplitude in summer and a relatively smaller one in autumn and winter. The ventilation quantity was significantly correlated with mixed layer height and mean wind speed in mixed layer. The seasonal difference of ventilation quantity was obvious with the largest value in summer and the smallest value in winter. The diurnal variation of ventilation quantity was basically consistent with mixing height and mean wind speed in mixed layer, which reached its maximum in the afternoon and could last until the evening.

Key words: Key words: ventilation quantity, multi-time scale, quantitative analysis, mixed layer height, mean wind speed in mixed layer

摘要： 利用重庆沙坪坝气象站1989—2018年30 a地面观测资料，定量分析重庆主城区通风量以及混合层高度、大气稳定度和混合层平均风速的多时间尺度变化特征。结果表明：重庆主城区通风量阶段性变化明显，2003年以前位于一个较高水平，且减少趋势明显；2003年以后通风量较低，近10 a转为增加趋势。重庆主城区通风量具有2~3 a的振荡周期。通风量四季的年代际变化与年平均基本一致。在不同季节，通风量的年际振荡强度有所差异。夏季振荡幅度最大，秋季和冬季相对较小。通风量的季节差异明显，夏季最大，冬季最小。通风量的日变化与混合层高度、混合层平均风速的日变化基本一致，在午后达到最大，并能维持到傍晚。重庆主城区通风量与混合层高度、混合层平均风速显著相关。

关键词:
关键词：通风量, 多时间尺度, 定量分析, 混合层高度, 混合层平均风速