Annual PM2.5 Grids from MODIS-Syrian Arab Republic

The Global Annual PM2.5 Grids from MODIS, MISR and SeaWiFS Aerosol Optical Depth (AOD) data sets represent a series of three-year running mean grids (1998-2012) of fine particulate matter (solid particles and liquid droplets) that were derived from a combination of MODIS (Moderate Resolution Imaging Spectroradiometer), MISR (Multi-angle Imaging SpectroRadiometer) and SeaWIFS (Sea-Viewing Wide Field-of-View Sensor) AOD satellite retrievals. Together the grids provide a continuous surface of concentrations in micrograms per cubic meter of particulate matter 2.5 micrometers or smaller (PM2.5) for health and environmental research. For each satellite-derived PM2.5 source, the total column retrievals of AOD were converted to near-ground PM2.5 levels using the GEOS-Chem chemical transport model to represent local relationships between AOD and PM2.5. A global decadal (2001-2010) mean PM2.5 concentration grid was also produced. The raster grids have a grid cell resolution of 6 arc-minutes (0.1 degree or approximately 10 km at the equator) and cover the global land surface from 70 degrees north to 55 degrees south. Compared to SEDAC’s earlier data set, Global Annual Average PM2.5 Grids from MODIS and MISR Aerosol Optical Depth (AOD), v1 (2001-2010), this data set provides higher accuracy; longer temporal range; higher resolution (0.1 x 0.1 degrees); and time varying AOD to PM2.5 relationships, necessary for appropriate representation of trends. <div><br /></div><div>This data was published in 2015.</div><div><br /></div><div>Source: <a href='http://sedac.ciesin.columbia.edu/data/set/sdei-global-annual-avg-pm2-5-modis-misr-seawifs-aod-1998-2012' style='line-height: 1.38461538461538;' target='_blank'>CIESIN</a></div>

基于中分辨率成像光谱辐射计（Moderate Resolution Imaging Spectroradiometer, MODIS）、多角度成像光谱辐射计（Multi-angle Imaging SpectroRadiometer, MISR）与海洋宽视场传感器（Sea-Viewing Wide Field-of-View Sensor, SeaWiFS）的气溶胶光学厚度（Aerosol Optical Depth, AOD）反演数据所构建的全球年度PM2.5栅格数据集，包含1998-2012年间逐年滚动三年平均的细颗粒物（固体颗粒与液滴）栅格产品，其数据源自上述三款卫星的AOD反演结果融合。该系列栅格可提供以微克/立方米为单位的直径2.5微米及以下颗粒物（PM2.5）浓度的连续空间分布数据，服务于健康与环境科学研究。针对每一款卫星反演的PM2.5数据源，研究团队借助GEOS-Chem化学传输模型，将AOD的整层大气反演结果转换为近地面PM2.5浓度，以此表征AOD与PM2.5之间的局地关联关系。本研究同时还生成了一套2001-2010年十年际全球平均PM2.5浓度栅格产品。该栅格产品的空间分辨率为6弧分（即0.1度，在赤道处约合10公里），覆盖北纬70度至南纬55度的全球陆地区域。相较社会经济数据与应用中心（SEDAC）早期发布的数据集《基于MODIS与MISR气溶胶光学厚度反演的全球年度平均PM2.5栅格，v1版（2001-2010）》，本数据集具备更高的精度、更长的时间跨度、更高的空间分辨率（0.1°×0.1°），以及可表征时间变化的AOD-PM2.5关联关系，这对准确还原浓度变化趋势至关重要。<div><br /></div><div>该数据集于2015年正式发布。</div><div><br /></div><div>数据来源：<a href="http://sedac.ciesin.columbia.edu/data/set/sdei-global-annual-avg-pm2-5-modis-misr-seawifs-aod-1998-2012" style="line-height: 1.38461538461538;" target="_blank">CIESIN</a></div>