Questions tagged [atmosphere-modelling]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
2
votes
0answers
46 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 ...
5
votes
1answer
82 views

What is the characteristical 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
votes
0answers
96 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 ...
11
votes
3answers
319 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
votes
1answer
169 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
votes
1answer
60 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 ...
7
votes
1answer
361 views

What's the prospect of air quality forecasting based on machine learning?

Air quality forecasting models which are useful for atmospheric scientist and government can be built based on numerical theory or statistic theory. The first approach outline the basic physics ...
3
votes
0answers
98 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
votes
0answers
239 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
votes
1answer
297 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
votes
2answers
748 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
votes
2answers
4k 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
votes
0answers
100 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
votes
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
votes
2answers
230 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
votes
2answers
227 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
votes
1answer
2k 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
votes
2answers
754 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
votes
0answers
188 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
votes
3answers
579 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
vote
1answer
120 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
votes
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
votes
0answers
128 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
votes
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
votes
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
votes
1answer
149 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
votes
1answer
259 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
votes
3answers
643 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
votes
0answers
201 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 ...
4
votes
2answers
1k 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
votes
1answer
284 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
votes
1answer
110 views

Quantitative mapping of air pollution Sifakis and Paronis

I am reading this paper about deriving AOT and I have found this ...
6
votes
0answers
78 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
votes
2answers
669 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
votes
1answer
418 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
votes
1answer
609 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
votes
1answer
887 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. ...
4
votes
1answer
2k views

How do I convert Relative Humidity into specific humidity [duplicate]

I am using NCEP_DOE reanalysis 2 data set. It include only relative humidity while I need specific humidity. How do I convert the relative humidity into specific humidity?
3
votes
1answer
152 views

Meaning of “Objectively analyzed”

I've found that there may possibly be many meanings of "objectively analyzed" and "objective analysis" in modeling and data assimilation. What are some of the accepted meanings?
12
votes
1answer
1k views

Numerical weather forecasting - resources for a programmer?

There is a community wiki question over at A good book or source for climate science and meteorology basics? that talks about meteorology basics. Building on that, but with a slightly different focus,...
8
votes
2answers
306 views

The climatological variance of albedo, soil moisture in weather models

Looking at WRF currently but I am sure this applies to most weather models there is a file (specifically LANDUSE.TBL) that specifies USGS derived albedo, soil ...
5
votes
0answers
190 views

Bulk and dynamic viscosity in the atmosphere

I'm studying the physics of the atmosphere but I'm struggling with the matter of viscosity (Navier-Stokes equation) for gravito-acoustic waves. From Landau-Lifschitz : $$ (T)_{ij} = -p\delta_{ij} + \...
7
votes
0answers
118 views

Shallow water height as vertical coordinate

In atmospheric physics we use often a variety of vertical coordinates, $z$ the height above some reference surface, or $r$ as distance from the planetary center. However sometimes it simplifies the ...
4
votes
1answer
518 views

How much do anthropogenic carbon aerosols (soot) affect the atmospheric radiation budget?

Anthropogenic carbon or black carbon (BC), particularly soot, is a product of many human activities, a major one being incomplete combustion of hydrocarbons. The occurrences of soot are mainly in ...
7
votes
1answer
121 views

What causes the semi-annual mesospheric meteoric potassium variability?

In a recent study presented in the article First global observations of the mesospheric potassium layer (Dawkins et al. 2014), space-borne resonance fluorescence observations confirmed previous LIDAR ...
12
votes
2answers
237 views

What atmospheric radiative effects, if any, do contrails cause?

First of all, this question is not about the conspiracy theory based chemtrails as in the linked question, from the answers there and from the question Equation for predicting contrail formation I ...
16
votes
2answers
3k views

Why is aerodynamic resistance defined inversely?

When I think of wind resistance, I always think of the friction co-efficient, in $\mathrm{ms^{-1}}$, because that's always the way that it was presented in highschool and undergraduate physics. But ...
21
votes
1answer
686 views

Significant difference between averaged wind speeds and averaged wind power density, for wind generation modelling?

Climate models outputs, particularly the reanalysis datasets, output wind speeds as zonal and meridional averages for the modelled time period (typically 1, 3 or 6 hours). So we get a 2-dimensional ...
3
votes
0answers
87 views

Is the number of high/low pressure regions different at low pressure levels at high pressure levels?

Is there a higher number of mid-latitude high/low pressure regions at 850 mb, as compared to the number of high/low pressure regions at 200 mb? And if so, why?
13
votes
1answer
201 views

How do Kelvin waves determine surface temperature variations?

Kelvin waves are basically waves that balance out the Coriolis force against topographic boundaries like coastlines and mountains. It seems very important in the oceans, for example. My question is ...

1
2