INIFOR - Mesoscale Interface for Initializing and Forcing PALM-4U

​INIFOR provides the meteorological fields of the velocity components, specific humidity and potential temperature required to initialize the urban-climate model PALM-4U as well as boundary data required for the offline nesting of PALM-4U into larger-scale models. The required meteorological fields are interpolated from output data of the mesoscale model COSMO.

Compilation

INIFOR is being compiled automatically whenever you compile PALM using palmbuild.

Minimal Usage Example

• Customize ./namelist (number or grid points and spacings, end_time)
• Run current_version/trunk/SCRIPTS/inifor -path <scenario path> -date <YYYYMMDD>

Usage

After compilation, the inifor binary resides in the $PALM_BIN path, i.e. in <PALM path>/current_version/trunk/SCRIPTS/.

In order to run, INIFOR requires three kinds of inputs:

1. hourly COSMO model output,
2. a steering namelist file, and
3. command-line options.

In addition, a static driver file may be supplied (see --static-driver option below) in order to pass the coordinates of the PALM origin to INIFOR. If no static driver is passed to INIFOR, origin coordinates are read from the namelist file.

A typical inifor call looks like this:

inifor --path /data/evaluation/20170729 --date 2017073006 \
       --init-mode profile -n namelist -o dynamic_driver.nc \
       --elevation 110 --input-prefix lff0_

Input data: COSMO model output

Overview

INIFOR processes COSMO model output which it requires to be stored in a set of netCDF files located in a user-specified path (see --path option). These are:

• hhl.nc: This file provides the COSMO numerical grid. (hhl abbreviates height of half layers, i.e. the heights of the vertical cell boundaries.)
• soil.nc: This file provides the COSMO soil map and is used to destinguish land from water cells.
• <prefix>YYYYMMDDHH-<suffix>.nc: Each of these files contains COSMO model of one time step at the given time in UTC (Y..year, M..month, D..day, H..hour).
  • The <prefix> distinguishes different DWD products, for instance COSMO analyses (laf) or forecasts (lff).
  • The <suffix> distinguishes four kinds of COSMO model output data, namely
    • flow (atmospheric fields)
    • soil (soil moisture and temperature)
  • For example, laf2016010100-flow.nc contains the atmospheric fields of the COSMO analysis of Januray 1st, 2016 for 0:00 UTC.

Required netCDF variables

Variables in hhl.nc

double rlon(rlon) ;
        rlon:standard_name = "grid_longitude" ;
        rlon:long_name = "longitude in rotated pole grid" ;
        rlon:units = "degrees" ;
        rlon:axis = "X" ;
double rlat(rlat) ;
        rlat:standard_name = "grid_latitude" ;
        rlat:long_name = "latitude in rotated pole grid" ;
        rlat:units = "degrees" ;
        rlat:axis = "Y" ;
char rotated_pole ;
        rotated_pole:grid_mapping_name = "rotated_latitude_longitude" ;
        rotated_pole:grid_north_pole_latitude = 40. ;
        rotated_pole:grid_north_pole_longitude = -170. ;
float HHL(time, height, rlat, rlon) ;
        HHL:long_name = "Geometric Height of the layer limits above sea level(NN)" ;
        HHL:units = "m" ;
        HHL:param = "6.3.0" ;
        HHL:grid_mapping = "rotated_pole" ;

Variables in soil.nc

float SOILTYP(time, rlat, rlon) ;
        SOILTYP:long_name = "soil type of grid (1...9, local soilType.table)" ;
        SOILTYP:units = "Numeric" ;
        SOILTYP:param = "196.3.2" ;
        SOILTYP:grid_mapping = "rotated_pole" ;

Variables in <prefix>YYYYMMDDHH-flow.nc files:

float W(time, height, rlat, rlon) ;
        W:long_name = "Vertical Velocity (Geometric) (w)" ;
        W:units = "m s-1" ;
        W:param = "9.2.0" ;
        W:grid_mapping = "rotated_pole" ;
float U(time, height_2, rlat, rlon_2) ;
        U:standard_name = "eastward_wind" ;
        U:long_name = "U-Component of Wind" ;
        U:units = "m s-1" ;
        U:param = "2.2.0" ;
        U:grid_mapping = "rotated_pole" ;
float V(time, height_2, rlat_2, rlon) ;
        V:standard_name = "northward_wind" ;
        V:long_name = "V-Component of Wind" ;
        V:units = "m s-1" ;
        V:param = "3.2.0" ;
        V:grid_mapping = "rotated_pole" ;
float T(time, height_2, rlat, rlon) ;
        T:standard_name = "air_temperature" ;
        T:long_name = "Temperature" ;
        T:units = "K" ;
        T:param = "0.0.0" ;
        T:grid_mapping = "rotated_pole" ;
float P(time, height_2, rlat, rlon) ;
        P:long_name = "Pressure" ;
        P:units = "Pa" ;
        P:param = "192.3.0" ;
        P:grid_mapping = "rotated_pole" ;
float QV(time, height_2, rlat, rlon) ;
        QV:standard_name = "specific_humidity" ;
        QV:long_name = "Specific Humidity" ;
        QV:units = "kg kg-1" ;
        QV:param = "0.1.0" ;
        QV:grid_mapping = "rotated_pole" ;

Variables in <prefix>YYYYMMDDHH-soil.nc files:

double depth_2(depth_2) ;
        depth_2:long_name = "depth_below_land" ;
        depth_2:units = "m" ;
        depth_2:positive = "down" ;
        depth_2:axis = "Z" ;
        depth_2:bounds = "depth_2_bnds" ;
float T_SO(time, depth, rlat, rlon) ;
        T_SO:long_name = "Soil Temperature (multilayer model)" ;
        T_SO:units = "K" ;
        T_SO:param = "18.3.2" ;
        T_SO:grid_mapping = "rotated_pole" ;
float W_SO(time, depth_2, rlat, rlon) ;
        W_SO:long_name = "Column-integrated Soil Moisture (multilayers)" ;
        W_SO:units = "kg m-2" ;
        W_SO:param = "20.3.2" ;
        W_SO:grid_mapping = "rotated_pole" ;

Namelist parameters

INIFOR mirrors a subset of the PALM-4U's Fortran namelists inipar and d3par and supports the following parameters:

inipar

Parameter name	Default value	Description
nx, ny, nz	None	Number of PALM-4U grid points in x, y, and z direction
dx, dy, dz(10)	None	PALM-4U grid spacings in x, y, and z direction [m]
dz_stretch_level	-9999999.9	Height above which the grid will be stretched [m]
dz_stretch_factor	1.08	Factor by which the grid will be stretched
dz_max	1000.0	Maximum vertical grid spacing [m]
dz_stretch_level_start(9)	-9999999.9	Array of height levels above which the grid is to be stretched vertically [m]
dz_stretch_level_end(9)	9999999.9	Array of height levels until which the grid is to be stretched vertically [m]
longitude, latitude	0.0	Geographical coordinates of the PALM-4U origin [deg]

d3par

Parameter name	Default value	Description
end_time	0.0	PALM-4U simulation time. INIFOR will produce hourly forcing data from the start date (see -d command-line option) to end_time seconds thereafter. [s]

Example namelist file

&inipar nx = 4679, ny = 3939, nz = 360
        dx = 10., dy = 10., dz = 10.
        dz_stretch_level = 2500.0, dz_stretch_factor = 1.08, dz_max = 100.0
        longitude = 13.082744, latitude = 52.325079
/

&d3par  end_time = 86400.0
/

Command-line options

INIFOR configuration

Option	Default value	Description
--averaging-mode <mode>	level	Selects how averaged quantities (large-scale forcing terms) are computed. INIFOR supports averaging along input model levels ('level') and along constant heights ('height').
-a, --averaging-angle <angle>	2.0	Width of the averaging box in longitudal and latitudal direction in the source coordinate system (COSMO rotated-pole) [deg].
-d, --date <date>	20130721	Start date of the simulation in the form YYYYMMDD or YYYYMMDDHH. If no hours (HH) are given, INIFOR assumes that the simulation starts at O UTC on that day.
-i, --init-mode <mode>	volume	Set the PALM-4U initialization mode. INIFOR can provide initial conditions as either profiles or three-dimensional fields. The corresponding modes are 'profile' and 'volume'.
-r, --surface-pressure <pressure>	1e5	Manually set the pressure at z=0 in the PALM-4U domain [Pa]. If not given, the surface pressure is computed from the COSMO pressure field.
-u, --geostrophic-u <velocity>	0	Manually specify the geostrophic wind in x direction [m/s]. If not given, the geostrophic wind is computed from the COSMO pressure field.
-v, --geostrophic-v <velocity>	0	Manually specify the geostrophic wind in y direction [m/s]. If not given, the geostrophic wind is computed from the COSMO pressure field.
-z, --elevation <height>	35	Specifies the elevation of the PALM-4U domain above sea level [m].

I/O

Option	Default value	Description
-l, --hhl-file <netCDF file>	<scenario path>/hhl.nc	Location of the netCDF file containing the vertical COSMO-DE grid levels, specifically the heights of half levels (hhl, i.e. vertical cell faces).
-n, --namelist <namelist file>	./namelist	Location of the PALM-4U namelist file. INIFOR expects the file to contain two namelists, inipar and d3par, from which it will read grid parameters and the simulation time.
-o, --output <output file>	./palm-4u-input.nc	Name of the INIFOR output file, i.e. the PALM-4U dynamic driver.
-p, --path <scenario path>	./	Scenario path, i.e. the path of the meteorological input data.
-s, --soil-file <netCDF file>	<scenario path>/soil.nc	Location of the netCDF file containing the COSMO-DE soil type map.
-t, --static-driver <netCDF file>	None	Location of the netCDF file containing the static driver file for the case to be simulated with PALM-4U.

File prefixes

Option	Default value	Description
--input-prefix <prefix>	laf	Set the file prefixes for all input files. Individual prefixes can be overwritten with the options below.
--flow-prefix <prefix>	laf	Set the file prefix of flow input files.
--radiation-prefix <prefix>	laf	Set the file prefix of radiation input files.
--soil-prefix <prefix>	laf	Set the file prefix of soil input files.
--soilmoisture-prefix <prefix>	laf	Set the file prefix of soil moisture input files.

Non-argument options

Option	Description
--debug	Enable additional terminal messages and netCDF output for debugging.
--version	Output version number and exit.