All Questions
1,323 questions
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'Physics behind the morphology of clouds' book recommendations?
Clouds are a wonderful and fascinating tracer of atmospheric motions, and I keep wondering if there's a textbook/popular science book out there that focuses on explaining the atmospheric dynamics/ ...
- 65k
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2
answers
208
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Why do airplanes sound louder when its cloudier?
I am from India, and now its monsoon season. Typically, during this time, the sky is filled with dark rain clouds. Me, along with several of my friends, have observed from childhood that the planes ...
CommunityBot
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4
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2
answers
1k
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Colors of the Aurora
I've seen several web pages that attempt to explain the colours of the aurora but they seem to gloss over or leave out certain details, so I'm still confused. For example, this page explains it in ...
- 137k
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1
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Does a pop pop boat work with vacuum above the water?
(Given that there is an internal oxygen source then, of course.)
In other words:
Does the fluid pressure due to the boat's pipe(s) being underwater add to the water being pressed into the tube(s) in ...
- 10.1k
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487
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How do you calculate light attenuation by wavelength at a given air mass coefficient?
I am trying to get a good view of light wavelength distribution as a function of viewing angle, with a specific interest as $z \approx 90^\circ$ near the horizon (sunrise/sunset). Air mass ...
CommunityBot
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153
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Why does the moon becomes red instead blue during an lunar eclipse?
While observing an lunar eclipse, I noticed that the moon is first covered by a distinct strip of blue light, to then at its apogee, the moon is completed covered by a red light. I understand that the ...
- 213k
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5
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987
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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 $\rho_0$...
CommunityBot
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3
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Elevation for far away objects
I am trying to use a PTZ (pan, tilt, zoom) camera to point at far away objects that I have an exact bearing and distance of.
My main problem is getting the correct 'tilt' or elevation angle to point ...
- 24.7k
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1
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42
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Does the Earth’s Geoelectric field affect its orbit around the Sun?
https://en.wikipedia.org/wiki/Atmospheric_electricity
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/geoelectric-field
Is the interaction between the electric field of the Sun and ...
- 213k
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2
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153
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Does night sky cooling need clear sky and why?
I think I understand what radiative cooling is in general. Each body which is at a non absolute zero temperature would emit electromagnetic waves and loose energy.
Now when it comes to night sky ...
- 213k
3
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1
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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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What factors and forces affect the velocity of volcanic emissions in the atmosphere?
Niche question for a niche subfield of Physics. While exploring the Sulfur Dioxide ($SO_2$) data from the Geostationary Environment Monitoring Spectrometer (GEMS), I noticed that during the moment ...
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1
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Lightning sprites
Lightning usually occurs due to an electrostatic discharge between an electrically-charged cloud and the Earth's surface, or between clouds. There are also sprites, electrical discharges that occur ...
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3
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Why are the northern lights so much less visible to the naked eye than to smartphone cameras?
The northern lights have been visible where I live recently, but I've found them to be practically impossible to see with the naked eye. Phone cameras, however, show them quite brilliantly. How is ...
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1
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Why is $ n(r) = \frac{dN(r)}{dr} $ positive if the cumulative distribution $ N(r) $ is decreasing?
I’m currently studying the physical characterization of atmospheric aerosols, and I’ve encountered a conceptual problem regarding the particle size distribution.
I understand that $ n(r) \, dr $ ...
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1
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220
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How can daylight have a higher colour temperature (e.g. 6500 K or D65) than sunlight in space?
Supposedly, daylight at midday has a colour temperature of 6500 K. This reference is also the standard for calibrating computer screens (that's how I fell into this). However, outside the atmosphere ...
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6
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6k
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How is wind created?
I know that 'blowing air is called wind', but what I don't know is, how is wind created?
And I don't want the answer from Google Search. I want to know more about wind at the atomic or molecular ...
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3
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1
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102
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Derivation of the solar resource at Earth's surface
I am reading Jenny Nelson's The Physics of Solar Cells and am a bit confused with the derivation of the solar irradiance at the Earth's atmosphere she supplies. I'll outline it here, and I provide ...
- 333
2
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3
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483
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Global warming and planetary thermodynamics
To a first approximation, the earth currently radiates out as low frequency thermal radiation the same amount of energy as it absorbs as high frequency solar radiation. (This ignores energy generated ...
- 2,825
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2
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50
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Atmospheric Physics to Quantum Phenomenon
Is there any possibility of application of Quantum mechanics to understand complex atmospheric phenomenon? Such as precise quantification in forecasting
- 65k
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0
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Determining the distance to an emission from "plume width" assuming a plume is gaussian
I am measuring pollutant concentrations, from a source downwind, using aircraft data. Occasionally, I observe an enhancement related to an upwind emission, and this enhancement lasts for some amount ...
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0
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24
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How can I calculate the heat transfers caused in Venus's atmosphere by a stellaser?
In Isaac Arthur's video Winter on Venus, he discusses using a stellaser to heat Venus’s atmosphere and remove its gases, but he doesn't go into much detail about the heat transfer involved in it.
The ...
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73
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Sea level rising - what is the effect of humidity?
Cause of Sea Level Rises
According to the report in World Economic Forum, sea level rise is the result of two effects:
Ice melting.
Ocean water expanding because of the temperature increase.
They ...
- 45.7k
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1
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88
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Why does Sun appear white at noon?
I have found several source citing the reason for the white apperance of sun is due to less scattering of light before sunlight reaches an observer on the Earth (as it is relatively closer to us at ...
- 99.9k
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1
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309
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Extremum principle for gradient wind balance
Dear Physics StackExchange,
as is well known, analytic solutions of the Navier-Stokes equations are only available for very special flows. Therefore, in most fields concerned with fluid dynamics, a ...
CommunityBot
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3
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2
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766
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Regarding the $\mathbf{E} × \mathbf{B} $ drift in the Earth's magnetic field
So I have a burning question: The only reason that the $\mathbf{E} × \mathbf{B} $ drift doesn't generate an electric current is because both the electrons and the positive ions move towards the same ...
CommunityBot
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4
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1
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220
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While flying over Rome we noticed that during sunset, there was a green color between the red and blue of the sunset sky. What causes it?
The picture has only been trimmed and not edited. The green is visible when the red or orange tapers off into the blue. Is this different from what causes the green flash? We were flying from Rome.
CommunityBot
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3
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611
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What is the refraction index in the upper atmosphere (e.g. thermosphere)?
I've been searching for the refraction index in the upper layers of atmosphere such as stratosphere and thermosphere but I can't find it, all that I've seen is all equations without any numbers that I ...
CommunityBot
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1
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288
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How has the Earth's air pressure varied over geological time scales?
It is estimated that the Earth is losing about $5 \times 10^7 kg$ per year. Most of it due to hydrogen loss. I suppose this has an impact on the pressure of the atmosphere in general.
Thus, I am ...
CommunityBot
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3
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67
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When can we expect a black-body radiation?
During the pandemic last few years, the Infrared thermometer is widely used to measure the body temperature.
However, the fundamental question or the question in the first place is, why do we expect ...
- 39.6k
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1
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520
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Color of sky from an airplane
My textbook says that the sky appears black to the passengers of an airplane flying at a high altitude. They further explain it by saying that this is because of the fact that the atmosphere of that ...
- 213k
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1
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66
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Feynman Lectures - 100V/m in the air
Feynman suggests that:
There is a vertical electric field E of 100 volts/m in the air.
This voltage is in part maintained through the action of thunderstorms. The highest part of our atmosphere has ...
- 99.9k
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5
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4k
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Why doesn't sun go all the way to the horizon during sunset?
This is a very silly question and I really don't know the answer to it but curious to know.
Everytime I see the pics of suset on beaches the sun appear to go all the way down to the surface of the ...
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1
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60
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How do these nearly-periodic small clouds form?
I recently saw these clouds when flying:
I wonder what causes them to create these many small lumps -- intuitively, I would expect water vapor to form a more-or-less uniform mist with much vaguer ...
- 97.8k
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2
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77
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What regulates the size of our atmosphere?
Our atmosphere is only about 100km thick before the official start of space. That is a mere 1.57307% of the radius of Earth (6,357km). The difference between the gratitational force at sea level and ...
- 11.2k
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1
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Atmospheric pressure and gas pressure
Can somebody please explain this to me. How is it possible the cap didn't fall since there's air trapped inside the container? If not mistaken, the trapped air has a pressure same as the atmospheric ...
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3
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580
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Nocturnal freezing of water: Calculation of radiation through atmosphere?
I recently came across an article in Wikipedia, which claimed that medieval civilizations used to leave water out overnight in an insulated pot during clear and calm nights, which results in the ...
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1
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472
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The Weight of Air A Human has to Bear
The average circumference of the human chest is $97$cm to $114 cm$. Let us, for the sake of simplicity, assume that this is a circle. The cross-sectional area of the human body then is $\approx 3 \...
CommunityBot
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3
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622
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Why does atmospheric drag speed up satellites?
I've read that old satellites slowly lose altitude when encountering the very thin atmosphere, and strangely enough they speed up. My theory is that the work done by the drag force is insignificant in ...
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What would the temperature of the tropics be if the atmosphere did not try to balance out heat the latitudinal surplus and deficit
The atmosphere acts to even out the heat imbalnce between the surplus at the tropics and the deficit at the poles. Assuming that the composition and density of the atmosphere stay the same, what ...
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2
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135
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Surely $\rm CO_2$ reflects incoming solar infrared radiation?
Is the greenhouse effect not cancelled out by the $\rm CO_2$ in the atmosphere reflecting solar infrared radiation back into space? It seems logical to me that, if $\rm CO_2$ reflects infrared shifted ...
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1
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299
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Why did the air not heat up in this experiment demonstrating the atmospheric greenhouse effect?
In the paper "Experimental Verification of the Greenhouse Effect", the authors (Hermann Harde, Michael Schnell (2022)) describe an experimental setup that they say demonstrates the ...
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7
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1k
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Why is methane considered an important greenhouse gas?
Methane’s absorption bands are centered at 3.2 and 7.2 microns -- far off the peak of the Planck spectrum for a 290 K blackbody near 16 microns. Moreover, its absorption bands overlap with the water ...
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3
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3k
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How does gravity overpower a vacuum?
While watching experiments with vacuum chambers, I had a thought.
If you put a sealed box at normal atmospheric pressure inside a vacuum chamber, pumped out the air and pierced the pressurized box I'd ...
- 30.2k
2
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2
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171
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Why can't we see green color in the sky? [duplicate]
From sunrise to sunset we can see a variety of colors in the sky.
For example, during morning the most dominant color is blue whereas during sunset orange,red,yellow and there shades are more dominant....
- 9,304
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55
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What is the range of noon sun color temperature, when a light meter reports full expected sunlight (+/- epsilon)?
My question came from trying to find what uncertainty bounds, if any, I can assign to a color temperature sensor, without access to an artifact with a precisely calibrated output spectrum.
This leads ...
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2
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549
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Is there an equation that can estimate chances of alien life in the universe?
Seeing how infinite the universe appears and out of all of those stars, planets, galaxies, there must be other life forms. Mathematically, the odds are very good. Is there a mathematical equation to ...
CommunityBot
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Can we use thermonuclear explosion to fight climate change? [closed]
Nuclear war can create nuclear winter, which is opposite to global warming. Can we detonate thermonuclear (because they don't create radiation) bombs somewhere to decrease global temperature?
- 97.8k
103
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7
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113k
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Why does the atmosphere rotate along with the earth?
I was reading somewhere about a really cheap way of travelling: using balloons to get ourselves away from the surface of the earth. The idea held that because the earth rotates, we should be able to ...
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1
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Is long-term weather forecast impossible in principle?
This question can be asked about any chaotic dynamical system, but hydrodynamics of the atmosphere makes it more concrete. Arnold describes his 1966 result as follows:
I have calculated the ...
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