392BC—2017AD柴达木盆地东北部降水变化及其与太阳活动和强火山喷发的联系

基于采自柴达木盆地内部牦牛山的祁连圆柏树木样芯，新建采样区域过去2710 a的树轮宽度年表，并计算了器测时期（1957—2017 AD）气象数据与树轮宽度年表的相关系数。结果表明：树轮宽度年表与上一年7月至当年6月降水量变化的相关性最高（r=0.753,n=60,p <0.01），基于此重建了该区392 BC—2017 AD上一年7月至当年6月的降水量变化。器测时期方差解释量高达64%。重建结果显示，在年代际尺度上存在9个湿润期（106—75 BC、6—39 AD、179—229 AD、581—646 AD、823—914 AD、1026—1095 AD、1378—1414 AD、1567—1609 AD和1985—2017 AD）和7个干旱期（328 BC—297 BC、86—151 AD、694—747 AD、1168—1199AD、1444—1525 AD、1680—1725 AD和1792—1860 AD）,1792—1860 AD是过去2400 a最干旱时期。功率谱分析结果表明，过去2400 a柴达木盆地东北部地区降水量存在2～8 a、40 a、80 a和225 a准周...

Precipitation variation and its linkage with solar activity and large volcanic eruptions during 392 BC-2017 AD in Northeastern Qaidam Basin,China

Based on the tree-ring increment cores of Juniperus przewalskii Kom. collected from the Maoniu Mountain in inner Qaidam Basin, the new 2710-year tree-ring width chronology was developed, and the correlation coefficients were calculated between the chronology and meteorological data during the instrumental period of 1957-2017. The results showed that the highest correlation existed between the total precipitation from July of previous year to June of current year and the chronology (r = 0.753, n = 60, p < 0.01). Based on the correlation relationship, total precipitation variation from July of previous year to June of current year was reconstructed from 392 BC to 2017 AD. The reconstruction explained 64% of the variation in the total precipitation from previous July to current June for the calibration period (1957-2017 AD). The results showed that there were nine wet periods which occurred during 106-75 BC, 6-39 AD, 179-229 AD, 581-646 AD, 823-914 AD, 1026-1095 AD, 1378-1414 AD, 1567-1609 AD and 1985-2017 AD, and seven dry periods occurring during 328-297 BC, 86-151 AD, 694-747 AD, 1168-1199 AD, 1444-1525 AD, 1680-1725 AD and 1792-1860 AD in the past 2409 years. Among these wet and dry periods, 1792-1860 AD was the driest period. Power spectral analysis revealed cyclic fluctuations of the precipitation series on 2~8 years, 40 years, 80 years and 225 years (p < 0.01). In addition, the solar minimum phases were in accord with the dry period in our study area in the past 2409 years, and the results of superposed epoch analysis showed that the precipitation decreased significantly in the following year after large volcanic eruptions observed at low-mid latitudes. The results indicated that solar activity and large volcanic eruptions were factors impacting precipitation variation in our study area.