甘肃省对流层甲醛柱浓度时空分布特征及影响因素研究

近年来，有着致癌性质的甲醛在大气中的含量逐年增加，加强对大气甲醛及其影响因素的监测意义重大。本文利用OMI卫星反演数据，对2008～2016年甘肃省对流层甲醛柱浓度的时空特征以及影响因子进行分析。结果表明：（1）甘肃省甲醛柱浓度空间分布极其不平衡，呈现出由甘肃南部向中部、西北部逐渐降低的趋势，这与甘肃省自东南向西北的植被分布有关，植被排放对大气甲醛有一定的贡献。（2）甲醛柱浓度年均值最低为7.15×10¹⁵ molec/cm²，出现在2008年，最高为10.66×10¹⁵ molec/cm²，出现在2011年；按照季节划分甲醛柱浓度均值，表现为夏季 > 冬季 > 春季 > 秋季，这与夏季光化学反应和甘肃省冬季采暖有关；甘肃省大气中的甲醛以自然因素为主，人为因素次之。（3）甲醛柱浓度变化不仅与自然因素的温度呈显著正相关，还与社会经济因素中的第二产业值、工业产值以及能源消耗等具有一定相关性。甘肃省甲醛柱浓度时空特征总体受当地自然和社会经济因素的综合影响。

Temporal-spatial Distribution of Tropospheric Formaldehyde in the Gansu Province and Its Affecting Factors

It has noted that the content of carcinogenic formaldehyde in the atmosphere is increasing recently, therefore, strengthening the monitoring of atmospheric formaldehyde and understanding its influence factors are important. In this paper, OMI satellite inversion data were used to analyze the spatial-temporal characteristics and to explore influencing factors of tropospheric formaldehyde column concentration in the Gansu Province during 2008-2016. The results showed that: (1) The spatial distribution of formaldehyde column concentrations in Gansu was extremely unbalanced with a trend of decreasing gradually from the south area to the middle and the northwest areas, this may be related to the distribution of vegetation from the southeast to the northwest of Gansu, the plant emission had a certain contribution to atmospheric formaldehyde. (2) The lowest average column concentration of formaldehyde (7.15×10¹⁵ molec/cm²) appeared in 2008, the highest one (10.66×10¹⁵molec/cm²) appeared in 2011. In terms of the seasonal variation, the mean column concentrations of formaldehyde decreased as summer> winter> spring> autumn, which could be interpreted by photochemical reactions in summer and heating activities in winter. The distribution of atmospheric formaldehyde in Gansu was controlled mainly by natural factors and was affected by artificial factors. (3) Besides the positive correlation with the natural factor, temperature, the variation of column concentrations of formaldehyde in Gansu was also correlated with the socio-economic factors, such as the secondary industry value, industrial output value and energy consumption. In summary, the spatial-temporal distribution characteristics of the column concentration of formaldehyde in Gansu were affected combinedly by local natural and socio-economic factors.