More configuration examples

Scale factor examples

Scale (or zero) emissions with a shapefile country mask

HEMCO has the ability to define country-specific scale factors. To utilize this feature, you must first specify a mask file in the NON-EMISSIONS DATA section of the HEMCO configuration file, such as:

#==============================================================================
# --- Country mask file ---
#==============================================================================
* COUNTRY_MASK /path/to/file/countrymask_0.1x0.1.nc CountryID 2000/1/1/0 C xy count * - 1 1

The mask file specified above was created from a shapefile obtained from the GADM database. The country mask netCDF file (countrymask_0.1x0.1.nc ) identifies countries by their ISO 3166-1 numeric code. Countries and their ISO3166-1-numeric codes are listed in the country_codes.csv file.

The country-specific scale factors can be specified in a separate ASCII file ending with the suffix .txt. Within the file the container name of the mask file (e.g. COUNTRY_MASK) must be given in the first line of the file. The lines following it define the country-specific scale factors. ID 0 is reserved for the default values that are applied to all countries with no specific values listed. All IDs must be integers. An example scalefactor.txt file is provided below:

# Country mask field name
COUNTRY_MASK

# Country data
# Name   | ID  | Scale factor
DEFAULT    0     1.0
CHINA      156   0.95
INDIA      356   1.10
KOREA      410   0.0

The scale factor(s) listed are interpreted by HEMCO the same way as other scale factors. Multiple values separated by / are interpreted as temporally changing values:

  • 7 values = Sun, Mon, …, Sat;

  • 12 values = Jan, Feb, …, Dec;

  • 24 values = 12am, 1am, …, 11pm (local time!).

The country-specific scale factors would then be defined in the Scale Factors section of the HEMCO configuration file as:

501 SCALE_COUNTRY /path/to/file/scalefactor.txt  - - - xy count 1

In an ESMF environment the filepath specified in HEMCO_Config.rc must be the absolute path to the file rather than use the $ROOT specifier. The scale factors can then be applied to the emission field(s) that you wish to scale. For example:

0 MIX_NO_IND MIX_Asia_NO.generic.025x025.nc NO_INDUSTRY 2008-2010/1-12/1/0 C xy kg/m2/s NO  1/27/25/1006/ 501 1/2 45

These steps can also be used to scale emissions for different regions (e.g. provinces, states) by providing HEMCO with a mask file containing the regions to be scaled.

Scale (or zero) emissions with a rectangular mask

Important

If you are using HEMCO versions prior to 3.5.0, you may encounter a bug when trying to follow this example. See Github issue: https://github.com/geoschem/HEMCO/issues/153 for a workaround.

Another way to scale all emissions over a country (or set them to zero) is to apply a rectangular mask.

For example, to set all emissions over Australia and surrounding islands to zero, add this line to the Masks section of the HEMCO configuration file:

1010 AUS_MASK 105.0/-46.0/160.0/-10.0 - 2000/1/1/0 C xy 1 1 105/-46/160/–10

Here you directly provide the lower left and upper right corner of the mask region mask instead of a netCDF file: lon1/lat1/lon2/lat2 You can then combine this mask with a scale factor of zero to eliminate any emissions over that area.

In Base emissions

0 HTAP_NO_IND /path/to/HTAP_NO_INDUSTRY.generic.01x01.nc emi_no 2008-2010/1-12/1/0 C xy kg/m2/s NO 1/27/25/501 1/2 4

In Scale Factors:

501 SCALE_AUS 0.0 - - - xy unitless 1 1010

In Masks:

# Defines a rectangular region that should cover AUS + surrounding islands
1010 AUS_MASK 105.0/-46.0/160.0/-10.0 – 2000/1/1/0 C xy 1 1 105.0/-46.0/160.0/-10.0

Scale emissions by species

You may define uniform scale factors for single species that apply across all emission inventories, sectors and extensions. These scale factors can be set in the Settings section of the HEMCO configuration file, using the EmissScale_<species-name>, where <species-name> denotes the name of a HEMCO species such as CO, CH4, NO, etc.

For instance, to scale all NO emissions by 50% add the line EmisScale_NO to the Settings section of the the HEMCO configuration file:

###############################################################################
### BEGIN SECTION SETTINGS
###############################################################################

ROOT:                        /path/to/HEMCO/data/directory
Logfile:                     HEMCO.log
... etc ...
EmisScale_NO                 1.5

### END SECTION SETTINGS ###

Zero emissions of selected species

To zero emissions of a given species (e.g. NO) from any inventory listed under Base Emissions, do the following:

  1. Create your own scale factor and assign value 0.0 to it. This must go into the Scale Factors section of the HEMCO configuration file:

    400 ZERO 0.0 - - - xy 1 1

  2. Apply this scale factor to all of the emissions entries in the HEMCO configuration file that you would like to zero out. For example:

    0 MIX_NO_IND  /path/to/MIX_Asia_NO.generic.025x025.nc NO_INDUSTRY  2008-2010/1-12/1/0 C xy kg/m2/s  NO  1/27/25/400/1006 1/2 45

This can be a useful way to set the emissions of some species to zero for sensitivity study purposes.

Note

All scale factors should be listed before masks.

Scale extension emissions globally by species

You may pass a global scale factor to the HEMCO extensions. For example, to double soil NO emissions everywhere, add the Scaling_NO to the section for the SoilNOx extension. This is located in the Extension Switches section of the HEMCO configuration file, as shown below:

104     SoilNOx           : on    NO
    --> Use fertilizer NOx:       true
    --> Scaling_NO        :       2.0

Scale summertime soil NOx emisions over the US

It is possible to pass uniform and/or spatiotemporal scale factors to some of the extensions, including SoilNOx.

For instance, suppose you want to halve summertime soil NOx emissions over the continental US. You can do this by defining a scale field (here, SOILNOX_SCALE) to the SoilNOx emission field in the Extension Switches section of the HEMCO configuration file:

104 SOILNOX_ARID    /path/to/soilNOx.climate.generic.05x05.nc  ARID     2000/1/1/0 C xy unitless NO -   1 1
104 SOILNOX_NONARID /path/to/soilNOx.climate.generic.05x05.nc  NON_ARID 2000/1/1/0 C xy unitless NO -   1 1
104 SOILNOX_SCALE   1.0                                        -        2000/1/1/0 C xy unitless *  333 1 1

SOILNOX_SCALE is just a dummy scale factor with a global uniform value of 1.0. The actual temporal scaling over the US is done via scale factor 333 assigned to this field. This approach ensures that all SoilNOx emissions outside of the US remain intact.

The next step is to define scale factor 333 (named SOILNOX_SCALE) in the Scale Factors section of the configuration file:

# Scale factor to scale US soil NOx emissions by a factor of 0.5 in month June-August
333 SOILNOX_SCALE 1.0/1.0/1.0/1.0/1.0/0.5/0.5/0.5/1.0/1.0/1.0/1.0 - 2000/1-12/1/0 - xy 1 1 5000

Scale factor SOILNOX_SCALE defines a monthly varying scale factor, with all scale factors being 1.0 except for months June-August, where the scale factor becomes 0.5. The last column of the SOILNOX_SCALE entry assigns mask number 5000 to this scale factor. This ensures that the scale factor will only be applied over the region spanned by mask 5000. This musk mast be defined in the Masks section of the HEMCO configuration file:

1005 USA_MASK      /path/to/usa.mask.nei2005.geos.1x1.nc  MASK 2000/1/1/0 C xy 1 1 -165/10/-40/90
5000 SOILNOX_MASK   -106.3/37.0/-93.8/49.0                 -    -         - xy 1 1 -106.3/37.0/-93.8/49.0

In this example, mask 5000 is defined as the region between 106.3 - 93.8 degrees west and 37.0 - 49.0 degrees north. If you want to apply the soil NOx scaling over the entire US, you can also just refer to the existing USA mask, e.g.:

# Scale factor to scale US soil NOx emissions by a factor of 0.5 in month June-August.
333 SOILNOX_SCALE 1.0/1.0/1.0/1.0/1.0/0.5/0.5/0.5/1.0/1.0/1.0/1.0 - 2000/1-12/1/0 - xy 1 1 1005

Mask file examples

Exercise care in defining mask regions

In an effort to reduce I/O HEMCO ignores any emission entries that are deemed “irrelevant” because there is another (global) emission entry for the same species and emission category (Cat), but higher hierarchy (Hier).

For instance, suppose you have the following two fields defined under Base Emissions:

0 TEST_1 file.nc var 2000/1/1/0 C xy 1 1 CO - 1 1
0 TEST_2 file.nc var 2000/1/1/0 C xy 1 1 CO - 1 2

In this case, during initialization HEMCO determines that TEST_1 is obsolete because it will always be overwritten by TEST_2 because of its higher hierarchy. But if there is a mask assigned to an emission inventory, HEMCO uses the provided mask domain to determine whether this inventory has to be treated as “global” or not.

Going back to the example above, let’s add a mask to TEST_2:

0 TEST_1 file.nc var 2000/1/1/0 C xy 1 1 CO -    1 1
0 TEST_2 file.nc var 2000/1/1/0 C xy 1 1 CO 1000 1 2

and let´s define the following mask:

1000 TEST_MASK mask.nc var 2000/1/1/0 C xy 1 1 -180/180/-90/90

HEMCO uses the mask range (180/180/-90/90) to define the extension of this mask. If that range covers the entire HEMCO grid domain, it considers every emission inventory linked with this mask as ¨global¨. In our example, TEST_2 would still be considered global because the mask extends over the entire globe, and TEST_1 is thus ignored by HEMCO.

However, changing the mask domain to something smaller will tell HEMCO that TEST_2 is not global, and that it cannot drop TEST_1 because of that:

1000 TEST_MASK mask.nc var 2000/1/1/0 C xy 1 1 -90/180/-45/45

Long story short: if you set the mask range to a domain that is somewhat smaller than your simulation window, things work just fine. But if you set the range to something bigger, HEMCO will start ignoring emission files.

Preserve fractional values when masking emissions

Question from a HEMCO user:

I see that when the mask files are regridded they are remapped to 0 or 1 via regular rounding. Unfortunately, this method will not work well for my application, because the region I am trying to zero out is a small region inside the 4x5 grid cell and thus the current mask will not change the emissions on a \(4^{\circ}{\times}5^{\circ}\) scale.

I was wondering whether it would be possible/straightforward to modify the mask regridding method such that \(4^{\circ}{\times}5^{\circ}\) emissions scale will scale with the fraction of the gird cell that is masked (e.g., if a quarter of the grid cells in one of the \(4^{\circ}{\times}5^{\circ}\) grid are masked, the emissions will scale down by 25%).

For this application, it may better to define your mask file in the Scale Factors section of the HEMCO configuration file.

By defining a mask in the Masks section, HEMCO identifies the data container type as MASK and treats the data as binary. Long story short:

###############################################################################
### BEGIN SECTION MASKS
###############################################################################

If your mask file is currently defined here ...

### END SECTION MASKS ###

If you instead move that line to the SECTION SCALE FACTORS then HEMCO will treat the mask as type SCAL. I believe that would preserve the regridded value (in your example 0.25) and apply that to the emissions in a 4x5 grid box.

###############################################################################
### BEGIN SECTION SCALE FACTORS
###############################################################################

... put your mask file here instead ...

### END SECTION SCALE FACTORS ###

Create emissions for geographically tagged species

Important

Tagging emissions by geographic regions is currently supported only for base emissions but not for emissions computed by HEMCO extensions. We hope to add this capability into a future HEMCO version.

If you are using HEMCO interfaced to an external model, and need to create emissions for geographically tagged species, follow thse steps.

  1. Define masks for your geographic regions in the Masks secton of the HEMCO configuration file:

    #==============================================================================
# Country/region masks
#==============================================================================
1001 MASK_1  -30/30/45/70    - 2000/1/1/0 C xy 1 1 -30/30/45/70
1002 MASK_2  -118/17/-95/33  - 2000/1/1/0 C xy 1 1 -118/17/-95/33
1003 MASK_3  my_mask_file.nc - 2000/1/1/0 C xy 1 1 105/-46/160/–10

# ... etc ...

    If your mask regions are rectangular, you can specify the longitude and latitude at the box corners (such as was done for MASK_1 and MASK_2). You may also read a mask definition from a netCDF file (as was done for MASK_3).

  2. In the Base Emissions section of the HEMCO configuration file, add extra entries for tagged species underneath the entry for the global species, such as:

    #==============================================================================
# --- EDGAR v4.2 emissions, various sectors ---
#==============================================================================
(((EDGAR

### Gas and oil ###
0 CH4_GAS__1B2a    v42_CH4.0.1x0.1.nc  ch4_1B2a  2004-2008/1/1/0 C xy kg/m2/s CH4   -    1 1
0 CH4_GAS__1b2a_a  -                   -         -               - -  -       CH4_a 1001 1 1
0 CH4_GAS__1b2a_b  -                   -         -               - -  -       CH4_b 1002 1 1
0 CH4_GAS__1b2a_c  -                   -         -               - -  -       CH4_c 1003 1 1
# ... etc ...

### Coal mines ###
0 CH4_COAL__1B1    v42_CH4.0.1x0.1.nc  ch4_1B1   2004-2008/1/1/0 C xy kg/m2/s CH4   -    2 1
0 CH4_COAL__1B1_a  -                   -         -               - -  -       CH4_a 1001 2 1
0 CH4_COAL__1B1_b  -                   -         -               - -  -       CH4_b 1002 2 1
0 CH4_COAL__1B1_c  -                   -         -               - -  -       CH4_c 1003 2 1
# ... etc ...``

This will put the total emissions into your CH4 tracer (tracer #1). It will then also apply the regional masks to the total emissions and then store them into tagged species (i.e. CH4_a, CH4_b, and CH4_c). These tagged species must also be defined in your external model with the same names.

HEMCO extensions examples

Fix MEGAN extension emissions to a specified year

Question submitted by a HEMCO user:

Is it possible to fix MEGAN emissions to a given year? I know this works for many other base emissions inventories, but MEGAN emissions are dependent on environmental variables.

Your best option may be to run the HEMCO standalone and save out MEGAN emissions for the desired year. Then, in a subsequent run, you can read in the HEMCO diagnostic output files containing the archived MEGAN emissions.

  1. Run the HEMCO standalone model. Make sure the following entries to your HEMCO_Diagn.rc file:

    EmisISOP_Biogenic  ISOP   108    -1  -1   2   kg/m2/s  ISOP_emissions_from_biogenic_sources
EmisISOP_Biogenic  ISOP   108    -1  -1   2   kg/m2/s  ISOP_emissions_from_biogenic_sources
EmisALD2_Biogenic  ALD2   108    -1  -1   2   kg/m2/s  ALD2_emissions_from_biogenic_sources
# ... etc for other MEGAN species ...

    In the above entries, 108 tells HEMCO to get the emissions from the MEGAN extension, which is listed in the Extension Switches section of the configuration file with ExtNr 108.

  2. Add the following lines in the Settings section of the HEMCO configuration file:

    DiagnFile:                   HEMCO_Diagn.rc
DiagnPrefix:                 HEMCO_diagnostics
DiagnFreq:                   Monthly

    For more information, see the sections on DiagnFile, DiagnPrefix, DiagnFreq.

  3. Turn off the MEGAN extension in the Extension Switches section of the configuration file.

    108     MEGAN                  : off   ISOP/ACET/PRPE/...etc additional species...

  4. Add entries for reading the fixed MEGAN emission that were archived in Step 1 under Base Emissions. For example:

    0 MEGAN_ISOP /path/to/HEMCO_diagnostic.2016$MM010000.nc EmisISOP_Biogenic 2016/1-12/1/1/0 C xy kg/m2/s ISOP - 4 1

    Note

    HEMCO category Cat = 4 is reserved for biogenic emissions.

  5. Run HEMCO in either standalone mode, or coupled to an external model, dependingon your application.

Add 2D emissions into specific levels

HEMCO can emit emissions into a layer other than the surface layer. For example:

0 EMEP_CO EMEP.nc CO 2000-2014/1-12/1/0 C xyL5 kg/m2/s CO 1/1001 1 2

will release the EMEP_CO into level 5 instead of level 1. Theoretically, you could create a separate HEMCO entry for every emission level (under Base Emissions:

0 EMEP_CO_L1 EMEP.nc CO 2000-2014/1-12/1/0 C xyL1 kg/m2/s CO 1 150/1001 1 2
0 EMEP_CO_L2 EMEP.nc CO 2000-2014/1-12/1/0 C xyL2 kg/m2/s CO 1 151/1001 1 2
0 EMEP_CO_L3 EMEP.nc CO 2000-2014/1-12/1/0 C xyL3 kg/m2/s CO 1 152/1001 1 2

and assign Scale Factors (e.g. 150, 151, 152) to specify the fraction of EMEP emissions to be added into each level:

151 EMEP_LEV1_FRAC 0.5 - - - xy 1 1
152 EMEP_LEV2_FRAC 0.1 - - - xy 1 1
153 EMEP_LEV3_FRAC 0.1 - - - xy 1 1``

But this approach is somewhat cumbersome. Also, this won’t give you the possibility to specifically emit a fraction above the PBL given that the PBL height is variable over time.

Use this notation (under Base Emissions) to tell HEMCO that you would like EMEP emissins to be added into levels 1 through 3:

0 EMEP_CO_L1 EMEP.nc CO 2000-2014/1-12/1/0 C xyL=1:3 kg/m2/s CO 1 1001 1 2

The emissions are then spread across the lowest 3 model levels based upon the model level thicknesses.

Instead of specifying the model levels, you may also specify the altitude in meters or use PBL for the planetary boundary layer:

# Emit from surface up to 2500 meters
0 EMEP_CO_L1 EMEP.nc CO 2000-2014/1-12/1/0 C xyL=1:2500m kg/m2/s C 1001 1 2

# Emit between 1000 and 5000 meters altitude
0 EMEP_CO_L1 EMEP.nc CO 2000-2014/1-12/1/0 C xyL=1000m:5000m kg/m2/s CO 1 1001 1 2

# Emit between 5000 meters altitude and model level 17
0 EMEP_CO_L1 EMEP.nc CO 2000-2014/1-12/1/0 C xyL=500m:17 kg/m2/s CO 1 1001 1 2

# Emit from the surface to the PBL top
0 EMEP_CO_L1 EMEP.nc CO 2000-2014/1-12/1/0 C xyL=1:PBL kg/m2/s CO 1 1001 1 2

HEMCO can also read the emission levvel from an external source (e.g. netCDF file) that is listed as a scale factor. This field can then be referred to using its scale factor ID. As an example, let’s assume daily varying emission heights for 2009-2010 are archived in emis_heights.nc as variable emish in units of m. available for years 2009 to 2010). You can then define a Scale Factor such as:

300 EMIT_HEIGHT emis_heights.nc emish 2009-2010/1-12/1-31/0 C xy m 1

and refer to this scale factor as the upper bound of the injection height under Base Emissions:

0 GFAS_CO GFAS_201606.nc cofire 2009-2010/1-12/1-31/0 C xyL=1:scal300 kg/m2/s CO - 5 3

It should be noted that HEMCO always regrids the fields to the model grid before doing any data operations. If the emission height file is very spotty and contains a lot of zeros the averaged injection heights may be too low. In this case it may be required to set all zeros to missing values (which are ignored by HEMCO) to achieve the desired result.

Vertically distributing emissions

In HEMCO 3.0.0 and later versions, the capability to vertically allocate emissions has been added. To achieve this, HEMCO first copies emissions to all levels when dimensions xyL* are specified. Scale factors can then be applied to determine distribute the emissions vertically.

For example, let’s assume that we have a file vert_alloc.nc containing the ratio of emissions to apply to each level for CEDS energy, industry, and ship emissions. We must add the following entries to under the Scale Factors section of the the HEMCO configuration file:

#==============================================================================
# --- CEDS vertical partitioning ---
#==============================================================================
(((CEDS
315 ENERGY_LEVS   vert_alloc.nc g_energy   2017/1/1/0 C xyz 1 1
316 INDUSTRY_LEVS vert_alloc.nc g_industry 2017/1/1/0 C xyz 1 1
317 SHIP_LEVS     vert_alloc.nc cmv_c3     2017/1/1/0 C xyz 1 1
)))CEDS

These scale factors are then applied to the CEDS_*_ENE, CEDS_*_IND, and CEDS_*_SHIP fields that are listed under Base Emissions. These fields are 2D in the CEDS data files, but we now can specify dimensions xyL* instead of xy to tell HEMCO to copy the field into each emissions level:

0 CEDS_CO_ENE CO-em-total-anthro_CEDS_$YYYY.nc  CO_ene  1970-2017/1-12/1/0 C xyL* kg/m2/s CO 26/37/35/315 1  5
0 CEDS_CO_IND CO-em-total-anthro_CEDS_$YYYY.nc  CO_ind  1970-2017/1-12/1/0 C xyL* kg/m2/s CO 26/316       1  5
0 CEDS_CO_SHP CO-em-total-anthro_CEDS_$YYYY.nc  CO_shp  1970-2017/1-12/1/0 C xyL*`kg/m2/s CO 26/317       10 5

Mathematical expressions examples

You may define mathematical expressions in the HEMCO configuration file. Similar to uniform values, these must be placed in in the sourceFile column. All expressions are evaluated during run-time. They can be used e.g. to model an oscillating emission source. All mathematical expressions must contain at least one time-dependent variable that is evaluated on-the-fly. Mathematical expressions are specified by using the prefix MATH:, followed by the mathematical expression. The expression is a combination of variables, mathematical operations, and constants (e.g. MATH:5.0+2.5*sin(HH).

Supported variables and operators

The following variable names and mathematical operations are currently supported:

Variable names

  • YYYY (current year)

  • MM (current month)

  • DD (current day)

  • HH (current hour)

  • NN (current minute)

  • SS (current second)

  • SS (current second)

  • DOY (day of year)

  • DOM (days in current month)

  • WD (Weekday: 0=Sun, 1=Mon .. 7=Sat)

  • LH (hour in local time)

  • PI (the constant PI)

Basic mathematical operators: + - / * ^ ( )

Advanced mathematical functions: sin, cos, tan, asin, acos, atan, sinh, cosh, tanh, sind, cosd, tand, log, log10, nint, anint, aint, exp, sqrt, abs, floor. The names refer to the equivalent Fortran functions.

Important

When using mathematical expressions, we recommend setting the sourceTime attribute to *, especially if you are using the short-term variables (HH, NN, SS, LH). This will ensure that your expression will get evaluated on every emission time step.

Example: Define a sinusoidal source

To define a sine-wave emission source of NO with an oscillation frequency of 24 hours, add the following line to section Base Emissions in the HEMCO configuration file. Place the mathematical expression under the sourceFile column (i.e. the 3rd column):

0 SINE_NO  MATH:sin(HH/12*PI) - * C xy kg/m2/s NO - 1 500

This defines an emission category (Cat) of 1 and hierarchy (Hier) of 500. No scale factors are applied.

Important

Mathematical expressions can produce negative emissions, which by default cause HEMCO to stop with an error. Negative emissions can be enabled by setting Negative values: 2 in the Settings section of the HEMCO configuration file.

In order to avoid negative values, you may specify an offset, as is shown below:

0 SINE_NO  MATH:2.0+sin(HH/12*PI) - * C xy kg/m2/s NO - 1 500

Other examples

Assign emissions to passive species in an external model

The HEMCO passive species module allows you to run a suite of passive species alongside any simulation, i.e. it works with all simulation types. To use the passive species within GEOS-Chem, follow these steps:

Let’s assume you are using HEMCO in an external model, and that you have two passive species named PASV1 and PASV2 that have constant emissions fluxes. Add the following entries to the Base Emissions section of the HEMCO configuration file:

# Assign PASV1 a flux of 0.001 kg/m2/s
0 PASV1_Flux 1.0e-3  - - - xy kg/m2/s PASV1 - 1 1

# Assign PASV2 a flux of 1e-9 kg/m2/s
0 PASV2_Flux 1.0e-9  - - - xy kg/m2/s PASV2 - 1 1

# ... etc for additional species ...

To define emissions for passive species that are geographically tagged, simply assign corresponding mask values in the third-to-last column:

0 PASV1_Flux 1.0e-3  - - - xy kg/m2/s PASV1 1000 1 1
0 PASV2_Flux 1.0e-9  - - - xy kg/m2/s PASV2 1001 1 1

# ... etc for additional species...

Here, 1000 and 1001 refer to mask definitions in the HEMCO configuration file.

Next, request HEMCO diagnostic output. Define the following entries in the diagnostics configuration file (aka HEMCO_Diagn.rc):

# Name       Spec  ExtNr Cat Hier Dim Unit     Longname
PASV1_TOTAL  PASV1 -1    -1  -1   2   kg/m2/s  PASV1_emission_flux
PASV2_TOTAL  PASV2 -1    -1  -1   2   kg/m2/s  PASV2_emission_flux

# ... etc for additional species ...

To activate these diagnostics, you must specify values for DiagnFile and DiagnFreq in the Settings section of the HEMCO configuration file:

DiagnFile:                 HEMCO_Diagn.rc
DiagnFreq:                 00000000 003000

The DiagnFile option tells HEMCO to read the diagnostic definitions in the file that you specify (the default is HEMCO_Diagn.rc). Use DiagnFreq to specify the diagnostic frequency (i.e. the interval at which diagnostics output will be created).