华中地区吸收性气溶胶时空分布特征及类型研究

利用2005-2019年OMI-OMAERUV L2气溶胶数据集，研究了近15年华中地区吸收性气溶胶指数（UVAI）的时空分布特征和主导气溶胶类型，探究下垫面变化和人为及气象因素的影响.结果表明：1在时间分布上，华中地区UVAI的年际变化整体呈波动上升趋势；2005-2008年UVAI波动下降，2009-2013年逐年增加并于2013年达到近15年来的最高值（0.767），2014-2019年逐年下降.2在空间分布上，UVAI整体由华中南部向北部递增，豫东平原、南阳盆地及武汉、长沙附近的城市群为高值区；UVAI的稳定性整体呈现“北低-南次之-中部高”的分布格局.3从季节变化来看，冬>春>秋>夏，冬季大部分区域由高值覆盖，夏季全境低值；气温、降水和UVAI均呈显著负相关；结合风场和压场进一步分析发现，加强源、较差的大气扩散条件和弱降水使冬季呈现大范围高值，夏季充沛雨水的冲刷作用叠加良好的大气扩散条件使得UVAI在夏季全境低值；气温、降水和大气扩散条件是导致UVAI呈明显季节性变化的重要环境因子.4一氧化碳指数（COI）与UVAI的季均和年均空间分布一致且随季节同步变化，冬季UVAI高值区域的COI值>2.8；华中地区的吸收性气溶胶为碳质主导.52005-2018年林地、湿地和水域面积分别增长21.1%、67.9%、2.3%，扩大了环境容量，提高了污染物的代谢速度；城市及建设用地面积增长14.3%，致使该类排放源逐年加强；UVAI与人口增长率和第一、二产业的增加值均呈显著正相关，结合大气排放清单分析，工业源、居民源、农业源为人为因素中的主导因素.

Spatial-temporal distribution and types of absorbing aerosol in Central China

Based on the OMI-OMAERUV L2 aerosol dataset from 2005 to 2019, the spatial-temporal distribution characteristics and dominant aerosol types of the absorbing aerosol Index (UVAI) were studied in Central China in the past 15 years, the changes of the underlying surface as well as the effects of human and meteorological factors were explored. The results showed that:1In time, the inter-annual variation of UVAI showed an increasing trend in central China. The fluctuation of UVAI declined from 2005 to 2008; from 2009 to 2013, it increased and reached the highest value of 0.767 in 2013, and decreased from 2014 to 2019. 2In spatial, the value of UVAI increased from southern central China to the north. The high value areas were in the eastern Henan Plain, Nanyang Basin and the urban agglomerations near Wuhan and Changsha. The distribution pattern of UVAI stability was "low in the north, second in the South and high in the central region". 3In season, winter>spring>autumn>summer, most areas were covered by high values in winter and low values in summer. Temperature, precipitation and UVAI were negatively correlated. Further analysis showed that the high value appeared in winter due to enhanced source, poor atmospheric diffusion conditions and less precipitation. Abundant rainfall and good atmospheric diffusion conditions could make UVAI low in summer. Temperature, precipitation and atmospheric diffusion are important environmental factors that caused the seasonal variation of UVAI. 4The spatial distribution of carbon monoxide index (COI) was consistent with that of UVAI, and the change was synchronous with seasons. The COI value of high UVAI area was more than 2.8 in winter. The absorption aerosol was dominated by carbon in Central China.5The area of woodland, wetland and water area increased by 21.1%, 67.9% and 2.3% respectively from 2005 to 2018, which expanded the environmental capacity and improved the metabolism rate of pollutants; the urban and construction land increased by 14.3%, resulting in the enhancement of such emission sources year by year. UVAI was positively correlated with population growth rate and the increase of primary and secondary industries. The analysis of air emission inventory showed that industrial source, residential source and agricultural source were the dominant factors in human factors.