An Evaluation of Four MODIS Collection 6 Aerosol Products in a Humid Subtropical Region
Moderate resolution imaging spectroradiometer (MODIS) aerosol optical depth (AOD) products have been widely used to characterize the temporal variations and spatial distributions of atmospheric aerosols. In the present study, we evaluate the performance of four Terra and Aqua MODIS Collection 6 (C6)...
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MDPI AG
2017-11-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/9/11/1173 |
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| author | Ming Zhang Bo Huang Qingqing He |
| author_facet | Ming Zhang Bo Huang Qingqing He |
| author_sort | Ming Zhang |
| collection | DOAJ |
| description | Moderate resolution imaging spectroradiometer (MODIS) aerosol optical depth (AOD) products have been widely used to characterize the temporal variations and spatial distributions of atmospheric aerosols. In the present study, we evaluate the performance of four Terra and Aqua MODIS Collection 6 (C6) quality assured AOD products in the Pearl River Delta (PRD) region, a humid subtropical region. The 10 km AOD products retrieved by the Dark Target (DT) and Deep Blue (DB) algorithms, the merged DT/DB (DTDB) 10 km product, and the DT 3 km AOD product were obtained for 2006–2015. These products were compared with Aerosol Robotic Network (AERONET) observations, and with each other. The Terra- and Aqua-derived AODs are quantitatively similar. However, there are significant differences among the four AOD products. The DT 10 km product correlates more closely with AERONET AOD observations than does the DB 10 km product. The latter tends to underestimate the AOD, whereas the former typically overestimates it for highly urbanized areas. The DTDB 10 km product is mainly derived from the DT 10 km product; it does not provide a gap-filled data set, because valid DB 10 km retrievals are not included in the merged product even when DT 10 km retrievals are unavailable. Therefore, the DT/DB merging protocol should be improved. The DT 3 km AOD product closely mimics the DT 10 km product; however, it contains fewer data than the DT 10 km product over water-contaminated areas. In addition, although the quality assured AOD products are recommended for use in quantitative applications by the MODIS aerosol science team, the sampling frequency of these products is generally lower than 25%. Thus, the sampling issues of these products should be considered in humid subtropical areas. |
| first_indexed | 2024-04-11T18:24:09Z |
| format | Article |
| id | doaj.art-5852f3e598444b5da5a222297c987a78 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-04-11T18:24:09Z |
| publishDate | 2017-11-01 |
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| series | Remote Sensing |
| spelling | doaj.art-5852f3e598444b5da5a222297c987a782022-12-22T04:09:40ZengMDPI AGRemote Sensing2072-42922017-11-01911117310.3390/rs9111173rs9111173An Evaluation of Four MODIS Collection 6 Aerosol Products in a Humid Subtropical RegionMing Zhang0Bo Huang1Qingqing He2School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, ChinaDepartment of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ChinaDepartment of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, ChinaModerate resolution imaging spectroradiometer (MODIS) aerosol optical depth (AOD) products have been widely used to characterize the temporal variations and spatial distributions of atmospheric aerosols. In the present study, we evaluate the performance of four Terra and Aqua MODIS Collection 6 (C6) quality assured AOD products in the Pearl River Delta (PRD) region, a humid subtropical region. The 10 km AOD products retrieved by the Dark Target (DT) and Deep Blue (DB) algorithms, the merged DT/DB (DTDB) 10 km product, and the DT 3 km AOD product were obtained for 2006–2015. These products were compared with Aerosol Robotic Network (AERONET) observations, and with each other. The Terra- and Aqua-derived AODs are quantitatively similar. However, there are significant differences among the four AOD products. The DT 10 km product correlates more closely with AERONET AOD observations than does the DB 10 km product. The latter tends to underestimate the AOD, whereas the former typically overestimates it for highly urbanized areas. The DTDB 10 km product is mainly derived from the DT 10 km product; it does not provide a gap-filled data set, because valid DB 10 km retrievals are not included in the merged product even when DT 10 km retrievals are unavailable. Therefore, the DT/DB merging protocol should be improved. The DT 3 km AOD product closely mimics the DT 10 km product; however, it contains fewer data than the DT 10 km product over water-contaminated areas. In addition, although the quality assured AOD products are recommended for use in quantitative applications by the MODIS aerosol science team, the sampling frequency of these products is generally lower than 25%. Thus, the sampling issues of these products should be considered in humid subtropical areas.https://www.mdpi.com/2072-4292/9/11/1173MODISAODAERONETsampling frequency |
| spellingShingle | Ming Zhang Bo Huang Qingqing He An Evaluation of Four MODIS Collection 6 Aerosol Products in a Humid Subtropical Region Remote Sensing MODIS AOD AERONET sampling frequency |
| title | An Evaluation of Four MODIS Collection 6 Aerosol Products in a Humid Subtropical Region |
| title_full | An Evaluation of Four MODIS Collection 6 Aerosol Products in a Humid Subtropical Region |
| title_fullStr | An Evaluation of Four MODIS Collection 6 Aerosol Products in a Humid Subtropical Region |
| title_full_unstemmed | An Evaluation of Four MODIS Collection 6 Aerosol Products in a Humid Subtropical Region |
| title_short | An Evaluation of Four MODIS Collection 6 Aerosol Products in a Humid Subtropical Region |
| title_sort | evaluation of four modis collection 6 aerosol products in a humid subtropical region |
| topic | MODIS AOD AERONET sampling frequency |
| url | https://www.mdpi.com/2072-4292/9/11/1173 |
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