Ma et al. (2025) Response and mechanisms of sub-daily precipitation over the Tibetan Plateau to regional climate change

Identification

• Journal: npj Climate and Atmospheric Science
• Year: 2025
• Date: 2025-12-12
• Authors: Yuanyuan Ma, Xiaoxue Hu, Xianhong Meng, Di Ma
• DOI: 10.1038/s41612-025-01275-7

Research Groups

• State Key Laboratory of Cryospheric Science and Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
• Zoige Plateau Wetland Ecosystem Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
• College of Atmospheric Sciences, Lanzhou University, Lanzhou, China

Short Summary

This study investigates the impact of regional climate change over East Asia (RCC) and the Tibetan Plateau (PCC) on sub-daily precipitation over the Tibetan Plateau using dynamical downscaling and a storyline attribution approach. It finds that RCC significantly reduces overall precipitation but enhances afternoon convective precipitation, while PCC exerts a smaller and less statistically significant impact.

Objective

• To separate and investigate the impacts of regional climate change over East Asia (RCC) and the Tibetan Plateau (PCC) on sub-daily precipitation characteristics (amount, frequency, intensity, and type) over the Tibetan Plateau.
• To elucidate the underlying physical mechanisms driving these changes and their associated spatial heterogeneity.

Study Configuration

• Spatial Scale: Tibetan Plateau (TP) and East Asia. Model domain: 280 × 220 grid cells, centered at (30°N, 105°E), with a horizontal grid spacing of 27 km and 38 vertical layers up to 50 hPa.
• Temporal Scale: Summer 2020 (June 1 to August 31). Sub-daily phases: morning (08:00–14:00 BST), afternoon (14:00–20:00 BST), evening (20:00–02:00 BST), and early morning (02:00–08:00 BST). Climate change trends were estimated for the post-1980 period (1980-2020).

Methodology and Data

• Models used:
  • Weather Research and Forecasting Model (WRF)
  • Ensemble members used different microphysical parameterization schemes: Thompson aerosol-aware, Purdue-Lin, WRF Single Moment 6-class (WSM6), Goddard, Morrison double-moment, WRF Double-Moment 6-class.
  • Other schemes: Betts-Miller-Janjic cumulus convection, Community Atmosphere Model longwave and shortwave radiation, Yonsei University planetary boundary layer, Noah land surface model.
• Data sources:
  • Observations: Daily surface rain gauge data from China Meteorological Administration (CMA) (83 stations), CN05.1 observational data (0.25° × 0.25°), GSMaP_Gauge product (0.1° × 0.1° spatial, 1 hour temporal resolution) from JAXA GPM mission.
  • Reanalysis: ERA5 (approximately 30 km spatial resolution) from ECMWF for calculating post-1980 climate change trends.
  • Initial and Boundary Conditions (IBCs): NCEP/FNL final analysis data (1° horizontal resolution, 6-hour temporal intervals).

Main Results

• Regional Climate Change over East Asia (RCC) significantly reduces overall precipitation over the Tibetan Plateau (TP), primarily due to decreased morning and stratiform precipitation.
• RCC enhances afternoon precipitation over the TP, mainly by increasing convective precipitation.
• RCC reduces precipitation frequency (PF) for total, convective, and stratiform precipitation across all sub-daily periods, with the most substantial decreases in the morning, particularly for stratiform precipitation.
• RCC reduces daily and morning precipitation intensity (PI) over the TP (except in the Eastern TP for daily PI), attributed to reduced stratiform PI. Conversely, it enhances PI during the afternoon, evening, and early morning across most of the TP, primarily driven by increased convective and stratiform PI.
• Regional Climate Change over the TP (PCC) has a noticeably smaller and generally less statistically significant impact on precipitation compared to RCC, primarily reducing morning precipitation due to reduced stratiform precipitation.
• The opposing morning–afternoon effects of RCC stem from differing physical mechanisms: RCC stabilizes the atmosphere and reduces moisture in the morning, suppressing convection, while it enhances atmospheric instability, moisture, and convective energy in the afternoon.
• Regional differences in RCC-induced precipitation changes are attributed to variations in moisture flux and atmospheric dynamics. In the morning, RCC weakens westerly moisture flux over western and northern TP, but enhances southerly/easterly flux in southeastern ETP. In the afternoon, RCC strengthens southerly/easterly moisture fluxes and convergence, particularly in the eastern TP.

Contributions

• First study to couple dynamical downscaling simulation with a storyline attribution approach to separate and quantify the distinct impacts of regional climate change over East Asia (RCC) and the Tibetan Plateau (PCC) on sub-daily precipitation over the TP.
• Provides detailed insights into the opposing effects of RCC on morning versus afternoon precipitation, and on convective versus stratiform precipitation, along with their underlying physical mechanisms.
• Highlights the significantly larger influence of RCC (East Asia) compared to PCC (Tibetan Plateau itself) on TP sub-daily precipitation characteristics.
• Utilizes an ensemble of WRF simulations with varying microphysical parameterization schemes to assess uncertainties and enhance the robustness of findings.

Funding

• National Natural Science Foundation of China (42325502, 42130610, 42275097, 42175054)
• National Key Research and Development Program of China (2024YFF1306204)
• CAS “Light of West China” Program
• Program of the Key Laboratory of Cryospheric Science and Frozen Soil Engineering, CAS (No. CSFSE-ZQ-2405)
• Nature Science Foundation of Gansu province (24JRRA080)

Citation

@article{Ma2025Response,
  author = {Ma, Yuanyuan and Hu, Xiaoxue and Meng, Xianhong and Ma, Di},
  title = {Response and mechanisms of sub-daily precipitation over the Tibetan Plateau to regional climate change},
  journal = {npj Climate and Atmospheric Science},
  year = {2025},
  doi = {10.1038/s41612-025-01275-7},
  url = {https://doi.org/10.1038/s41612-025-01275-7}
}