16
votes
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Why are deserts mostly located on the western side of continents?
Some of the driest deserts on Earth occur in the western side of continents and they are called Coastal Deserts. Examples of such deserts are the Atacama desert (Chile, the driest desert on Earth), ...
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9
votes
Why is Egypt so dry?
If you take a look at the atmospheric circulation pattern, the Hadley Cells in particular, they tell the story. The northern edge of Africa is on the descending edge of a Hadley Cell, which means
...
- 1,185
8
votes
Why are deserts mostly located on the western side of continents?
Because of the Coriolis Effect, the prevailing winds on the earth between about the Tropic of Capricorn and the Tropic of Cancer go from the East to the West (knows as the Trade Winds). To get to the ...
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7
votes
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How to install ESMF and ESMFPy in Ubuntu using gfortran, gcc, python?
First download the esmf tar file from http://www.earthsystemmodeling.org/esmf_releases/public/ESMF_7_1_0r/reg/ESMF_Framework_Down.html
Then install netcdf library and gfortran compiler using
...
- 454
5
votes
Accepted
Why air parcel is on a circular trajectory when considering Coriolis force
The parcel in question is not moving in a straight line. It is a particle at rest in the reference frame rotating earth. A "fixed" observer in space would see a particle moving in circles ...
- 1,165
5
votes
Accepted
How do academics/institutions run large climate simulations given the computing challenges?
This question is a little vague, with multiple aspects, but I shall do my best.
Computing resources
Some universities have their own clusters or supercomputers. But many countries also have regional ...
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4
votes
Accepted
Why is the pressure on the poles higher in Summer and lower in Winter?
My answer will only relate to the question in the title: Why is pressure on the poles higher in summer and lower in winter?
Due to the axis tilt of the earth the winter hemisphere gets less heated by ...
- 1,165
3
votes
Accepted
How to derive the total potential energy of the atmosphere?
First, let's acknowledge this fact: $$c_p=R+c_v \tag{1}$$,
where $R$ is the specific gas constant.
This means that $x=R/c_p$.
Rearranging the equation, we can see that $$P+I=\int{c_p\left(\frac{P}{P_{...
- 8,809
3
votes
Latent heat and global circulation
Latent heat is released when water vapor turns to liquid\solid water. So latent heat is released where there is precipitation. So you're looking primarily at places where there is lots of moist ...
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3
votes
Buoyancy frequency
You can, but the form changes. it is
$N^2=\frac{g}{T}(\frac{dT}{dz} + Γ)$
where $Γ$ is the dry adiabatic lapse rate, given by $g/c_p$
where $c_p$ is the specific heat of air at constant pressure.
3
votes
How do academics/institutions run large climate simulations given the computing challenges?
Another UK perspective here to supplement Semidiurnal Simon’s answer (which reflects my experience too).
The UK research community is dominated by a single family of models known collectively as the ...
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3
votes
Accepted
Convert Geopotential Height's Unit from $m^2 s^{-2}$ to hPa
The geopotential is the work (force x distance) required to bring a 1kg object to a certain height. The units of work are $kg \frac {m^2}{s^2}$ Dividing by the unit mass gives the work per kilogram ...
- 383
2
votes
Accepted
Why does relative vorticity in spherical coordinates have an extra term as compared to the usual cartesian derivation?
The best way to see this extra term is to consider a bug moving along a latitude circle at constant speed $|u|$ in a constant direction arounf the poles. If the bug is moving along a geodesic then ...
- 4,041
2
votes
Air pressure, fronts and temperature
Well, to start with, air does not strictly go from high pressure to low pressure. For example, in geostrophic balance winds will move perpendicular to the pressure gradient.
Fronts form in a process ...
- 8,809
2
votes
Accepted
What does the "strength" of a circulation cell refer to?
If I recall correctly from my bachelor lectures the strength of the Hadley or Ferrell cells are often described in terms of kg/s (or sverdrup, so 109 kg/s), so i.e. mass flow of air.
I am not sure if ...
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2
votes
Latent heat and global circulation
Latent heat release is critical for the general circulation, in particular the tropical overturning circulation (Hadley & Walker circulations). The release of latent heat is the dominant diabatic ...
- 47
2
votes
Why does the Hadley cell descend at 30 degrees latitude?
Air usually subsides at 30 degrees because at that latitude it is cool enough to allow it to sink.
Your question on why air rises at 60 degrees; this is not because of convection since insolation (how ...
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2
votes
How to convert the units of specific cloud liquid water from ERA5 (kg/kg) to kg/m2?
I got the solution https://www.researchgate.net/post/How_to_convert_the_units_of_specific_cloud_liquid_water_from_ERA5_kg_kg_to_kg_m2
and
https://www.nwpsaf.eu/site/download/documentation/rtm/...
- 454
2
votes
How to install ESMF and ESMFPy in Ubuntu using gfortran, gcc, python?
Actually, you probably shouldn't install it. If you're comfortable using Linux, then you would be better advised to use the docker container instead, with it already installed. That way your system ...
2
votes
How to search for the nearest non nan value in 2d xarray dataset
If I were you, I would exclude the NaN values and then perform gridding on the resulting irregularly spaced data.
There are already the tools to perform this in Python and using the library SciPy
...
- 459
1
vote
Vertical air speed
That's... a pretty specific question.
Well, we start with making assumptions. Let's write the continuity equation with the Boussinesq approximation: $$\frac{\partial \omega}{\partial P}=-\frac{\...
- 8,809
1
vote
Temperature Advection using finite differences with gridded data
So i don't know for how many timesteps you've integrated. And I don't really understand what you have done to obtain the temperature $\rm T[t,s,y,x]$ in your second box, but this seems a bit like a ...
- 3,172
1
vote
Can we see the circulation cells in wind maps?
Yes, the wind cells are just a toy model, where we can suppose that the homogenity of the Earth and other things. But there are other things and Earth isn't same on the all points, so the ...
- 638
1
vote
Temperature Advection using finite differences with gridded data
I've come to a solution. I have followed @gansub's suggestion to check what there is already there, before reinventing the wheel. I found MetPy's code very (too) well structured, so the code for ...
- 652
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