The study of the composition or dynamics of the gaseous layers around planets, often applied to questions on Earth's atmosphere but can be applicable to all planets & moons in the solar system.

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10 views

Ionospheric electron density measurements

I've been working on measuring total electron column density (TEC) with multi frequency GPS data. In theory, signal delay caused by TEC differences should affect the code and carrier nearly evenly in ...
-2
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0answers
21 views

Why are cirrus cloud those that contribute the most to climate forcing?

I read everywhere that most of the forcing produced by clouds is done by cirrus but I can't figure out why. It's obviously related to their IR absorption - emission...
22
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4answers
2k views

Difference between sunrise and sunset?

Other than knowing which direction is east and which direction is west, or observing for a sufficient timespan (to determine the direction of motion), is there any way of telling whether what one is ...
6
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2answers
170 views

Expression for Atmospheric Pressure with Altitude, including Tidal Forces

Is this simple to obtain? I've tried to modify the constant-gravity model to use the $GM/r^2$ form instead, but my result was shown to be wrong with some testing. Constant Gravity Model You can ...
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1answer
14 views

Albedo and radiative forcing

I'm a bit confused on the definitions of radiative forcing and albedo. Consider this textbook problem. Suppose that the albedo of the earth increases by 0.01 in 265 years, ie $A(t) = ...
107
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11answers
20k views

Is the butterfly effect real?

Is the butterfly effect real? It is a well known statement that a butterfly can, by flapping her wings in a slightly different way, cause a hurricane somewhere else in the world that wouldn't occur if ...
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2answers
8k views

Is there an upper frequency limit to ultrasound?

Wikipedia has this diagram of the acoustic frequency spectrum: Is there an upper limit to the frequencies you can transmit through the air? Are they absorbed more and more at higher frequencies, ...
11
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5answers
5k views

How does humidity affect the path of a bullet?

Background Last night, I was reading the FM 23-10 (The U.S. army official field manual for sniper training), and I've noticed that they're potentially teaching snipers incorrect information. ...
11
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3answers
432 views

What is the safe distance to a supernova explosion?

In other words, what stars near the Sun may have an impact on the Solar system equilibrium or the Earth life if they become supernova ? Is SN 1987 A too far ?
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2answers
481 views

How does rogue planet PSO J318.5-22 stay 800ºC?

According to this article, the rogue planet (meaning a planet which does not orbit a star) PSO J318.5-22 has a surface temperature of 800ºC and weather that features molten iron rain. Without a star ...
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0answers
20 views

Velocity Profile of the Upper Atmosphere

Consider an Earth-Centered Inertial (ECI) frame in which the tangential (to Earth's surface) velocity is measured. Now consider obtaining constant average velocity profiles of the atmosphere as a ...
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2answers
1k views

Why does the Sun turn red near sunset?

At daytime the Sun's light is yellowish if not near white. Why when the Sun starts to go down that it's light turn more red. I don't think the earth's rotation is so rapid to cause a red shift. Why ...
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4answers
9k views

How Earth protected from the gamma rays generated by Sun?

Sun is generating energy by nuclear fusion. And nuclear fusion will emit energy in the form of gamma rays. Normally earth's ozone filtering the Ultraviolet radiation. And magnetic fields of earth ...
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2answers
57 views

How fast could you suck up the atmosphere [closed]

So kind of a strange question, but if i had a 1000 foot wide hose with endless storage space, whats the quickest possible time it could be used to suck up the entirety of the Earth's atmosphere. ...
2
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2answers
10k views

If blue light has a higher energy than red light, why does it scatter more?

As $E=hf=\frac{hc}{\lambda}$, blue light - with a smaller wavelength - should have a higher energy. However, it is the case that blue light scatters the most. Why is it that higher energy rays scatter ...
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1answer
53 views

Would 10 metres of liquid air be as effective against cosmic radiation as Earth's atmosphere? [closed]

Assuming ballpark figures which give a depth of 10m if the Earth's atmosphere was liquefied, would that be as effective a protection against ionizing radiation from space as the gaseous atmosphere is? ...
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2answers
332 views

What is atmospheric stratification?

In the context of atmospheric stability, what are the meanings of stable or unstable stratification? What is stratification?
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1answer
25 views

Why Nitrogen is still (almost) 3 times as abundant as Oxygen in Troposphere? [duplicate]

I learned that our atmosphere has ~78% Nitrogen and ~21% Oxygen. If I fill a glass with 21% water and 78% Canola Oil, the more dense (and thus heavier) water will take a full bottom later and Canola ...
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0answers
52 views

Maximum temperature possible on earth

What is maximum temperature that can we have on earth on a single day? Lets say an air mass is static over an area and there is no way for air mass to move, sun warming it up would increase ...
7
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4answers
272 views

Do hail stone fall down just when it is created?

Density of ice is much higher than air. Then how can hail stone remain in earth atmosphere before they fall down ?
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1answer
36 views

Atmospheric pressure question [closed]

I'm asked to find at what altitude atmospheric pressure falls to 10% of the mean sea level value. I have found the expression for the variation of pressure with altitude to be $$p = p_0e^{-h \over ...
3
votes
2answers
71 views

Ideal gas equation and atmosphere of Venus

I'm teaching myself some basics of the ideal gas law and working out simple density equations for atmospheric gases at various altitudes. When I applied the gas law to Venus' atmosphere at its ...
3
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2answers
2k views

Why is the atmosphere transparent in the visible spectrum?

One of the great 'coincidences' in physics is that the Sun happens to shine most brightly at exactly the wavelengths our eyes can see; it's an easy explanation that our eyes evolved to make the most ...
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2answers
34 views

How to combine albedos

I have estimations of the Earth's surface albedo for a region (0.13), as well as an estimation of the atmosphere albedo (0.3 at a solar zenith angle of 1 rad). My question is, how do I find the ...
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3answers
1k views

How is the mechanism of greenhouse gases interacting with IR radiation?

How does atmospheric CO2 and other Greenhousgases (GHG) affect the incoming (from sun) and outgoing (from earth) radiation. I understand that at certain wavenumbers (or areas of wavenumbers) in the ...
2
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2answers
6k views

Why is England so cloudy?

Why, physically, some regions of the globe are affected by a noticeable cloudiness respect to others? Is the reason why some places are also rainy the same?
6
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5answers
6k views

Why is the sky of the moon always dark?

Why is the sky of the moon always dark compared to the sky of the earth, doesn't it have day and night like earth?
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0answers
20 views

If Earth's atmosphere would be cooled, how would its pressure change relative to its temperature?

I have a feeling it would not behave like an ideal gas? For example, if the atmosphere were to cool down at a constant 1 atm to 90 K, oxygen would liquefy. If changing of pressure would be ...
4
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1answer
39 views

Why does the composition of the air does not change with altitude?

Air contains about 78% nitrogen and 21% oxygen independent of altitude (up to 100 km). Why is this? Shouldn't the concentration of nitrogen increase with higher altitudes since nitrogen has a lower ...
0
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1answer
66 views

What height is atmospheric pressure half that at sea level?

$PV = NT$, where T is a constant $P = \rho g h$ but I don't think this equation can hold in this form as the density is most definitely not constant as we go up in the atmosphere $\rho = ...
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3answers
782 views

How can planes land on a rotating Earth?

If the earth is rotating (e.g. at 1000km per hour, at the equator), how can planes safely land on a moving runway?
4
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3answers
826 views

Why is the current atmosphere made of nitrogen (75.5%)?

As I read a book on meteorology, 4 billion years ago, atmosphere was made by steam, carbon dioxide, carbon dioxide and a few nitrogen. Then photosynthesis came, run by underwater organisms, which led ...
11
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6answers
3k views

Can low-gravity planets sustain a breathable atmosphere?

If astronauts could deliver a large quantity of breathable air to somewhere with lower gravity, such as Earth's moon, would the air form an atmosphere, or would it float away and disappear? Is there a ...
0
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0answers
51 views

From coriolis force, cyclone goes wrong direction

note, comment below (BowlOfRed) asked for more detail, so this is more a re-write than an edit. In an idealised weather system, there can be a high pressure area, and a low pressure, and air goes ...
4
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1answer
54 views

How much of Ultraviolet is cut out when Sun moves to the Horizon?

EDIT: Original question was whether or not we need to wear sunglasses when Sun is at the horizon. But it was confusing to many users whether it is on-topic or not. So the details are adjusted. From ...
2
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1answer
39 views

Atmospheric pressure below sea level

If I go up in the air the amount of oxygen decrease and the atmospheric pressure gets lower. What would happen if i dig a hole 100 km down? does atmospheric pressure go up? when is the pressure so ...
11
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2answers
608 views

Energy from man-made tornadoes

Peter Thiel just paid $300,000 to Canadian inventor Louis Michaud who is working to construct useful "man-made tornadoes" or "atmospheric vortex engines" which could be components of future power ...
10
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5answers
20k views

How does carbon dioxide or water vapour absorb thermal infra red radiation from the sun?

We are all told at school water vapour and carbon dioxide are the top two greenhouse gases, and that they absorb thermal infra red radiation, trap heat and warm up the Earth. My question is how do ...
7
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1answer
135 views

What colour would the sky of a high-oxygen, high-argon, high-water vapour atmosphere be?

Although this is a hypothetical, I think it is nevertheless a legitimate physics problem. I would very much appreciate any answers you can give. What colour would the sky be, both at daytime and at ...
2
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1answer
49 views

Atmospheric pressure of Venus?

I have seen the calculations on the atmospheric pressure of Venus - 90 times that of earth. With gravity very similar to earth, how does Venus do that. The calculations I have seen assume constant ...
7
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3answers
2k views

What determines the apparent radius of the rainbow?

Let's say I know how to compute the apparent radius of a rainbow from the viewpoint of the observer: take a photo of the scene, measure the distance to a known reference object, and its dimensions. ...
5
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2answers
1k views

Do asteroids create sonic boom while entering the atmosphere?

Because of the lack of any materials to propagate sound, it can't spread in space. There's the air in the atmosphere, but its volume mass increases constantly (either linear or exponential, I don't ...
4
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1answer
64 views

What is this optical phenomenon, as looked from outer space? [duplicate]

I just saw a photo from NASA. This is it. This is beautiful. But i am not being able to understand, what are those red and green lines above the earth surface? These cannot be due to Rayleigh ...
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3answers
135 views

Rayleigh equation as explanation for sky being blue

I've been reading up on the internet as to why the sky is blue. The answer usually cites Rayleigh scattering that I've checked on wikipedia: https://en.wikipedia.org/wiki/Rayleigh_scattering: $$ ...
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0answers
38 views

Why In Thermosphere is He and O divided as measured? [closed]

If we look Thermosphere a bit closer. we found out that Helium and Oxygen is divided peculiarily. This picture below shows the Earth looked below the south pole. So the orbiting direction is shown in ...
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4answers
3k views

What experiments prove the greenhouse effect?

What experiments prove that heat can be "trapped" by a layer of material with suitable optical properties, such as carbon dioxide? I've read a little on Wikipedia but I've got only some names, not the ...
0
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0answers
13 views

How much pressure would be on Mars if the icecaps melted?

I was wondering, The martian polar ice caps are made of water and CO2. All documentaries say that melting the poles can add pressure. How much pressure would there be? I know that every summer they ...
14
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5answers
73k views

Why does the road look like it's wet on hot days?

Often, I'll be driving down the road on a summer day, and as I look ahead toward the horizon, I notice that the road looks like there's a puddle of water on it, or that it was somehow wet. Of course, ...
0
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0answers
73 views

Covering the whole world in an EMP

I recently thought about shutting down the whole worlds electronics, and naturally ended up with an EMP. I know that EMPs are generated when nuclear bombs explode, but nuclear bombs have some unwanted ...
0
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3answers
32 views

Pressure and altitude

I am going to ask a simple question, for sure. The pressure with respect to the altitude is given by this formula Where sea level standard atmospheric pressure p0 = 101325 Pa sea level standard ...