Zhao (2026) Trends in extreme temperatures and their associations with atmospheric-oceanic circulation indices in the Qilian Mountains

Identification

• Journal: Theoretical and Applied Climatology
• Year: 2026
• Date: 2026-01-14
• Authors: Peng Zhao
• DOI: 10.1007/s00704-026-06019-y

Research Groups

• School of Computer Science, Huainan Normal University, Huainan, Anhui, China

Short Summary

This study investigated the variability and trends of extreme temperature indicators in the Qilian Mountains (QLM) from 1979 to 2017 and their associations with atmospheric-oceanic circulation indices. It found significant warming trends for most extreme temperature indicators, particularly an accelerated warming in the 1990s, with the Arctic Multidecadal Oscillation (AMO) identified as a particularly prominent influencing factor.

Objective

• To investigate the spatiotemporal patterns of extreme temperature indicators in the Qilian Mountains.
• To analyze the trends of these extreme temperature indicators from 1979 to 2017.
• To investigate the relationship between these extreme temperature indices and large-scale atmospheric and oceanic circulation patterns.

Study Configuration

• Spatial Scale: Qilian Mountains (QLM), northwestern China (97°24’−103°46’E; 36°43’−39°42’N), spanning approximately 800 km east-west and 200–400 km north-south, with altitudes of 4,000–6,000 m. Data collected from 23 meteorological stations within and on the periphery of the QLM.
• Temporal Scale: 1979–2017 (39 years). Analysis also included sub-periods: 1979–1989, 1990–1999, and 2000–2017.

Methodology and Data

• Models used:
  • Statistical methods: Mann-Kendall (MK) trend test, nonparametric Sen’s slope method, MK mutation test, Pearson correlation analysis.
  • Extreme Temperature Indices (ETCCDI): Ten indices categorized as absolute (TXx, TXn, TNn, TNx), threshold (ID0, FD0), and percentile-based (TN10p, TX10p, TN90p, TX90p).
• Data sources:
  • Daily temperature records (1979–2017) from 23 meteorological stations in the Qilian Mountains, sourced from China’s National Meteorological Information Center (NMIC).
  • Six atmospheric and oceanic circulation indicators: Arctic Multidecadal Oscillation (AMO), Arctic Oscillation (AO), East Atlantic/Western Russia (EA/WR), Multivariate ENSO Index (MEI), North Atlantic Oscillation (NAO), and Pacific Decadal Oscillation (PDO).

Main Results

• From 1979 to 2017, four absolute extreme temperature indices (TXx, TXn, TNn, and TNx) exhibited significant upward trends, with rates such as TXx at 0.579 °C/10a, TNx at 0.612 °C/10a, TNn at 0.615 °C/10a, and TXn at 0.288 °C/10a.
• Warm indices (TX90p and TN90p) showed significant upward trends (p < 0.01), with a particularly rapid increase observed during the 1990s.
• Cold indices (TX10p and TN10p) showed downward trends, with a sharp decline occurring in 1997.
• Threshold indices (ID0 and FD0) also presented distinct decreasing trends (p < 0.01).
• Extreme temperature indicators were strongly associated with atmospheric and oceanic circulation patterns. The Arctic Multidecadal Oscillation (AMO) had the most prominent influence, showing a strong positive correlation with warm extremes (e.g., TN90p: r = 0.782, p < 0.01) and a robust inverse relationship with cold extremes.
• The East Atlantic/Western Russia (EA/WR) pattern emerged as a significant suppressor of TN90p (r = -0.567). Multivariate ENSO Index (MEI), North Atlantic Oscillation (NAO), and Pacific Decadal Oscillation (PDO) demonstrated dampening effects on warm extremes. The Arctic Oscillation (AO) exhibited negligible statistical associations.
• The 1990s was identified as a critical decade of accelerated warming for extreme temperatures in the QLM.

Contributions

• This research enhances the understanding of extreme temperature dynamics in the topographically complex Qilian Mountains ecosystem.
• It establishes novel statistical linkages between extreme temperature metrics and large-scale atmospheric and oceanic circulation patterns in the QLM, providing mechanistic insights into how oceanic oscillations influence mountain climates in this remote region, which was previously scarce in the literature.
• The study confirms the accelerated warming of extreme temperature indices since the 1990s and highlights the dominant role of the Arctic Multidecadal Oscillation (AMO) in modulating these changes in the QLM, aligning with and contributing to broader regional understandings across China.

Funding

• Ministry of Education Employment-Oriented Talent Cultivation Project (No.2025032488671)
• Ministry of Education Collaborative Talent Cultivation Project (No.2503111703)

Citation

@article{Zhao2026Trends,
  author = {Zhao, Peng},
  title = {Trends in extreme temperatures and their associations with atmospheric-oceanic circulation indices in the Qilian Mountains},
  journal = {Theoretical and Applied Climatology},
  year = {2026},
  doi = {10.1007/s00704-026-06019-y},
  url = {https://doi.org/10.1007/s00704-026-06019-y}
}