Documentation for the Global Annual PM2.5 Grids from MODIS, MISR and SeaWiFS Aerosol Optical Depth (AOD) with GWR, 1998-2016

The Global Annual PM2.5 Grids from MODIS, MISR and SeaWiFS Aerosol Optical Depth (AOD) with GWR, 1998-2016 consist of annual concentrations (micrograms per cubic meter) of ground-level fine particulate matter (PM2.5), with dust and sea-salt removed. This data set combines AOD retrievals from multiple satellite instruments including NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging SpectroRadiometer (MISR), and the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS). The GEOS-Chem chemical transport model is used to relate this total column measure of aerosol to near-surface PM2.5 concentration. Geographically Weighted Regression (GWR) is used with global ground-based measurements to predict and adjust for the residual PM2.5 bias per grid cell in the initial satellite-derived values. These estimates are primarily intended to aid in large-scale studies. Gridded data sets at 0.01 degrees are provided to allow users to agglomerate data as best meets their particular needs. Data sets are gridded at the finest resolution of the information sources that were incorporated, but do not fully resolve PM2.5 gradients at the gridded resolution due to influence by information sources at coarser resolutions. The data are distributed as GeoTIFF files and are in WGS 84 projection.1998-2016年基于MODIS、MISR和SeaWiFS气溶胶光学厚度（Aerosol Optical Depth, AOD）并结合地理加权回归（Geographically Weighted Regression, GWR）的全球年度PM2.5格网数据集，包含经除尘和海盐去除后的近地面细颗粒物（PM2.5）年度浓度数据，单位为微克每立方米。该数据集整合了美国国家航空航天局（NASA）中分辨率成像光谱仪（Moderate Resolution Imaging Spectroradiometer, MODIS）、多角度成像光谱辐射计（Multiangle Imaging SpectroRadiometer, MISR）以及宽视场海洋观测传感器（Sea-Viewing Wide Field-of-View Sensor, SeaWiFS）等多颗卫星载荷的气溶胶光学厚度反演结果。研究采用GEOS-Chem化学传输模型，将气溶胶整柱观测值与近地面PM2.5浓度建立关联。本研究结合全球地面观测数据，利用地理加权回归（GWR）对卫星反演得到的初始格网PM2.5浓度的逐格网残差偏差进行预测与校正。该数据集的估算结果主要用于支撑大规模区域或全球尺度的相关研究。数据集提供了0.01度分辨率的格网数据，以便用户根据自身研究需求灵活聚合数据。数据集采用整合数据源的最高分辨率进行格网划分，但由于受低分辨率数据源的影响，无法完全还原格网尺度下的PM2.5浓度梯度。数据以GeoTIFF格式分发，采用WGS 84坐标系。

搜集汇总

背景与挑战

背景概述

该数据集提供了1998年至2016年全球年度PM2.5网格数据，基于MODIS、MISR和SeaWiFS卫星的气溶胶光学厚度（AOD）反演，结合GEOS-Chem化学传输模型和地理加权回归（GWR）校正，生成去除了灰尘和海盐的地面PM2.5浓度估计。数据以0.01度分辨率网格化，以GeoTIFF格式分发，适用于大尺度环境研究，但受限于信息源分辨率，无法完全解析网格内的PM2.5梯度变化。