Centennial Summer Minimum Temperature Reconstruction of Surkhandarya River Basin in Uzbekistan Based on Tree Ring Data

ABSTRACT The intensification of climate anomalies in recent years has heightened the significance of climate prediction. Reconstructing past climate records provides crucial opportunities for extending climatic records and gaining deeper insights into climate change mechanisms. This study collected 105 increment cores from Juniperus rigida Siebold & Zucc. in the Surkhandarya River Basin of Uzbekistan to investigate the relationship between tree radial growth and climatic factors, thereby reconstructing regional climate variations. The findings include: (1) Summer minimum temperature emerges as the primary climatic factor limiting J. rigida radial growth in the Surkhandarya River Basin. (2) The mid‐20th century witnessed an extended cold phase followed by gradual warming, showing temperature variations consistent with patterns observed across Central Asia. Over the past century, eight extreme cold years and seven extreme warm years were identified, with warm extremes predominantly concentrated in the early 21st century. (3) The spatial correlation analysis between the reconstructed minimum temperature series and global land‐sea temperatures demonstrates that the reconstructed minimum temperature sequence exhibits strong spatial representativeness for global terrestrial temperature variations, while sea surface temperature anomalies exert an indirect influence on temperature changes within the study region. (4) Wavelet analysis reveals distinct quasi‐periodic oscillations of 3–5 years, 11–14 years, 18–20 years, and 29–30 years cycles in the temperature reconstruction, suggesting potential linkages between Surkhandarya River Basin minimum temperature variations and ENSO (El Niño‐Southern Oscillation), sunspot activity, PDO (Pacific Decadal Oscillations), NAO (North Atlantic oscillation), and AMO (Atlantic Multidecadal Oscillation).

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