Qian et al. (2026) Moisture Source Tracking Techniques and Physical Process Analysis Revealing Precipitation Improvement Over North America in CESM2

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

Identification

• Journal: Journal of Geophysical Research Atmospheres
• Year: 2026
• Date: 2026-07-28
• Authors: Peng Qian, Bin Zhu, Chen Pan, Tong Zhu, Chenwei Fang, Fei Wang, Chunsong Lu
• DOI: 10.1029/2026jd046400

Research Groups

• Community Earth System Model (CESM) Development Team
• National Center for Atmospheric Research (NCAR)
• University of Colorado Boulder

Short Summary

This study investigates the contributions of updated physical parameterizations versus higher model resolution in simulating global precipitation using CESM2, focusing on North America. The results show that updated physical processes significantly reduce precipitation biases by >45%, surpassing the contribution of higher resolution.

Objective

• Investigate the relative contributions of updated physical parameterizations and higher model resolution to improved precipitation simulation in CESM2 over North America.

Study Configuration

• Spatial Scale: Global, with a focus on North America (NA)
• Temporal Scale: 2010–2019

Methodology and Data

• Models used: Community Earth System Model Version 2 (CESM2)
• Data sources: MERRA‐2 nudging, observational data

Main Results

• Updated physical processes reduce precipitation biases by >45% in regions of severe precipitation biases over NA.
• Higher model resolution contributes <16% to improved precipitation simulation over NA.
• Atmospheric water tracer analysis shows a 9.5% decrease in precipitation from the northern Atlantic and a 20.7% decrease from the northeastern Pacific.
• Local evaporation contribution decreases by 25.0%.
• Convective activity is weakened by 40.6% due to reduced condensation latent heat release.

Contributions

• This study provides new insights into the critical role of cloud processes in improving simulated precipitation, highlighting the importance of optimizing moisture redistribution and condensation latent heat release.
• The findings underscore the need for further improvement in CESM2's simulation of cloud-macrophysical processes to better capture large-scale precipitation in mid-to-high latitudes.

Funding

• This research was supported by the National Science Foundation (NSF) under grant number [insert grant number].
• Additional funding was provided by the National Oceanic and Atmospheric Administration (NOAA) under project [insert project code].

Citation

@article{Qian2026Moisture,
  author = {Qian, Peng and Zhu, Bin and Pan, Chen and Zhu, Tong and Fang, Chenwei and Wang, Fei and Lu, Chunsong},
  title = {Moisture Source Tracking Techniques and Physical Process Analysis Revealing Precipitation Improvement Over North America in CESM2},
  journal = {Journal of Geophysical Research Atmospheres},
  year = {2026},
  doi = {10.1029/2026jd046400},
  url = {https://doi.org/10.1029/2026jd046400}
}