Questions tagged [meteorology]
Meteorology is the interdisciplinary scientific study of the atmosphere.
136 questions
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Latent heat transfer coefficient over the ocean?
I'm currently calculating for the surface turbulent latent heat flux over the Pacific. The formula I have needs a $C_E$ which is the latent heat transfer coefficient.
I've read several studies that ...
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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 ...
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Expanding the barotropic nondivergent potential vorticity equation: Which vector calculus property/identity to apply for dot product and del operator?
I am trying to expand the barotropic nondivergent potential vorticity (PV) equation [link]
$$\frac{\partial \zeta}{\partial t} = -\vec{V} \cdot \nabla(\zeta + f)$$
where $\zeta$ is the relative ...
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Formulation of the Moist Adiabatic Lapse Rate Equation
In the relationship r = ϵe/p−e: mixing ratio of the mass of water vapour to the mass of dry air.
Question: What is ϵe
For clarification see question Moist adiabatic lapse rate
I know that the ratio ...
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What happens to the "curvature term" in the equations of motion for a rotating fluid near Earth's poles?
For a rotating fluid in spherical geometry, one of the terms of the equations of motion is the "curvature term". For example, for the zonal component of velocity (corresponding to eastward ...
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Why does warm, moist air generate a low-pressure area? [closed]
In school, I learned the mechanism of high and low pressure areas, which roughly goes like this:
In the tropics, the sun warms up the air during the day. Water evaporates, so that the air gets warm ...
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Is angular momentum conserved on a spinning sphere, specifically Earth [closed]
Specifically in relation to meteorology. I was wondering if the angular momentum an object, lets say a parcel of air has due to the roation about the earths axis. Is it conserved if moved to a ...
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Forecasted temperature in the shade vs. theoretical temperature in the sun
I understand that different objects absorb different amounts of light (blackbody absorption). I wonder how feasible it would be to calculate the approximate temperature in the sun based upon the ...
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Katabatic Wind: if the ground "radiates" it's heat during the night, why doesn't the air above it warm?
In this picture (from EasyPPL mock exam) and in a few other sources (e.g. https://www.britannica.com/science/katabatic-wind) it is stated that at night, the ground radiates heat and the air passing ...
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How can flow along a stream line with constant pressure spatially change its velocity?
I'm going crazy:
In meteorology there is a term "geostrophic wind". It is wind moving along surfaces of constant pressure.
https://en.wikipedia.org/wiki/Geostrophic_wind
How is the step from
...
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Confusion about the horizontal pressure gradient force being equal to the gradient of the geopotential in pressure coordinates
I see many sources in atmospheric dynamics express the following:
$\frac{1}{\rho}(\nabla p) = \nabla_p \phi$
For example this source equation 10.
The reasoning given is that $\frac{1}{\rho}(\frac{\...
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Application Of Kirchoff's Law In A Desert [closed]
Homework Statement::
Sand is rough and black so it is a good absorber and radiator of heat depending on temperature.
During the day, sand's radiation of the sun's energy superheats the air and causes ...
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How does cosmic rays influence aerosol growth?
I have read about aerosol formation increasing due to ionisation but unable to understand what actually goes into the process? Can someone please explain how cosmic rays help in aerosol formation? ...
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Do forests create wind?
Forests evapotranspire more water vapor into air than surrounding areas, have more clouds, and are usually cooler (because of evaporative cooling). How does this affect the air pressure of forests? ...
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How come air masses displace air when it moves rather than mixing with it? [duplicate]
It seems if you had one mass or air moving towards another air mass, that the molecules within that first air mass would be able to penetrate into the second air mass because the distance between air ...
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Does a tower bell ringing prevent thunderstorms?
Introduction
This is the beginning of an apparently physics-unrelated question which involves 1700-1800 Italian law, atmospheric processes, sound waves propagating through fluids, and lightning ...
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How would a rainbow from a divergent light source look like?
Many explanations of the shape of rainbows as constant angle reflections do assume the light, incident on rain droplets, to be a parallel beam of light rays. That might for the sun-earth system be ...
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Temperature-Humidity-Wind (THW) index for hot and cold weather [duplicate]
Does anyone know the formula (or the algorithm, even a fortran code) to calculate the Temperature-Humidity-Wind (THW) index not from the heat index but in general? (someone published a (too simple?) ...
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Any lecture notes or easy explanation of Holton's Meteorology?
I am struggling with understanding Holton's Dynamic Meteorology. Any lecture notes based on the book with easy explanations will help.
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Why is air considered to rise adiabatically?
Do air parcels not push against other air and do work on them? When air molecules within an air parcel bump into air molecules outside the air parcel do they not transfer energy to them?
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Is the downforce of rain on airplanes negligible?
Is the downward pressure exerted by raindrops in even a strong storm on a lightweight aircraft negligible?
Someone better informed may likely improve the following reasoning, cobbled together from ...
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What determines handedness of wind circulation around pressure extrema in the atmosphere?
I'm reading a textbook (Atmospheric Science - An Introductory Survey 2nd ed, John M. Wallace • Peter V. Hobbs) which states (p14):
The winds observed in the Earth’s atmosphere closely parallel the ...
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Blob of falling water
If a "blob" of about 100-200ml of water is dropped from higher than about a first floor (using English nomenclature: ground, first floor, second, etc), it'll stay together as a blob until it'...
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Do clouds get hotter while producing raindrops and snowflakes?
I know that in clouds water particles condensate to form raindrops. I believe surface energy should be released in form of thermal energy. Will this newly created thermal energy increase the average ...
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I know the temperature and air pressure at specific height, can I estimate the temperature at different height?
I know what the temperature is at a specific height, and I know the air pressure there.
Is it possible to estimate the temperature at a different height?
(It's a public weather station, it has an API, ...
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How to measure wind speed non-accoustically without moving parts? [closed]
I heard that there are ways to measure wind speed independent of the direction other than the usual anemometer or acoustic Doppler profilers, with a setup without any moving parts. Could somebody ...
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Why does moderately distant lightning sound the way it does: relatively quiet high pitched thunder first, and then much louder low pitched thunder?
Why does thunder, that is heard about five or ten seconds after the lightning is seen, start as relatively quiet high pitched 'crackling' thunder which is, about five or ten seconds later than that, ...
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Can I simplify computational fluid dynamics using the average values in 9 squares on an excel spreadsheet?
I wrote an excel VBA program that shows how a dye diffuses through water by taking one
spreadhsheet cell and getting the average dye concentration for this cell and 8 of its immediate neighbours and ...
user291777
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Does cold dry air rich in static electricity cause the Hessdalen lights in Norway?
I have read many articles on the Hessdalen lights ( which many professional scientists think are plasmas).
https://en.wikipedia.org/wiki/Hessdalen_lights
I have concluded that cold dry air rich in ...
user291777
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If cold air is denser then why is compression associated with atmospheric heating?
If cold air is denser than warm air then I would assume compression of air would cause air to cool and expansion would cause air to heat up. Why is it the opposite?
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Estimating the upper limit for cloud formation?
I know that on our planet, the highest clouds reach up to the tropopause, roughly 10km above ground (varying from polar regions to tropics). If we ignore overshooting Cumulonimbus cloud tops and other ...
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How does one determine which signs to take for the Gradient Wind Equations?
Under geostrophic balance, one can write
$$\frac{V^2}{R}+fV-fV_g=0$$ where $V:$wind speed, $V_g:$ geostrophic wind speed, $f:$ Coriolis parameter, and $R:$ radius of curvature.
Solving for $V$, we can ...
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Does warm air on a macroscopic scale tend to produce more wind (turbulence)?
I am a private pilot and noticed something. Flying in the colder winter days seems way calmer and less turbulent to me than flying during the summer. Now because I do not have that much of experience ...
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How to calculate Water Vapor Pressure?
So, we know that
$$\text{Relative Humidity(%)}=\frac{\text{Actual Water Vapor Pressure}}{\text{Saturation Vapor Pressure}}$$
Now, we can find saturation vapor pressure only from the ambient ...
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How is the spin of hurricanes explained from an inertial frame?
I have read that hurricanes spin because of the Coriolis effect. Since the Coriolis force is a ficticious force, which is only present in a frame that is rotating w.r.t. to an inertial one, I am ...
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What is the explanation for the elevated levels of iodine-131 near Vermont shown in this video?
At 9:07 in the latest Veritasium video, we see a map showing elevated levels of iodine-131 in the United States. The big band through the mid-west makes perfect sense to me; nuclear weapons tests ...
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What would be Earth's temperature under a very efficiente greenhouse atmosphere?
Assume that Earth has an atmosphere made out of a very efficient greenhouse gas (e.g. a very, very thick wator vapor atmosphere).
In that case, what would be the surface temperature (or the ...
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Why do airplanes make a humming sound when airborne while the engines (when on the ground) make a steady sound?
I know experience-based questions are a bit tricky on this site but isn't every theory based on common experience?
Every time I hear an air jetliner flying over at a high altitude it seems the engines ...
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Does an overcast sky alter the sound waves coming from above it (like the sound of an airplane)?
This morning, in our little backyard, I heard an airplane that was flying above the clouds, which were completely and uniformly covering the blue sky, as if they formed one big homogeneous grey mass. ...
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In spectroscopy, what element does green indicate presence of in the atmosphere?
And what element does visible green glow indicate in our own atmosphere?
https://youtu.be/HDlsdVuv6qQ
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Ventilators and evaporative cooling
I've recently read that ventilators make sweat or water in your skin to be more likely to evaporate. How can that be the case? If the temperature does not increase, how can it provoke such an effect?
user257107
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Can pressure gradient force be balanced by Coriolis force?
I was learning about wind from my class textbook. In that there is first a description of forces affecting the velocity and direction of wind followed by that is geostrophic wind.
My question is:
At ...
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Relation between vertically integrated precipitable water and precipitation
My background is not in meteorology, but I am interested in climate models of tidally-locked planets of red-dwarf stars. I recently found a great review of different conditions on such planets modeled ...
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What causes this "hem of his garment" aurora (or is it fake)? [closed]
This picture of a "hem of his garment" aurora in Finland is going the rounds today. Is it real, and if so what causes it to be white instead of the green shades normally associated with aurora.
When ...
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Why is the Weibull distribution used to describe wind speeds?
Frequently, it is stated that the distribution of wind speed at a certain location can be described by the so-called Weibull distribution:
$$
W(x;\lambda,k):=\frac{k}{\lambda}\left(\frac{x}{\lambda}\...
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How to calculate energy released by formation of frost on window during winter?
When the T ambient is low, we can see frost formation when the surface of window or surface is less than 0 degree C. But how to calculate the energy released during that frost formation at the window ...
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Is there a molecular diffusion component to wind?
I'm thinking of vapor pressure from terrestrial water: A highly evaporating area in the ocean creates a volume of high relative humidity, the vapor tends to move to less humid air and by molecular ...
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Does elevation change the temperature at which snow falls?
I have read that snow falls at 32 degrees F. While at an altitude of nearly 8,000 feet above sea level, I found it snowing, but the temperature was more than 40 degrees F. Perhaps the indicator is ...
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What is the hygropause?
I've been reading on planetary atmospheres and I've encountered this term which I can't find defined anywhere on the web.
What is the definition of Hygropause?
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Size of a raindrop
Thinking about the fact that raindrops come with a typical size I was wondering how this can be determined.
I am pretty sure that the friction with air and the quantity of water in the clouds are ...
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