| 4 | | Before carrying out a model run, the user has to determine a data set - the model parameters - e.g. how many grid points are to be used, how large the horizontal and vertical grid spacing should be, which kind of boundary conditions are to be used for the individual variables, which numerical schemes implemented in the model are to be used, how long the simulated time should be, at which times and points plot output are supposed to be made, etc.\\\\ |
| 5 | | These data are assigned with the help of so-called "''NAMELIST-driven input''" (FORTRAN - NAMELIST – input). The chosen values of the model parameters are written into an ASCII file with fixed format, which is expected by the model as an input file under the local name [../iofiles#PARIN PARIN]. On this file the parameters are represented by their variable names they have in the model. These parameters can be assigned one or more values, depending on the type and size the variable has. The following example shows the format of the file [../iofiles#PARIN PARIN]:\\\\ |
| | 4 | Before carrying out a model run, the user has to determine the model parameters. These data are assigned with the help of so-called "''namelist-driven input''" (Fortran - namelist– input). The chosen values of the model parameters are written into an ASCII file with fixed format, which is expected by the model as an input file under the local name PARIN. On this file the parameters are represented by their variable names they have in the model. These parameters can be assigned one or more values, depending on the type and size the variable has. The following example shows the format of the file [../iofiles#PARIN PARIN]:\\\\ |
| 18 | | \\ |
| 19 | | The parameters are separated into four different groups which all start with the so-called NAMELIST group names. These are {{{&initialization_parameters}}}, {{{&runtime_parameters}}} and {{{&packagename_parameters}}} as well as {{{&user_parameters}}}. In each case a group is terminated with one backslash ("/"). Between the beginning of the line and the group name at least one blank has to be typed. Between the group names and the "/", the values are assigned to the variables. The example shows that in principle all FORTRAN data types are allowed. For more details concerning the NAMELIST syntax, refer to appropriate FORTRAN manuals.\\\\ |
| 20 | | Parameters belonging to the group {{{&initialization_parameters}}} are first read by PALM. These are the initialization parameters. Second, the so-called run parameters belonging to the group {{{&runtime_parameters}}} are read in, then the parameters for steering the optional software packages (group {{{&packagename_parameters}}}, the string "{{{packagename}}}" must be replaced by the NAMELIST group name of the respective package) as well as user-defined parameters (group {{{&user_parameters}}}). The four groups must be given in this order, the last groups, {{{&packagename_parameters}}} and {{{&user_parameters}}}, may be omitted. If several [../packages software packages] are selected, further NAMELIST groups may be inserted before the group {{{&user_parameters}}}. |
| 24 | | * The '''[../inipar initialization parameters]''' are steering the basic settings of the model run. They define e.g. the number of the grid points, the numerical schemes to be used, initial and boundary conditions to be applied, how the three-dimensional fields are initialized at the beginning of a model run (constant value profiles or 1D-model-pre-run, the initial temperature profile etc.). These parameters apply to the total model run and thus can not be changed with restart runs! If one tries to change these values within the NAMELIST input file of a restart run, then these changes are ignored (sole exception is the parameter [../inipar#initializing_actions initializing_actions], which must be given the value '' 'read_restart_data' '' for restart runs). |
| | 20 | The groups must be given in this order, the last groups, {{{&<module_name>_parameters}}} and {{{&user_parameters}}}, may be omitted. The namelist groups differ as follows: |
| | 21 | |
| | 22 | * [../inipar initialization parameters] steer the basic settings of the model run. They define e.g. the number of the grid points, the numerical schemes to be used, initial and boundary conditions to be applied, how the three-dimensional fields are initialized at the beginning of a model run (constant value profiles or 1D-model-pre-run, the initial temperature profile etc.). These parameters apply to the total model run and thus **can not be changed with restart runs**! If one tries to change these values within the namelist input file of a restart run, then these changes are ignored (sole exception is the parameter [../inipar#initializing_actions initializing_actions], which must be given the value '' 'read_restart_data' '' for restart runs). |
| 30 | | Starting from version 3.2, the {{{particles-package}}} is part of the default model, so it does not have to be switched on using '''mrun'''-option {{{-p}}}. However, the respective parameters have still to be set by using the NAMELIST group [../parpar particle_parameters].\\\\ |
| 31 | | The user-defined parameters are assigned by the user within the NAMELIST group name {{{&user_parameters}}} (see [../userint/userpar here]). They steer actions programmed by the user. By default, this group has only one parameter ([../userpar#region region]). If the user don't want to assign any values to the user-defined parameters, the group {{{&user_parameters}}} may be omitted. The group name {{{&user_parameters}}} can be changed by the user in the user-defined code. In addition to this, further NAMELIST groups may also be declared (all within routine [source:palm/trunk/SOURCE/user_parin.f90 user_parin]). A simple but complete example of the input file PARIN can be found [../examples/cbl here]. This example file can be used together with the [../configexample configuration file] for the execution of a model test run.\\\\ |
| | 28 | * [wiki:doc/app/userpar user-defined parameters] are assigned by the user within the namelist group name {{{&user_parameters}}}. They steer actions programmed by the user. |
| | 29 | |
| | 30 | In addition to this, further namelist groups may also be declared (all within routine [source:palm/trunk/SOURCE/user_parin.f90 user_parin]). A simple but complete example of the input file PARIN can be found [../examples/cbl here]. |
| | 31 | |
