Changes in the atmospheric helium isotope ratio over the past 40 years
Changes in the atmospheric helium isotope ratio over the past 40 years
复制标题
近40年大气氦同位素比值变化
DOI：
10.1002/2013gl057681
复制
发表时间：
2013
影响因子：
5.2
通讯作者：
L. Evans
中科院分区：
文献类型：
--
作者：
J. Lupton;L. Evans
我们比较了1973年至2013年40年间太平洋海洋空气中5个样本的氦同位素比与二级气体标准。在另一项实验中，我们直接比较了1973年和2013年在加州的拉霍亚同一地点收集的空气样本中的3 He/4 He比率，消除了任何地理偏见。两个实验都与大气3 He/4 He的零时间变化率一致。我们对太平洋海洋空气中3 He/4 He比值变化率的最佳估计是−0.0014 ± 0.0045%/yr（2σ），这表明空气氦仍然是陆地氦同位素测量的有效标准。
We have compared the helium isotope ratio in five samples of Pacific marine air spanning the 40 year period between 1973 and 2013 against a secondary gas standard. In a separate experiment we directly compared the 3He/4He ratio in air samples collected in 1973 and 2013 at the same location in La Jolla, California, eliminating any geographical bias. Both experiments are consistent with zero time rate of change for atmospheric 3He/4He. Our best estimate for the rate of change of the 3He/4He ratio in Pacific marine air is −0.0014 ± 0.0045%/yr (2σ), indicating that air helium is still a valid standard for terrestrial helium isotope measurements.