Wen et al. (2025) Terrain-Driven Variability of Raindrop Size Distribution and Rainfall Kinetic Energy in Shaanxi, China, and Implications for Microphysics Estimation

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

Identification

• Journal: Journal of Hydrometeorology
• Year: 2025
• Date: 2025-11-03
• Authors: Long Wen, Yongyong Ma, Gang Chen, Jiming Sun
• DOI: 10.1175/jhm-d-25-0094.1

Research Groups

Not explicitly mentioned in the abstract. Research was conducted in Shaanxi Province, China, covering the Qinling–Daba Mountains and the Loess Plateau.

Short Summary

This study investigated the spatial variability of raindrop size distribution (DSD) across terrain gradients in Shaanxi Province, China, using six years of disdrometer observations. It revealed a pronounced south-north DSD gradient, with larger raindrops and higher kinetic energy in the semiarid Loess Plateau compared to the humid Qinling–Daba Mountains, amplifying soil erosion risks, and developed robust Dm-based estimators for key microphysical quantities.

Objective

• To demonstrate and quantify the variability of raindrop size distribution (DSD) across terrain gradients in semiarid regions, specifically Shaanxi Province, China.
• To understand the implications of this DSD variability for rainfall microphysics, kinetic energy (KE), and soil erosion risks.
• To establish Dm as a universal microphysical constraint for deriving robust estimators of key microphysical quantities and process rates.

Study Configuration

• Spatial Scale: Shaanxi Province, China, encompassing the humid Qinling–Daba Mountains and the semiarid Loess Plateau.
• Temporal Scale: Six summers (2019–2024).

Methodology and Data

• Models used: No specific named models (e.g., ISBA, mHM) were used. The study derived empirical relationships and robust estimators based on the mass-weighted mean diameter (Dm).
• Data sources: 92 disdrometer observations.

Main Results

• A pronounced south-north DSD gradient was observed across terrains in Shaanxi Province.
• The site-averaged mass-weighted mean diameter (Dm) increased, while the normalized intercept parameter (log10 Nw) decreased rapidly from mountains to plateaus.
• The humid Qinling–Daba Mountains exhibit higher seasonal rainfall (>800 mm) dominated by a high concentration of small raindrops.
• The semiarid Loess Plateau shows frequent occurrences of large raindrops, leading to higher kinetic energy (KE) (25 out of 28 stations > 20 J m⁻² mm⁻¹) compared to the Qinling–Daba Mountains (only 2 out of 25 stations > 20 J m⁻² mm⁻¹).
• This DSD shift amplifies soil erosion risks in the vulnerable loessial substrates of the Loess Plateau.
• Site-averaged Dm–log10 Nw pairs demonstrated consistent evolution throughout Shaanxi with increasing rain rate.
• Dm was established as a universal microphysical constraint, enabling the derivation of robust estimators for KE, accretion/evaporation rates, and mass-weighted terminal velocity of DSD, which encode terrain-mediated DSD heterogeneity.

Contributions

• Provides the first comprehensive characterization of DSD variability across diverse terrain gradients in a semiarid region (Shaanxi Province, China).
• Quantifies the significant south-north DSD gradient and its direct impact on rainfall kinetic energy and amplified soil erosion risks in the Loess Plateau.
• Develops novel, Dm-based universal microphysical estimators for key rainfall microphysical quantities (KE, accretion/evaporation rates, mass-weighted terminal velocity), overcoming limitations of traditional methods by incorporating terrain-mediated DSD heterogeneity.
• Offers critical semiarid DSD benchmarks crucial for improving model microphysics parameterization, advancing remote sensing–based KE retrievals, and informing targeted soil conservation strategies for erosion hotspots.

Funding

Not explicitly mentioned in the abstract.

Citation

@article{Wen2025TerrainDriven,
  author = {Wen, Long and Ma, Yongyong and Chen, Gang and Sun, Jiming},
  title = {Terrain-Driven Variability of Raindrop Size Distribution and Rainfall Kinetic Energy in Shaanxi, China, and Implications for Microphysics Estimation},
  journal = {Journal of Hydrometeorology},
  year = {2025},
  doi = {10.1175/jhm-d-25-0094.1},
  url = {https://doi.org/10.1175/jhm-d-25-0094.1}
}