Jiang et al. (2025) Assessment of Fengyun-4B precipitable water vapor using GNSS, radiosonde, and ERA5 data

Identification

• Journal: Advances in Space Research
• Year: 2025
• Date: 2025-12-27
• Authors: Chunhua Jiang, Yilin Cui, Huizhong Zhu, Xiang Gao, Liang Chen, Shaoni Chen, Meng Gao, Hongjuan Yu
• DOI: 10.1016/j.asr.2025.12.087

Research Groups

• School of Geomatics, Liaoning Technical University
• College of Geological Engineering and Geomatics, Chang’an University

Short Summary

This study thoroughly assesses the Fengyun-4B (FY-4B) satellite's precipitable water vapor (PWV) products using Global Navigation Satellite System (GNSS), radiosonde, and ERA5 reanalysis data, revealing high consistency with reference data but varying accuracy influenced by latitude, coastal proximity, PWV magnitude, and seasonal and regional climate types.

Objective

• To conduct a thorough assessment of the precipitable water vapor (PWV) products from the Geostationary Interferometric Infrared Sounder (GIIRS) carried by the Fengyun-4B (FY-4B) satellite.

Study Configuration

• Spatial Scale: Regional scale over China, including specific analyses for coastal areas, the Qinghai-Tibet Plateau, and Northwest China.
• Temporal Scale: One year, from January to December 2023, with seasonal analysis.

Methodology and Data

• Models used: The study assesses the FY-4B GIIRS PWV product; no specific atmospheric or hydrological models were used for the assessment itself, rather reference data for comparison.
• Data sources: Fengyun-4B (FY-4B) satellite precipitable water vapor (PWV) products from the Geostationary Interferometric Infrared Sounder (GIIRS), Global Navigation Satellite System (GNSS) data, radiosonde data, and ERA5 reanalysis data.

Main Results

• FY-4B PWV shows high consistency with both GNSS and radiosonde measurements, with correlation coefficients of 0.97 for both comparisons.
• The Root Mean Square (RMS) of FY-4B PWV is 4.41 mm when compared to GNSS, 6.02 mm compared to radiosonde, and 5.20 mm compared to ERA5.
• The bias of FY-4B PWV is -0.14 mm relative to GNSS, -4.23 mm relative to radiosonde, and -2.47 mm relative to ERA5.
• The accuracy of FY-4B PWV decreases with increasing latitude and shows larger errors in coastal areas.
• FY-4B tends to underestimate water vapor (negative deviation) when PWV exceeds 40 mm.
• Seasonally, the RMS peaks in summer, followed by spring and autumn, and is lowest in winter.
• Climate types in different geographical regions of China influence the retrieval accuracy of FY-4B PWV.
• In the Qinghai-Tibet Plateau region, the RMS difference calculated by different data quality evaluation indicators reaches millimeter level, and the relative error is larger than that of Northwest China.

Contributions

• Provides the first thorough and comprehensive assessment of the Fengyun-4B GIIRS PWV products using multiple independent and widely recognized reference datasets (GNSS, radiosonde, and ERA5 reanalysis).
• Offers detailed insights into the spatial and temporal characteristics of FY-4B PWV accuracy, identifying specific limitations related to latitude, coastal regions, high PWV values, and seasonal variations.
• Highlights the influence of climate types on FY-4B PWV retrieval accuracy across different geographical regions of China, particularly for complex terrains like the Qinghai-Tibet Plateau.

Funding

Not explicitly mentioned in the provided text.

Citation

@article{Jiang2025Assessment,
  author = {Jiang, Chunhua and Cui, Yilin and Zhu, Huizhong and Gao, Xiang and Chen, Liang and Chen, Shaoni and Gao, Meng and Yu, Hongjuan},
  title = {Assessment of Fengyun-4B precipitable water vapor using GNSS, radiosonde, and ERA5 data},
  journal = {Advances in Space Research},
  year = {2025},
  doi = {10.1016/j.asr.2025.12.087},
  url = {https://doi.org/10.1016/j.asr.2025.12.087}
}