Questions tagged [atmosphere-modelling]

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2answers
278 views

Is there an atmospheric data database somewhere on the web?

For a personal project, i wanted to develop a global atmospheric database, to compile data like wind speed and direction, temperature, etc. from different sources. My question is this : Does such a ...
4
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1answer
806 views

How to properly setup a domain in NWP model (WRF) according to meteorological input data

I want to setup a mesoscale weather prediction model (WRF or something else) to work with NCEP/GFS meteorological input data with resolution of 0.25deg. My question is how to choose a proper size for ...
7
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3answers
614 views

Correlation and causation

Linear correlation (Pearson's) is vastly applied in meteorology/climatology to assess the relationship between two variables, say precipitation and SST, for example. However, we know that correlation ...
6
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1answer
101 views

Does thermal bubble initiated in WRF dissipate over time?

I am running idealised supercell simulation using WRF model. The supercell storm is initiated with a thermal bubble. I just wonder if the thermal bubble is only affecting the initial temperature. I ...
3
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0answers
62 views

Equation for Atmospheric Pressure Tide

Using Pressure sensors - I found out that there is a daily pressure wave-like pattern with peaks at 9:00 & 21:00 (local time). I want to construct an equation to explain this phenomena, probably ...
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0answers
540 views

SIGINT error WRF

I am trying to run WRF 3.8.1 using ncep2 but after a while the run stops and I get following error: ...
6
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1answer
1k views

Why is WRF-Chem not reading my emissions data?

I've been trying to run WRF-Chem with my emissions but they are not being read by WRF-Chem. RADM2. I have emissions for the whole week, so io_style_emissions = 2 ...
3
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2answers
2k views

How to interpret the values of moisture flux convergence?

I have a time series of moisture flux convergence. The values show positive and negative. What are these positive and negative values say? Can somebody help me how to interpret it? How it is related ...
9
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2answers
2k views

How to compute du/dx and dv/dy in moisture flux convergence?

I have $u$-wind, $v$-wind and specific humidity. I would like to compute moisture flux convergence at a grid point. So I need to compute the value of $q(\frac{du}{dx} + \frac{dv}{dy})$ My question is ...
5
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1answer
3k views

Running WRF with ECMWF GRIB2 model levels

ECMWF model data comes in a hybrid GRIB format, that is, model level output is stored in GRIB2 messages, whereas surface data still uses GRIB1 format. Ungrib is unable to understand this hybrid GRIB ...
6
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2answers
86 views

Does hydroxyl radical chemistry in air quality models create numerical stability problems?

Atmospheric mixing ratios of the hydroxyl radical have relatively short lifespans (on the order of microseconds). When modeling air quality or the weather, the time step is usually much larger than ...
7
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3answers
1k views

Why are inversion layers so important in meteorology?

I keep hearing the term "inversion layer" when reading about pollution and meteorology. I know it vaguely amounts to "some place where the gradient of temperature is inverted". But why are inversion ...
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1answer
129 views

How can I implement a visualization of archived convective data from numerical weather models?

I've always found geographic visualizations of surface/mixed-layer CAPE models and other weather data to be incredibly interesting. Here's a map featured by the Capital Weather Gang over at the ...
3
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1answer
3k views

How does humidity vary with height in the Earth's atmosphere?

I am busy with the development of an "environment" model that can be used for flight simulation of all kinds of flight vehicles — ranging from quad-copters, unmanned aerial vehicles, manned aircraft, ...
2
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0answers
51 views

What would be characteristic time of the escape of an 1atm air (or oxygene atmosphere) from the Moon?

(related question) I am thinking on the Moon if it would have an oxygen atmosphere. What would be the characteristic time of its escape? Although the Moon has a much lower escape velocity as the ...
6
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1answer
114 views

What is the characteristic time of the loss of the Earth atmosphere, how can it be calculated?

Somewhere I've read it is in the order of some tens of billions of years, but unfortunately I can't find any reference with it in Google. I suspect, the losses are coming mainly from analyzing the ...
5
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0answers
100 views

Dig in the rationality of model evaluation of WRF with land-based station data

I use WRF (Weather research and forecasting) model for in regional scale meteorology simulation. And then, the WRF output files will be deemed as criterial input data applying for chemical transport ...
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3answers
341 views

Does finer input data lead to a better model accuracy?

Climate and chemical transport models all need input files including meteorology data, emission inventory, surface data (e.g. land use type) to initialize the simulation field. Take the case of WRF ...
9
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1answer
195 views

Why should dynamical downscaling of meteorological data be made incrementally?

When downscaling meteorological data by using limited area models, many support forums recommended you to downscale incrementally in small steps. For example let's assume that your input data is on a ...
2
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1answer
63 views

Interpolating Merra reanalysis

Merra re-analysis ara available for a coarser horizontal grid with resolution of 0.625 × 0.5 degrees providing differents parameters : Precipitation, Temperature ....This been said, I want to ...
3
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0answers
99 views

Correlation analysis with primary air pollutants and secondary formed ozone

The Ph.D dissertation Assessment of air quality in Northern China by using the COSMO-ART model in conjunction with satellite and ground-based data which was written by Stefanie Schrader in KIT German....
4
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0answers
275 views

How to transform the inventory data from degrees to kilometers

First all, my question was different from the question Converting grid resolution from degrees to kilometers. In chemical transport modeling, the pollutant source inventory was an essential input ...
5
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1answer
310 views

How does the tornado chaser locate the spot?

In my opinion, tornado is hard to forecast in three different aspects: The size of tornado is about 100 ~ 1000 m which can't be represented well in weather model or detected by limited weather ...
6
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2answers
897 views

Take all the CO2 in the atmosphere and put it into a layer on the surface of earth, how thick would the layer be?

I teach a Middle School (year 8) Geometry course and have a student attempting to answer this question. My assumptions: earth's radius is $3959 \text{ mi}$ earth is a sphere There is approximately $3 ...
4
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2answers
5k views

Interpolate Gaussian grids to regular fixed grids using bilinear interpolation?

I want to regrid GCM data available on Gaussian grids to regular grids, say at 1 deg X 1 deg. How to do this using CDO or Python ...
2
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0answers
101 views

Numerical methods for solving shallow-water equations with a source

What are the numerical methods used for solving shallow water equations (PDEs) with a mass source, at the synoptic scales of the atmosphere, if I have a finite east-west boundary (may be periodic wave ...
12
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1answer
2k views

Why is WRF most often configured at 3:1 nesting ratio?

In WRF application, nested domain has always been used for weather/air quality modeling for the place of interest in a better resolution. The figure below illustrates this: I have noticed that the ...
4
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2answers
298 views

Why does computation cost increase 24 times when the spatial resolution doubles?

In a Chinese book, I read about the relationship between the numerical model spatial resolution and the computation cost. It states: when the spatial resolution of model is finer, the result ...
2
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2answers
242 views

Data source of the planetary boundary layer (PBL)

PBL is one key physical quantities aimed at analysing the condition of air pollution in an area of interest. From WRF simulation, I can get the variable PBLH whixh ...
3
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1answer
3k views

Calculate precipitation from WRF model output

From WRF output file, I find 3 variables related to the precipitation (unit: mm) 1. Precipitation variable name: pr unit:$kg/(m^{2}s^1)$ variable: RAINC+RAINNC comments: $dt(...
10
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2answers
858 views

Technique to delete spin-up frames from WRF

I'm a user of WRF V3.5 aiming at meteorological simulation. Sometimes, I'll run the model for a long period. My attempt I split the long period(e.g 1 year) into serval short ones. For ...
3
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0answers
206 views

Pasquill-Gifford stability class data for one station

On my project, Stability classes is an useful tool to analysis the weather condition for one place. Using R Package Worldmet, I can get the hourly weather ...
9
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3answers
611 views

How bad is geo-engineering?

It is just curiosity that forced me to ask this question. At some point in time, if we can't control global $\sf{CO_2}$ emissions, temperature will increase until a tipping point and it will be a ...
1
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1answer
182 views

Is there a formula for heat retained by an atmosphere, based on density and composition?

I'm looking for a formula, either precise or an approximation (it's for a video game so it's ok to have somewhat rough numbers), that determines heat retained from the sun by an atmosphere, based on ...
3
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0answers
3k views

How to convert eta level to pressure level in WRF model

I am working WRF outputl file and require to extract wind and temp values at 850 hPa, 700 hPa and 500 hPa pressure levels. As the WRF vertical coordinates are based on eta level, I am having trouble ...
5
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0answers
135 views

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? ...
13
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1answer
2k views

What is the formula used for atmospheric visibility?

I am working on NCEP GFS data to plot various maps. One such plot I would like to have is visibility. I have seen some of the sites showing visibility charts and the source of the data was shown as ...
4
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0answers
85 views

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 ...
5
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1answer
175 views

Why are "ground level" air quality monitors really on rooftops?

There are many papers that talk about the air quality at ground-level in cities, observed by air quality monitors. Some monitors are located above the building(not actually on the ground). For ...
10
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1answer
270 views

What principles do we consider when selecting an air pollution monitor location?

I'm working on a project aiming at finding some potential point as a new air pollutant monitor site for a city to measure $SO_2$, $NO_2$, $PM_{2.5}$, etc. After modeling the surface concentration of ...
8
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3answers
807 views

What exactly is a model grid?

I have just begun reading some notes about modelling and can't seem to understand what a 1°x1° grid or a 2.5° grid or 1/4° grid is. I know it is something related to the resolution of the area over ...
8
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0answers
202 views

Modeling swirling storms

I'm looking to demonstrate the rotational behaviour of swirling storms with a numerical simulation. So far it includes pressure-gradient, Coriolis acceleration, frictional forces and the acceleration ...
6
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2answers
2k views

Historical NWS GFS forecast data

The National Weather Service (NWS) makes the results from its Global Forecast System model (GFS) available for download as GRIB2 files. While accessing current (or recent) forecasts is straight-...
2
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1answer
286 views

Why is radiation and total precipitation not available in ERA Interim Reanalysis at step 0?

ERA Interim reanalysis http://apps.ecmwf.int/datasets/data/interim-full-daily/levtype=sfc surface level variables such as radiation and precipitation, but also many others, are only available at time ...
3
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1answer
113 views

Quantitative mapping of air pollution Sifakis and Paronis

I am reading this paper about deriving AOT and I have found this ...
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0answers
84 views

Spatial variability in ocean surface winds

For the near-surface winds over the ocean, many model products and satellite footprints have spatial resolutions on the order of tens of kilometers. I'm interested in knowing how much the winds (both ...
6
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2answers
787 views

What is the meaning of step in ERA reanalysis data?

The webpage to download ERA data includes an option called "time" which is intuitive, but also an option called "step". I can't find an explanation of the meaning of this. It can't be a time step ...
7
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1answer
420 views

How will global warming affect climate systems like the ENSO or the MJO?

How will global warming influence climate systems such as the Madden–Julian Oscillation (MJO) or the El Niño Southern Oscillation (ENSO)?
5
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1answer
738 views

What is the height above ground of NCEP/NCAR Reanalysis 1 variables?

I am confused regarding the height above ground of this data set. http://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.html I have to reprocess this data set and need to know this piece of ...
6
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1answer
986 views

Specific humidity range in tropical lowlands?

I am running a land biosphere model that uses meteorological data as drivers. The model has a threshold of 32g/kg for specific humidity. The data I am using taken from a reanalysis performed by J. ...