Analysis of Sun photometer measured and satellite retrieved aerosol optical depth (AOD) data has shown that major aerosol pollution events with very high fine mode AOD (>1.0 in midvisible) in the China/Korea/Japan region are often observed to be associated with significant cloud cover. This makes remote sensing of these events difficult even for high temporal resolution Sun photometer measurements. Possible physical mechanisms for these events that have high AOD include a combination of aerosol humidification, cloud processing, and meteorological covariation with atmospheric stability and convergence. The new development of Aerosol Robotic Network Version 3 Level 2 AOD with improved cloud screening algorithms now allow for unprecedented ability to monitor these extreme fine mode pollution events. Further, the spectral deconvolution algorithm (SDA) applied to Level 1 data (L1; no cloud screening) provides an even more comprehensive assessment of fine mode AOD than L2 in current and previous data versions. Studying the 2012 winter-summer period, comparisons of Aerosol Robotic Network L1 SDA daily average fine mode AOD data showed that Moderate Resolution Imaging Spectroradiometer satellite remote sensing of AOD often did not retrieve and/or identify some of the highest fine mode AOD events in this region. Also, compared to models that include data assimilation of satellite retrieved AOD, the L1 SDA fine mode AOD was significantly higher in magnitude, particularly for the highest AOD events that were often associated with significant cloudiness.
Bibliographical noteFunding Information:
We thank Hal Maring (NASA Headquarters) and Steve Platnik (NASA GSFC) for their continuing support and long-term commitment to the AERONET project. MODIS aerosol data are avail able freely from https://laadsweb.nas- com.nasa.gov. More information about Deep Blue is available at https://deep- blue.gsfc.nasa.gov, and more informa tion about Dark Target is at https:// darktarget.gsfc.nasa.gov. J. S. Reid’s and P. Xian contributions were provided by the Office of Naval Research Code 322 (N0001418WX00442). For the Yonsei University team, this research was supported by the National Strategic Project-Fine particle of the National Research Foundation of Korea(NRF) funded by the Ministry of Science and ICT(MSIT), the Ministry of Environment(ME), and the Ministry of Health and Welfare(MOHW). (NRF-2017M3D8A1092022) We also thank two anonymous reviewers and Lorraine Remer for providing valuable reviews that led to strengthening of this paper.
All Science Journal Classification (ASJC) codes
- Aquatic Science
- Water Science and Technology
- Soil Science
- Geochemistry and Petrology
- Earth-Surface Processes
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science