西安冬季能见度变化初析  

Preliminary analysis of winter visibility variation in Xi'an,China

作　　者：王浥尘[1,2] 曹军骥[1,3] 王启元[3] 任鹏奎[4] 肖舜[1,5] 

机构地区：[1]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710075 [2]中国科学院大学,北京100049 [3]西安交通大学环境科学与工程系,西安710049 [4]青海省地质调查院,西宁810012 [5]陕西省气象局,西安710014

出　　处：《地球环境学报》2012年第5期1048-1052,共5页Journal of Earth Environment

基　　金：中国科学院战略性先导科技专项(XDA05100401)

摘　　要：能见度的研究主要集中在中东部地区，而西部地区一些城市也遭受着低能见度的影响。本文初步研究了西安2011年冬季能见度的变化情况及其影响因子，并对2012年1月份四次能见度极低事件进行了初析。通过功率谱分析发现，能见度、相对湿度、PM2.5；、SO2、NO2具有3～4天的周期性变化规律。通过对能见度、相对湿度和PM2.5，日均值、逐步回归方程的建立，表明相对湿度在冬季西安能见度变化中起到了重要的作用。这可能和高相对湿度引起的吸湿增长有关。降水发生过程中能见度先降低后增加，后来的增加则是由于降水造成空气中颗粒物的湿沉降，进而使能见度有所升高。初步分析表明冬季能见度极低事件是高PM2.5；质量浓度和相对湿度综合作用的结果。Most visibility study focused on central eastern or coastal areas in China, whereas some cities in western areas have been suffering serious visibility impairment. This study mainly focused on the variation of visibility and its influence factors in Xi＇ an during winter time. Similar periodicities were found in visibility, relative humidity（RH） ,PM2. s, SO2 and NO2. Through analysis of daily average values, 24-hour variations and stepwise regression, we found that RH plays an important role in the variation of visibility due to its high values leading to hygroscopic growth of particles. Visibility was decreasing at first and then increasing during precipitation process resulting from wet deposition of particles later causes the increase of visibility. High concentration of PM2.5 and RH are blamed for there extremely low visibility events.

关 键 词：能见度 相对湿度 PM2 .5 西安 冬季 

分 类 号：P427.2[天文地球—大气科学及气象学]