# Questions tagged [atmosphere-modelling]

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### 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 ... 47 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,...
32 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 ...
28 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 ...
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 ...
47 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 ...
1 vote
20 views

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### 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 ...
37 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. ...
1 vote
85 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, $R$ ...
73 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 ...
1 vote
20 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 ...
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 ...
111 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 ...
64 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 ...
147 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 ...
133 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 ...
72 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 ...
184 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 ...
51 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 ...
410 views

### Is spin-up really required to run the WRF-Chem model and if so, what determines the time period of the spin-up?

For example, I am interested in making a simulation for some chemical species for 2019. I am planning to provide NCEP/GDAS FNL meteorological data at 0.25 degree and CAM-Chem chemical boundary layer. ...
1 vote
92 views

### Tornado prediction or forecasting by supercomputers [closed]

Can tornadoes be predicted or forecasted using supercomputers?
49 views

### What is the atmospheric percentage of oxygen produced by trees and phytoplankton every year?

I know that every year carbon sinks remove ~20Gt of CO2 (about half of our emissions), and release a comparable amount of O2 , But I want to know how much O2 the carbon sinks produce annually ...
134 views

### How to convert $\ce{NO2}$ mixing ratio (ppmv) into $\ce{NO2}$ column density(moles/m2)?

I have a WRF-chem output with NO2 mixing ratio for 37 levels, for my analysis I need to convert it into into column density. How do I do that?
93 views

### Nobel prize Manabe's 1967 code for solving the 1D atmospheric thermal equilibrium model

Does someone know where to find a (hopefully modern) version of the numerical code for solving the 1D atmospheric thermal equilibrium model, the one Syukuro Manabe & Richard T. Wetherald used in ...
78 views

### Would the atmosphere move rigidly with ground if you ignored wind?

I know this sounds basic but I've wondered about this for a long time and I'm still confused. In aviation, air speed is ground speed minus wind speed. If wind speed is zero, air speed equals ground ... 67 views

### Climate on Venus after it becomes tidally locked

Suppose, Venus becomes tidally locked. Will its dark side cool enough so that the CO2 from atmosphere to precipitate in liquid form to make an ocean?
34 views

### Difference in values if the source region lies outside or within the nested grid domain with boundary conditions from coarser resolution

I want to see the anthropogenic influence of one region(source) to another region(receptor). I would be conducting nested grid simulation. But, the nested grid simulation will be limited to receptor ...
522 views

### Meaning of ECMWF model levels

I am trying to understand the actual meaning of the ECMWF L137 model levels. In the link I provided, both pressures (in hPa) and heights (in m) are given for every level. But which actually defines ...
167 views

### 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 ...