为什么地球的影子是蓝色的吗?- 江南体育网页版- - - - -地球科学堆江南电子竞技平台栈交换 最近30从www.hoelymoley.com 2023 - 03 - 31 - t16:33:17z //www.hoelymoley.com/feeds/question/13265 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/13265 10 为什么地球的影子是蓝色的吗? 卡米洛·Rada //www.hoelymoley.com/users/11908 2018 - 02 - 01 - t21:20:49z 2021 - 01 - 28 - t09:40:40z < p >之后,每一个日落,太阳一走了,我总是喜欢看到< a href = " https://en.wikipedia.org/wiki/Belt_of_Venus " rel = " noreferrer " > < / >金星带在另一边,紧随其后的是< a href = " https://en.wikipedia.org/wiki/Earth%27s_shadow " rel = " noreferrer " > < / >地球的影子。< / p > < p >这是一幅我(你会发现更好的网络)。粉紫色带上面的皮带是金星,和蓝色的乐队在底部是地球的影子。

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This figure from Sky & Telescope explains it well:

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While contemplating these beauties, I've had hard time understanding why we see the colors we do. To my eyes, the belt of Venus looks purple, which didn't makes sense to me, as the very short wavelength of purple light should have been scattered long before arriving back there. Then all made sense when I realized that if you mix blue and red light you get purple. So the color comes from the blue mixed with the red light backscattered by the high atmosphere that is still illuminated by the Sun.

However, I can't still figure out why the Earth's shadow looks blue, and I haven't been able to find an answer (here some links about the Earth's shadow but without an explanation of the color: 1, 2, 3).

We know the sky is blue and the sunset red to due the preferential scattering of blue light by the air. But: How can the air in the Earth's shadow scatter blue light if it doesn't get any direct illumination, and any indirect illumination getting back there should be VERY depleted in blue (i.e. mostly red light)?

I thought the fact that the belt of Venus scatters red instead of blue as the rest of the atmosphere, is precisely because back there there is no more blue light left, so the weaker scattering of red light becomes noticeable (please let me know if I'm wrong there).

Or is the air actually emitting blue light in some sort of fluorescence/glowing?

PS: As this is a purely atmospheric phenomena I though it would be better suited here than in the Astronomy SE.

//www.hoelymoley.com/questions/13265/-/13266 # 13266 8 答案由大卫Hammen为什么地球的影子是蓝色的吗? 大卫Hammen //www.hoelymoley.com/users/239 2018 - 02年- 02 - t01:43:49z 2018 - 02年- 02 - t01:43:49z < blockquote > < p >我的眼睛,看起来金星带紫色,这对我来说没有意义,因为紫色光的波长非常短的应该是分散之前到达。那么有意义,当我意识到,如果你把蓝色和红光紫色。< / p > < /引用> < p >你有这部分。紫色不是紫色。紫罗兰是一种光谱的颜色在高频端可见部分的光谱,而紫色是谱外的颜色在< a href = " https://en.wikipedia.org/wiki/Line_of_purples " rel = " noreferrer " >紫色线< / >从近紫外到近红外。我们看到颜色轮而不是一条直线。一个可能的解释是,长波长(“红”)锥有一个紫色的二次反应。光谱紫光激发波长短、长波长锥,但如此一个谱外的红色和蓝色的光。< / p > < p >,这就是你看到的金星带——柔和的红色和蓝色,或紫色(或者红色,或玫瑰色粉红色)。< / p > < blockquote > < p >所以颜色是蓝色和红色的光背散射的高层大气,仍被太阳照亮。然而,我仍然无法弄清楚为什么地球的阴影看起来是蓝色的。

The backscattered red light doesn't come from the high atmosphere. It comes from the troposphere. The high atmosphere (the stratosphere and above) contains very few particulates. The upper atmosphere is the only part of the atmosphere that remains sunlit above the eastern horizon after sunset. The sunlight hitting the upper atmosphere is Rayleigh scattered, so you see that very faint blue scattered light. You don't see the backscattered reddish light from the particulate-containing lower atmosphere at the eastern horizon because that part of the atmosphere is fully in the Earth's shadow above the eastern horizon.

//www.hoelymoley.com/questions/13265/-/20734 # 20734 7 回答由Ruslan为什么地球的影子是蓝色的吗? Ruslan //www.hoelymoley.com/users/12360 2021 - 01 - 28 - t09:40:40z 2021 - 01 - 28 - t09:40:40z < blockquote > < p >如何在地球的影子散射蓝光如果不得到任何直接照明,以及任何间接照明恢复应该有非常贫蓝(即主要是红灯)?< / p > < /引用> < p >你是完全正确的。如果你只模拟光散射,你会得到这样的结果:一个浅黄色的天空,有点红带的金星,地球和一个灰色的影子:< / p > < p > < a href = " https://i.stack.imgur.com/3FOmY.png " rel = " noreferrer " > < img src = " https://i.stack.imgur.com/3FOmY.png " alt = "在这里输入图像描述" / > < / > < / p > < p >但我们平流层包含少量的臭氧,它吸收光谱的橙色地区被称为< a href = " https://en.wikipedia.org/wiki/Chappuis_absorption " rel = " noreferrer " > Chappuis乐队< / >:< / p > < p > < img src = " https://i.stack.imgur.com/RrEhx.png " alt = " Chappuis带谱" / > < / p > < p >在白天太阳光线传播气氛在一个小角度,跨越一个低数量的臭氧,所以天空的颜色也不影响(见化学问题。SE: < a href = " https://chemistry.stackexchange.com/q/111389/2133 " >臭氧气体有什么确切的颜色? < / >)。但黄昏阳光穿过一大层大气水平,因此Chappuis吸收非常突出。< / p > < p >上面的仿真一样,但由于臭氧包括(稍高的曝光),会是这个样子:< / p > < p > < a href = " https://i.stack.imgur.com/bdp5H.png " rel = " noreferrer " > < img src = " https://i.stack.imgur.com/bdp5H.png " alt = "在这里输入图像描述" / > < / > < / p > < p >为什么影子蓝色(橙色)比其他地方的天空?因为影子,没有从单一散射光:来自太阳的射线必须至少两次散落到地上的观察者。这使得瑞利散射乘数<跨类= " math-container " > \ propto \美元λ^ {4}$ < / span >申请两次,从而增加的蓝色分量inscattered光相对红组件。大气OTOH,另部分不是影子,意味着他们有贡献的光散射一次,只有一次幂的乘数。< / p >
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