Version 3.1 mainly holds bugs fixes and smaller improvements in the core model.

Important Note :
Simulation results obtained with Version 3.1 might differ from results calculated with other versions. (If everything would remain the same, there would be no sense in improvement)
Therefore it is essential, that you continue using the same model version all through one project.
If you decide to change to a newer model version inside one study, you should re-calculate all simulations to make sure that the results are scientifically sound.

1. Bug-Fix in Km/Kh Calculation
   
2. Review of pollutant Dispersion Routines
   
3. Review of Flow Solver (SOR algorithm)
   
4. Changed Interpretation of Soil Humidity IMPORTANT
   
5. Improved Batch-Manager
   
6. Face Lift of Software Interface
   
7. New Options for Telescoping Grids
   
8. Saver Time Steps in Spin Up Phase
   
9. Limit in Iterations for all Energy Balance Calculations
   
10. SELECT.VAR Option removed
    
11. [POSITION| Information moved to Area Input File
    
12. Backward Compatibility removed
    
13. Reorganisation of Folders
    
14. Small Changes in Output File Variables
    
15. Improved Sky-View Factor Calculation
    
16. Improved Flow Calculation Stability (BETA 3)
    
17. Project Directory enforced (BETA 3)
    

1. Bug-Fix in Km/Kh calculation
   • There has been a programming error in the calculation of the Km turbulent exchange coefficient (and of the other K's consequently) that has been removed in V3.1.
   • However, the results obtained by V3.1 differ from those obtained by V3.0.
2. Review of pollutant dispersion routines
   • The pollutant dispersion has been re-worked and partyl re-coded. This should fix a number of problems arising due to numerical instability.
3. Review of flow solver (SOR algorithm)
   • The flow solver has been adjusted to increase calculation speed.
4. Changed interpretation of soil humidity IMPORTANT
   • The relative soil humidity as input value was related to the saturation value of the soil.
   • This has been changed. Relative wetness is now related to the field capactiy.
5. Improved Batch-Manager
   • The interface for starting a batch job has been extended with a preview and the option to cancel the run.
6. Face lift of software interface
7. New options for telescoping grids
   • V3.1 allows you to define a z-level where the telecoping starts (see here).
8. Saver time steps in spin up phase
   • During the first 30 min of model simulation time, the smallest available time step will always be used.
9. Limit in iterations for all energy balance calculations
   • The maximum amount of allowed iteration cycles for solving the energy balance has been limited to 300 iterations.
   • This prevents the whole model from hanging in an endless loop if a single surface or leaf energy balance cannot be solved for whatever reason.
10. SELECT.VAR option removed
    • The option to select which variables are written into the _ATM_ files has been dropped s they caused too often missing variables and disappointed user.
11. [POSITION| information moved to Area Input file
    • The position information (location of area in terms of longitude, latitude and reference time zone) has been moved to the Area Input File.
12. Backward compatibility removed
    • ENVI-met 3.1 will only accept files that follow the new format specifications. In case of the Area Input Files that means that you need to open your old files in the V3.1 ENVI-met Editor and save them in order to use them with ENVI-met V3.1. In case of the .CF configuration file, all old sections must be removed.
13. Reorganisation of folders
    • In order to allow a more flexible project management and a better integration of the different ENVI-met applications, the names and the meaning of folders have been reorganised.
    • Especially, the global databases for soils, profils and plants have been moved from the \input folder to the \sys.basedata folder for a better separation with the “normal” input files of the model simulations.
14. Small changes in output files variables
    • Adjustmens to the variables written into the output files, please check the summary of variables of the associated file type.
15. Improved Sky-View factor calculation
    • The algorithm has been improoved for a finer resolution of the results.
16. Improved flow calculation stability (since BETA 3)
    • The flow solver algorithm has been reviewed an changed in order to improove performance and stability.
17. Project directory enforced (BETA 3)
    • In oder to further separate the model from the input files, the user must select a project directory during setup. (See MYALIAS.DAT)