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Please note that this tutorial requires Metview version 5.0 or later. |
A case study
In this case study will run FLEXPART to simulate the imaginary eruption of the Icelandic volcano Eyjafjallajökull.
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.
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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 icon that was used to generate the data in folder 'Prepare'. The corresponding macro code can also be found there.
| Info |
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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. |
Running a forward simulation
Enter folder 'fwd'.
We will run FLEXPART to simulate a volcano eruption by releasing of some SO2 from the Icelandic volcano Eyjafjallajökull.
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| Info |
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Please note that these are not the original outputs form FLEXTRA but were converted to formats more suitable for use in Metview. For details about the FLEXPART outputs please click here. |
Visualising gridded fields
Since the output GRIB files cannot be handled by To plot a particular parameter and level we need to filter the desired dataset from the resulting FLEXPART output file. Unfortunately, Metview's standard Grib Filter icon because cannot handle these files (partly due to the he local GRIB definitions we use). Therefore definition the use) so we need to use other means to cope with this task. For this reason and also to make FLEXPART output handling easier a set of Metview Macro Library Functions were developed.
The macro to visualise the concentration fields on a given level is 'plot_level.mv'.
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#Metview Macro
# **************************** LICENSE START ***********************************
#
# Copyright 2017 ECMWF. This software is distributed under the terms
# of the Apache License version 2.0. In applying this license, ECMWF does not
# waive the privileges and immunities granted to it by virtue of its status as
# an Intergovernmental Organization or submit itself to any jurisdiction.
#
# ***************************** LICENSE END ************************************
dIn="result_fwd_conc/"
inFile=dIn & "conc_s001.grib"
lev=8000
par="mdc"
#Read fields on the given height level
g=mvl_flexpart_read_hl(inFile,par,lev,-1,-1)
#The countour levels
cont_list=[1,10,50,100,150,200,250,500,750,1000,2000,6000]
#Define contour shading
conc_shade = mcont(
legend : "on",
contour : "off",
contour_level_selection_type : "level_list",
contour_level_list : cont_list,
contour_label : "off",
contour_shade : "on",
contour_shade_method : "area_fill",
contour_shade_max_level_colour : "red",
contour_shade_min_level_colour : "RGB(0.14,0.37,0.86)",
contour_shade_colour_direction : "clockwise",
contour_method: "linear"
)
#Define coastlines
coast_grey = mcoast(
map_coastline_thickness : 2,
map_coastline_land_shade : "on",
map_coastline_land_shade_colour : "grey",
map_coastline_sea_shade : "on",
map_coastline_sea_shade_colour : "RGB(0.89,0.89,0.89)",
map_boundaries : "on",
map_boundaries_colour : "black",
map_grid_latitude_increment : 5,
map_grid_longitude_increment : 5
)
#Define geo view
view = geoview(
map_area_definition : "corners",
area : [40,-25,66,9],
coastlines: coast_grey
)
#Title
title=mvl_flexpart_title(g,0.3,"ng m**-3")
plot(view,g,conc_shade,title) |
to deal with the FLEXPART grib files. Please look into the visualisation macros to see how to use them. The most important Metview Macro Library Functions are as follows:
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