2005~2017年全球大气边界层SO2时空变化

使用2005~2017年遥感数据研究了全球大气边界层SO₂时空分布特征及变化趋势.结果表明：空间分布上SO₂呈现空间异质性，大气高SO₂柱量值集中在以火山喷发为代表的自然源区域和以工业排放为代表的人为源及附近区域；一、二、三级SO₂柱量值在全球范围内整体呈现纬度地带性分布特征，北半球受人为影响较为明显，分界线在陆地区域向南凸出，海洋上向北凹陷，而南半球受人为影响较小，分界线呈现与纬线平行趋势；2005~2017年全球大气边界层SO₂单元栅格年均值整体呈现先增后减趋势，火山喷发导致2008、2009、2011年夏季出现了明显的波动，其余季节无显著变化；全球范围内大气边界层SO₂年内变化，伴随太阳直射点南北移动，2005~2014年一级SO₂柱量值延纬向对称轴的纬度，除10~12月份外，其余月份与对应月15日太阳赤纬基本吻合.

Temporal and spatial distribution characteristics of global atmospheric boundary layer SO2 based on remote sensing data from 2005 to 2017

As the main precursor of the smog and acid rain in the atmosphere, SO₂ plays an important role to the near-surface O₃ pollution. Meanwhile, SO₂ also affects the global and local atmospheric circulations because its strong absorption on the ultraviolet influences the solar radiation dramatically. Therefore, it is beneficial to study the temporal and spatial distributions of SO₂ and their variations. In this paper, the spatial and temporal distributing features of SO₂ at global atmospheric boundary layer were studied by the remote sensing data from 2005 to 2017. A spatial heterogeneity was observed from the analyzing results. Specifically, the high columns of SO₂mainly concentrated on the volcanic eruption areas as a natural source and on the industrial emission areas as an anthropogenic source. The first, second and third grades of SO₂ columns distributed zonally in the whole world. It was evidently affected by the human emissions in the Northern Hemisphere that the boundary line of SO₂ column grades protruded southward on the land and sunk northward on the ocean. In the Southern Hemisphere, on the contrary, the boundary line paralleled to the latitude. From 2005 to 2017, the annual average of SO₂ unit grid values at the global atmospheric boundary layer was increasing before 2011 and then decreasing. During this period of time, the volcanic eruptions led to obvious variations in the summer of 2008, 2009 and 2011. The alteration of SO₂ at the atmospheric boundary layer was associated with the movement of the direct solar radiation point within each year. From 2005 to 2014, the latitudinal axis of symmetry of the first grade SO₂ columns matched with the 15^th day's solar declination of each month, except October, November, and December.