Interannual trends in stable oxygen isotope composition in precipitation of China during 1979-2007: Spatial incoherence
Interannual trends in stable oxygen isotope composition in precipitation of China during 1979-2007: Spatial incoherence
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1979-2007年中国降水稳定氧同位素组成的年际变化趋势：空间不相干性
DOI：
10.1016/j.quaint.2017.07.029
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发表时间：
2017
影响因子：
2.2
通讯作者：
Qu Deye
中科院分区：
文献类型：
--
作者：
Yang Sen;Zhang Mingjun;Wang Shengjie;Liu Yangmin;Qiang Fang;Qu Deye
根据稳定水同位素比对组二期（SWING2）编制的同位素大气环流模式（GCM）模拟，研究了1979—2007年中国降水同位素组成的年际变化和趋势。涉及六次同位素GCM模拟，并应用每个网格降水中稳定氧同位素的月序列来计算1979年至2007年的线性趋势。大多数同位素GCM模拟显示δ18O呈增加趋势，而GISS-E（NCEP）结果显示出下降趋势。在华北和西北的大部分地区，GCM模拟与地表温度呈正相关。氧同位素组成与地表气温的相关系数一般从沿海到内陆逐渐增大。 LMDZ（自由）模拟的中国西北地区降水δ18O观测值与模拟值之间的相关性在不同分区和配备同位素的GCM中最好（r = 0.73）。 GCM模拟与BW模型的对比均显示δ18O低值区在青藏高原，高值区在华南地区。利用同位素GCM模拟的中国大气水线（斜率7.63~8.26，截距9.25~11.92）与全球大气水线相似，相关系数均达到0.01水平。
According to the simulations of isotope-equipped general circulation models (GCMs) compiled by the Stable Water Isotope Intercomparison Group Phase2 (SWING2), the interannual variability and trend of precipitation isotopic composition in China during 1979–2007 are studied. Six simulations of isotope-enabled GCMs are involved, and monthly series of stable oxygen isotopes in precipitation for each grid are applied to calculate the linear trends from 1979 to 2007. Most isotope-equipped GCM simulations show an increasing trend inδ18O, while the GISS-E (NCEP) result shows a decreasing trend. In most areas of north China and northwest China, the GCM-simulations positively correlate with surface temperature. The correlation coefficients between oxygen isotope composition and surface air temperature generally increase from coast to inland. The correlation between observed and simulatedδ18O in precipitation of northwest China simulated by LMDZ (free) is best (r= 0.73) among different subregions and isotope-equipped GCMs. The comparison of GCMs simulations and BW model all show the low value region ofδ18O is in the Tibetan Plateau and the high value in south China. China's meteoric water line simulated using isotope-enabled GCMs (slopes range from 7.63 to 8.26, and intercepts range from 9.25 to 11.92) is similar to the global meteoric water line, and all the correlation coefficients are statistically significant at the 0.01 level.