Simulations of Stable Isotopic Variations in Precipitation and Comparison with Measured Values in Yunnan Province, China
Received date: 2011-01-04
Request revised date: 2011-10-10
Online published: 2012-01-20
Copyright
Using the MUGCM simulations, the variation features of stable isotopes in precipitation, amount effect and relationship between δD and δ18O, on the diurnal, monthly and yearly time scales in Yunnan Province, China, are analyzed. There is significant amount effect for the isotopes in precipitation, whether on the diurnal time scale or on the monthly or the yearly time scales. Compared with the measured values, the simulated δ18O in precipitation shows the stronger correlation with precipitation. For the single station, the local meteoric water line (LMWL) is simulated well at Mengzi and Tengchong, however at Simao and Kunming, the simulated results do not reproduce truly the measured relationship between δD and δ18O in precipitation with the higher LMWL slopes, which implies that the model may overestimate the depletion of the HDO over such a particular areas like Yunnan.
Key words: Yunnan; stable isotopes; simulation; amount effect; the meteoric water line (MWL)
ZHANG Xin-ping , GUAN Hua-de , SUN Zhi-an , SUN Guang-lu , ZHANG Xin-zhu , WU Hua-wu . Simulations of Stable Isotopic Variations in Precipitation and Comparison with Measured Values in Yunnan Province, China[J]. SCIENTIA GEOGRAPHICA SINICA, 2012 , 32(1) : 121 -128 . DOI: 10.13249/j.cnki.sgs.2012.01.121
Fig. 1 The location of sampling stations of Mengzi, Tengchong, Simao and Kunming in Yunnan, China图1 位于云南省的取样点蒙自、腾冲、思茅和昆明站的位置 |
Fig. 2 The measured (left) and simulated (right) daily δ18O in precipitation and the variations of precipitation amount at Mengzi, Tengchong and Simao stations in 2003图2 蒙自、腾冲、思茅站实测的(左)和模拟的(右)日降水δ18O和日降水量随时间的变化(2003年) |
Table 1 Comparison of standard deviations and correlated coefficients of measured and simulated daily δ18O, δD and d in precipitation at Mengzi, Tengchong and Simao stations表1 蒙自、腾冲、思茅三站实测的和模拟的日降水同位素(δ18O、δD和d)的标准差σ和相关系数的比较 |
站点 | δ18O | δD | d | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
实测 | 模拟 | r | 实测 | 模拟 | r | 实测 | 模拟 | r | ||||||
蒙自 | 4.77 | 3.79 | 0.50 | 36.59 | 31.05 | 0.54 | 5.54 | 4.11 | 0.13 | |||||
腾冲 | 4.63 | 4.20 | 0.44 | 30.59 | 36.21 | 0.35 | 4.65 | 4.102 | 0.35 | |||||
思茅 | 4.46 | 3.40 | 0.36 | 32.60 | 28.41 | 0.42 | 9.00 | 3.86 | -0.27 |
Fig. 3 The measured (red) and simulated (black) amount effect on the diurnal time scale at Mengzi (a), Tengchong (b) and Simao (c)图3 蒙自(a)、腾冲(b)和思茅(c)站实测的(红色)和模拟的(黑色)日时间尺度下的降水量效应 |
Fig. 4 The measured (red) and simulated (black) LMWL on the diurnal time scale at Mengzi (a), Tengchong (b) and Simao (c)图4 蒙自(a)、腾冲(b)和思茅(c)站实测的(红色)和模拟的(黑色)日时间尺度下的LMWL |
Fig. 5 The measured (red curve) and simulated (black curve) monthly variations of δ18O (top) and δD (bottom) in precipitation at Kunming图5 昆明站实测的(红色实线)和模拟的(黑色实线)月降水中δ18O(上)和δD(下)随时间的变化 |
Fig. 6 The measured (red) and simulated (black) amount effect on the monthly time scale at Kunming图6 昆明站实测的(红色)和模拟的(黑色)月时间尺度下的降水量效应 |
Table 2 Comparison of standard deviations of measured and simulated δ18O, δD and d in precipitation on the monthly and yearly time scales at Mengzi, Tengchong and Simao stations表2 昆明站实测的和模拟的月、年降水同位素(δ18O、δD和d)标准差σ的比较 |
δ18O | δD | d | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
实测 | 模拟 | r | 实测 | 模拟 | r | 实测 | 模拟 | ||||
月值 | 4.36 | 2.95 | 0.66 | 29.80 | 25.57 | 0.68 | 12.30 | 2.42 | |||
年值 | 1.22 | 0.59 | 0.57 | 7.94 | 5.07 | 0.66 | 4.62 | 0.62 |
Fig. 7 The measured (red) and simulated (black) LMWL on the monthly time scale at Kunming图7 昆明站实测的(红色)和模拟的(黑色)月时间尺度下的LMWL |
Fig. 8 The measured (red) and simulated (black) yearly variations of δ18O (top) and δD (bottom) in precipitation at Kunming图8 昆明站实测的(红色)和模拟的(黑色)降水中δ18O(上)和δD(下)的逐年变化 |
The authors have declared that no competing interests exist.
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