Questions tagged [models]

A tag for questions about conceptual, analytical or numerical models used in Earth science disciplines.

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8
votes
3answers
325 views

Understanding the Mercator Projection

To illustrate my problem, let's say I have lattitude and longitude coordinates, such as 38.871105, -77.056042. I want to be able to calculate the new lattitude and longitude if, say, I moved 300m ...
3
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1answer
38 views

Run Hydrus-1D from the command line

Hydrus-1D, is a modeling environment for analysis of water flow and solute transport in variably saturated porous media. This program has a graphical environment which works very well, however a lot ...
3
votes
0answers
17 views

what is a sensitivity analysis in heavy rain 2D surface / 1D drainage network models

For my thesis, the lecturer proposed to make a "sensitivity analysis" with a 2D surface model connected with a 1D drainage Network model for a storm rain event. However, I'm having problems to figure ...
3
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2answers
93 views

Do tectonic plates “float” over the mantle and “collide” like icebergs?

I'm always hearing about tectonic plates as large chunks of crust floating on the mantle just like boats. In timescales of millions of years they move and even collide. But I'm starting to think this ...
2
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0answers
38 views

ERA-5 data downloader… other than CDS-API?

The CDS API does not behave well on our machines. Has anyone had any luck scripting their own ERA-5 reanalysis large-data download script? Perhaps something that is not nearly as large, clunky, and ...
1
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1answer
21 views

Modelling extreme rainfall events: 'blanket approches' when considering soil infiltration

For my thesis on modelling an extreme rainfall event with a 2D surface runoff model I'm supposed to consider the effect of soil infiltration on the runoff: In my work description it says I'm supposed ...
2
votes
2answers
117 views

Why rely on climate models as opposed to paleoclimate data?

Something I hear often from climate scientists, and indeed even politicians, is that we "don't understand climate change very well". And, I'm sure this is true since the climate is a complex adaptive ...
1
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1answer
87 views

Effects of Centrifugal Force on Gravity Vectors?

I've been asked this question twice now from our favourite science denying community, and I don't know how to parse it. I can do centrifugal force and gravity given mass, but have never tried to even ...
1
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1answer
34 views

Community change along urban rural gradient

I was wondering whether someone has an idea about how to investigate community changes of plants/animals along an urban-rural gradient? I have a large data set consisting of plant/animal abundance and ...
2
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1answer
59 views

How reanalysis data influence our research/results?

I am a student and I have a very simple and yet important question about reanalysis data. Recently, I attended a workshop where various other students discussing the use of ERA5 reanalysis data on ...
1
vote
2answers
54 views

Is there a general equation to know how big of an area is affected by an earthquake?

If you visit USGS earthquakes listing, you get 3 points of information for each earthquake: Location, depth, magnitude. My question is, is there a way to approximate how big of an area is affected? ...
2
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2answers
49 views

What does slat and elat (slon, elon) in latitude and longitude values mean?

I have data from the national storm prediction center that is marked with values of : elat slat elon slon ...
0
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0answers
44 views

Caspian Sea oil deposits

Azerbaijan appears to have vast development in its oil sector. Images on google earth show oil platforms connected by road ways far out into the Caspian Sea of the coast of Baku. Why is the majority ...
0
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1answer
68 views

Can living where magnets are abundant provide a mini-magnetoshere?

Are there a mini-magnetosphere within the magnetosphere similar to mini-magnetosphere found on the Moon? Is there a map of these areas that would resemble the white swirls in the picture below? The ...
0
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0answers
99 views

Moisture flux convergence/divergence calculation in Grads

I want to calculate moisture flux divergence/convergence in 850 hpa for the summer and I have monthly mean gridded data sdfopen shum.mon.mean.nc sdfopen uwind.mon.mean.nc sdfopen vwind.mon.mean.nc ...
2
votes
1answer
79 views

What types of high-level mathematics are useful in doing climate modelling/meteorology?

I'm aware that PDEs, linear algebra, numerical analysis and such are staples of most applied mathematical endeavors. I want to know if there are other areas of "higher" mathematics that have useful ...
2
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2answers
113 views

Why doesn't Wolfram Alpha show low gravitational acceleration for the Hudson Bay?

I thought I would be clever and add a new answer to Hudson Bay Has Low Gravity? by using Wolfram Alpha to report gravitational acceleration for different locations, but it looks like my cleverness ...
1
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0answers
55 views

Does tropical rain forest as defined by the Holdridge Life Zone classification exist in any meaningful prevalence?

I've been recently introduced to the Holdridge life zones and their method of classification, and have been somewhat concerned/confused by the definitions of tropical rain forest as described by the ...
7
votes
2answers
190 views

Debunking weather conspiracy with statistics - why does temperature rise then fall for last weekend in June in recent years

I have a conspiracy-prone friend who believes that people are controlling the weather to ensure good weather for a large, annual festival (last weekend in June in San Francisco). As a scientist, (not ...
0
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0answers
16 views

Do snow and ice have different temperatures at their interface?

tl;dr: For snow on top of ice, is the temperature at the base of the snowpack always (practically) the same as the temperature at the top of the ice? I was trying to understand how the thermodynamics ...
2
votes
1answer
89 views

Which ocean is going to be swallowed by the Supercontinent Cycle, Atlantic or Pacific?

The register shows several supercontinents have been formed on Earth's History: "The most recent supercontinent, Pangaea, formed about 300 million years ago (0.3 Ga). There are two different ...
2
votes
1answer
90 views

How can I create multi model ensemble from output of 3 CMIP5 models?

I have a output of 3 models of CMIP5, they are CCSM4, IPSL and MPI. I have two scenarios RCP 2.6 and RCP 8.5 for each model. I want to know that how can I create a multi model ensemble from these 3 ...
2
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0answers
59 views

Do any of the ECMWF ensemble forecasts have the associated true values?

I am looking for a dataset of ensemble forecasts and the associated true observed values. For example, a dataset containing $n$ ensemble forecasts of the temperature in 24 hours and the observed ...
1
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0answers
20 views

Model impact of atmopsheric circulation changes on precipitation dD of a region

I'm looking to model the impact of broad scale atmospheric circulation changes on the hydrogen isotope ratio of precipitation for a given region. As an example, what impact does a high pressure system ...
1
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0answers
20 views

Glen's power-law alternatives

For glacier models, there exist alternatives to the Glen's power-law? I searched on internet, but I have not found other alternatives.
2
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2answers
122 views

Modelling sea levels with gravitational parameters

Are there any publicly available programs or source code for modelling global (or local) changes in sea level which include parameters for gravitational tidal effects? I have a physics background, ...
5
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3answers
2k views

What are the domains of Earth Science?

Increasingly confused by all the "spheres" and agreed relationships between them. As a result, I am looking for a singular answer that clearly states at the very least what the top-level and secondary ...
1
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0answers
22 views

The DRASTIC groundwater vulnerability model and it's relevance today

I am reading a groundwater pollution vulnerability study by Mark Angle of the Ohio Dpet. of Natural Resources (ODNR) for my county. The model used to assess the groundwater vulnerability for the ...
13
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2answers
1k views

Model types: Robust diagnostic versus prognostic

I wonder whether someone knows a clear definition/description of 1) Robust diagnostic models Forcing with data from initial state aimed at future predictions? 2) Prognostic models Tie model ...
1
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0answers
33 views

Seeking CMIP5 or CMIP6 globally in .nc format

Is there in some ftp storage, a pre-processing CMIP5 data for direct download in netcdf extention?
3
votes
0answers
102 views

Difference between GDAS and GFS data

What is the exact difference between GFS 0.25 and GDAS 0.25 data which is available in http://nomads.ncep.noaa.gov/. And are the GFS 0.5 and 1 degree data available in the above url and here the same?...
4
votes
1answer
185 views

Coupling recharge with 1D groundwater flow model

Suppose we are modeling 1D groundwater flow in an aquifer of extent $x$ from $A(x=0)$ to $C$. Lets say for unsteady state conditions, the input is at $A(x=0)$, we can model piezometeric response at $B ...
1
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0answers
22 views

What's the difference between “loading” and “receiving” in water quality modeling?

I see some models described as simulating 'receiving water quality' and others as 'pollutant loading' models. What is the difference between loading and receiving models in this context? I am more ...
5
votes
2answers
149 views

Comparing Pros and Cons of SWAT and HSPF

To model hydrology in a watershed, two of the most famous and widely used distributed models are SWAT and HSPF. I have some good understanding of HPSF, but I don't know when and why should one prefer ...
3
votes
0answers
47 views

Simple numerical model of tide with an elliptic scheme

I have recently been given the task of developping a coastal model for tides. I have a few requirements, it must not be time stepping in order to be as fast as possible and in finite differences ...
3
votes
0answers
18 views

Statistical dependence of mean annual soil evaporation and mean annual precipitation globally

I am studying a simple dynamical system that represents a plant and water system, similar to Klausmeier. In Klausmeier model the mean annual precipitation and the soil evaporation are introduced as ...
5
votes
1answer
117 views

What's the difference between these most basic, first-order models for estimating runoff?

There are a lot of variations of basic, first-order hydrology models to estimate runoff from rainfall with a few other parameters. From what I can tell, most very basic rainfall-runoff models use one ...
2
votes
0answers
48 views

Internal energy, enthalpy, and work in the atmosphere

I'm writing a toy radiative-convective atmospheric model and need to relate the heat flux convergences (either surface sensible heat flux or the radiative flux) to changes in atmospheric layer ...
3
votes
0answers
102 views

Do 360 day calendars affect climate models?

I was recently reading Zach Holman's blogpost on time and remembering that I've had to work with CMIP5 output that used a 360 day calendar, rather than a 365 day or a Greogrian (or Proleptic Gregorian)...
3
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0answers
1k views

Moisture flux convergence in GrADS

I want to calculate vertically integrated moisture flux convergence (VIMFC) in GrADS. But when I give the following instruction it marks me errors: ...
2
votes
0answers
53 views

The difficulties for the simulation of atmospheric metals

Atmospheric metals usually reside in aerosols with complex source origins. The concentrations distribution of metals especially for those with high toxicity (Pb, Cd, Ni, V) should be informative for ...
6
votes
1answer
223 views

Seismic migration concepts

In Dr Hua-Wei Zhou's book Practical Seismic Data Analysis (2014), he includes and explains figures from previous classic works (i.e. Schneider, 1971) in order to describe migration from a fundamental ...
5
votes
1answer
2k 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 ...
10
votes
3answers
591 views

How to run earth system, land surface and climate models?

I am interested in earth system models, land surface models and climate prediction models. I found a lot of online information on different models, including CIMP5, and the Earth System Modeling ...
5
votes
1answer
79 views

Nonlinear Stokes equations for glacier modeling

What is the difference between $$\operatorname{div}(-\mu(u)\nabla u+pI)=f\tag{1}$$ and $$\operatorname{div}(-\mu(u)(\nabla u\color{red}{+(\nabla u)^\mathsf{T}})+pI)=f\tag{2}$$ from the physical ...
1
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0answers
36 views

Watershed scale water quality indices

I understand water quality indices play a fundamental role in modelling water quality as they integrate multiple water quality parameters to bring about a single dimensionless digit that represents ...
8
votes
1answer
136 views

How to model bed load transport in channels of non-rectangular cross sections

All the formulas presented in the relevant technical literature refer to channels of rectangular cross section — the formulas assume a constant depth of flow right across the channel section. I need ...
8
votes
1answer
716 views

Are we now and/or have we been in the RCP8.5 scenario?

Is it generally understood that we (globally) have been living in an RCP8.5 scenario over the past 7-8 years? Such that a predictive climate model using RCP8.5 assumptions that was run circa 2011 can ...
9
votes
5answers
895 views

Correct phrase for a 'forgetful' natural system?

This is a rather general question: assume I have a system that has a certain 'forgetful' property, which means that while I can offset its current state for a moment, it will eventually return to its ...
3
votes
1answer
146 views

Wavewatch III data

I need to simulate some ocean data on the south coast of France, near to Marseilles. Ideally I am looking for parameters such as wind direction, wind speed, significant wave height, peak wave period ...