This tutorial demonstrates how to run a forward simulation with FLEXPART and how to visualise the results in various ways.
| Expand | ||||||
|---|---|---|---|---|---|---|
| ||||||
|
| Note |
|---|
Please enter folder 'forward' to start working. |
| Info |
|---|
In this tutorial we will simulate a volcano eruption by releasing some SO2 from the Icelandic volcano Eyjafjallajökull. |
The simulation itself is defined by the 'fwd_conc' FLEXPART Run icon and the 'rel_volcano' FLEXPART Release icon, respectively. Both these are encompassed in a single macro called 'fwd_conc.mv'. For simplicity will use this macro to examine the settings in detail.
The macro starts with defining the release like this:
| Code Block | ||
|---|---|---|
| ||
rel_volcano = flexpart_release(
name : "VOLCANO",
starting_date : 0,
starting_time : 15,
ending_date : 2,
ending_time : 12,
area : [63.63,-19.6,63.63,-19.6],
top_level : 9000,
bottom_level : 1651,
particle_count : 10000,
masses : 1000000
) |
This says that the release will happen over a 45 h period between heights 1651 and 10000 m at the location of the volcano and we will release 1000 tons of material in total.
| Info |
|---|
Please note that
|
The actual simulation is carried out by calling flexpart_run():
| Code Block | ||
|---|---|---|
| ||
#Run flexpart (asynchronous call!)
r = flexpart_run(
output_path : "result_fwd",
input_path : "../data",
starting_date : 20120517,
starting_time : 12,
ending_date : 20120519,
ending_time : 12,
output_field_type : "conc",
output_flux : "on",
output_trajectory : "on",
output_area : [40,-25,66,10],
output_grid : [0.25,0.25],
output_levels : [500,1000,2000,3000,4000,5000,6000,7000,8000,9000,10000,11000,12000,13000,14000,15000],
release_species : 8,
releases : rel_volcano,
release_units : "mass",
receptor_units : "mass"
)
print(r) |
Here we defined both the input and output path and specified the simulation period, the output grid and levels as well. We also told FLEXPART to generate gridded mass concentration and flux fields and plume trajectories on output..
| Info |
|---|
The actual species that will be released is defined as an integer number (for details about using the species see here). With the default species settings number 8 stands for SO2. |
If we run this macro (or alternatively right-click execute the FLEXPART Run icon) the results (after a minute or so) will be available in folder 'result_fwd'. The computations actually took place in a temporary folder then Metview copied the results to the output folder. If we open folder 'result_fwd' we will see three files there:
- conc_s001.grib is a GRIB file containing the gridded concentration fields
- flux_s001.grib is a GRIB file containing the gridded flux fields
- tr_r1.csv is a CSV file containing the plume trajectories
| Info |
|---|
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 click here. |
To process and visualise the results please see these pages:
| Children Display |
|---|