Himawari-8/AHI and MODIS Aerosol Optical Depths in China: Evaluation and Comparison
The geostationary earth orbit satellite—Himawari-8 loaded with the Advanced Himawari Imager (AHI) has greatly enhanced our capacity of dynamic monitoring in Asia−Pacific area. The Himawari-8/AHI hourly aerosol product is a promising complementary source to the MODerate resolution...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-04-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/11/9/1011 |
| _version_ | 1798031634749980672 |
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| author | Tingting Jiang Bin Chen Karen Kie Yan Chan Bing Xu |
| author_facet | Tingting Jiang Bin Chen Karen Kie Yan Chan Bing Xu |
| author_sort | Tingting Jiang |
| collection | DOAJ |
| description | The geostationary earth orbit satellite—Himawari-8 loaded with the Advanced Himawari Imager (AHI) has greatly enhanced our capacity of dynamic monitoring in Asia−Pacific area. The Himawari-8/AHI hourly aerosol product is a promising complementary source to the MODerate resolution Imaging Spectroradiometer (MODIS) daily aerosol product for near real-time air pollution observations. However, a comprehensive evaluation of AHI aerosol optical depth (AOD) is still limited, and the difference in performances of AHI and MODIS remains uncertain. In this study, we evaluated the Himawari-8/AHI Level 3 Version 3.0 and MODIS Collection 6.1 Deep Blue AOD products over China against AOD measurements from AErosol RObotic NETwork (AERONET) sites in a spatiotemporal comparison of the products from February 2018 to January 2019. Results showed that AHI AOD achieved a moderate agreement with AERONET with a correlation coefficient of 0.75 and a root-mean-square-error of 0.26, which was slightly inferior to MODIS. The retrieval accuracy was spatially and temporally varied in AHI AOD, with higher accuracies for XiangHe and Lulin sites as well as in the morning and during the summer. The dependency analysis further revealed that the bias in AHI AOD was strongly dependent on aerosol loading and influenced by the Ångström Exponent and NDVI while those for MODIS appeared to be independent of all variables. Fortunately, the biases in AHI AOD could be rectified using a random forest model that contained the appropriate variables to produce sufficiently accurate results with cross-validation R of 0.92 and RMSE of 0.15. With these adjustments, AHI AOD will continue to have great potential in characterizing precise dynamic aerosol variations and air quality at a fine temporal resolution. |
| first_indexed | 2024-04-11T20:00:48Z |
| format | Article |
| id | doaj.art-d4a2f39b6c5b4d93a6a736a76e75a7ef |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-04-11T20:00:48Z |
| publishDate | 2019-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-d4a2f39b6c5b4d93a6a736a76e75a7ef2022-12-22T04:05:39ZengMDPI AGRemote Sensing2072-42922019-04-01119101110.3390/rs11091011rs11091011Himawari-8/AHI and MODIS Aerosol Optical Depths in China: Evaluation and ComparisonTingting Jiang0Bin Chen1Karen Kie Yan Chan2Bing Xu3Department of Earth System Science, Tsinghua University, Beijing 100084, ChinaDepartment of Earth System Science, Tsinghua University, Beijing 100084, ChinaDepartment of Earth System Science, Tsinghua University, Beijing 100084, ChinaDepartment of Earth System Science, Tsinghua University, Beijing 100084, ChinaThe geostationary earth orbit satellite—Himawari-8 loaded with the Advanced Himawari Imager (AHI) has greatly enhanced our capacity of dynamic monitoring in Asia−Pacific area. The Himawari-8/AHI hourly aerosol product is a promising complementary source to the MODerate resolution Imaging Spectroradiometer (MODIS) daily aerosol product for near real-time air pollution observations. However, a comprehensive evaluation of AHI aerosol optical depth (AOD) is still limited, and the difference in performances of AHI and MODIS remains uncertain. In this study, we evaluated the Himawari-8/AHI Level 3 Version 3.0 and MODIS Collection 6.1 Deep Blue AOD products over China against AOD measurements from AErosol RObotic NETwork (AERONET) sites in a spatiotemporal comparison of the products from February 2018 to January 2019. Results showed that AHI AOD achieved a moderate agreement with AERONET with a correlation coefficient of 0.75 and a root-mean-square-error of 0.26, which was slightly inferior to MODIS. The retrieval accuracy was spatially and temporally varied in AHI AOD, with higher accuracies for XiangHe and Lulin sites as well as in the morning and during the summer. The dependency analysis further revealed that the bias in AHI AOD was strongly dependent on aerosol loading and influenced by the Ångström Exponent and NDVI while those for MODIS appeared to be independent of all variables. Fortunately, the biases in AHI AOD could be rectified using a random forest model that contained the appropriate variables to produce sufficiently accurate results with cross-validation R of 0.92 and RMSE of 0.15. With these adjustments, AHI AOD will continue to have great potential in characterizing precise dynamic aerosol variations and air quality at a fine temporal resolution.https://www.mdpi.com/2072-4292/11/9/1011aerosol optical depth (AOD)Himawari-8MODISvalidationChina |
| spellingShingle | Tingting Jiang Bin Chen Karen Kie Yan Chan Bing Xu Himawari-8/AHI and MODIS Aerosol Optical Depths in China: Evaluation and Comparison Remote Sensing aerosol optical depth (AOD) Himawari-8 MODIS validation China |
| title | Himawari-8/AHI and MODIS Aerosol Optical Depths in China: Evaluation and Comparison |
| title_full | Himawari-8/AHI and MODIS Aerosol Optical Depths in China: Evaluation and Comparison |
| title_fullStr | Himawari-8/AHI and MODIS Aerosol Optical Depths in China: Evaluation and Comparison |
| title_full_unstemmed | Himawari-8/AHI and MODIS Aerosol Optical Depths in China: Evaluation and Comparison |
| title_short | Himawari-8/AHI and MODIS Aerosol Optical Depths in China: Evaluation and Comparison |
| title_sort | himawari 8 ahi and modis aerosol optical depths in china evaluation and comparison |
| topic | aerosol optical depth (AOD) Himawari-8 MODIS validation China |
| url | https://www.mdpi.com/2072-4292/11/9/1011 |
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