Strong link of large volcanic eruptions and climatic and hydrological changes recorded by tree rings in the river source area of Southern High Asia since 1200 A.D.

YOUPING CHEN; FENG CHEN ; HELI ZHANG; MAO HU; SHIJIE WANG; MARTÍN ARIEL HADAD; FIDEL A. ROIG

Quaternary Sciences

Chinese Academy of Sciences

Lugar: Beijing; Año: 2021 vol. 41

1001-7410

Long-term climate proxy data is very important for understanding past climate changes and ases the influences of large volcanic eruptions.A total of 81cores were taken from Picea brachytyla tres in the Zhujiaola Mountain，southeasternTibetan plateau (31°3′N，96°58′E; 4277m a.s.l.) inJune，2020. All cores were air-dried prior to mounting and sanding， and prepared following standard dendrochronological techniques. And the CoRecorder9.4 ring analyzer with accuracy of 0.01mm was used to measure the tree-ring width of all cores.The quality of cross-dating was checked by using the COFECHA program. Finally，the standard chronology since 1135 A.D. was developed by ARSTAN program for subsequent analysis. Climate-growth relationship analysis between entre e ring width chronology and climate data showed that mean minimum temperature from November of previous year to current year February was the main factor controlling tree-ring growth in the Zhujiaola Mountain，southeastern Tibetan plateau，and the total precipitation from August of previous year to current year May states on the growth effect are significant. Mean minimum temperature from previous November to February since A.D. 1200 were then reconstructed based on the tree-ring width chronology using a simple linear regression model. The reconstruction explained 47.1% of the variance in the instrumental temperature records during the calibration period (1954~2019 A.D.). The reconstruction exhibits decadal to inter-decadal temperature variability，with cold periods occurring in 1206~1227，1234~1332，1356~1372，1465~1548，1588~1602，1728~1832，1899~1935 and 1947~1987， and warm periods in 1333~1355，1373~1388，1397~1464，1549~1587，1603~1634，1643~1727，1833~ 1898，1936~1946 and 1988~2019. Meanwhile，the reconstruction contains ten extreme cold years (1474，1504， 1534，1757，1789，1793，1817，1968，1972 and 1982) and twenty three extremely warm years (1407，1410， 1412，1422，1423，1424，1448，1673，1674，1682，1683，1694，1698，1700，1701，1702，1706，1708， 2000，2013， 2015， 2016 and 2017). The temperature fluctuations of the reconstructed sequence were in accordance with other temperature reconstruction in the southeastern Tibetan plateau. All of above mentioned information demonstrated the reliability of reconstructed temperature. At the same time，the temperature reconstruction sequence verified the cooling effect after 27 large volcanic eruptions since 1200 A.D.，including the large volcanic eruptions of Samalas in 1258 and Tambora in 1815. In addition，the comparison between the temperature reconstruction sequence and the related river runoff data shows that the strong volcanic eruption may cause significant decrease in the temperature of the river source area in Southern High Asia，and may further slowed down the water cycle，resulting in the decrease of river runoff in Southern High Asia.