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The gravity wave and acoustic wave calculation in atmospheric models

I am wondering about the gravity wave (as well as the acoustic wave) calculation in atmospheric model. I know that the non-hydrostatic model should take the internal gravity wave and acoustic wave ...
Floris Chen's user avatar
1 vote
0 answers
6 views

How is cloud column water calculated in GDAS model files?

The question NOAA helpfully provides model outputs from the Global Data Assimilation System (GDAS) for the past 10 days (https://nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/prod/). Products include ...
unstar782's user avatar
0 votes
2 answers
49 views

Effect of changes in the air's nitrogen-oxygen-carbondioxide proportions

I recall (although, perhaps wrongly), from my PADI scuba diving books, that air is made up of 78% nitrogen, 0.8% CO2 and 1.2% O2. I was wondering, what would happen to our lungs (or to that of any ...
Joselin Jocklingson's user avatar
1 vote
0 answers
14 views

Oxygen concentrations in the air and absorption rates at sea, even under windy conditions

If I measure the amount of oxygen in the air at sea, is it the same as if I measure it on land? What if there is wind? Does oxygen concentration, change, in the middle of wind? What about the ability ...
Joselin Jocklingson's user avatar
5 votes
1 answer
96 views

What would be the atmospheric pressure if the atmosphere was 2/3 the density of water?

I came across a theory that proposed that earth's atmosphere must have had a density of 660 kg/m^3 during the mesozoic, and the gigantic size the dinosaurs attained on land was only possible due to ...
A.J's user avatar
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2 votes
0 answers
23 views

Can frictional force be un-aligned with wind direction?

There is a well known solution to Navier-Stokes equations for atmospheric boundary layer according to Ekman (see for instance PalArya's book "Introduction to Micrometeorology" or Holton's &...
MichaelW's user avatar
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1 vote
0 answers
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Why shear stress vector must be parallel to flow in this example?

In the book by S. Pal Arya "Introduction to Micrometeorology" there is a chapter about Laminar Ekman Layers. I refer to the following example: Variables are: U, V wind velocity in x, y ...
MichaelW's user avatar
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1 vote
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Water and Atmospheric Conditions in Earth prehistory

I pose this question as a curious enthusiast lacking formal education in chemistry or Earth sciences. My intrigue has been kindled by various articles and discussions and while I may not be certain of ...
user51552's user avatar
0 votes
1 answer
146 views

grib_to_netcdf: error while loading shared libraries: libnetcdf.so.11: cannot open shared object file: No such file or directory

I am trying to download CAMS data from CDS and the error in the header is printed. If I understand well a necessary file is missing from my conda environment. (I am working in a cluster with CentOS 7)....
Dimitris Tsiaousidis's user avatar
2 votes
1 answer
66 views

Where can I obtain the raw atmospheric data that weather forecast images are based on?

There is a lot of weather forecast data available online, such as this one https://www.wetter3.de/animation_dt.html But as a student, where do I get according raw GFS data instead of images to do my ...
MichaelW's user avatar
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1 vote
1 answer
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What would Earth's atmosphere be like today if life had never existed on it?

I'm also interested in understanding the mechanisms that affect what happens to the various gases in the atmosphere over time. That is, do they get locked away in minerals, stay in the atmosphere, or ...
phil1008's user avatar
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3 votes
0 answers
52 views

What is the correct velocity to calculate propagation speed of a Rossby Wave?

Rossby Waves have different phase- and group velocities. For a pure zonal wave with wave number k they are $$v_p=\overline u - \frac{\beta}{k^2}$$ $$v_g=\overline u + \frac{\beta}{k^2}$$ So group ...
MichaelW's user avatar
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4 votes
1 answer
185 views

Shouldn't the permanent snow line be considerably higher in the Alps and on Mt Hood if temperature falls 6.5°C per 1000 meters?

The permanent snow line in the Alps is around 10,000 ft (3,000 m) elevation. This was further confirmed by a passenger flight I took late June where the screen showed 0°C (freeze point) around 10,000 ...
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3 votes
0 answers
55 views

How to explain "Vacuum Cleaner Effect" for upper level PV anomaly?

In Jonathan Martin's Book "Mid-Latitude Atmospheric Dynamics" there is a chapter dedicated to anomalies of potential vorticity (PV). The scenario shown in the image below depicts a situation,...
MichaelW's user avatar
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0 answers
34 views

How to use CMIP6 to predict windspeed in the future?

I'm very new to climate modelling and forecasting, I have chosen a project to forecast wind energy output in the future using wind speed prediction, I wish to use CMIP6 to predict. But I have very ...
Phil's user avatar
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2 votes
1 answer
35 views

Estimate EPW AMY parameters from HRRR Analysis

I am working to create Energy Plus Weather (EPW) Actual Meteorological Year (AMY) files from NOAA HRRR Model analysis. The provided links detail the 35 parameters required for the AMY model and ...
J Edward Hammond's user avatar
4 votes
0 answers
48 views

Why positive PV Anomaly moves westwards?

In Jonathan Martin's Book "Mid-Latitude Atmospheric Dynamics" there is a chapter about PV anomalies. As an example, a positive PV anomaly is discussed. What is the reason, that high PV is ...
MichaelW's user avatar
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3 votes
0 answers
60 views

What is the deeper difference between QG Omega equation and QG Height tendency equation?

The quasi-geostrophic $\omega$-Equation is a diagnostic equation for $\omega$ (=dp/dt = vertical motion) in terms of geopotential. It is derived in a few steps by manipulating vorticity and ...
MichaelW's user avatar
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1 vote
0 answers
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Comparing expressions for Ertel Potential Vorticity and Quasi Geostrophic Potential Vorticity

In Meteorology there is a quantity called "Ertel Potential Vorticity" $q_e$ which is conserved considering isentropic flow ($\theta=const)$: $$\frac{d}{dt}\left(\frac{1}{\rho} \vec \eta \...
MichaelW's user avatar
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0 answers
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Setting specific humidity vertical profile in an LES

I am working with an LES (Large-Eddy Simulation) model, and I want to define the vertical profile of specific humidity (qt) based on a given temperature profile (thl). However, I am not sure how to ...
bowserilis's user avatar
3 votes
1 answer
88 views

Why is one term missing in the derivation of continuity equation in isentropic coordinates?

In the book by Jonathan E. Martin "Mid-Latitude Atmospheric Dynamics - A First Course" the continuity equation for isentropic coordinates is derived by applying conservation of mass: $\...
MichaelW's user avatar
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1 vote
1 answer
60 views

Why is mixing ratio at LCL not the same as for starting condition?

I asked a question regarding mixing ratio and wet adiabatic lifting in https://stackoverflow.com/questions/76244447/why-is-mixing-ratio-at-lcl-not-the-same-as-for-starting-condition. I don't want to ...
MichaelW's user avatar
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4 votes
1 answer
69 views

Is equivalent potential temperature constant also for dry adiabatic processes?

Equivalent Potential Temperature, defined as $$\theta_e = \theta \cdot e^{qL/c_pT}$$ with $\theta$ denoting potential temperature and q the specific moisture of water remains constant for wet ...
MichaelW's user avatar
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4 votes
0 answers
85 views

Why atmospheric temperature lapse rate doesn't have a discontinuity at 0°C when ice is formed?

When trying to calculate the adiabatic lapse rate of moist air based on known values of basic thermodynamic properties of the constituents (ice, water, vapor,...) I came to the following question: ...
MichaelW's user avatar
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3 votes
1 answer
67 views

Why is latent heat of water vapor included in specific enthalpy of moist air?

In a lecture book we read about latent heat of moist air. I would have guessed, that the total specific enthalpy of moist air, comprised of $m_d$ kg of dry air and $m_v$ kg of water vapor is (we have ...
MichaelW's user avatar
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1 vote
0 answers
70 views

Which way is the more computationally efficient for running WRF-Chem with one way nesting: (a) by setting feedback to '0' or (b) using ndown.exe?

I want to run WRF-Chem with one-way nesting because of the limitations of my system (a linux server with 378 GB of RAM and 32 processors). I have gone through the WRF user guide, which explained how ...
Ankan's user avatar
  • 31
4 votes
1 answer
152 views

Do I understand pressure coordinates in the right way?

The question is simple: I still have problems with atmospheric pressure coordinates: Given the pressure dependence in the picture, what are the velocity coordinates of an air parcel moving with $\vec ...
MichaelW's user avatar
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3 votes
0 answers
62 views

How is Wind oriented in a Jet Streak?

Recently I found this tutorial video about Jet streaks (want to mention I'm only in second term so my knowledge is not advanced yet). Originally I was looking for the topic because of a particular ...
MichaelW's user avatar
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4 votes
1 answer
61 views

How to estimate altitude of tropopause of other planets?

Is it possible to come up with a formula to estimate the height of the tropopause and the upper layer lapse rate only based on atmospheric composition and other atmospheric parameters (not relying on ...
Redirectk's user avatar
  • 272
2 votes
1 answer
98 views

Why are there different Notations of Vorticity Equation?

I'm a student of meteorology in first year. This time my question is not about a particular problem I have, but rather about teaching and learning: In a recent lecture on atmospheric dynamics we ...
MichaelW's user avatar
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2 votes
0 answers
96 views

Moist adiabatic lapse rate

I asked this question in the Physics SE but it still lies unanswered. Hopefully Earth Science SE is more knowledgeable in the matter. Wikipedia gives the following equation to calculate the moist ...
Redirectk's user avatar
  • 272
3 votes
1 answer
97 views

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 ...
MichaelW's user avatar
  • 935
2 votes
1 answer
57 views

How can speed of geostrophic wind change when forces are always perpendicular to speed?

Equation for acceleration of an air parcel is $$D \vec U/Dt = -2 \vec \omega \times \vec U -\frac{1}{\rho} \vec \nabla p + \vec g$$ Now, for geostrophic wind, U is parallel to the contour lines of ...
MichaelW's user avatar
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2 votes
1 answer
54 views

What does the index "p" mean in the gradient of geopotential in pressure coordinates?

Currently I hear a series of tutorial videos on atmospheric dynamics as a first starting preparation for reading more detailed material, such as Holton. In particular I refer to this part: https://www....
MichaelW's user avatar
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4 votes
0 answers
115 views

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 ...
MichaelW's user avatar
  • 935
7 votes
1 answer
1k views

What is the atmospheric pressure at the deepest point of the Kidd mine?

At 2735 m (8973 ft) below sea level, the Kidd mine reportedly has the deepest non-marine point of the Earth's surface (since the Kola borehole is sealed). I wonder what the pressure down there is, as ...
Giovanni's user avatar
  • 175
2 votes
0 answers
64 views

Why is the quantity "Geopotential" important in meteorology?

So far I understood, geopotential $\Phi$ is just defined by $$\vec \nabla \phi = \vec g$$ But because g can be taken to be constant within troposphere, it is nothing but $$\Phi(z) = g \cdot z + C$$ So ...
MichaelW's user avatar
  • 935
3 votes
1 answer
205 views

How is centrifugal force identified in equations of fluid motion in the rotating reference system of earth?

I spent already days on the following: In one of my meteorology scripts the equations for conservation of momentum in the rotation reference system of earth are given by: The apparent forces are in ...
MichaelW's user avatar
  • 935
2 votes
0 answers
39 views

Which atmosphere model(s) put the upper end of the tropopause isothermal layer at 25 km and why?

The International and U.S. Standard atmospheres have a layer between 11 km (36,000 ft) and 20 km (66,000 ft) where the temperature is constant with altitude. This includes older versions of the U.S. ...
Why On Earth's user avatar
1 vote
1 answer
101 views

divergence of static stability identical parameters

All, The static stability of the atmosphere is defined as: $\sigma =-\dfrac{T}{\theta} \dfrac{d\theta}{dp}= \dfrac{dT}{dp}-\dfrac{R}{c_p} \dfrac{T}{p}$ where: $T$ is temperature, $P$ is pressure, $R$ ...
Kernel's user avatar
  • 111
4 votes
1 answer
75 views

Where does this refractive index formula come from: $n_{1} = n - 1 = \frac{77.6P}{T} 10^{-6}$

In this equation, $n_{1} = n - 1 = \frac{77.6P}{T} \cdot 10^{-6}$ the variable P is the total air pressure and T is expressed in Kelvin. This equation describes the refractive index of moist air as EM ...
Electrolyte's user avatar
1 vote
0 answers
28 views

What does the refractive index static coefficient measure and how is it derived?

From my understanding the refractive index structure coefficient $C_{n}^2$ measures atmospheric turbulence, but I'm not entirely sure as the literature seems to imply that there are slightly different ...
Electrolyte's user avatar
1 vote
3 answers
1k views

Python, R or etc.? [closed]

I was wondering which programming language is most used in the geosciences? I have now started programming with Python but I am reading more and more about R! I would like to ask the experienced ...
Weiss's user avatar
  • 2,003
4 votes
2 answers
113 views

Estimating meteorological visibility from air chemical and particulate composition

I have found here an answer that provides formula that only takes into account vapors, pressure and temperature - What is the formula used for atmospheric visibility? Is there an approach that also ...
Fima Rotter's user avatar
5 votes
1 answer
69 views

Clarification of dry deposition of particles

I found a formula for the dry deposition speed of particles and an electric circuit analogy to go with it. I would like some clarification on this figure: I'm mostly interested in the top right ...
theWrongAlice's user avatar
4 votes
1 answer
155 views

A problem of the 2-Layer hydrostatic model

The 2-layer hydrostatic model is like this And the pressure of the two layers and the top are and it is easy to find the horizontal gradient of $p_1$ and $p_2$ \begin{equation} \begin{aligned} \nabla ...
 Hou's user avatar
  • 103
3 votes
1 answer
141 views

Why does the Earth's atmosphere appear to no longer follow the curvature beyond the terminator line?

I had noticed this on Google Earth and Celestia already. Here's an image from the ISS: As you can see on the horizon, at the terminator the atmosphere doesn't seem to follow the curvature any longer ...
Giovanni's user avatar
  • 121
5 votes
0 answers
82 views

Retrieve surface values in hybrid sigma cordinate system

I need to retrieve surface values of a parameter in high mountainous region that are in hybrid sigma coordinate system. From what I have understood, hybrid sigma coordinate has three layers in the ...
Mala Pokhrel's user avatar
9 votes
0 answers
217 views

How to convert units of averaging kernel from DU/DU to ppbv/ppbv

For validation of model data, I want to compare the ozone data from model to the satellite results downloaded from the following link: The satellite data are in DU(Dobson Unit) while the model data ...
Mala Pokhrel's user avatar
2 votes
1 answer
54 views

Can historical emissions data be used for a future WRF-Chem model run?

I am new to running the WRF-Chem model, so this question maybe a little elementary. I wanted to perform an year-long simulation of certain chemical species for 2019 and for that, is it sufficient to ...
Sujai Banerji's user avatar