LBLRTM

LBLRTM_v12.1

Date: November 2011

Updated aer_v_3.1 line parameter database included in this release:

Corrected CO₂ line parameters. See notes on our AER line parameter "what's new" page.
Included line parameters for SF₆ and ClONO₂. See notes on our AER line parameter "what's new" page.

Source code updated to FORTRAN 90 (.f90). (D. Weisenstein)
New modules define physical constants in a single place in the code. (D. Weisenstein)

phys_consts.f90 defines fundamental physical constants.

planet_earth.f90 defines Earth-related constants.

Updates to lblatm.f90:

Corrected molecular weight for C₂H₄. (M. J. Alvarado, K. E. Cady-Pereira)

Updates to fftscn.f90 and fftscn_dbl.f90:

LPTFFT was increased by a factor of 4. This gives better accuracy for regions with large changes in radiance (e.g., CO₂ nu3 bandhead region). (M. J. Alvarado, G. Uymin)

When param keyword is non-zero for a Gaussian line shape (JFN = -2), truncate the Gaussian in the time domain based on the maximum optical path difference. (M. J. Alvarado, G. Uymin)

Fixed cross-section related bugs related to CLONO2 and F13. (V. H. Payne)
Corrected various issues with variables that had not been properly initialized. (M. J. Alvarado)
Updated lblrtm instructions.

LBLRTM_v12.0

Date: January 2011

Updated aer_v_3.0 line parameter database included in this release:

HITRAN2008 line parameters adopted with notable exceptions for H₂O, CO₂, and O₂ in spectral regions where validations against high quality measurements have shown that alternative parameters provide better consistency. See notes on our AER line parameter "what's new" page.

Line coupling for CO₂ for isotopologues 1 through 7, following the approach of Lamouroux et al (2010) but consistent with the aer_v_3.0 line file.

Line coupling parameters for the v4 and v3 bands of CH₄, following the approach of Tran et al. (2006) but consistent with HITRAN 2008 line parameters.

Updated MT_CKD_2.5.2 continuum model included in this release:

Added ‘if’ tests needed for speed improvements in monortm (K. E. Cady-Pereira, E.J. Mlawer)

Other software updates include:

In N2 pure rotation band, fixed incorrect indexing related to contribution from N2-O2 (E.J. Mlawer, A.E. Lipton, V.H. Payne)
Increased number of output points in all continuum modules to prevent possible truncation at high wavenumber end (E.J. Mlawer, S.A. Clough, C.H. Kohler)

Near-IR O2 continuum to allow for calculations over domains greater than 2000 cm-1; needed by standalone continuum code (E.J. Mlawer, P. Hedelt)

O2 fundamental to correct 5 cm-1 shift (E.J. Mlawer, S.A. Clough, C.H. Kohler)

Rayleigh is now computed for IAERSL=5 (E.J. Mlawer, K.E. Cady-Pereira)

Updated historical information (E.J. Mlawer, V.H. Payne)

Updates to cross-section files:

3 new cross-sections to the archive [acetone (CH3COCH3), PAN, CH3CN]. The acetone data was derived by A. Waterfall (Thesis, 2003); PAN and CH3CN were obtained from HITRAN 2008.

Documentation of cross-section data now provided.

Updates have been made to non-LTE subroutines and to TAPE4 (non-LTE input) format:

A distinction between vibrational temperature profiles for minor isotopologues of a given molecule now enabled. (V. Payne and D. Weisenstein)
An error has been fixed that led to small discrepancies between the TAPE5 temperature profile and the temperature profile for states in LTE when using IHIRAC=4 (D. Weisenstein)
Bug fix related to compiler-dependent memory allocation and to starting-wavenumber dependent differences in the application of the radiation field within non-LTE calculations (D. Weisenstein, M. Alvarado, E. Mlawer).

Simplified makefile system in the build directory; includes new platforms such as Windows and capability to easily add new platforms.

Updated lblrtm_instructions.

LBLRTM_v11.7

Date: January 2010

MT_CKD_2.5 continuum modifications included in this release are based on analyses of IASI, AIRS, and AERI measurements in the region past the bandhead of the CO₂v3 band (~2385 cm^-1):

Introduction of temperature dependence of CO₂ continuum absorption from 2386-2434 cm^-1based on line shape calculations; validated with IASI measurements (E.J. Mlawer and V.H. Payne)
Modification of CO2 continuum coefficients from 2000-3000 cm^-1from IASI and AERI (from ARM) measurements (E.J. Mlawer, V.H. Payne, and M.W. Shephard)
Modification of water vapor self continuum coefficients from 2000-3200 cm^-1from IASI and AIRS measurements; fit based on near-IR studies of Bicknell et al. (2006) and Fulghum and Tilleman (1991) (E.J. Mlawer and V.H. Payne)

The AER line parameter database has been updated to aer_v_2.4 and includes:

The carbon dioxide line positions and intensities in this file are from the Carbon Dioxide Spectral Database, maintained by S. Tashkun, Tomsk, as implemented in the hitran_mipas_pf3.2 line file (Flaud et al., 2003). The CDSD parameters have been implemented in the spectral range 597-2500 cm-1, and the first order line coupling coefficients re-calculated using the formalism of Niro et al. (2005). The CDSD line parameters and coupling coefficients have been validated using AIRS and IASI data.
Water vapor line shifts and line-width temperature dependences have been updated for numerous lines from 436 to 2396 cm^-1 with calculations provided by R. R. Gamache (personal communication). These updated water vapor line parameters have been validated using data from AIRS, IASI and from the ARM NSA AERI-ER.

Very Important: Accompanying this LBLRTM release is a spectroscopic line file containing line coupling(mixing) parameters, and a corresponding LNFL program that converts the ascii line file into an input binary file for LBLRTM. Since the CO2 continuum and the CHI factor depend on the line coupling, the line coupling must be used in the calculations in order to obtain accurate results.

LBLRTM_v11.6

Date: June 2009

MT_CKD_2.4 continuum modifications included in this release are:

Modifications to the water vapor continuum arise from new analyses of ARM measurements in the microwave and far-IR regions (S.A. Clough, J. Delamere, V.H. Payne, E.J. Mlawer)

Analyses of measurements in the microwave are based primarily on the two-channel MWR (23.8 and 31.4 GHz) at SGP, with supporting evidence from 150 GHz MWRHF measurements during the COPS campaign and from 170 GHz GVRP measurements at SGP (Payne et al., 2009).
Measurements in the far-IR were from the AERI_ext at the NSA site, in the time surrounding and including the RHUBC-I campaign (Delamere et al., 2009).

Solved the issue of N2 Jacobians being included in the Jacobians generated for other molecules (MT_CKD_2.2)(S.A. Clough and M.W. Shephard)
Fixed an issue with the water vapor Jacobians in which the analytic Jacobians were dependent on the starting wavenumber (MT_CKD_2.3)(K.E. Cady-Pereira and S. Tjemkes)

Other analytic Jacobian related issues resolved in this release include:

Fixed an issue with TOA Jacobians producing NaN in the top layer. (S.A. Clough and Paolo Antonelli)
Fixed a documentation error in the LBLRTM instructions. (K.E. Cady-Pereira)

Fixed a coding error is the solar source function. (K.E. Cady-Pereria and S. Ferron)

Modified LBLRTM to handle underflow problem in convolution routine. (M.W. Shephard, S.A. Clough, G. Uymin)

Modified the LBLRTM default option for zeroing very small atmospheric profile amounts. (S.A. Clough and Hal Woolf)

Note: Accompanying this release are water vapor spectroscopy improvements contained in the new aer_v_2.2 line parameter file.

LBLRTM_v11.3

Date: November 2007

Included NO2 as a cross-section in list of cross-section molecule aliases. Modified LBLRTM to include a default profile for NO2 when it is specified as a cross-section. The default profile is identical to that when an NO2 profile is requested for use when NO2 lines are present. (J. Delamere, S.A. Clough)

Molecules number extended to include molecule # 39; ch3oh (S.A. Clough)

Fixed an error in the scaling option. (J. Delamere, S.A. Clough)

Corrected and indexing issue in the N2 continuum that effected calculations below 350 cm-1 (S.A. Clough, Bill Snow, Bob d'Entremont, M.W. Shephard)

Very Important: Accompanying this LBLRTM release is a new line file containing Niro et al. (2005) line coupling parameters (aer_v_2.1) and corresponding LNFL_v_2.5 program that converts the ascii line file into an input binary file for LBLRTM.Since the CO2 continuum and the CHI factor depend on the line coupling, the line coupling must be used in the calculations in order to obtain accurate results.

LBLRTM_v11.1

Date: July 2007

The continuum for CO2 has been calculated using Niro et al. (2005) line coupling with a factor of 0.75 applied to the nu_3 band. This factor was chosen to get the best agreeement with airs test cases in the nu_3 spectral region. (S.A. Clough, M.W. Shephard, V.H. Payne)
The the value of chi factor for CO2 set to 1. This has been made possible because the apparent sub-lorentzian line shape at the nu_3 bandhead is now taken care of with Niro et al. (2005) line coupling. (S.A. Clough, M.W. Shephard, V.H. Payne)
The directory structure has been modified to be similar with standard release packages. For example: The program is now compiled in a "build" directory instead of the top level; the executable file still get placed in the top level directory.

Very Important: Since the CO2 continuum and the CHI factor depend on the line coupling, the line coupling must be used in the calculations in order to obtain accurate results. Therefore, accompanying this LBLRTM release is a new line file containing Niro et al. (2005) line coupling parameters (aer_v_2.0) and corresponding LNFL_v_2.4 program that converts the ascii line file into an input binary file for LBLRTM.

LBLRTM_v10.7

Date: June 2007

The option for reading spectral cloud optical depths has been changed: IAERSL must now be set to 2 to invoke this option (S.A. Clough)
Modification was made so that the correct 'plotting' of transmittances from optical depths occurs. (S.A. Clough)
Number of input levels (sonde levels) has been increased to 6000. (S.A. Clough and J. Delamere)
A test has been added for ikmax to provide a proper result for a horizontal (or single) layer with aerosols. (S.A. Clough)
Capability to scale cross section (xs) profiles has been added. (S. A. Clough)
Incorrect implementation of IMRG 40 and 41 (42 and 43) option for Analytic Jacobians has been corrected. (S. A. Clough)
A change was made to enable execution with g95 in single and double precision.
A change was made to enable the proper opening/closing of file. (M.W. Shephard, J. Gu, and D. Feldman)
Variable specifications were modified to be consistent within the module and to ensure proper performance with the single precision solar file for both single and double versions of lblrtm. (S. A. Clough)

LBLRTM_v10.3

Date: August 2006

Treatment of mixing ratios has been made more consistent and the volume molar density has been treated more precisely. For example, the coding was modified to allow for variable mixing ratios of nitrogen and oxygen. This is useful for mixing ratios of nitrogen and oxygen different from earth values. (S.A. Clough)
Continuum module was also made more flexible for atmospheres that do not have fixed nitrogen and oxygen values. (S.A. Clough)
The nitrogen collision induced fundamental has been modified using data provided by Walter Lafferty at NIST. There is minimal change in the results from the previous implementation. (S.A. Clough, W. Lafferty, and E.J. Mlawer)
Fixed an error in the coding of the subroutines that load the continuum coefficients into the arrays. Roundoff protection was not provided and in certain cases the loading of the array could be in error by one element. (S.A. Clough)
Fixed an issue associated with the new scaling capability. (S.A. Clough and M.W. Shephard)
The role of IOD=3 has been made more general and more robust. (see instructions) (K.E. Cady-Pereira and S.A. Clough)
IMRG=10 is no longer an available option. The same results can be obtained with IMRG=1. (S.A. Clough and K.E. Cady-Pereira)

LBLRTM_v10.1

Date: June 2006

Modifed the program so that the layer optical depth calculation options work as specified in the instructions and are consistent with versions previous to LBLRTM_v10.0. (S.A. Clough and M.W. Shephard)

LBLRTM_v10.0

Date: May 2006

Modified the Analytic Jacobian calculations to be more efficient and accurate (S.A. Clough).
Added the capability to scale the molecular profile values (S.A. Clough).
MT_CKD_v1.3 : Modified CO2 continuum based primarly on LBLRTM validations with SHIS/TES/AIRS observations (M.W. Shephard)
Correction for horizontal propagation with aerosols for any altitude above 1 m (0.001 km) (T. Scharlemann and S.A. Clough).
Modified LBLRTM implementation of TIPS so that it can handle molecules with HITRAN molecule numbers larger than 33.(S.A. Clough and M.W. Shephard)
Also, available for the LBLRTM calculations are additonal CO2 P/Q/R line coupling adapted from Niro et al. (2005) for the CO2 v2 (600-800 cm-1). The line coupling parameters are provide with the spectroscopic line parameters and in the LNFL (www.rtweb.aer.com) example. LNFL merges the line coupling paramters with a spectroscopic line database to create input spectroscopic parameters for LBLRTM (M.W. Shephard and S.A. Clough).

F. Niro, K. Jucks, J.-M. Hartmann, Spectra calculations in central and wing regions of CO2 IR bands. IV : Software and database for the computation of atmospheric spectra, in J Quant Spectrosc Radiat Transfer. Vol. 95, 2005, pp. 469-481.

LBLRTM_v9.4

Date: Jan 2005

Fixed a small bug typo bug in the hydrostatic routine in LBLRTM (S.A. Clough).

LBLRTM_v9.3

Date: Oct 2004

Fixed a small bug in the analytic derivatives/jacobians routine in LBLRTM that occured when cross-sections are specified when computing derivatives/jacobians. (H. Snell)

LBLRTM_v9.2

Date: Sept 2004

Implementation of analytic derivatives/jacobians in LBLRTM. This effort was supported by EUMETSAT and designed to require a minimal amount of setup time on the part of the user while exploiting pre-existing LBLRTM calculation options. Refer to the user instructions and the new FAQ document for more details. (H. Snell, M.W. Shephard, S.A. Clough, and S. Tjemkes)

The foreign water vapor continuum has been modified in the 250-500 cm-1 region to provide improved agreement with AERI extended range measurements from SHEBA and the North Slope of Alaska ARM site. The consequence is that in this spectral region, the MT_CKD_1.1 foreign continuum provides results similar to those previously obtained with CKD_2.4.1. (S.A. Clough and J. Delamere)

A correction to the collision induced nitrogen continuum absorption in the 0-350 cm-1 region has been implemented. The magnitude of the increase is approx. 35 % from 0-250 cm-1. (S.A. Clough and R. Tipping)

LBLRTM_v8.4

Date: April 2004

Minor bug fixs to the LOWTRAN7 routin in LBLRTM (lbllow.f) that includes the moving of an ENDIF to the proper location and the proper alignment of ZMDL and ALTZ arrays (S.A. Clough and S. Shald)

In the continuum module, the coding of the partial pressure of water vapor has been simplified by introducing a varaiable h2o_frac. The factor of 1.e-20 has been removed from Wtot. In conjunction with this, the factor of 1e-20 has been removed from the calculation of fractions for the other species, including the Rayleigh scattering section. (S.A. Clough)

The common blocks in several subroutines have been modified to eliminate compiler "Warning" Messages (S.A. Clough)

Minor bug fix in postsub.f (S.A. Clough)

Changes to xmerge.f to get it ready for analytic derivation implementation. (H. Snell)

LBLRTM_v8.3

Date: December 2003

Minor bug fix to the SCNMRG routine. (M.W. Shephard and J. Gu)

LBLRTM_v8.2

Date: October2003

Minor bug fix to the LOWTRAN7 routine in LBLRTM (lbllow.f), which accounts for clouds and aerosols. (S.A. Clough)

Added a makefile and utility in order to run LBLRTM on LINUX INTEL. (M.W. Shephard and H. Nair)

LBLRTM_v8.1

Date: October2003

The following are descriptions of important changes contained in LBLRTM v8.1:

The partition function routine has been changed to TIPS_2003 [Fischer,J., R.R. Gamache, A. Goldman, L.S. Rothman and A. Perrin. Total internal partition sums for molecular species in the 2000 edition of the HITRAN database, JQSRT 2003;82:401-412.] (S.A. Clough)

The number of molecules that can be handled is 38, consistent with HITRAN 2000. (S.A. Clough)

The chi factor for carbon dioxide has been modified. The chi factor is now computed in a separate subroutine. (S.A. Clough)

The cumulus cloud option is now working. (S.A. Clough and M.W. Shephard)

The line coupling coefficients for the oxygen lines in the microwave region have been modified based on the data of Cimini et al. (2003). (K. Cady-Pereira and S.A. Clough)

The method of handling the temperature correction for transitions with unknown lower state energies has been modified. (S.A. Clough and M.W. Shephard)

The CO2 Mixing Ratio parameter read from TAPE5 (if non zero) prevails over all other input values. This provides a ready means to globally change the carbon dioxide mixing ratio. (S.A. Clough)

Spectral range over which carbon dioxide continuum has been increased by a factor of 7.0 has been extended to 0-1200 cm-1. (S.A. Clough)

LBLRTM v7.04

Date: April 2003

The following are descriptions of important changes contained in LBLRTM v7.04:

The interface between LBLRTM and LOWTRAN7 has been updated to run operationally (i.e. including aerosols and clouds). (S.A. Clough, M.W. Shephard, and S. Tjemkes)

To function more efficiently as a stand alone program the common blocks in LBLATM has been made more consistent. (S.A. Clough and D. Turner)

LBLRTM v7.03

Date: March 2003

The following are descriptions of important changes contained in LBLRTM v7.03:

There was code implemented to report and skip over spectral lines that cannot be handled properly by TIPS in LBLRTM. (H. Snell and S.A. Clough)

Pressures adjacent to 35 km in the built in US STD ATMOS was modified. (W.O. Gallery)

LBLRTM v7.01

Date: February 2003

This is update notice #11 for users of LBLRTM, the Line By Line Radiative Transfer Model

The following are descriptions of important changes contained in LBLRTM v7.01:

Completely new water vapor continuum model (0-20,000cm-1): MT_CKD_1.0. See the release notes for the mt_ckd continuum for further details. (E.J. Mlawer, D.C Tobin and S.A. Clough)

LBLRTM modified to read the single precision SOLAR.RAD file when running LBLRTM in double precision (solar applications) (S.A. Clough).

Fixed a bug when using cross sections (XS directory) specified on pressure levels when the first reference altitude is zero. (M.W. Shephard)

For LBLATM (IATM=1), volume mixing ratio values on TAPE6 (output) have been changed from ppv to ppmv with the units indicated in the text. This provides consistency with volume mixing ratio input for LBLATM (TAPE5). Note that the vmr variables internal to the code are ppv. (M.W. Shephard)

Increased the maximum number of LBLATM input levels from 3400 to 4000 in order to input full radiosonde profiles. (M.W. Shephard)

Increased the portability of LBLRTM by providing makefiles and utilities to run LBLRTM on IBM (AIX) and on OS X (Mac). (S.A. Clough, M.W. Shephard, P. VanDelst, A. Goldman)

Note: This version of LBLRTM has been executed on the following platforms:

System	Mfr.	Compiler	sgl	dbl
IRIX	SGI		f90,f77	f90,f77
SOLARIS	SUN		f90,f77	f90,f77
AIX	IBM		f90	f90
LINUX	----	PGI	f90	f90
OS X	Apple	Absoft	f90	f90
		g77 (gnu)	g77

Makefiles are included for the compilers appearing in bold in the above table.

**f90** for compiling LINUX in double precision, the script "linux_dbl_script" must be executed which includes the appropriate makefile.

LBLRTM has previously been run by us on DEC alpha, Cray, MS_dos, and HP platforms. The associated utilities used are included in this release but are likely outdated.

LBLRTM v6.12

Date: October 2002

This is update notice #10 for users of LBLRTM, the Line By Line Radiative Transfer Model

The following are descriptions of important changes contained in LBLRTM v6.12:

An important change has ben implemented for the calculation of the optical depth for the carbon dioxide bands in the 500 cm-1 - 900 cm-1 region. The chi line shape factor and the continuum for carbon dioxide have been modified in this region resulting in an overall increased absorption. These changes were principally based on validations with the U. Wisconsin interferometric measurements: HIS (CAMEX), SHIS (AFWEX) and AERI (ARM NSA site). These modifications should be considered as preliminary with further improvements expected in the near future. (Clough/Shephard/Delamere/Tobin/Turner/Revercomb)

The continuum module for this release is designated ckd_2.4.2 reflecting the modification to the carbon dioxide continuum. No change has been made to any other continuum contributions for this release.

The capability to perform the radiative transfer for down looking scenes with a Lambertian surface has been added. The down welling flux is obtained from a radiance calculation at the diffusivity angle (secant = 1.67). (Clough/Shephard)

Corrected a spectral interpolation error in the utilization of the EMISSIVITY and RELECTIVITY data files. (VanDelst)

Problem in version 6.01 for line coupling in the microwave region fixed. (F. Evans)

Correction of redundant Rayleigh extinction contributions when both the continuum and the lowtran modules are invoked. (Qilong Min, Minzheng Duan)

The line rejection files, REJ1 and REJ4, now have the value of the spectral sampling interval, DV, stored in the files. This enables the performance of subsequent radiative transfer calculations with exactly the same sampling at each layer. (Shephard)

Increased portability of the model. In particular, compatibility with PGI LINUX compiler (both f77 and f90) established. The utility modules (UTIL_XXX) have been updated.

Note, for double precision on the PGI LINUX platform one must run the "src/linux_dbl_script" script before compiling with the makefile "makefiles/makelbl.pgi_linux_f90_dbl". (Shephard/ Clough)

LBLRTM v6.01

Date: February 2002

This is update notice #9 for users of LBLRTM, the Line By Line Radiative Transfer Model

The following are descriptions of important changes contained in LBLRTM v6.01:

Capability to input atmospheric profile on either altitude or pressure grid, and to output quantities on either altitude or pressure grid.

Capability to compute quantities for atmospheric layers which are not in local thermodynamic equilibrium (Non-LTE option).

The exponential function and the exact 'linear in tau' function are now tabulated at 5000 values. A table lookup is used in the radiative transfer calculation. It should be noted that this adds a small element of discreteness into the calculation.

Update of universal constants.

Continuum model CKD 2.4.1 contains collision induced O2 (15000 û 29870 cm-1) continuum (Greenblatt et al., 1990).

Changed name of input files containing surface properties from "EMISSION" and "REFLECTION" to "EMISSIVITY" and "REFLECTIVITY".

A 'bug' in the fourth function contribution to the optical depth for lines with line coupling has been corrected.

A number of errors associated with the 'scanmrg' options have been corrected.

Makefiles for creating both single and double precision executables for a number of platforms have been included. It is to be noted that the same line file works properly with either the single or double precision executable.

Note: LNFL and the line parameter database have also been updated.

Atmospheric and Environmental Research