Measurements to Evaluate and Improve Satellite-Based Estimates of Air Quality

世界卫生组织估计，暴露在细颗粒物(PM2.5)中是全球过早死亡的主要环境相关原因。在全球范围内，地面观测的覆盖面不足以评估人类长期接触PM2.5的情况。卫星遥感在提供区域到全球范围的PM2.5暴露信息方面前景看好，但从卫星遥感推算地面气溶胶质量浓度的准确性和精确度存在局限性和悬而未决的问题。不确定的一个关键来源是无云条件下特定天桥时间的年平均PM2.5与柱状气溶胶光学厚度的关系的全球分布。我们建议为地面监测站设计仪器，以评估和加强卫星遥感估计，以便在健康影响研究和风险评估中应用。拟议的仪器将主要在人口稠密的地区测量每小时一次的PM2.5，这些地区靠近现有的测量气溶胶光学厚度的地面太阳光度计。因此，这一工具将使关键测量能够评估和改进对PM2.5暴露的全球估计。

The World Health Organization estimates that exposure to fine particulate matter (PM2.5) is the leading environmentally-related cause of premature mortality worldwide. Ground-based observations have insufficient coverage at the global scale to assess long-term human exposure to PM2.5. Satellite remote sensing offers promising prospects for providing information on exposure to PM2.5 at regional-to-global scales, but there are limitations and outstanding questions about the accuracy and precision with which ground-level aerosol mass concentrations can be inferred from satellite remote sensing. A key source of uncertainty is the global distribution of the relationship of annual average PM2.5 with columnar aerosol optical depth at specific overpass times during cloud-free conditions. We propose instrumentation for ground-level monitoring stations designed to evaluate and enhance satellite remote sensing estimates for application in health effects research and risk assessment. The proposed instrumentation would measure hourly PM2.5 primarily in highly populated regions in close proximity to existing ground-based sun photometers that measure aerosol optical depth. As a result, this instrumentation would enable critical measurements to evaluate and improve global estimates of PM2.5 exposure.