LBLRTM v12.10
August 2020

* The Planck function and its derivative are now calculated analytically rather than using look up tables (I. Polonsky, E.Mlawer)

* The code has been reformatted with modern indentation and subroutine and function end statements, allowing for
* greater readability (I.Polonsky)

* Added six cross-section molecules: SF6, NF3, C2F6, HCHO,  HFC-245fa, and HFC-236fa. (I.Polonsky)

* Introduced MT_CKD_3.4: Collision-induced absorption in the oxygen A-band was modified to be consistent with OCO-2 ABSCO 5.1  (E.J. Mlawer, J. Mascio, V.H. Payne, B. Drouin, F. Oyafuso).

LBLRTM v12.9
August 2019

* Module oprop.f90 was revised to allow handling of the UV O2 lines (M.J. Iacono, E.J. Mlawer)

* Updated to MT_CKD 3.3 (E.J. Mlawer)

* Accommodated extension of solar irradiance to 86500 cm-1 (M.J. Iacono)

* added BrO to cross-sections (K.E. Cady-Pereira, R.L. Pernak)

* fixed aliases for cross sections HFC-134a and HFC-141b (K.E. Cady-Pereira, R.L. Pernak, E.J. Mlawer)

* made small adjustments to solar variability code (M.J. Iacono, K.E. Cady-Pereira)

* Added space after STOP in lblatm.f90 to prevent issues on some compilers (M.J. Alvarado, K.E. Cady-Pereira, D.D. Turner)

LBLRTM v12.9_beta
December 2017 (not publicly released)

* Small adjustment to BBFN() in xmerge.f90 to ensure correct rounding to integer (Y. Ma, M.J. Alvarado, E.J. Mlawer)
 
* Set lower limit for Rayleigh to 820 cm-1 (K.E. Cady-Pereira, J.S. Delamere)

LBLRTM v12.8
August 2017

* The continuum was updated to MT_CKD_3.2, which has new self continnum coeffients
  in window regions for wavenumbers greater than 2000 cm-1 and updated self
  continuum temperature dependence from 1800-3500 cm-1 (E.J. Mlawer, M.J. Alvarado)
  K.E. Cady-Pereira)

LBLRTM v12.7.1
July 2017 (not publicly released)

* The error tolerance in BBFN was reduced, making the Planck function evaluation
  more accurate (E.J. Mlawer, K.E. Cady-Pereira)
* The continuum was updated to MT_CKD_3.1, which includes collision-induced
  absorption in the oxygen A-band (E.J. Mlawer, D. Gombos, V.H. Payne, B. Drouin,
  K.E. Cady-Pereira)

LBLRTM v12.7
March 2017

* The capability to handle solar variability as modeled by the NRLSSI2 model
  has been added. (K.E. Cady-Pereira, E.J. Mlawer, M.J. Iacono)

* Code to handle non-unity surface emissivity for flux calculations was 
  implemented. Similar code was added to radsum. (E. J. Mlawer, X.Chen, X. Huang,
  H. Cheng, M.J. Alvarado)

* Fixed a bug in modules that calculate optical depths (e.g. oprop, nonlte) to 
  allow the code to work properly when users input values of SAMPLE other than
  the default. For the default value of SAMPLE=4, the optical depths of narrow 
  lines can have an accuracy that is inferior to the stated accuracy of LBLRTM. 
  This can manifest itself in a greater-than-expected dependence of the output 
  values on the initial wavenumber (v1) input to the calculation. This issue can 
  now be avoided by using a greater value for SAMPLE, such as 8 or 16 (max value 
  allowed is 32). However, the computation time will be greater when SAMPLE is 
  increased. (Y. Ma, E.J. Mlawer, M.J. Alvarado)

* Fixed a bug related to the pressure shifts of oxygen and nitrogen lines when
  additional broadening parameters are used. (K.E. Cady-Pereira, E.J. Mlawer,
  M. J. Alvarado)

* Fixed a minor indexing bug in the cross-section code. (E.J. Mlawer, Y. Ma,
  M.J. Alvarado)


LBLRTM v12.6
November 2016

* The continuum has been updated to MT_CKD v3.0, which included modifications
  to the H2O foreign continuum from 0-600 cm-1 and the self continuum in the 
  microwave that resulted from an analysis of measurements taken at the ARM
  RHUBC-II campaign and a re-analysis of RHUBC-I measurements. (E.J. Mlawer, 
  D.D. Turner, S.N. Paine, V.H. Payne)     

                                          
LBLRTM v12.5
July 2016

* The continuum has been updated to MT_CKD v2.8, which has modifications
  to the H2O foreign continuum in all window regions > 1800 cm-1, the H2O
  self continuum from 1880-2390 cm-1, and the efficiency of N2 collision-
  induced absorption with respect to H2O from 2000-2900 cm-1. (E.J. Mlawer 
  and M.J. Alvarado)

* Saved a variable used by the output code to solve problems when code 
  was compiled with ifort. (K.E. Cady-Pereira and S. DeSouza-Machado)


LBLRTM v12.4
February 2016

* LBLRTM has been updated to accommodate all molecules and isotopologues 
  in HITRAN 2012. This requires the use of LNFL v3.0 to prepare the input 
  binary line file or TAPE3. (M. J. Alvarado, M. J. Iacono) 

* LBLRTM now allows the use of gas-specific broadening parameters, such as 
  CO2 broadened by H2O, when the IBRD flag is activated. This requires the use 
  of LNFL v3.0 to prepare the input binary line file or TAPE3. 
  (K. E. Cady-Pereira)

* LBLRTM now allows for the input of isotopologue profiles; thus the
  default HITRAN ratios are no longer the only option for users. 
  (K. E. Cady-Pereira, M. J. Iacono)

* The continuum has been updated to MT_CKD v2.7, including the addition of 
  the first overtone of the N2 fundamental band. (E. J. Mlawer, D. Gombos)

* Several new cross-section molecules have been added to LBLRTM, 
  including isoprene. (K. E. Cady-Pereira, G. Uymin)

* Fixed a bug in calculation of altitude when the user specifies an input 
  profile on pressure levels. Now the hydrostatic equation is applied 
  with no interpolation of the informational altitudes in the input profile. 
  (K. E. Cady-Pereira, E. J. Mlawer, E. Morgan)

* Fixed a bug in the calculation of the analytic Jacobians for temperature 
  in the MT_CKD 2.7 continuum. (K. E. Cady-Pereira, E. J. Mlawer, C. Lampen)

* Fixed a bug in the calculation of the O2 and N2 foreign widths from the 
  HITRAN air widths. (K. E. Cady-Pereira, M. J. Alvarado, E. J. Mlawer).

* Fixed a bug in the calculation of the radiation term near 1000 cm-1. 
  (E.J. Mlawer, M. J. Alvarado, S. DeSouza-Machado)

* Fixed several minor bugs in the PANEL and RADFNI subroutines that have 
  negligible impacts on the model results. (Y. Ma, M. J. Alvarado, 
  E. J. Mlawer) 
 

LBLRTM v12.2
Oct 2012

* Please note that we no longer recommend the use of the LOWTRAN aerosol 
  options in LBLRTM (IAERSL = 1 or 7), as they are severely out of date. 
  We recommend using the spectral absorption by layer (IAERSL=5) option 
  instead to model an absorber with slowly varying spectral dependence via 
  the file 'in_lblrtm_cld'. This allows you to input spectrally dependent 
  optical depths at each level. AER will not be providing debugging support 
  for runs using LOWTRAN going forward.

* Fixed bug in fftscn.f90 and fftscn_dbl.f90 for truncated Gaussian 
  line shapes (JFN = -2, variable 'param' non-zero). In v12.1, the 
  assumed definition of maximum optical path difference (max OPD) for 
  this function was a factor of 2 off from how this parameter is defined 
  for other FTS scan functions in LBLRTM. For example, to model the IASI 
  line shape in LBLRTM v12.2, you should enter 1.968 cm for the maximum 
  optical path difference (including field of view correction) in the TAPE5 
  and set param to 0.25. Note that v12.1 would give identical results to v12.2 
  if 3.936 cm is entered as the max OPD in v12.1. (M. J. Alvarado)

* Fixed bug that prevented calculating analytic Jacobians for 
  standard model atmospheres. (A. Merrelli, M. J. Alvarado)

* Fixed variable initialization bugs in lblrtm.f90 and postsub.f90.
  (E. Rusin, M. J. Alvarado)

* New module (lblparams.f90) to define LBLRTM array dimensions 
  in a single place in the code. (D. Weisenstein, M. J. Alvarado)

* Increased use of structures (defined in struct_types.f90) in oprop.f90
  and nonlte.f90. (D. Weisenstein)

* Updated makefiles to automatically delete *.mod files before recompiling
  and fixed flags for xlf90 compiler. (Bi YanMeng, M. J. Alvarado)

* Downwelling Solar and Non-Local Thermodynamic Equilibrium (NLTE) examples
  added to package. (M. J. Alvarado, K. E. Cady-Pereira)

LBLRTM v12.1
Oct 2011

* .f files updated to .f90 (D. Weisenstein)

* New modules to define physical constants in a single place in the code:
  - phys_consts.f90 to define fundamental physical constants
  - planet_earth.f90 to define Earth-related constants

* lblatm.f90
  - Corrected molecular weight for C2H4 (M. J. Alvarado, K. E. Cady-Pereira)

* fftscn.f90 and fftscn_dbl.f90 (M. J. Alvarado)
  - 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).
  - 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.

* Fixed cross-section related bugs (V. H. Payne)
  - Capitalization of CCLF3 in FSCDXS
  - Corrected "C" spectral range for CLONO2 in FSCDXS and added the C range spectral
    files to the xs_files directory
  - Reverted to HITRAN 2000 data for CLONO2 to avoid issues with large number of xs
    data points

* Corrected various issues with variables that had not been properly initialized
  (M. J. Alvarado)

* Updated lblrtm instructions.

LBLRTM v12.0
Jan 2011

* contnm.f (MT_CKD_2.5.2)
  - 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 modified to allow for calculations over domains greater than 2000 cm-1; 
	needed by standalone continuum code (E.J. Mlawer, P. Hedelt)
	* O2 fundamental modified 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)

* Added 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.

* lblatm.f
  - Bugs introduced in v11.8.1 lblatm.f common block changes repaired.

* 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 v11.8.1 (AER internal release only)
May 11, 2010

1) lblatm.f

   - Removed BTZ and RGAS variables, replaced with BOLTZ and GASCON from constant
  data block in lblrtm.f

  - Fixed bug in which if REF_LAT is 0.0 on the input file, it was reset to 45.  
  Now using string read for ref_lat variable and converting afterwards.

  - Revised gravity formulation to use "grav" constant rather
  than hard-wired value of 9.80612 in the formula for g0.

2) Added gravity, specific heat of air, molecular weight of air, sec/day to NIST data 
block in rrtm.f; Updated NIST constants in lblrtm.f; Modified common blocks accordingly; 
removed AIRMWT data statement from lblatm.f

3) lbllow.f: removed AIRMWT data statement 

LBLRTM_v11.8
May 2010

NOTE: In tagging v11.8, I did not check in the makefiles so the compile will still produce v11.7

1) The non-LTE routines have been updated to read an updated TAPE4 input format. 
   - The updated TAPE4 format puts the vibrational state information for each molecule 
   into the TAPE4 with the vibrational temperature profiles. Previously, vibrational 
   state information was hard-coded into the source code.  The updated TAPE4 format 
   also specifies the isotopologue number associated with each vibrational state.

   - Instruction manual was updated.

LBLRTM_v11.7
January 2010

1) 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 CO2 v3 band (~2385 cm-1):

	- Introduction of temperature dependence of carbon dioxide continuum absorption 
	from 2386-2434 cm-1 from IASI measurements (E.J. Mlawer and V.H. Payne)

	- Modification of carbon dioxide continuum coefficients from 2000-3000 cm-1 from 
	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-1 from 
	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)


LBLRTM_v11.6


1) There were several analytic Jacobian related issues resolved in this release.

-  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)

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

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

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

5)  MT_CKD_2.2: Solved the issue of N2 Jacobians being included in the Jacobians generated for other molecules (S.A. Clough and M.W. Shephard) 

6)  MT_CKD_2.3: Fixed an issue with the water vapor Jacobians in which the analytic Jacobians were dependent on the starting wavenumber. (K.E. Cady-Pereira and S. Tjemkes) 

7)  MT_CKD_2.4:  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).

LBLRTM_v11.3

1) 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)
        
2) Molecules number extended to include molecule # 39;  ch3oh
   (S.A. Clough)
        
3) Fixed an error in the scaling option.
   (J. Delamere, S.A. Clough) 

4) 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)  


LBLRTM_v11.1

1) 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)

2) The the value of chi 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)

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 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

1)  The option for reading spectral cloud optical depths has been changed:
    IAERSL must now be set to 5 to invoke this option
    (S.A. Clough)

2) Modification was made so that the correct 'plotting' of transmittances from
   optical depths occurs.
   (S.A. Clough)

3) Number of input levels (sonde levels) has been increased to 6000.
   (S.A. Clough and J. Delamere)

4) A test has been added for ikmax to provide a proper result for a horizontal (or single) layer with aerosols.
   (S.A. Clough)

5) Capability to scale cross section (xs) profiles has been added.
   (S. A. Clough)

6) Incorrect implementation of IMRG 40 and 41 (42 and 43) option  for Analytic Jacobians has been corrected.
   (S. A. Clough)

7) A change was made to enable execution with g95 in single and double precision.

8) A change was made to enable the proper opening/closing of file. 
   (M.W. Shephard, J. Gu, and D. Feldman) 

9) 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

1) 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)

2) Continuum module was also made more flexible for atmospheres that do not have
   fixed nitrogen and oxygen values. (S.A. Clough)

3) 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)

4) 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)

5) Fixed an associated with the new scaling capability has been found and fixed.
   (S.A. Clough and M.W. Shephard)     
   
6) The role of IOD=3 has been made more general and more robust. (see instructions)
   (K.E. Cady-Pereira and S.A. Clough)

7) 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

1) 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

1) Modified the Analytic Jacobian calculations to be more efficient and accurate.
   (S.A. Clough)

2) Added the capability to scale the molecular profile values
   (S.A. Clough)

3) MT_CKD_v1.3 : Modified CO2 continuum based primarly on LBLRTM validations with SHIS/TES/AIRS observations
   (M.W. Shephard)

4) Correction for horizontal propagation with aerosols for any altitude above 1 m (0.001 km).
   (T. Scharlemann and S.A. Clough)   

5) 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)

6) 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 parameters 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

1) Fixed a minor bug in the hydrostatic calculation where a variable name was
   mistyped.

2) Modified the double precision f90 makefile for OS X.  


LBLRTM_v9.3

1) Fixed a minor bug in the analytic derivative computation.
   (H. Snell)

LBLRTM_v9.2

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

LBLRTM_v9.1

1)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 
  North Slope of Alaska (NSA).  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).

LBLRTM_v9.0

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

LBLRTM_v8.4

1) 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)

2) 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)

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

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

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


LBLRTM_v8.3

1) Minor bug fix in SCNMRG subroutine.
   (M.W. Shephard and J. Gu)

LBLRTM_v8.2

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

2) Added makefiles and utilities to run LBLRTM on LINUX INTEL.
   (M.W. Shephard and H. Nair) 

LBLRTM_v8.1


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)

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

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

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

5) 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)

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

7) 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)

8) 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

1) 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)

2) 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

1) 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)

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


LBLRTM_v7.01

1) Completely new water vapor continuum model (0-20,000 cm-1):  MT_CKD_1.00
    See the release notes for the MT_CKD continuum for further details.
    (E.J. Mlawer, D.C Tobin and S.A. Clough)

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

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

4) 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)

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

6) 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.


    


