monoRTM

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Contents

1. Cloning
2. Directory Structure
3. Building monoRTM
4. Running monoRTM

If any build or run issues occur, please create an issue or contact the AER-RC Group.

Cloning the Latest Release

Assuming the output directory should be monoRTM:

git clone --recursive [email protected]:AER-RC/monoRTM.git

--recursive is important, because this repository is linked with our common FORTRAN modules repository that are required in the model builds. If this keyword is forgotten, one can do:

git submodule init
git submodule update

in the monoRTM directory.

Currently, the latest release is monoRTM v5.6, and it is recommended that this be the version that users clone and checkout (rather than the master branch). To do this, one needs to simply checkout the v5.6 tag:

git checkout tags/v5.6

No releases before v5.6 are available via GitHub, but they can be requested by emailing [email protected]. For information on previous releases, please visit the What's New Wiki page.

Instead of cloning, users can also download a monoRTM tarball and unpack it:

tar xvf monortm_v5.6.tar.gz

Directory Structure

The MONORTM directory contains several sub-directories described briefly below:

Name	Description
README	This file
build	Contains makefiles for MonoRTM for different platforms
run	Contains files required to run MonoRTM. run_monortm_example is a script to run some examples TAPE3_spectral_lines.dat.0_55.v5.0_fast contains the spectral line information Note that if you wish to run a faster calculation with fewer microwave spectral lines or for a spectral range outside the wavenumber range of the spectral line file supplied in the examples, you can create a line file using MonoLNFL, which iscontained in this release package. run/in contains sample input files: _dn: denotes sample input files for downwelling radiance calculations _up: denotes sample input files for upwelling radiance calculations MONORTM.IN: input compatible with lblrtm (ex-TAPE5), IATM=1. IDL code to generate profiles in TAPE5 format from ARM netCDF radiosonde files is available in the idl sub-directory MONORTM_PROF.IN : contains layer data, IATM=0 (this is a copy of TAPE7 which is generated by a run where IATM=1 run/out will hold the output from MonoRTM: MONORTM.OUT MONORTM.LOG (if LBLATM is ON) - TAPE6 file TAPE7 (if LBLATM is ON)
src	contains all source files needed by MonoRTM.
doc	detailed instructions manual about MonoRTM, in ASCII format.
idl	tool for creating monortm input from ARM sonde files.

Building monoRTM

To start, descend into the build directory:

cd build
make -f make_monortm $TARGET

The TARGET environment variable depends on the user's operating system, compiler, and desired precision. Available targets are:

Target	Description	Compiler
aixIBMsgl	IBM/AIX OS using IBM fortran,single precision	xlf90
linuxPGIsgl	Linux OS using PGI fortran,single precision	pgf90
linuxGNUsgl	Linux OS using GNU fortran,single precision	gfortran
linuxG95sgl	Linux OS using G95 fortran,single precision	g95
inuxINTELsgl	Linux OS using Intel fortran,single precision	ifort
mingwGNUsgl	Windows unix shell environment using gfortran,single precision	gfortran
osxABSOFTsgl	Mac OS_X using Absoft Pro fortran,singleprecision	f90
osxGNUsgl	Mac OS_X using GNU fortran,singleprecision	gfortran
osxIBMsgl	Mac OS_X using IBM XL fortran,singleprecision	xlf90
osxINTELsgl	Mac OS_X using Intel fortran,single precision	ifort
sunSUNsgl	Sun/Solaris OS using Sun fortran,single precision	sunf90
sgiMIPSsgl	SGI/IRIX64 OS using MIPS fortran,single precision	f90
aixIBMdbl	IBM/AIX OS using IBM fortran,double precision	xlf90
linuxPGIdbl	Linux OS using PGI fortran,double precision	pgf90
linuxGNUdbl	Linux OS using GNU fortran,double precision	gfortran
linuxG95dbl	Linux OS using G95 fortran,double precision	g95
inuxINTELdbl	Linux OS using Intel fortran,double precision	ifort
mingwGNUdbl	Windows unix shell environment using gfortran,double precision	gfortran
osxABSOFTdbl	Mac OS_X using Absoft Pro fortran,doubleprecision	f90
osxGNUdbl	Mac OS_X using GNU fortran,doubleprecision	gfortran
osxIBMdbl	Mac OS_X using IBM XL fortran,doubleprecision	xlf90
osxINTELdbl	Mac OS_X using Intel fortran,double precision	ifort
sunSUNdbl	Sun/Solaris OS using Sun fortran,double precision	sunf90
sgiMIPSdbl	SGI/IRIX64 OS using MIPS fortran,double precision	f90

Running monoRTM

To generate example output:

cd run
run_monortm_examples

Note that you may have to modify the executable name in run_monortm_examples to match the name of the executable that you have created.

Example inputs and outputs can be found in the example tarball.

Tailoring monoRTM to Specific Needs

MONORTM is a driver program that calls the core module called the Monochromatic Optical Depth Model (MODM). The inputs to MODM could be modified inside monortm.f90 directly or through the input file MONORTM.IN (same type of format as LBLRTM's TAPE5), see instructions for more details. MonoRTM is a forward model. MonoRTM is designed to be very flexible. We can either use it as a black box and control everything from the MONORTM.IN input file, or one can modify the code itself and recompile it. In the latter, it is structured in such a way that the changes should always be done in monortm.f90 (the driver program). The other auxillary files (monortm_sub.f90, modm.f90, lblatm.f90, lblrtm_sub.f, tips_2003.f and isotope.dat) should normally not be touched, except in rare situations. In case there is an update in the continuum calculations a new contnm.f90 module will be generated and sent to the users (or made available on the WEB/ftp site).

The core of MonoRTM is the computation of the optical depths. It is designed as a subroutine for flexibility and could be easily plugged in a different radiative transfer model if needed.

Outputs of MonoRTM:

The records stored in MONORTM.OUT are the following:

Record	Description
NPR	Profile index used (not necessarily in order)
FREQ	Frequency in GHz (or wavenumbers, for wavenumbers greater than 100 cm-1)
BT(I)	Brightness temperature in Kelvin
TMR(I)	Mean radiating temperature (K)
RAD(I)	Radiance (W/(cm^2 ster cm^-1))
TRTOT(I)	Total transmittance (no unit: between 0 and 1)
WVCOLMN	Integrated water vapor amount along the optical path in cm
CLWCOLMN	Integrated cloud liquid water along the optical path in mm
TMPSFC	Surface/target temperature in K
EMISS(I)	Surface/target emissivity (no unit, between 0 and 1)
REFLC(I)	Surface/target Reflectivity (no unit , between 0 and 1)
ANGLE	Angle in degrees
OTOT	Total column-integrated optical depth due to all species
OTOT_*	Total column-integrated optical depth by molecules with line data
ODXSEC	Total column-integrated optical depth due to all cross-section molecules

Contact

Any comments or questions should be forwarded to Karen Cady-Pereira ([email protected])

AER , Radiation and Climate Group

131 Hartwell Avenue

Lexington, MA 02421 USA

Tel: 1 781 761 2216

Fax: 1 781 761 2299