Abstract
Abstract. Recently launched multichannel geostationary Earth orbit (GEO) satellite sensors, such as the Geostationary Ocean Color Imager (GOCI) and the Advanced Himawari Imager (AHI), provide aerosol products over East Asia with high accuracy, which enables the monitoring of rapid diurnal variations and the transboundary transport of aerosols. Most aerosol studies to date have used low Earth orbit (LEO) satellite sensors, such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multi-angle Imaging Spectroradiometer (MISR), with a maximum of one or two overpass daylight times per day from midlatitudes to low latitudes. Thus, the demand for new GEO observations with high temporal resolution and improved accuracy has been significant. In this study the latest versions of aerosol optical depth (AOD) products from three LEO sensors – MODIS (Dark Target, Deep Blue, and MAIAC), MISR, and the Visible/Infrared Imager Radiometer Suite (VIIRS), along with two GEO sensors (GOCI and AHI), are validated, compared, and integrated for a period during the Korea–United States Air Quality Study (KORUS-AQ) field campaign from 1 May to 12 June 2016 over East Asia. The AOD products analyzed here generally have high accuracy with high R (0.84–0.93) and low RMSE (0.12–0.17), but their error characteristics differ according to the use of several different surface-reflectance estimation methods. High-accuracy near-real-time GOCI and AHI measurements facilitate the detection of rapid AOD changes, such as smoke aerosol transport from Russia to Japan on 18–21 May 2016, heavy pollution transport from China to the Korean Peninsula on 25 May 2016, and local emission transport from the Seoul Metropolitan Area to the Yellow Sea in South Korea on 5 June 2016. These high-temporal-resolution GEO measurements result in more representative daily AOD values and make a greater contribution to a combined daily AOD product assembled by median value selection with a 0.5∘×0.5∘ grid resolution. The combined AOD is spatially continuous and has a greater number of pixels with high accuracy (fraction within expected error range of 0.61) than individual products. This study characterizes aerosol measurements from LEO and GEO satellites currently in operation over East Asia, and the results presented here can be used to evaluate satellite measurement bias and air quality models.
Highlights
Atmospheric aerosol particles are composed of solid and liquid matter and have diameters of a few nanometers up to several micrometers and lifetimes from a single day to tens of days
When we combined all of these products for the fusion aerosol optical depth (AOD), it has a higher f (0.61) than the individual products, except for Multiangle Imaging Spectroradiometer (MISR) (0.77) and multiangle implementation of atmospheric correction (MAIAC) (0.65), and a high N (869), low root-mean-square error (RMSE) (0.16), and high R (0.87)
Choi et al (2018) showed that Geostationary Ocean Color Imager (GOCI) AOD is reliably accurate for the period 2011–2015, it is negatively biased during the 2016 campaign period
Summary
Atmospheric aerosol particles are composed of solid and liquid matter and have diameters of a few nanometers up to several micrometers and lifetimes from a single day to tens of days. Aerosol particles affect the atmospheric radiation balance by scattering and absorbing incident top-ofatmosphere (TOA) sunlight and light scattered from the surface, as well as by interacting with clouds (e.g., by changing cloud distributions, optical properties, and precipitation by acting as cloud condensation nuclei) with global climate effects (IPCC, 2013). Many developing countries in East Asia have both large anthropogenic emission sources and natural aerosol sources, such as the Taklamakan and Gobi deserts and wildfire regions. For this reason, East Asia currently has one of the most heavily polluted atmospheres in the world W. Kim et al, 2007; Mehta et al, 2016; Yoon et al, 2014; Zhao et al, 2017)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
