<p>Because of the increasing evidence of the widespread adverse effects on human health from exposure to poor air quality and the recommendations by the World Health Organization to significantly reduce PM2.5 in order to reduce these risks, it has become necessary to have better estimates of surface air quality globally. However, surface measurements useful for monitoring particulate exposure are scarce, especially in developing countries which often experience the worst air pollution. Therefore, other methods are necessary to augment estimates in regions with limited surface observations.</p>
<p>The prospect of using satellite observations to infer surface air quality is attractive; however, it requires knowledge of the complicated relationship between satellite-observed aerosol optical depth (AOD) and surface concentrations. This relationship is often based on models. Several recent studies have made use of a &ldquo;satellite-derived&rdquo; PM2.5 in order to estimate chronic or long-term exposure to outdoor atmospheric pollutants.</p>
<p>In this talk, I will first discuss a specific investigation focused on understanding aerosol sources in the Southeastern US which illustrates how satellite and surface observations do not always provide a consistent picture of air quality. Next I will more broadly discuss how satellite PM2.5 can be used to derive mortality estimates in the United States and China. Because there is a desire for acute exposure estimates, especially with regards to extreme events, we examine these impacts on both short- and long-term timescales. I will also discuss the uncertainties associated with the satellite-derived product and highlight when and where the satellites may offer additional constraints on PM2.5 premature mortality estimates.</p>