Comparison of FY-4A/AGRI SST with Himawari-8/AHI and In Situ SST
The Fengyun-4A (FY-4A) satellite is a new-generation geostationary meteorological satellite developed by China. The advanced geosynchronous radiation imager (AGRI), one of the key payloads onboard FY-4A, can monitor sea surface temperature (SST). This paper compares FY-4A/AGRI SST with in situ and H...
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MDPI AG
2023-08-01
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| Online Access: | https://www.mdpi.com/2072-4292/15/17/4139 |
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| author | Chang Yang Lei Guan Xiaohui Sun |
| author_facet | Chang Yang Lei Guan Xiaohui Sun |
| author_sort | Chang Yang |
| collection | DOAJ |
| description | The Fengyun-4A (FY-4A) satellite is a new-generation geostationary meteorological satellite developed by China. The advanced geosynchronous radiation imager (AGRI), one of the key payloads onboard FY-4A, can monitor sea surface temperature (SST). This paper compares FY-4A/AGRI SST with in situ and Himawari-8/advanced Himawari imager (AHI) SST. The study area spans 30°E–180°E, 60°S–60°N, and the study period is from January 2019 to December 2021. The matching time window of the three data is 30 min, and the space window is 0.1°. The quality control criterion is to select all clear sky and well-distributed matchups within the study period, removing the influence of SST fronts. The results of the difference between FY-4A/AGRI and in situ SST show a bias of −0.12 °C, median of −0.05 °C, standard deviation (STD) of 0.76 °C, robust standard deviation (RSD) of 0.68 °C, and root mean square error (RMSE) of 0.77 °C for daytime and a bias of 0.00 °C, median of 0.05 °C, STD of 0.78 °C, RSD of 0.72 °C, and RMSE of 0.78 °C for nighttime. The results of the difference between FY-4A/AGRI SST and Himawari-8/AHI SST show a bias of 0.04 °C, median of 0.10 °C, STD of 0.78 °C, RSD of 0.70 °C, and RMSE of 0.78 °C for daytime and the bias of 0.30 °C, median of 0.34 °C, STD of 0.81 °C, RSD of 0.76 °C, and RMSE of 0.86 °C for nighttime. The three-way error analysis also indicates a relatively larger error of AGRI SST. Regarding timescale, the bias and STD of FY-4A/AGRI SST show no seasonal correlation, but FY-4A/AGRI SST has a noticeable bias jump in the study period. Regarding spatial scale, FY-4A/AGRI SST shows negative bias at the edge of the AGRI SST coverage in the Pacific region near 160°E longitude and positive bias in high latitudes of the southern hemisphere. The accuracy of FY-4A/AGRI SST depends on the satellite zenith angle and water vapor. Further research on the FY-4A/AGRI SST retrieval algorithm accounting for the variability of water vapor will be conducted. |
| first_indexed | 2024-03-10T23:14:15Z |
| format | Article |
| id | doaj.art-4dc52741edc54303b4c979522f2770f2 |
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| language | English |
| last_indexed | 2024-03-10T23:14:15Z |
| publishDate | 2023-08-01 |
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| spelling | doaj.art-4dc52741edc54303b4c979522f2770f22023-11-19T08:44:58ZengMDPI AGRemote Sensing2072-42922023-08-011517413910.3390/rs15174139Comparison of FY-4A/AGRI SST with Himawari-8/AHI and In Situ SSTChang Yang0Lei Guan1Xiaohui Sun2College of Marine Technology, Faculty of Information Science and Engineering, Ocean University of China, Qingdao 266100, ChinaCollege of Marine Technology, Faculty of Information Science and Engineering, Ocean University of China, Qingdao 266100, ChinaCollege of Marine Technology, Faculty of Information Science and Engineering, Ocean University of China, Qingdao 266100, ChinaThe Fengyun-4A (FY-4A) satellite is a new-generation geostationary meteorological satellite developed by China. The advanced geosynchronous radiation imager (AGRI), one of the key payloads onboard FY-4A, can monitor sea surface temperature (SST). This paper compares FY-4A/AGRI SST with in situ and Himawari-8/advanced Himawari imager (AHI) SST. The study area spans 30°E–180°E, 60°S–60°N, and the study period is from January 2019 to December 2021. The matching time window of the three data is 30 min, and the space window is 0.1°. The quality control criterion is to select all clear sky and well-distributed matchups within the study period, removing the influence of SST fronts. The results of the difference between FY-4A/AGRI and in situ SST show a bias of −0.12 °C, median of −0.05 °C, standard deviation (STD) of 0.76 °C, robust standard deviation (RSD) of 0.68 °C, and root mean square error (RMSE) of 0.77 °C for daytime and a bias of 0.00 °C, median of 0.05 °C, STD of 0.78 °C, RSD of 0.72 °C, and RMSE of 0.78 °C for nighttime. The results of the difference between FY-4A/AGRI SST and Himawari-8/AHI SST show a bias of 0.04 °C, median of 0.10 °C, STD of 0.78 °C, RSD of 0.70 °C, and RMSE of 0.78 °C for daytime and the bias of 0.30 °C, median of 0.34 °C, STD of 0.81 °C, RSD of 0.76 °C, and RMSE of 0.86 °C for nighttime. The three-way error analysis also indicates a relatively larger error of AGRI SST. Regarding timescale, the bias and STD of FY-4A/AGRI SST show no seasonal correlation, but FY-4A/AGRI SST has a noticeable bias jump in the study period. Regarding spatial scale, FY-4A/AGRI SST shows negative bias at the edge of the AGRI SST coverage in the Pacific region near 160°E longitude and positive bias in high latitudes of the southern hemisphere. The accuracy of FY-4A/AGRI SST depends on the satellite zenith angle and water vapor. Further research on the FY-4A/AGRI SST retrieval algorithm accounting for the variability of water vapor will be conducted.https://www.mdpi.com/2072-4292/15/17/4139sea surface temperatureFY-4AAGRIHimawari-8AHI |
| spellingShingle | Chang Yang Lei Guan Xiaohui Sun Comparison of FY-4A/AGRI SST with Himawari-8/AHI and In Situ SST Remote Sensing sea surface temperature FY-4A AGRI Himawari-8 AHI |
| title | Comparison of FY-4A/AGRI SST with Himawari-8/AHI and In Situ SST |
| title_full | Comparison of FY-4A/AGRI SST with Himawari-8/AHI and In Situ SST |
| title_fullStr | Comparison of FY-4A/AGRI SST with Himawari-8/AHI and In Situ SST |
| title_full_unstemmed | Comparison of FY-4A/AGRI SST with Himawari-8/AHI and In Situ SST |
| title_short | Comparison of FY-4A/AGRI SST with Himawari-8/AHI and In Situ SST |
| title_sort | comparison of fy 4a agri sst with himawari 8 ahi and in situ sst |
| topic | sea surface temperature FY-4A AGRI Himawari-8 AHI |
| url | https://www.mdpi.com/2072-4292/15/17/4139 |
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