< p >这不是实际的水是什么输给了空间,因为在高层大气水通常分离到其他分子或离子。氧离子外流经常被认为是代表行星大气层的水的流失。的全球地球率随外流率< span class = " math-container " > 10美元^ {25}$ < / span > <跨类= " math-container " > 10美元^ {26}s ^ {1} $ < / span >,根据地磁活动(< a href = " https://ui.adsabs.harvard.edu// abs / 2017 agufm.p11b2506s /文摘”rel = " noreferrer " >引用< / >)。< / p > < p >海报的引用(作者)寄给我我们可以阅读:< / p > < blockquote > < p >如果我们假设氧气对应水损失(麦克尔罗伊自律,Hunten和[1970]),然后一个氧损失率~ <跨类= " math-container " > 10美元^ {25}s ^ {1} $ < / span >对应~ 300美元<跨类=“math-container”> \文本{g s} ^ {1} $ < / span >水的损失。在太阳系的年龄(45亿年~ <跨类= " math-container " > \ $ 1.4 * 10 ^ {17} $ < / span > s)这个损失率< span class = " math-container " > \ $ 4.2 * 10 ^ {19} $ < / span > g的水。< / p > < /引用> < p > <强>当前图是等价的损失~每天25920升,或9467 <跨类= " math-container " > \文本{m} ^ 3美元每年< / span >。< / >强,参考图似乎本文< a href = " https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2010GL045075 " rel = " noreferrer " >通过遥远的尾巴逃跑O +等离子板< / >,用测量的< a href = " https://en.wikipedia.org/wiki/STEREO " rel = " noreferrer " >立体量B(太阳能地面天文台的关系)航天器< / >。< / p > < p > < >强,对应于总损失超过地球历史上42000 <跨类= " math-container " > \文本{公里}^ 3美元< / span >的水,相当于海平面变化的12厘米。< / >强然而,这是一个简单的推断当前的利率,因为他们承认他们不知道如何模型地球的磁气圈会表现在过去当太阳弱。虽然,阳光较弱是合理的期望损失小。< / p > < p >这个值是完全不同的< a href = " http://sciencenordic.com/earth-has-lost-quarter-its-water " rel = " noreferrer " >你指出的文章< / >。在这种情况下他们使用氢代替氧作为代理的损失水损失:< / p > < blockquote > < p >知道多少氢从海洋消失在过去的四十亿年里使研究人员计算,海洋失去了大约四分之一的地球早期以来的水。< / p > < /引用> < p >他们说:< / p > < blockquote > < p >今天大气中富含氧气,它与氢和氘反应重现水,落回地球的表面。 So the vast bulk of the water on Earth is held in a closed system that prevents the planet from gradually drying out. That suggests that the limiting factor for the existence of water is now the abundance atmospheric oxygen (although oxygen in rocks if very abundant). So it would make sense to use now Oxygen loss as proxy for water loss, but in the past, before the atmosphere was flooded with oxygen, maybe hydrogen loss was a better proxy.
They suggests that methanogenesis can free hydrogen atoms and make them liable to be loss to space, but when it is part of a water molecule it is safe. Methanogenesis would have been much more common in the past when the atmosphere was rich in methane (50 to 500 richer than today).
To wrap up, it seem that there is no consensus about the actual amount of water loss trough Earth's history. Different proxies give different values. Some proxies might be representative to some periods in Earth's past, but other proxies are more representative of other periods. And unfortunately we don't have yet a good reconstruction of the composition and density of the atmosphere throughout Earth's history.
But we do know with some confidence, that while you where reading this answer, one or two liters of water were loss to space.