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This tutorial explains how to use the FLEXPART Lagrangian dispersion model within Metview

Excerpt


Note
titleRequirements

Please note that this tutorial requires Metview version 5.0 or later.

Preparations

First start Metview; at ECMWF, the command to use is metview (see Metview at ECMWF for details of Metview versions). You should see the main Metview desktop popping up.

The icons you will work with are already prepared for you - please download the following file:

Panel
titleDownload

flexpart_tutorial.tar.gz

and save it in your $HOME/metview directory. You should see it appear on your main Metview desktop, from where you can right-click on it, then choose execute to extract the files.

Alternatively, if at ECMWF then you can copy it like this from the command line:
    cp -R /home/graphics/cgx/tutorials/flexpart_tutorial ~/metview

You should now (after a few seconds) see a flexpart_tutorial folder. Please open it up.

The input data

The input data is already prepared for you and is located in folder 'Data'. You will find a FLEXPART Prepare -old icon that was used to generate the data in folder 'Prepare'. The corresponding macro code can also be found there.

You do not need to run the data preparation. However, if you wish to do so please note that it requires MARS access and you must set the Output Path parameter accordingly.

Tutorials

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DRAFT

How to prepare FLEXPART input data?

How to run FLEXPART?

To run a FLEXPART simulation you need to use the FLEXPART Run icon.The simulation itself requires:

  • input meteorological fields
    These can be generated for FLEXPART using the FLEXPART Prepare icon or with an external application.
  • the FLEXPART executable
    At ECMWF it is centrally installed and does not need to be specified in FLEXPART Run. For a custom-build executable or at other sites please follow the instructions in FLEXPART setup.
  • some FLEXPART resources
    FLEXPART needs a set of files to carry out a simulation: IGBP_int1.dat, OH_7lev_agl.dat, surfdata.t, surfdepo.t. At ECMWF these are centrally installed and do not need to be specified in FLEXPART Run. At other sites please follow the instructions in FLEXPART setup.
  • setting the SPECIES to be released
    The species we can be used in a FLEXPART simulation must be described by a set of definition files. See details about their usage here. 
  • specifying the releases
  • defining the run conditions
  • the path to the output files
    Metview runs FLEXPART in a temporary folder then converts the results and copies them into this folder. FLEXPART outputs can be large so take it into account when selecting this path.

How to specify the FLEXPART executable?

How to specify the SPECIES?

The species (chemical elements) released during a simulation are specified as integer numbers in the Release Species parameter in FLEXPART Run. The integer ID of the individual species are taken from the name of the species definition files.These have to be located in the directory defined via the User Species Path parameter in FLEXPART Run or if it is left blank (this is the default value) Metview will use the MV_FLEXPART_SPECIES environment variable.

At ECMWF 

The SPECIES are located in the directory specified by MV_FLEXPART_SPECIES. The contents of this directory is the same as that of folder option/SPECIES in the FLEXPART distribution. Here each species is represented by a file called SPECIES_NNN , where NNN is the integer ID of the given species.The table below summarises what species are available by default:

...

SPECIES_001

...

SPECIES_002

...

SPECIES_024

...

SPECIES_009

...

SPECIES_019

...

SPECIES_020

...

At other sites

Using your own

filenames defining the ind

can be specified for using these two parameters:

User Species Path

Specifies the location of the user defined species files. Both an absolute and relative path can be given here. If it is left blank (this is the default value) Metview will use the MV_FLEXPART_SPECIES environment variable to locate the species.  

Release Species

Specifies the list of the species released for the simulation. At all release locations the same species are emitted. The species are identified by the NNN number appearing in the the name of the SPECIES_NNN files. These files contain the physical and chemical properties of species.  

 

On ecgate in your metview version MV_FLEXPART_SPECIES is set to

/usr/local/apps/flexpart/902/options/SPECIES

(you could find out this path by running your metview version with the -help option; this prints out,  among other things, all the FLEXPART related env variables).

 

The contents of this directory was simply taken from the FLEXPART distribution. If you want create your own species definition you need make a copy of this directory and add your own species to it. Then set the path in User Species Path so that FLEXPART could pick up your definitions.

 

The location of the FLEXPART executable and that of some other files/directories have to be specified for Metview. These locations can be defined either through a set of Metview environment variables or via parameters in the FLEXPART Run icon (these latter take precedence). The table below summarises what actually is needed to set for Metview.

 

...

The directory containing the following files:

  • IGBP_int1.dat
  • OH_7lev_agl.dat
  • surfdata.t
  • surfdepo.t

...

These files are distributed in the FLEXPART source inside folder option

...

A set of species are distributed in the FLEXPART source inside folder option/SPECIES

...

 

How to define the species?

Forward simultaions

Fields

Trajecories

receprotros

volume fill

fluxes

cross section

time-height diagram

total column

age class

backward simulation

residence time

fluxes

trajecory