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atm_init

The application atm_init creates an atmospheric data file with initial air parcel positions. The code will generate air parcels in a simple manner with user-defined settings.

# calling atm_init
$ ./atm_init  <ctl> <atm_out>

The following specific configuration parameters can be used to determine the release position:

parameter purpose default
INIT_T0 Release time range start [s] 0
INIT_T1 Release time range end [s] 0
INIT_DT Release time interval [s] 1
INIT_Z0 Release altitude range start [km] 0
INIT_Z1 Release altitude range end [km] 0
INIT_DZ Release altitude interval [km] 1
INIT_LON0 Release longitude range start 0
INIT_LON1 Release longitude range end 0
INIT_DLON Release longitude interval 1
INIT_LAT0 Release latitude range start 0
INIT_LAT1 Release latitude range end 0
INIT_DLAT Release latitude interval 1

Followings are some optional parameters for controlling the release of air parcels:

  • INIT_REP: This parameter controls the number of air parcels in each release position. The default value is 1.
  • INIT_MASS: Total release mass [kg]. The default value is 0.
  • INIT_VMR: Volume mixing ratio of each air parcel [ppv]. The default value is 0.
  • INIT_ST/INIT_SZ/INIT_SLON/INIT_SLAT: If this parameter is set to non-zero value, the air parcels are released with a Gaussian distribution in time/altitude/longitude/latitude. The parameter value represents the full width at half maximum.
  • INIT_UT/INIT_UZ/INIT_ULON/INIT_ULAT: If this parameter is set to non-zero value, the air parcels are released with a uniform distribution in time/altitude/longitude/latitude. The parameter value represents release range.
  • INIT_EVENLY: If this parameter is set to 1, the number of air parcels released will be weighted by the cosine of latitude so that the air parcels are evenly distributed globally.
  • INIT_IDX_OFFSET: Offset value added to air parcel indices. This parameter allows customization of the starting index for air parcels, which can be useful for domain decomposition or when combining multiple initialization runs. The default value is 0.

Note: Instead of using the control file the configuration parameters can also be appended to the function call.