Questions tagged [atmospheric-circulation]
The atmospheric-circulation tag has no usage guidance.
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Why does relative vorticity in spherical coordinates have an extra term as compared to the usual cartesian derivation?
With $u, v$ denoting the components of wind velocity along zonal (x) and meridional (y) direction, atmospheric (relative) vorticity is usually defined by
$$\zeta_z = \frac{\partial v}{\partial x} -\...
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How should one even try to start thinking about quantifying the total emissions footprint for the planet?
I was recently reading a paper in which nine planetary boundaries have been proposed. The paper uses modeling and literature assessment to quantify safe and just Earth system boundaries (ESBs) for ...
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Why air parcel is on a circular trajectory when considering Coriolis force
According to Coriolis force an air parcel is deflected in the absence of other forces by the acceleration (Holton, 4th Edition):
These equations lead to circular motion.
This figure is from a Matlab ...
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What has been going on in the atmosphere over the past couple weeks?
First there was a once-a-century bomb cyclone 2000 miles wide that froze the entire Eastern US. Gigantic US winter storm leaves millions without power and cancels holiday plans
Then Europe had a ...
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Book on atmosphere dynamics
I plan to study a good introductory book on atmospheric dynamics:
which one is more recommended? My background is a university degree in physics, but I'm new to meteorology.
An Introduction to
...
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Air pressure, fronts and temperature
I have spent hours on this topic and I seem unable to make sense of it.
If air moves from high pressure toward low pressure, and wind is the movement of air due to differences in pressure, how can, ...
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What does the "strength" of a circulation cell refer to?
I'm reading articles about climate models for possible exoplanets, and I'm confused as to what the "strength" of a Hadley or Ferrell cell refers to. Does it refer to wind speed? Wind force?
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Compute upwind flux for gridded data
I'm trying to compute something called the "Drying Ratio" following: Eidhammer, 2018
The drying ratio is the ratio of the precipitation to the incoming vapor flux. So,
$DR = \frac{F_{in} - ...
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Why does cloud cover seem to "ride" a wave that propagates westward near the equator in this video?
https://www.youtube.com/watch?v=wVRbeGc_6zM
Notice that the cloud cover over Africa and South America is correlated in a way that seems to be highlighting some kind of large-scale easterly wave ...
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How do academics/institutions run large climate simulations given the computing challenges?
I have been brushing up on numerical methods for PDEs lately, and climate models provide such a rich set of models and ideas to practice with. However, I was a little confused about how academics can ...
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How to derive the total potential energy of the atmosphere?
In one of Lorenz’s paper (I mean the meteorologists Edward Lorenz), he stated that the total potential energy of the whole atmosphere $P + I$ (means the sum of potential energy and internal energy) is
...
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Vertical air speed
Assuming that the divergence varies linearly with the pressure between the surface
(1000 hPa) and the tropopause (200 hPa). Can someone tell me how do we calculate the vertical speed on the pressure ...
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How to search for the nearest non nan value in 2d xarray dataset
I have a 2d xarray dataset and I am having several nan values in the dataset. These nan values need to be filled with the nearest non-nan values in the 2d array. How do I do this?
I am trying to ...
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Why is the pressure on the poles higher in Summer and lower in Winter?
Just to give context, this was not my original question but one that I ended up stuck with while trying to find a cause for the following observation (which is almost universally true for temperate ...
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How to install ESMF and ESMFPy in Ubuntu using gfortran, gcc, python?
I am trying to regrid some of my latitude-longitude grid files to tripolar ocean grid and found that ESMF can be useful. However, I am finding it hard to install the same.
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How to convert the units of specific cloud liquid water from ERA5 (kg/kg) to kg/m2?
I am trying to initialize my model with the cloud liquid water data from ERA5. My model IITM-ESM which evolved from CFSv2 takes in the cloud liquid water information in $\small\mathsf{kg/m^2}$. ...
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Can we see the circulation cells in wind maps?
Earth famously possesses three distinct circulation cells per hemisphere.
Now out of curiosity one could use a weather app, like windy, to display the wind structures at ground level globally, and ...
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Application of vorticity tendency equation
I have a question about the dynamics of westward propagating vortices.
In meteorology, the vorticity tendency is often used to explain the westward propagation of vortices (cyclonic circulation).
A ...
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Initiation of Rossby waves during MJO
I am trying to understand the basic dynamics of MJO, where I find several studies which relate it to the initiation of equatorial Rossby and Kelvin waves. Though MJO is an eastward propagating wave, I ...
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Temperature Advection using finite differences with gridded data
Advection of a scalar quantity, such as temperature (T), by the horizontal wind, is defined as follows:
$-\textbf{U}\cdot\nabla T$
where $\textbf{U}$ is the horizontal wind vector, $\textbf{U}=(u,v)$...
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For fine particles to get dispersed throughout the globe via atmospheric circulation, in what level of the atmosphere would they have to travel?
For molecular-sized particles to disperse around the entire planet, would they have to reach the stratosphere, or could air currents in the troposphere distribute them? Are particles dispersed ...
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Internal energy, enthalpy, and work in the atmosphere
I'm writing a toy radiative-convective atmospheric model and need to relate the heat flux convergences (either surface sensible heat flux or the radiative flux) to changes in atmospheric layer ...
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Why are deserts mostly located on the western side of continents?
I read somewhere in a book that mostly desert found in the western part of a continent. So my question is that why is it so? I searched on the internet but I didn't get a reasonable answer for that.
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Latent heat and global circulation
What is the relation of latent heating and the global circulation of the atmosphere?
Do you know some references about this relationship?
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Why is Egypt so dry?
If you look at this wind map (for July, but following the link you can also view other months):
you will see that Egypt gets its air from the Mediterranean sea. During other months it could get less ...
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Buoyancy frequency
The buoyancy frequency, $N$ is defined as $N^2=\frac{gd\theta}{\theta dz}$, where $\theta$ is the potential temperature (I see it as a measure of the deviation from the adiabatic nature),
$z$ is the ...
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Forced shallow-water equation with diabatic heating as the source term
How to obtain the divergence of velocity field $\left(\nabla.\mathbf{u}\right)$ with ${Q}$ (something proportional to the diabatic heating rate) as the source term from the thermodynamic equation?
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Physics based circulation models
How useful are physics based models when considering circulations at synoptic scales? Are they useful? Can we not make predictions, observe trends based on data alone? I am studying A.E.Gill's model ...
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How is there enough $\ce{O2}$ in the atmosphere to breathe if you are in a desert with no plants?
Humans depend on $\ce{O2}$ for breathing. The source of $\ce{O2}$ is photosynthesis by plants or cyanobacteria in the ocean.
How is it, that when people travel through deserts or the Arctic / ...
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Why do the dry and moist adiabatic lapse rates converge with height?
Near the surface, the slope of the moist adiabats are much steeper than dry adiabats due (as I understand it) to the the latent heat released as water vapour condenses. The difference is amplified at ...
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Relation between direction of shear and tropical cyclone formation
In an earlier question/answer Why are there no cyclones in the southern Atlantic basin there was a point raised about direction of shear(abetting/retarding) cyclone formation. It appears ...
user1066
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Monsoonal interactions with mid latitude disturbances
For the past few years in succession India has witnessed extreme flooding events caused by monsoonal troughs colloding with what appears transitory mid latitude disturbances and these appear to ...
user1066
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Is everything affecting everything on Earth?
If a single butterfly can alter the future, then can't every single action keep the future in chaos? According to the question about butterfly effects, this must be so, is it not? If this is an ...
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How long does it take for the atmosphere to mix?
If I release a say, one litre of gas, at a particular point on the planet, how soon, on average, would it take to be distributed evenly (mixed) across the entire earth's atmosphere?
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What factors determine the number of Hadley cells for a planet?
We know (think?) that Earth has three Hadley cells per hemisphere, but from observing gas giants such as Jupiter, we see that they have many more cells. According to a link from a comment in this ...
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Is it possible for a sting jet to form over a continental landmass?
Sting jets are thought to be responsible for some of the most damaging winds associated with extratropical cyclones in the mid-latitudes. So far they have only been confirmed in the European region, ...
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Why does the Hadley cell descend at 30 degrees latitude?
George Hadley's initial model of the Hadley cell described air as being heated at the equator, ascending, and then moving aloft pole-wards where it would cool and descend. Meanwhile surface air would ...
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Why does the El Niño Stop?
The reason for the initiation of the El Niño is unknown, but what is well known is how it progresses once initiated. The West Pacific warm pool begins to drift East, and the strength of the trade ...
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Why does the meandering pattern of the jet stream itself propagate?
It is well known that the jet stream follows an overall meandering pattern, but what is less well known is that this meandering pattern itself moves as a wave with a velocity much slower than the ...
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