Xing et al. (2025) Quantifying the spatial extent and attenuation of lake thermal regulation at diurnal scales under extreme heat

Identification

• Journal: Weather and Climate Extremes
• Year: 2025
• Date: 2025-12-16
• Authors: Zikang Xing, Yunliang Li, Yufeng Dai, Jianhui Wei, Miaomiao Ma, Xuejun Zhang, Hui Gao, Harald Kunstmann
• DOI: 10.1016/j.wace.2025.100847

Research Groups

• State Key Laboratory of Lake and Watershed Science for Water Security, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China
• State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
• Institute of Meteorology and Climate Research (IMK-IFU), Karlsruhe Institute of Technology, Campus Alpin, Garmisch-Partenkirchen, Germany
• Research Center on Flood and Drought Disaster Reduction of the Ministry of Water Resources, China Institute of Water Resources and Hydropower Research, Beijing, China
• Institute of Geography, University of Augsburg, Augsburg, Germany
• Centre for Climate Resilience, University of Augsburg, Augsburg, Germany

Short Summary

This study used WRF modeling and directional buffer analysis to quantify the spatial extent and attenuation of Poyang Lake's thermal regulation during extreme heat, revealing pronounced diurnal asymmetry in cooling (40 km, -1.16 °C, 0.28 °C per 10 km) and warming (70 km, +0.97 °C, 0.13 °C per 10 km) effects.

Objective

• To investigate the spatial propagation dynamics and underlying physical mechanisms of lake-induced thermal regulation during extreme heat, focusing on Poyang Lake, China.
• To quantify the spatio-temporal patterns of daytime lake cooling and nighttime warming under extreme heat.
• To characterize the propagation dynamics of lake thermal regulation (including horizontal/vertical extent, directional preference, and attenuation processes).
• To elucidate the underlying physical mechanisms governing these spatial propagation patterns.

Study Configuration

• Spatial Scale: Poyang Lake (29.2°N, 116.3°E) and its surrounding region (25–31.2°N, 112–120°E) in China. WRF model domains: D1 (30 km horizontal resolution, 140 × 140 grid points), D2 (5 km horizontal resolution, 246 × 246 grid points). Vertical discretization: 38 levels up to 50 hPa.
• Temporal Scale: June to September 2022, focusing on diurnal scales (typical daytime hour 15:00 local time, typical nighttime hour 06:00 local time) during the 2022 Yangtze River Basin heatwave.

Methodology and Data

• Models used:
  • Weather Research and Forecast model (WRF) version 4.3.3.
  • Coupled with a one-dimensional mass and energy balance lake model originating from the Community Land Model version 4.5 (CLM4.5), modified by Gu et al. (2015), based on the Hostetler lake model framework.
  • WRF physical schemes: WSM5 (microphysics), YSU (planetary boundary layer), Noah Land Surface Model (surface), revised MM5 Monin–Obukhov (surface layer), Betts–Miller–Janjic (BMJ) (cumulus parameterization for D1 and D2), RRTM (longwave radiation), Dudhia (shortwave radiation).
• Data sources:
  • Initial and boundary conditions: ERA5 global reanalysis (0.25° × 0.25° horizontal resolution, hourly).
  • Land cover data: European Space Agency’s Climate Change Initiative (CCI-LC) dataset (300 m resolution, Noah-modified 21-category IGBP-MODIS classification).
  • Lake temperature initialization correction: MODIS Land Surface Temperature (LST) products (MOD11A1, Collection 6, 1 km resolution).
  • Validation data: ERA5-Land reference dataset (10 km horizontal resolution, hourly) for 2-m air temperature (Ta). Daily mean Ta observations from three meteorological stations (Lushan, Jingdezhen, Changbei) from China Meteorological Administration.

Main Results

• Pronounced diurnal asymmetry in lake-induced thermal effects:
  • Daytime cooling: Exhibits an intensity of -1.16 °C, with its influence confined within a 40 km radius, showing a relatively rapid attenuation rate of 0.28 °C per 10 km. Vertical influence is confined below 900 hPa.
  • Nighttime warming: Exhibits an intensity of +0.97 °C, propagates 1.75 times farther than its daytime counterpart, extending up to 70 km downwind, while maintaining a slower attenuation rate of 0.13 °C per 10 km. Vertical impacts extend up to 700 hPa.
• Directional analysis reveals north-oriented propagation of lake thermal effects, influenced by prevailing southerly winds and lake-land breeze.
• The mechanisms driving these patterns include enhanced turbulent mixing during daytime, which weakens and confines lake cooling effects, and stable nighttime atmospheric stratification and enhanced advection, which extends lake warming influences.

Contributions

• Provides the first comprehensive quantification of the spatial extent and attenuation rates of lake thermal regulation for a large lake (Poyang Lake) under unprecedented extreme heat stress.
• Advances the understanding of inland water bodies as active climate regulators, particularly in mitigating regional climate extremes under anthropogenic warming.
• Offers critical insights and quantitative parameters (40 km daytime, 70 km nighttime attenuation scales) for improving lake representation in regional climate models and guiding nature-based heat adaptation strategies in lake-rich regions.
• Elucidates the underlying physical mechanisms (turbulent mixing, atmospheric stability, advection, lake-induced circulations) governing the diurnal asymmetry in lake effect propagation.

Funding

• National Key Research and Development Program of China (2023YFC3206001)
• National Natural Science Foundation of China (42401049)
• China Postdoctoral Science Foundation (2024M763367)
• Jiangxi Provincial Natural Science Foundation (20252BAC200244)
• Science Foundation of Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences (NIGLAS2022GS08)
• Youth Innovation Promotion Association of the Chinese Academy of Sciences (Y2023084, 2022067)
• Key Program of Natural Science Foundation of Jiangxi Province (20242BAB26044)
• Jiangxi “Double Thousand Plan” (jxsq2023101105)
• IWHR Internationally-Oriented Talent for International Academic Leader Program (0203982012)
• BMFTR funded KARE_II project (01LR2006D1)

Citation

@article{Xing2025Quantifying,
  author = {Xing, Zikang and Li, Yunliang and Dai, Yufeng and Wei, Jianhui and Ma, Miaomiao and Zhang, Xuejun and Gao, Hui and Kunstmann, Harald},
  title = {Quantifying the spatial extent and attenuation of lake thermal regulation at diurnal scales under extreme heat},
  journal = {Weather and Climate Extremes},
  year = {2025},
  doi = {10.1016/j.wace.2025.100847},
  url = {https://doi.org/10.1016/j.wace.2025.100847}
}