上海地区AQI变化特征及与气象因素的相关性

基于上海地区2012—2016年逐日PM2.5、PM10、CO、O3、SO2、NO2的分指数(individual air quality index,IAQI)数据以及同期气象要素(风速、降水量、气温、相对湿度、总云量、低云量)、逆温数据和高空大气环流数据,分析了上海地区空气质量指数的时间变化特征和气候要素对空气质量的影响,并选取PM 2.5和O3污染天气过程及其邻近的非污染天气过程,对比分析高空大气环流形势的差异。结果表明:上海地区出现PM2.5、PM10和NO2污染天气在冬季最多,分别为31.4 d、10.0 d和14.8 d,而O3污染天气在夏季最多(18.8 d)。风速和低云量是影响PM2.5污染的重要气象因素,最大相关系数分别为-0.313和-0.261,O3污染则与气温和日照时数密切相关,最大相关系数分别为0.449和0.363,PM2.5、O3污染的发生也与前一日以及当日出现逆等温天气存在较好的相关性。在PM2.5污染天气过程,上海位于槽后高压前部,850 hPa有较强西北风,而非PM 2.5污染天气过程中上海位于高压后部,低层850 hPa为东南风。在O 3污染天气和非污染天气过程,中国东部长波射出辐射(Outgoing Longwave Radiation,OLR)分别为正、负距平,副热带高压控制下上海晴热少云,易引起O3污染,反之上海上空云系多,不容易出现污染。

Influences of Urban Temperature on the Electricity Consumption of Shanghai

By using data of daily electricity consumption and temperature for the period 2003–2007 in Shanghai, the variation of energy consumption and the correlations between energy consumption and temperature are analyzed. The results indicate that winter and summer are the two peak seasons of energy consumption due to the urban residential heating and cooling demand. The base temperature of electricity and daily temperature is 10℃ in winter and 22℃ in summer respectively. When the outdoor temperature is below 10℃, the heating demand becomes obvious, and with over 22℃ the cooling demand. The spatial distribution of cooling degree-days(CDD) and heating degree-days(HDD) clearly shows urbanization effects. By the influence of urbanization the central city experiences greater CDD in summer and lower HDD in winter. The projected temperature for 2011–2050 implies a significant increase in CDD and a decrease in HDD. This may have implications on the future energy demand if the current energy consumption pattern does not change.