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21

Well for one, this will surely be the speed of planetary rotation and the wind speeds your atmosphere can generate in North-South-direction. In my understanding those cells form as N-S winds flow and become deflected from this direction. So the number of cells will be determined by the winds that start either at the equator or the pole and the distance that ...

15

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), the Baja California desert (USA/Mexico), the Namibia desert (southwestern Africa), and the Atlantic coastal desert of Morocco/western Sahara/Mauritania. In mid-...

12

The Hadley cell was proposed and works only for a non-rotating earth. When we consider the earth's spin, we have to consider the Coriolis force as well. Because of this force air cannot travel in one unhindered cell from the equator to pole or back. So there must be an odd number of cells together so that the air rising and falling in the adjacent cells is ...

10

The time scale of interhemispheric tropospheric transport is in the order of one year (Chapter 4 of the book Introduction to Atmospheric Chemistry written by Daniel J Jacob). This is not an exact answer to your question, but might be a fair enough number for the problem you have in mind.

9

I wouldn't characterize the movement of the jetstream as a "less well known" problem, at least not to anyone who has sat through a synoptic meteorology class. The jetstream from a dynamic point of view is just an enhanced gradient in the heights on a constant pressure surface (or pressures on a constant height surface) and there are many factors the ...

9

Do you know what the weather will be in four hours time? You can probably make a very confident guess. How about this time tomorrow? You can probably make a reasonably confident guess. How about this time, in fourteen days exactly? Now, you're much less confident. That's because weather is a chaotic system, and it's very sensitive to boundary conditions. ...

9

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 Having lost most of its water vapor to condensation and precipitation in the upward branch of the Hadley cell circulation, the descending air is dry. As the ...

7

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 sudo apt-get install git tcsh pkg-config sudo apt-get install gfortran sudo apt-get install netcdf-bin libnetcdf-dev libnetcdff-dev sudo apt-get install openmpi-bin ...

7

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 west coast of a continent within those latitudes, an air mass blowing from above an ocean must cross the entire continent. Along the way, the air mass causes ...

7

If you look closely at the diagram you'll notice height isn't the primary cause for the convergence between the adiabats, though it is the driver. Note that toward the upper right there is still appreciable difference between the adiabats and as you move to the left the height they converge at decreases. The reason for this, as your intuition suggests, ...

7

The direction of the vertical shear plays a large role in cyclogenesis, where easterly shear tends to enhance the formation of cylones and westerly shear tends to suppress it (Tuleya and Kurihara, 1981). Internal waves are responsible for large transfers of energy across vast distances. Therefore, they play important roles in a wide array of atmospherical (...

6

The media loves the butterfly effect, but they also love to mis-portray what it means. When Lorenz gave his talk "Predictability: Does the Flap of a Butterfly’s Wings in Brazil Set Off a Tornado in Texas?", that made the media pay attention to the emerging field of chaos theory. The media focused on the title of his talk. It sounds so cool! They didn't read ...

6

I think it is important to think of the El Niño as just one of the components of a large scale global atmospheric-oceanic phenomenon known as the El Niño and the Southern Oscillation (ENSO). ENSO takes shape as fluctuations of the rainfall, wind, ocean currents and waves. They are by nature very irregular. The Southern Oscillation (SO) was first discovered ...

5

Here are two parts of an answer, but this is by no means complete. Most monsoonal research is focused on explaining the monsoonal passage through the plains of the Indian subcontinent. Very few papers can be found on how the same troughs cause rainfall at 3000 meters. I would like an authoritative reference on Monsoonal Mountain Meteorlogy. All that is ...

5

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 or national facilities. For example, ARCHER2 is the latest iteration of the UK's national supercomputer service. Small amounts of computing time are available ...

3

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 $$P+I=\int{c_p\left(\frac{P}{P_{00}}\right)^{R/c_p}\Theta dM}\tag{2}$$ Notice that $\left(\frac{P}{P_{00}}\right)^{R/c_p}$ is the Exner function. By extension,$$P+I=\int{c_p T dM}\tag{3}$$ If ...

3

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 solar radiation. This leads to a high temperature gradient from equator to the winter hemisphere pole (strong baroclinicity). In contrast we have a low ...

3

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 convection... the ITCZ near the equator and then the midlatitudes. I would believe that all of that latent heat release aloft should mean more heat is moved ...

3

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 Unified Model. The code for these is owned by the UK's national weather and climate modelling center, the Met Office, and used gratis under license by academics....

2

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 obviously not because of convection since insulation is no longer really intense here, but instead due to frontal uplift. When warm air meets cooler air masses from the poles at roughly 60, it being less ...

2

The short answer is, $\ce{O2}$ is all around us! You aren't breathing the $\ce{O2}$ that the trees next to you are respirating (at least not much). No matter which way the wind is blowing, you will have sufficient oxygen content. A "can't breathe" feeling comes from inhaling pollutants or extremely dry air (in which case you need to drink more water). ...

2

Look at it this way: According to the American National Center of Atmospheric research, the Earths atmosphere weighs 5.148 x 10^^18 kg., and that atmosphere is composed of about 20.8 to 20.9% oxygen (depending on moisture content of the air). So the Earths atmosphere contains about 1.07 million trillion kgs of oxygen. The 7.5 billion (or so) humans on the ...

2

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 heating of the tropical atmosphere, and provides much of the upward mass flux in the deep tropics (the ascending branch of the overturning circulation). In ...

2

When I look at problems like these I first check to see if there is a well tested and well documented implementation already rather than reinventing the wheel. In this case MetPy temperature advection is a well tested software that does many of the things meteorologists want including calculating finite differences with the right map scale factors. Since ...

2

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 https://scipy-cookbook.readthedocs.io/items/Matplotlib_Gridding_irregularly_spaced_data.html But please document exactly what step you are doing and why. ...

2

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 stays clean and you can have someone else maintain it for you. Check docker hub for different versions and find the one you like (here). Install docker using: ...

2

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/docs_rttov12/rttov_gas_cloud_aerosol_units.pdf In the above link the conversions between $\small\mathsf{kg/kg}$ , $\small\mathsf{g/m^3}$ , $\small\mathsf{kg/m^2}$ ...

1

That's... a pretty specific question. Well, we start with making assumptions. Let's write the continuity equation with the Boussinesq approximation: $$\frac{\partial \omega}{\partial P}=-\frac{\partial u}{\partial x}-\frac{\partial v}{\partial y}=D\tag{1}$$. If we assume a priori that the divergence varies linearly with pressure, then we can write divergence ...

1

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 instantaneous winds don't follow their cells. Of course, it is possible (by pure statistics) that sometimes in the Earth history, the majority of the winds was aligned with ...

1

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 advection was sparse among several different functions; not so immediate to trace back and put a function together. However, GrADS brings a very nice example on how ...

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