为什么在辐射平衡模型中忽略了太阳长波和地球短波辐射?-地江南体育网页版球科学堆栈交换江南电子竞技平台 最近30个来自www.hoelymoley.com 2023 - 04 - 03 - t22:09:29z //www.hoelymoley.com/feeds/question/13708 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/13708 6 为什么在辐射平衡模型中忽略了太阳长波和地球短波辐射? Abigal彼得斯 //www.hoelymoley.com/users/12507 2018 - 03 - 23 - t19:41:36z 2018 - 03 - 25 - t00:59:48z 在一项作业中,我得到了这样一个问题:

解释为什么太阳辐射在大气“长波”计算中被忽略,而地球辐射在大气“短波”计算中被忽略。

我意识到被认为是短波辐射的波长是那些小于或等于4$\mu m$的波长。我知道我们说随着波长的增加,来自地球的辐射会增加,而太阳辐射也会增加。< / p >

As a result of this, Why are the sun's long-wave radiation and the Earth's short-wave radiation neglected?

Any explanation would be much appreciated!

//www.hoelymoley.com/questions/13708/-/13709#13709 2 为什么太阳长波辐射和地面短波辐射在辐射平衡模型中被忽视? f.thorpe //www.hoelymoley.com/users/543 2018 - 03 - 24 - t01:42:39z 2018 - 03 - 24 - t20:05:04z 重要的是要记住黑体近似于地球和太阳的辐射。请注意,来自太阳的长波能量辐射是多么的小,而地球的辐射是如何达到峰值的。我推测,这个问题与地球表面被太阳短波辐射加热,地球低层大气被地球表面加热有关。这是一个普遍的误解,认为地球能感受到来自太阳的热“热”(长波)。相反,地球正在吸收短波辐射,然后将这些能量作为长波辐射重新辐射到大气中。< / p >

enter image description here

//www.hoelymoley.com/questions/13708/-/13711#13711 5 为什么太阳长波和地面短波辐射在辐射平衡模型中被忽视? 卡米洛·Rada //www.hoelymoley.com/users/11908 2018 - 03 - 24 - t05:32:53z 2018 - 03 - 24 - t05:53:30z 这是因为长波(LW)对应的太阳辐射的一部分可以忽略不计,短波对应的太阳辐射的一部分可以忽略不计。< / p >

You can make an experiment yourself using NASA's Radiance calculator. By adjusting the parameters for Earth's and the Sun you will get the following plot of energy flux at different wavelengths enter image description here (The red line is the radiation spectra of the Sun and the blue line that of the Earth)

The cool thing about this tool is that you can see the actual data (or download it as a spreadsheet) and estimate the total energy flux between any range of wavelength (the area under the curve).

In this case, for SW radiation (0.1 - 4 $\mu m$) and LW radiation (4 - 100 $\mu m$) you get the following numbers

Sun LW: $1.98 \times 10^7 W m^{-2} {sr}^{-1}$
Sun SW: $1.95 \times 10^5 W m^{-2} {sr}^{-1}$
Sun Total: $2.00 \times 10^7 W m^{-2} {sr}^{-1}$

Earth LW: $1.24 \times 10^2 W m^{-2} {sr}^{-1}$
Earth SW: $1.82 \times 10^{-1} W m^{-2} {sr}^{-1}$
Earth Total: $1.23 \times 10^2 W m^{-2} {sr}^{-1}$

So in terms of percentages:

Sun: 99.03% SW and 0.97% LW

Earth 0.15% SW and 99.85% LW

That illustrate my initial point: LW is negligible for the Sun and SW negligible for Earth. Therefore, in simple models you can ignore both solar LW and terrestrial SW.

And why it is that way?

Well the reason is because the peak of the emissions decrease inversely proportional to temperature (according to Wien's law), while the total power grows MUCH faster, proportional to the fourth power of the temperature (according to Stefan-Boltzmann law). So the Sun been much hotter, produce an enormously larger amount of energy per square meter, but most of that energy is delivered in much shorter wavelength.

Note: It is interesting to note that despite that it is OK to neglect solar LW it is still 1580 times stronger than terrestrial LW.

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