汪永英　孙琪　李昭　韩冬荟　孟琳　郭敏　段文标

摘要[目的]探究不同林型对PM2.5的调控作用和净化效应，进而研究气象因子与PM2.5质量浓度的相关性。[方法]以哈尔滨城市森林3种不同林型为主要研究对象，选择3种典型天气条件，PM2.5质量浓度进行连续12 h的观测。

[结果]晴天时PM2.5质量浓度最小；而在降水之后的阴天条件下，其质量浓度是晴天时的1.34倍，日变化幅度不大；多云天气时，PM2.5质量浓度的增加明显，日变化幅度较大，其质量浓度是晴天时的1.69倍。3种不同林型对PM2.5均会起到一定的净化效应，各天气条件下净化效应从大到小依次为晴天、阴天、多云。晴天时，PM2.5质量浓度与气压达到极显著正相关；多云时，PM2.5质量浓度与气温呈极显著负相关，而与相对湿度和气压呈极显著正相关，与风速的相关性不显著；阴天时，PM2.5质量浓度与气象因子的相关性较低，与风速呈负相关，与气压、气温和相对湿度呈正相关，但均未达到显著性水平。[结论]建议人们选择晴天条件下在樟子松林内进行休闲活动，且活动时间选择在午后；PM2.5质量浓度变化趋势因天气条件差异而不同。

关键词 典型天气条件；城市森林；PM2.5；质量浓度

中图分类号 S176 文献标识码 A 文章编号 0517-6611（2016）05-175-05

Abstract[Objective]To research the regulatory effects and purification effects of different forest types on PM2.5； and to study the relationship between meteorological element and PM2.5 concentration.[Method]With three different forest types in Harbin as the research object， PM2.5 mass concentration in 12 h was continuously observed with three typical climate conditions.[Result]PM2.5 concentration was the minimum in sunny day. In cloudy days after precipitation， its concentration was 1.34 times of the clear day with a small range of daily change. In cloudy days， PM2.5 concentration increased obviously with relatively great range of daily change； its concentration was 1.69 times of the sunny day. The three different forest types had certain purification effects on PM2.5， which were in the order of sunny days > overcast day > cloudy day. In sunny days， PM2.5 mass concentration had extremely significant positive correlation with air pressure. In overcast day， PM2.5 mass concentration had extremely significant negative correlation with air temperature， had extremely significant positive correlation with relative humidity and air pressure， but showed no significant correlation with wind speed. In cloudy day， PM2.5 mass concentration had poor correlation with meteorological factor， showed negative correlation with wind speed， and had positive correlation with air pressure， temperature and relative humidity. All these did not reach significant correlation.[Conclusion]It suggests people choose sunny day for leisure activities in Pinus sylvestris forest in the affternonn. The trend of PM2.5 concentration varies with weather conditions.

Key words Typical weather conditions； Urban forest； PM2.5； Mass concentration

2015年入冬以来，雾霾天气再次成为人们关注的焦点[1]，除在华北和东北地区发生严重外，华东地区的南京也难逃“霾”伏，雾霾笼罩中国近1/3 的国土面积。其覆盖范围、影响程度，达到了前所未有的地步。PM（ particulate matter）即为颗粒物，PM2.5是大气中直径≤2.5 μm的固体颗粒或液滴的总称，俗称细颗粒物。