Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China.
Proc Natl Acad Sci U S A. 2014 Feb 25;111(8):2903-8. doi: 10.1073/pnas.1319238111. Epub 2014 Feb 10.
An annually resolved and absolutely dated ring-width chronology spanning 4,500 y has been constructed using subfossil, archaeological, and living-tree juniper samples from the northeastern Tibetan Plateau. The chronology represents changing mean annual precipitation and is most reliable after 1500 B.C. Reconstructed precipitation for this period displays a trend toward more moist conditions: the last 10-, 25-, and 50-y periods all appear to be the wettest in at least three and a half millennia. Notable historical dry periods occurred in the 4th century BCE and in the second half of the 15th century CE. The driest individual year reconstructed (since 1500 B.C.) is 1048 B.C., whereas the wettest is 2010. Precipitation variability in this region appears not to be associated with inferred changes in Asian monsoon intensity during recent millennia. The chronology displays a statistical association with the multidecadal and longer-term variability of reconstructed mean Northern Hemisphere temperatures over the last two millennia. This suggests that any further large-scale warming might be associated with even greater moisture supply in this region.
一段跨度为 4500 年、每年分辨率且绝对日期的年轮宽度年表，是利用来自青藏高原东北部的化石、考古和活树刺柏样本构建的。该年表代表了年平均降水量的变化，在公元前 1500 年后最为可靠。该时期重建的降水显示出向更湿润条件的趋势：在至少三千五百年的时间里，过去 10、25 和 50 年的时期似乎都是最湿润的时期。公元前 4 世纪和公元 15 世纪后半叶发生了显著的干旱期。重建的最干旱年份（自公元前 1500 年以来）是公元前 1048 年，而最湿润的年份是 2010 年。该地区的降水变化似乎与近几千年来亚洲季风强度推断的变化无关。该年表与过去两千年重建的北半球平均温度的多年际和更长时间尺度变化具有统计学关联。这表明，任何进一步的大规模变暖都可能与该地区更大的水分供应有关。
