中国八大经济区域5月与7月CO地面浓度时空分布规律研究

Spatial and temporal variation of near-ground CO concentration in the Eight Economic Regions in China in May and July,2013

利用2013年5月与7月全国76个城市CO地面小时浓度连续自动监测数据,分析了我国八大经济区域春(5月)、夏(7月)季CO地面浓度的时空分布规律.结果发现,76个城市春夏季CO浓度日变化基本一致,1 d中CO最低浓度出现于傍晚17:00左右,但各个区域峰值出现的时间略不同,多数地区出现于早晨8:00—10:00,南部沿海地区出现于凌晨1:00;CO地面浓度季节变化明显,5月CO地面浓度高于7月,但西北地区7月CO地面浓度高于5月;西北地区和长江中游地区春夏季CO地面浓度变化差异大,南部沿海地区季节变化小;黄河中游和北部沿海等地区CO地面浓度相对较高,东北地区CO地面浓度较低.机动车尾气排放是造成CO空间分布差异的原因之一.

Hourly data of near-ground carbon monoxide( CO) concentration of 76 cities in China in May and July 2013 were collected from Chinese government air quality-monitoring network and employed to analyze the spatial and temporal variation in the Eight Economic Regions in China. It is clear that the diurnal variations of near-ground CO concentration are consistent among 76 cities in May and July. The lowest CO concentrations appear at 5 p.m.,whereas the highest CO concentrations appear at 8—10 a. m. for most cities but at 1 a. m. for cities located in the southern coastal region. However,the near-ground CO concentration distribution reveals significant seasonal variations; the CO concentrations in May are higher than that in July except for the cities in northwest region. The seasonal diversities of CO concentration in northwest region and the middle reach of the Yangtze River are much higher while that in southern coastal region is lower. It is also shown that CO concentration in middle reach of the Yellow River and northern coastal region is relatively higher and that in northeast region is relatively lower. Emission load from vehicle is one of the causes of CO spatial distribution.