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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2
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2answers
54 views

How is 'Fog' in summer (sea-elevation) possible? [on hold]

I am residing in New Delhi (pardon me for any irrelevant data I might include), and I noticed a really interesting thing. It's an average $30^{\circ}\mathrm{C}$ out here, and yet, most/some weather ...
2
votes
2answers
37 views

What conditions are necessary for Birkeland currents to form?

If charged particles flow through non-magnetised space will they form Birkeland current? Or can such currents only form along existing magnetic field lines? Part of the reason I ask is this: http://...
-3
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0answers
45 views

How far would the atmosphere have to extend before we couldn't see the sun? [on hold]

Ignoring dust, haze, clouds or ice crystals. Just 100% clean air.
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2answers
38 views

Temperature distribution in a column of air

Say there is a sealed cylinder of air that has a height $\mathrm{h}$ and area $\mathrm{A}$ on the ends. The initial temperature throughout the column is $T_0$ and has a uniform initial density $\rho_0$...
3
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3answers
280 views

Why is there less UV light on earth in winter

So I have often read that, at least in e.g. northern Europe, in the colder seasons, there is not enough UV (-B) light arriving from the sun, so many people have not enough vitamin-D from that. At ...
0
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3answers
66 views

How high do you need to be so as to not rotate along with Earth?

So, I saw this meme about some minister commenting that the Earth doesn't rotate, for if it did then planes only need to be in the air and the destination city would come to it. I know this is absurd ...
0
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1answer
53 views

Can an object take off from A, do not move (in the air) but land at a different place? [closed]

Can an object take off at a point A on the surface of the Earth and then land after some time only to land at a different place where it initially took off (because in the mean time the Earth has ...
1
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2answers
52 views

Are clouds forming above a certain height? [closed]

Are clouds forming above a certain height (300m+) and if they do, how are they staying above that certain height and aren't forming let's say at 20-30m from ground. What keeps them so high?
3
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0answers
52 views

How to correctly calculate the colour of the sky?

It is well-known that the sky is blue due to Rayleigh-scattering. What bothers me though is the question how to actually calculate the spectrum of the scattered sunlight. Yes, use one of the ...
0
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1answer
45 views

How much and what kind of sunlight passes through a cloud?

I've read that 80% of sunlight is passing through clouds. Now there a small clouds and big clouds so it should be some average. Is this true or is the amount of sunlight passing throug a cloud really ...
0
votes
1answer
20 views

How to account for lower tropospheric horizontal refraction

With regards to the lowest 5kms of the troposphere, the International Standard Atmosphere models don't support a notion of a linear increase in air density along Horizontal axes. Yet, the path of ...
0
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0answers
10 views

What is the relationship between atmospheric refraction and path curvature?

Light traveling in a "curved" trajectory suggests a linear increase of the refractive index over the entire distance (uninterrupted super-refraction). A lapse in the increase of the refractive index ...
3
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0answers
49 views

Behaviour of Altimeter at different temperatures

I have realized that the Altimeter of my bike computer (it uses Air Pressure to determine altitude and needs to be calibrated every start) is not consistent at different temperatures. At the Start ...
0
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0answers
23 views

Clarification regarding atmospheric opacity

I have taken a look at the related questions Can someone explain to me the concept of atmosphere opacity? and Why can spacecraft observe terrestrial gamma rays, but terrestrial observers not ...
0
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1answer
68 views

Are lighter molecules in the air more affected by earth gravity?

Or: Why are raindrops falling? In vacuum a heavy (big mass) object is attracted by gravity with the same speed as a light object as shown on the moon with the hamer and the feather. But on earth ...
1
vote
2answers
44 views

Why would El Niño affect atmospheric CO2 measurements?

Starting with this article in Gizmodo: El Niño Has Pushed Our Planet Past a Major Climate Milestone and then to this commentary in Nature Climate Change El Niño and a record CO2 rise there seems to ...
-1
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1answer
57 views

Is aviation exhaust the culprit for climate change? [closed]

The ongoing climate change is the biggest threat to the human civilization. The recent 4-year drought in California, other droughts and floods in different parts of the world are posing serious ...
10
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2answers
113 views

Why does a rolling thunder always starts with a high pitch and ends with a deep, low sound? [duplicate]

Rolling thunders always come cracking in with a high frequency, and the sound grows more deep as the rolling advances, ending with the deep sound of a roaring lion. Why? This is not the same question ...
0
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0answers
35 views

Ultra-cold gas giant atmospheres

In the troposphere, which has the bulk of the atmospheric mass, it's colder at higher altitudes due to adiabatic lapse. Gas giants have several different chemicals that condense into cloud decks at ...
1
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0answers
16 views

Generic Rayleigh effect experiment - nothing happens for water

On youtube, a bunch of Rayleigh scattering experiments (e.g this one are set up with some compound being added to water in order to invoke the effect. Why is there no Rayleigh effect for "pure" water?...
3
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0answers
21 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 ...
22
votes
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 ...
1
vote
1answer
19 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) = 0.300+\frac{0.01}...
2
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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 ...
-3
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2answers
63 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. Edit:...
1
vote
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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1answer
27 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 ...
1
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0answers
57 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 ...
0
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1answer
49 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 a}$...
3
votes
2answers
84 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 ...
0
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0answers
21 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 considered,...
1
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2answers
36 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 ...
4
votes
1answer
61 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
94 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 $\rho = \frac{M}{V}$...
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3answers
804 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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1answer
57 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
votes
1answer
46 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 ...
0
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0answers
54 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 ...
7
votes
1answer
149 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
votes
1answer
72 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 ...
4
votes
1answer
67 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 ...
2
votes
3answers
151 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: $$ I=...
1
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0answers
42 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 ...
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 ...
0
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0answers
76 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
34 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 ...
1
vote
1answer
30 views

dry adiabatic lapse rate

Adiabatic lapse rate is defined as $$ \Gamma_a \equiv -\left(\frac{dT}{dz}\right)_{\rm parcel}=-\frac{R_{\rm a} T}{c_p \,p}\left(\frac{dp}{dz}\right)_{\rm parcel} = \frac{g}{c_p} $$ $R_a$ is gas ...
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votes
1answer
97 views

Is climate change caused by humans? [closed]

Some people argue it is not because it is caused by solar cycles (sometimes the sun brights more than others thus increasing the Earth's temperature) and that the energy that $CO_2$ traps isn't enough ...
0
votes
1answer
66 views

what is the relation between heat capacity and mixing ratio

I am supposed to derive an expression for the specific heat capacity $c_p$ for air with a water vapour mass mixing ratio of $\mu$. The hint is: (Use the fact that $c_p= (\frac{\partial H}{\partial T})...
16
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8answers
4k views

How do stars from far away affect Earth?

I know that we obviously get light (or we wouldn't be able to see them), but are there any other ways that they affect Earth and maybe just our solar system in general?