Wang et al. (2025) Understanding Overland Satellite-Based Precipitation Errors in IMERG Products as a Function of Input Sources

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Hydrometeorology
• Year: 2025
• Date: 2025-07-16
• Authors: Jianxin Wang, David B. Wolff, Jackson Tan, George J. Huffman
• DOI: 10.1175/jhm-d-25-0047.1

Research Groups

• GPM (Global Precipitation Measurement) mission Science Team
• GPM Ground Validation effort

Short Summary

This study evaluates the performance of the IMERG V07B precipitation product against its predecessor V06B over the conterminous United States. The results demonstrate that V07B provides superior precipitation detection and reduced systematic bias across all seasons, particularly in winter.

Objective

• To evaluate and compare the precipitation statistics of IMERG V06B and V07B using ground-based radar as a reference.
• To trace precipitation retrieval errors to specific sensor sources and the utilization of infrared (IR) input.

Study Configuration

• Spatial Scale: Conterminous United States (CONUS)
• Temporal Scale: Multi-seasonal analysis covering a retrospective period of over two decades

Methodology and Data

• Models used: Integrated Multi-satellitE Retrievals for GPM (IMERG) versions V06B and V07B.
• Data sources: Quality-controlled Multi-Radar Multi-Sensor (MRMS) system (ground-based radar precipitation estimates).

Main Results

• IMERG V07B exhibits clear improvements over V06B in all seasons, with the most significant gains observed during winter.
• V07B shows a reduction in systematic bias and uncertainty.
• There is a measurable increase in precipitation detectability in V07B.
• Improvements are attributed to:
  • Enhanced algorithms for passive microwave (PMW) and infrared (IR) retrievals.
  • Inclusion of PMW retrievals over frozen surfaces.
  • Upgraded intercalibration addressing previous bias sources in V06B.

Contributions

• Provides the first extensive evaluation of IMERG V07B versus V06B at native resolutions using ground-based radar data over the CONUS region.
• Offers a detailed decomposition of retrieval errors into hit bias, missed-precipitation bias, and false-precipitation bias, linking them to specific sensors.

Funding

• Not specified in the provided text.

Citation

@article{Wang2025Understanding,
  author = {Wang, Jianxin and Wolff, David B. and Tan, Jackson and Huffman, George J.},
  title = {Understanding Overland Satellite-Based Precipitation Errors in IMERG Products as a Function of Input Sources},
  journal = {Journal of Hydrometeorology},
  year = {2025},
  doi = {10.1175/jhm-d-25-0047.1},
  url = {https://doi.org/10.1175/jhm-d-25-0047.1}
}