Wang et al. (2025) Day‐to‐Day Temperature Variability in Meteorological Observations and Reanalysis Data Over China

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

Identification

• Journal: Earth and Space Science
• Year: 2025
• Date: 2025-11-01
• Authors: Xuejie Wang, Kaicun Wang, Yuna Mao, Guocan Wu
• DOI: 10.1029/2025ea004573

Research Groups

Not specified in the abstract.

Short Summary

This study quantifies day-to-day temperature variability (DTD) across China using observations and reanalysis data, revealing distinct spatiotemporal patterns and an earlier occurrence of extreme DTD events, thereby enhancing understanding of synoptic-scale temperature changes.

Objective

• To quantify day-to-day temperature variability (DTD) across China.
• To analyze the spatiotemporal variations of DTD using meteorological station observations and four reanalysis datasets.
• To evaluate the performance of reanalysis datasets (JRA55, ERA5, and two others) in representing DTD compared to observations.
• To investigate the characteristics and trends of extreme DTD events (DTDmax1, DTDmax5, DTDmax10).

Study Configuration

• Spatial Scale: China, with analysis across different river basin regions (e.g., Songliao River Basin, Southwest River Basin, Yangtze River Basin).
• Temporal Scale: 1980 to 2022 (43 years). Analysis focuses on day-to-day variability (synoptic scale) and annual cycles.

Methodology and Data

• Models used: Not applicable; the study uses existing reanalysis products as data sources.
• Data sources:
  • Meteorological station observations.
  • Four reanalysis datasets, specifically JRA55 and ERA5 are mentioned.

Main Results

• The annual cycle of DTD across China ranges from 1.4 °C to 2.5 °C, with larger magnitudes observed in spring and winter compared to summer.
• Significant regional heterogeneity in DTD exists, with the highest annual mean DTD in the Songliao River Basin (2.18 °C) and the lowest in the Southwest River Basin (1.08 °C).
• Among the reanalysis datasets, DTD values from JRA55 are closest to observations, exhibiting a maximum correlation of 0.98 in the Southwest River Basin and a minimum Root Mean Square Error (RMSE) of 0.01 °C in the Yangtze River Basin.
• DTD trends derived from JRA55 and ERA5 are comparable to those from observational data.
• Large DTD values (DTDmax1, DTDmax5, DTDmax10) are primarily characterized by rapid cooling, with DTDmax1 showing a fluctuation range of 3.29 °C to 14.59 °C.
• DTDmax1 events predominantly occur in spring and winter, and their occurrence date has become earlier by approximately 8.8 days per decade (p < 0.05) across the study area between 1980 and 2022.

Contributions

• Provides a comprehensive quantitative analysis of day-to-day temperature variability (DTD) across China at the synoptic scale.
• Offers a valuable evaluation of multiple reanalysis datasets for their ability to accurately represent DTD, identifying JRA55 as the most consistent with observations.
• Characterizes the spatiotemporal patterns and long-term trends of both average and extreme DTD events.
• Enhances the understanding of synoptic-scale temperature changes, which is crucial for improving disaster warning and mitigation strategies.

Funding

Not specified in the abstract.

Citation

@article{Wang2025DaytoDay,
  author = {Wang, Xuejie and Wang, Kaicun and Mao, Yuna and Wu, Guocan},
  title = {Day‐to‐Day Temperature Variability in Meteorological Observations and Reanalysis Data Over China},
  journal = {Earth and Space Science},
  year = {2025},
  doi = {10.1029/2025ea004573},
  url = {https://doi.org/10.1029/2025ea004573}
}