Spatio-Temporal Variations in the Associations between Hourly PM2.5 and Aerosol Optical Depth (AOD) from MODIS Sensors on Terra and Aqua.

Minho Kim,Xingyou Zhang,Yang Liu,James B Holt

doi:10.4236/health.2013.510a2002

Abstract

Recent studies have explored the relationship between aerosol optical depth (AOD) measurements by satellite sensors and concentrations of particulate matter with aerodynamic diameters less than 2.5 μm (PM2.5). However, relatively little is known about spatial and temporal patterns in this relationship across the contiguous United States. In this study, we investigated the relationship between US Environmental Protection Agency estimates of PM2.5 concentrations and Moderate Resolution Imaging Spectroradiometer (MODIS) AOD measurements provided by two NASA satellites (Terra and Aqua) across the contiguous United States during 2005. We found that the combined use of both satellite sensors provided more AOD coverage than the use of either satellite sensor alone, that the correlation between AOD measurements and PM2.5 concentrations varied substantially by geographic location, and that this correlation was stronger in the summer and fall than that in the winter and spring.

Highlights

Particulate matter less than 2.5 μm in aerodynamic diameter (PM2.5) is a category of air pollutant that consists of solid particles and liquid droplets in organic and inorganic substances
We found that the mean number of days with valid aerosol optical depth (AOD) data was higher with use of the combined Terra and Aqua datasets (117) than with use of either the Terra dataset (91) or the Aqua dataset (78) alone (Figure 1)
We observed that integrated AODs with Terra and Aqua provide more sufficient observations with valid monthly-average AODs across all ground monitoring stations, as depicted in Figures 3(c) and (d)

Summary

Introduction

Particulate matter less than 2.5 μm in aerodynamic diameter (PM2.5) is a category of air pollutant that consists of solid particles and liquid droplets in organic and inorganic substances. According to the US Environmental Protection Agency (EPA) [2], the major components of PM2.5 in the eastern United States are sulfate, organic carbon, and ammonia; in the western United. PM2.5 is small enough to be inhaled through the throat and nose, and exposure to PM2.5 has been associated with increased risk for respiratory and cardiovascular diseases and death [3,4,5,6]. Because of these adverse health effects, federal, state, and local government agencies across the continental United States have established a ground-level

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Results

Conclusion