Warm season temperature reconstruction in North China based on the tree-ring blue intensity of Picea meyeri

YUE WEIPENG; ROIG, FIDEL A.; CAO HONGHUA; CHEN QIAOMEI; HADAD M. A.; HU MAO; CHEN FENG; ZHAO XIAOEN

JOURNAL OF GEOGRAPHICAL SCIENCES

SCIENCE PRESS

Lugar: Marrickville NSW; Año: 2023 vol. 33 p. 2511 - 2529

1009-637X

In the past 30 years, observational climate datasets reveal a significant a drying andwarming trend over in North China. Understanding of climatic variability over North China andits driving mechanism in a long-term perspective is, however, limited to a few sites only, especiallythe lack of temperature reconstructions based on latewood density and blue intensity.In this study, we developed a 281-year latewood blue intensity chronology based on 45 coresof Picea meyeri in western North China. Based on the discovery that the warm season(May?August) mean maximum temperature is the main controlling factor affecting the changein blue light reflection intensity, we established a regression model that explained 37% of thevariance during the calibration period (1950?2020), allowing to trace the mean maximumtemperature up to 1760 CE. From the past 261 years, we identified seven persistent hightemperature periods (1760?1773, 1778?1796, 1805?1814, 1869?1880, 1889?1934, 1984?2000, 2004?2020) and three persistent low temperature periods (1815?1868, 1935?1963,1969?1983) in North China. Comparisons of a nearby temperature reconstructions and climategridded data indicate that our reconstruction record a wide range of temperature variationsin North China. The analysis of links between large-scale climatic variation and thetemperature reconstruction showed that there is a relationship between extremes in the warmseason temperature and anomalous SSTs in the equatorial eastern Pacific, and implied thatthe extremes in the warm season temperature in North China will be intensified under futureglobal warming.