Ambiente

Create
new
subfolder
named
“met”
inside
your
project
folder

Open
Aermet
View

AERMET: Pre-Processing Meteorological Data
for Use In the AERMOD Model

Select
‘New’

Hourly
Surface
Observations
(*.dat file)

Site
Characteristics

AERMET
program

Name new
Aermet
project file
and save in
“met” folder

Go to Webmet.com, download files into the met subfolder, thenunzip them in
the met subfolder. Note also for this site the anemometer height = 22 ft and
the base elevation = 179 ft.

SCRAM surface file:

Make sure years match

Aermet upper air file:

Twice Daily
Temperature
Soundings
(*.ua file)

Hourly Surface
Data File
(*.sfc file)
Hourly
Vertical
Profile File
(*.pfl file)

Aermod
Dispersion
Model

Select hourly surface datafile
(.dat file) from met subfolder

The surface met data file will automatically display the appropriate conversion
here. In this case, the station recorded the data in local time.

Select hourly upper air data file
(.ua file) from met subfolder

Select the Upper Air Menu

The upper air data file will automatically display an adjustment to local time. This is
because this data isrecorded using Greenwich Mean Time which, in this particular
case, is 5 hours ahead of Eastern Standard Time.

1.
2.
3.

Select the Sectors Menu

Add Site information by clicking on “Copy from Hourly and Upper Air Data”
Enter the Anemometer Height (22 feet from the relevant Webmet page)
Then Select the Sectors and Surface Parameters Tab

2

1

3

1.
2.
3.
4.

Make sure ‘winddirection sectors’ = 1
Specify annual averages (no seasonal effects
assumed here)
Then click on the dotted tab and a menu will appear
(see right)’
Choose the default “Urban” land-use value by
selecting the appropriate row

1.

Repeat this process for the Bowen ratio and the
surface roughness

Now Run Aermet.

AERMET: Pre-Processing Meteorological Data
for Use In the AERMOD ModelHourly
Surface
Observations
(*.dat file)

Site
Characteristics

AERMET
program
Twice Daily
Temperature
Soundings
(*.ua file)

Now open ISCAermod View

Hourly Surface
Data File
(*.sfc file)
Hourly
Vertical
Profile File
(*.pfl file)

Aermod
Dispersion
Model

From the “Model” menu, make sure you choose Aermod
Under the File menu, choose “New Project”

Name theISC-Aermod
Project file and save it in the
project folder

These choices are the same as before

Set domain extents to 10,000 meters and SW corner to 0,0

A menu will pop up asking for details about the source
Chosen source location
in modeling domain
coordinates
Select the stack tool, place the pointer
at a location in the middle of the
modeling domain, then click once to
set thesource location

Enter typical values:
Stack height: 100 m
Emission rate: 1 g/sec
Exit Velocity: 10 m/s
Stack Diameter: 3 m
Click on the “Tip”
Button for information
on stack gas
temperature. Select the
Ambient Temperature
Option (the program
artificially sets the stack
temperature to 0K if it is
the same as the
surroundings).

Location of newly created point source

You can alsoenter grid
values with this menu.
The receptor grid is shown here.
Select polar coordinate system for receptor grid. Point
at the source location, then click and drag the pointer
away from the source to establish the receptor grid. If
the grid is near the source, you can zoom in first using
the zoom tool. You can erase the grid anytime.

Click and drag a second, larger polar receptorgrid over the first one.
To zoom out, select the
domain tool modeling
domain and click OK on the
pop-up menu. This will
display the entire domain.

Close window to return to main program

Load the met files (surface .dat file and upper air .ua file) from
The receptor grids are shown in the table. Now
choose the met data menu

your project folder that you created earlier with Aermet....