Liu et al. (2026) Can the water vapor from the hinterland Tibetan Plateau affect the cloud and precipitation of the Source Region of the Three Rivers?

Identification

• Journal: Climate Dynamics
• Year: 2026
• Date: 2026-01-09
• Authors: J. Chen, Shengjun Zhang, Yi Zhao, Kai Yang
• DOI: 10.1007/s00382-025-08015-w

Research Groups

• State Key Laboratory of Climate System Prediction and Risk Management, China Meteorological Administration, Aerosol-Cloud and Precipitation Key Laboratory, School of Atmospheric Physics, Nanjing University of Information Science & Technology, Nanjing, China
• State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China
• State Key Laboratory of Physical Oceanography & College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao, China

Short Summary

This study reveals a previously overlooked cross-basin water vapor transport mechanism from the lake-rich hinterland Tibetan Plateau (endorheic region) to the Source Region of the Three Rivers (exorheic region) during the warm season. Strong surface heating over the lake group region uplifts moisture, which is then advected eastward by westerlies at mid-to-upper tropospheric levels, significantly contributing to heavy precipitation in the downstream SRTR with a 23-hour lag.

Objective

• To investigate the thermal and moisture transport processes between the lake-rich hinterland Tibetan Plateau (endorheic region) and the Source Region of the Three Rivers (exorheic region) during the warm season.
• To determine how water vapor from the lake group region regulates vapor flux and affects cloud and precipitation formation in the SRTR.

Study Configuration

• Spatial Scale: Tibetan Plateau (TP), focusing on the lake group region (endorheic basin, approximately 30°–35° N, 80°–91° E) and the Source Region of the Three Rivers (SRTR, exorheic basin, approximately 31°39′N to 37°10′N and 89°24′E to 102°27′E, covering about 302,500 square kilometers).
• Temporal Scale: Warm season (May–September) from 2013 to 2023. Analysis also categorized into May–June, July–August, and September periods.

Methodology and Data

• Models used:
  • Atmospheric apparent heat source (Q₁) derived using the "inverse algorithm" by Yanai et al. (1973).
  • Water vapor transport vector approach for flux calculations.
• Data sources:
  • ERA5 reanalysis (European Centre for Medium-Range Weather Forecasts - ECMWF): Temperature, precipitation, total column water, specific humidity, and wind field. Temporal resolution: 1 hour, Spatial resolution: 0.25° × 0.25°. Period: 2013–2023.
  • MOD06_L2 (NASA, Terra/Aqua satellite, MODIS sensor): Cloud Top Temperature (CTT), Cloud Top Pressure (CTP), and Cloud Water Path (CWP). Spatial resolution: 1 kilometer, Temporal resolution: 5 minutes.

Main Results

• A significant positive correlation (0.61, p = 9.9 × 10⁻⁷) was found between the atmospheric apparent heat source ([Q₁]) of the SRTR and the lake group region, indicating thermal coupling.
• The lake group region exhibits persistently negative precipitation efficiency (Rp) anomalies, suggesting that abundant water vapor is not efficiently converted to precipitation locally, making it available for transport.
• A significant positive correlation exists between the Rp anomaly in the lake group region and SRTR precipitation, particularly for heavy precipitation events (r = 0.26 for heavy-grid ratio, r = 0.22 for mean intensity, both p < 0.01).
• A 23-hour lagged Pearson correlation (r = 0.44, p < 0.01) was observed between the lake group region's Rp anomaly and SRTR precipitation, providing temporal evidence for eastward water vapor transport.
• Water vapor transport between the lake group region and SRTR peaks in July–August, with the highest horizontal flux occurring at mid-to-high levels (450–500 hPa), consistent with advection by westerly flow.
• During high-correlation events, a distinct mid-tropospheric channel (400–450 hPa) of intense horizontal vapor flux (approximately 8.17 grams per square meter per second) is observed over the lake group region, leading to strong horizontal water vapor convergence (e.g., -4.9 × 10⁻⁶ per second) in the SRTR.
• Deep convective clouds (Cloud Top Temperature < 230 Kelvin, Cloud Water Path > 2000 grams per square meter) are more frequent in SRTR during July–August, coinciding with peak precipitation and enhanced vertical water vapor transport.

Contributions

• Proposes and validates a novel cross-basin, thermodynamically linked water vapor transport corridor between the endorheic lake-rich hinterland TP and the exorheic SRTR, revealing a previously underappreciated intra-plateau hydrological connection.
• Shifts the focus of moisture sources for SRTR precipitation from solely external pathways to include significant internal moisture exchange within the Tibetan Plateau.
• Provides robust temporal evidence (23-hour lag) for the transport mechanism, directly linking thermal activity and moisture availability in the lake group region to downstream precipitation in the SRTR.
• Highlights the critical role of strong surface heating and low precipitation efficiency in the lake group region in creating an atmospheric vapor reservoir that supplies downstream convection and precipitation.
• Offers new insights into the complex water cycle and regional climate dynamics of the Tibetan Plateau.

Funding

• National Key Research and Development Program of China (No. 2023YFC3007504)
• National Science Foundation of China (42075067)
• Open Research Program of the State Key Laboratory of Severe Weather (Grant Nos. 2023LASW-B25)
• Jiangsu Graduate Student Research Innovation Program (KYCX25_1617)
• Jiangsu Graduate Student Research Innovation Program (KYCX25_1605)

Citation

@article{Liu2026Can,
  author = {Liu, Ziqian and Chen, J. and Zhao, Tianliang and Zhang, Shengjun and Zhao, Yi and Yang, Kai},
  title = {Can the water vapor from the hinterland Tibetan Plateau affect the cloud and precipitation of the Source Region of the Three Rivers?},
  journal = {Climate Dynamics},
  year = {2026},
  doi = {10.1007/s00382-025-08015-w},
  url = {https://doi.org/10.1007/s00382-025-08015-w}
}