近14年西北地区甲醛柱浓度的时空变化研究

基于臭氧监测仪（OMI）卫星反演数据，对2005~2018年西北4省区域大气甲醛柱浓度数据进行提取及分析，探讨其时空变化特征及影响因素.结果表明：在时间变化上，14a甲醛柱浓度整体呈先上升后下降的波动变化趋势，夏秋季显著高于冬春季，且冬季均值略高于春季.在空间分布上，甲醛柱浓度自西向东、自北向南逐渐升高，高值区集中于陕西和甘肃东南部及青海西南部；低值区集中于宁夏、青海和甘肃的西北部；稳定性呈现出东部分散、西部集聚、差异显著的分布格局.影响甲醛柱浓度变化的因素包括自然和人为因素，自然因素中，甲醛柱浓度受地形影响显著，与风向、气温均呈现显著正相关；人为因素中，甲醛柱浓度与人口密度、地区生产总值、工业废气排放量及建筑房屋竣工面积均表现出正相关关系，与工业废气排放量的相关度最高.大气中甲醛分子与气溶胶粒子二者间呈显著正相关关系，这进一步说明甲醛浓度受到了诸多因素的综合影响，但气溶胶粒子、气温及工业废气的排放是主导因素.

Spatio-temporal variation of formaldehyde column concentration in Northwest China in the past 14 years

The atmospheric formaldehyde column concentration data of four provinces in Northwest China from 2005 to 2018 based on ozone monitoring instrument (OMI) were extracted, and their spatio-temporal change and influencing factors were discussed. The results showed that: in time variation, formaldehyde column had increased firstly and then decreased during 14 years, concentration of formaldehyde column in summer and autumn was significantly higher than that in winter and spring, and the average value in winter was slightly higher than spring. In terms of spatial distribution, formaldehyde column increased from west to east and north to south. High value areas were concentrated in Shaanxi, south-eastern of Gansu and south-western of Qinghai low value areas were concentrated in Ningxia, Qinghai and north-western of Gansu. Stability analysis showed that formaldehyde column was distributed in central and eastern parts, and the distribution was obvious. The main factors affected the change of formaldehyde column concentration including natural and human factors. In natural factors, concentration of formaldehyde column was signally affected by topography,wind direction and temperature. In human factors, it was positively correlated with population density, regional GDP, industrial waste gas emission and construction housing completion area. Among them, industrial waste gas emission was the main impact factor. There was a significant correlation between formaldehyde and aerosol particles in atmosphere. This further indicated that the change of formaldehyde concentration was affected by many factors, but aerosol particles, temperature and emission of industrial waste gas were the dominant factor.