Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature Data

The advanced geosynchronous radiation imager (AGRI) aboard the Chinese Fengyun-4A (FY-4A) satellite can provide operational hourly sea surface temperature (SST) product. However, the temporal and spatial variation of the errors for this product is still unclear. In this article, FY-4A/AGR...

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Main Authors: Quanjun He, Xin Hu, Yanwei Wu
Format: Article
Language:English
Published: IEEE 2023-01-01
Series:IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Subjects:
Online Access:https://ieeexplore.ieee.org/document/9966802/
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author Quanjun He
Xin Hu
Yanwei Wu
author_facet Quanjun He
Xin Hu
Yanwei Wu
author_sort Quanjun He
collection DOAJ
description The advanced geosynchronous radiation imager (AGRI) aboard the Chinese Fengyun-4A (FY-4A) satellite can provide operational hourly sea surface temperature (SST) product. However, the temporal and spatial variation of the errors for this product is still unclear. In this article, FY-4A/AGRI SST is evaluated using the in situ SST from 2019-2021, and a cumulative distribution function matching method is adopted to reduce the errors. Statistical results show that the mean bias and root-mean-square error (RMSE) of FY-4A/AGRI SST are −0.37 °C and 0.98 °C, the median and robust standard deviation (RSD) are −0.30 °C and 0.90 °C. The variations in daily and monthly errors are large and there are no prominent seasonal variations during the period analyzed. There are negative biases exceeding −1.0 °C in low-mid latitude regions and larger positive biases in southern high latitude region. There are dependencies of satellite SST minus in situ SST on satellite zenith angle and on SST itself. After the bias correction, the bias and RMSE are reduced to −0.02 °C and 0.72 °C, and the median and RSD are reduced to 0.00 °C and 0.60 °C. On the time scale, the fluctuation ranges of bias and median are smaller. The difference of satellite SST minus in situ SST can reflect the diurnal variation of SST. The biases are generally within ±0.2 °C in full disk. The error dependencies on satellite zenith angle and SST are also greatly reduced.
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spelling doaj.art-641aec15a48a4f3a9d71ad8c54506a3f2022-12-22T02:57:18ZengIEEEIEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing2151-15352023-01-011626727710.1109/JSTARS.2022.32257299966802Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature DataQuanjun He0https://orcid.org/0000-0001-9098-0206Xin Hu1Yanwei Wu2Guangzhou Meteorological Satellite Ground Station, Guangzhou, ChinaGuangzhou Meteorological Satellite Ground Station, Guangzhou, ChinaGuangzhou Meteorological Satellite Ground Station, Guangzhou, ChinaThe advanced geosynchronous radiation imager (AGRI) aboard the Chinese Fengyun-4A (FY-4A) satellite can provide operational hourly sea surface temperature (SST) product. However, the temporal and spatial variation of the errors for this product is still unclear. In this article, FY-4A/AGRI SST is evaluated using the in situ SST from 2019-2021, and a cumulative distribution function matching method is adopted to reduce the errors. Statistical results show that the mean bias and root-mean-square error (RMSE) of FY-4A/AGRI SST are −0.37 °C and 0.98 °C, the median and robust standard deviation (RSD) are −0.30 °C and 0.90 °C. The variations in daily and monthly errors are large and there are no prominent seasonal variations during the period analyzed. There are negative biases exceeding −1.0 °C in low-mid latitude regions and larger positive biases in southern high latitude region. There are dependencies of satellite SST minus in situ SST on satellite zenith angle and on SST itself. After the bias correction, the bias and RMSE are reduced to −0.02 °C and 0.72 °C, and the median and RSD are reduced to 0.00 °C and 0.60 °C. On the time scale, the fluctuation ranges of bias and median are smaller. The difference of satellite SST minus in situ SST can reflect the diurnal variation of SST. The biases are generally within ±0.2 °C in full disk. The error dependencies on satellite zenith angle and SST are also greatly reduced.https://ieeexplore.ieee.org/document/9966802/Advanced geosynchronous radiation imager (AGRI)bias correctionerror evaluationfengyun (FY)-4Asea surface temperature (SST)
spellingShingle Quanjun He
Xin Hu
Yanwei Wu
Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature Data
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Advanced geosynchronous radiation imager (AGRI)
bias correction
error evaluation
fengyun (FY)-4A
sea surface temperature (SST)
title Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature Data
title_full Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature Data
title_fullStr Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature Data
title_full_unstemmed Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature Data
title_short Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature Data
title_sort evaluation and improvement of fy 4a x002f agri sea surface temperature data
topic Advanced geosynchronous radiation imager (AGRI)
bias correction
error evaluation
fengyun (FY)-4A
sea surface temperature (SST)
url https://ieeexplore.ieee.org/document/9966802/
work_keys_str_mv AT quanjunhe evaluationandimprovementoffy4ax002fagriseasurfacetemperaturedata
AT xinhu evaluationandimprovementoffy4ax002fagriseasurfacetemperaturedata
AT yanweiwu evaluationandimprovementoffy4ax002fagriseasurfacetemperaturedata