Release notes history

This is update notice for users of 4A/OP. It shows major revisions. Minor revisions are not listed.
The following are descriptions of significant changes contained in the current version of the software package.
A detailed description of the revision history is available in the Reference Documentation.

2010-2012

• Added user option to simulate scattering effects of clouds (cirrus…)
• New atlases of pre-calculated optical thicknesses that include:
  • an improvement for effects of CO₂ line-mixing
  • the new GEISA 2009 spectroscopy
  • the pressure shift for H₂O, CO₂ and N₂O
  • updated reference gas mixing ratio profiles
  • improved TIPS’ formulation
• Minor bug fixes in a few routines of the model
• Updated and improved Graphical User Interface

2007-2009

• Implementation of the limb viewing geometry:
  • Refined geometry module
  • Option for limb view simulation
  • Height dependence of gravity acceleration
• Implementation of the user option to simulate scattering effects (coupling with DISORT and SOS codes). Option is active only in Earth view geometry and for aerosols
• New atlases of pre-calculated optical thicknesses:
  • that make the code more precise
  • that include:
    • an updated line-mixing for CO₂
    • the new GEISA 2008 spectroscopy
    • the pressure shift for H₂O
    • updated gas mixing ratio profiles,
    • improved CFC’s formulation
• Minor bug fixes in a few routines of the model
• Updated and improved Graphical User Interface

2005-2006

• Optical thicknesses of CFC molecules are now stored in Atlases. This modification allows users to use their own CFC mixing ratio profiles and to calculate the corresponding Jacobians.
• Implementation of user option for simulation of the solar contribution to spectral radiance and Jacobians.
• Replacement of optical thickness atlases computed with GEISA 97 by atlases computed with up-to-date spectroscopy from the GEISA 2003 Edition.
• Improved capabilities of the updated Graphical User Interface.
• Miscellaneous minor corrections.

2003-2004

• Minor fixed bugs in a few routines of the model.
• Updated and improved Graphical User Interface.

December 2002

• Added various possible units for Jacobians in output ASCII files.

November 2002

• Added hole convolution option for computer time saving in some particular cases. This option speeds up convolution computing when Jacobian calculation is selected. It slightly slows it when convolution is done with a spectrum only. Note that results computed with this option are physically the same as those computed without it, even if there is a numerical difference between them.
• Added statistics tool for the computation of the difference between two spectra and the corresponding statistics.

October 2002

• Added user-defined spectral emissivity functions.
• The plan-parallel atmosphere assumption has been replaced by a spherical atmosphere approximation.

September 2002

• The original code 4A2000 written in Fortran 77 developed at LMD has been ported in Fortran 90.
• The wave numbers initially in simple precision are now in double precision.