
You will find descriptions of the changes to the NESTDOWN version 3
source code in this file. Each release will be a complete tar file
such as this. 

The current release is 3.7 (December 23, 2004)

========================================================

Bug fixes and changes in V3.7:

1. Bug fixes:

- Add more selective comparisons to check if correct data 
  is being used.

  Affected file:
  src/module_header_data.F

- Modify domain consistency tests to allow for tolerable 
  differences in real header locations.

  Affected file:
  src/module_header_data.F

2. Changes and improvements:

- Reduce min RH from 5% to 1%
  
  Affected file:
  src/module_base_state.F

- Add INTEL compiler flags. PGI wil remain default. To compile 
  with INTEL, type "make intel"

  Affectd file:
  Makefile

- Reduce AIX optimization from -O3 to -O0. This reduces the compile 
  time from around 15min to about 2 seconds. Effect on run time is
  negligible.

  Affectd file:
  Makefile
========================================================

Bug fixes and changes in V3.6:

1. Bug fixes:

Bug fixes:

- Fix the mixing ratio computation to change from specific 
  humidity to mixing ratio.

  Affected file:
  src/module_base_state.F

- Change gas constant from 287. to 287.04 to be consistent with
  it's used elsewhere in the modeling system programs.

  Affected files:
  src/module_base_state.F, module_vert_interp.F

- Add a fix to ensure that seaice fraction will always be between 
  0 and 1 after interpolation.

  Affected files:
  src/module_horiz_interp.F, nestdown.F

- Add canopy water/moisture field to the masked fields for doing 
  interpolation.

  Affected file:
  src/nestdown.F

2. Changes and improvements:

- Add additional NOAH LSM variables

  Affected files:
  src/module_horiz_interp.F, nestdown.F

- Optimization on the IBM has been lowered to -00. 
  Although -02 and -03 will work. -00 is much faster.

  Affected file:
  Makefile

========================================================

Bug fixes and changes in V3.5:

1. Bug fixes:

- fix memory leak when not starting at first available time.

2. Changes and improvements:

- Allow vertical nesting. This is done by providing to NESTDOWN 
  a new namelist variable sigma_f_bu (a variable similar to that 
  used in INTERPF). If you don't want to add or substract vertical
  levels in NESTDOWN, just remove the namelist variable in 
  namelist.input.


========================================================

Bug fixes and changes in V3.4:

1. Bug fixes:

- Correct a memory leaking error.

  Affected files:
  module_all_io.F, module_lateral_bdy.F, nestdown.F


2. Changes and improvements:

- Simplify the way make is done. Now one needs only to type 'make'
  to compile on one's machine. (Changes in tar file since 6/7/00.)

  Affected files:
  Makefile, configure.rules, macros_pregrid, macros_regridder (new)
  src/Makefile

- Wind adjustment removed as done in MM5 nest initialization.
  (Changes in tar file since 6/7/00.)

  Affected files:
  src/nestdown.F

- Set default sst_to_ice_threshold value to -9999. If you want to
  use it, set it to the value you desire. (Changes in tar file since 2/11/00.)

  Affect files:
  namelist.input

- There is no more wind adjustment when base state (which is a function of terrain)
  changes. This is consistent with IOVERW=2 option in MM5.

  Affected file:
  src/nestdown.F

========================================================

Updated 01/25/00:

- Allow NESTDOWN to work with MMINPUT file with masking fields.
  NESTDOWN is recommended to generate nest input files for MM5
  if using OSU LSM model option.

- Allow time period for processing to be less than a full day.
  Use less_than_24h = .TRUE. in record1 of namelist.input file.

- Allow change of SST to land ice catagory if SST is cold enough.
  Use sst_to_ice_threshold = 'a temp value' in record2 of 
  namelist.input file.

- Allow multiple output times. Use ifdatim in record5.

- Fix memory leak.

- Fix a bug when interpolating vertical motion field, w. This
  could cause difference in generated files.

========================================================

Updated 09/24/99:

- Positive definite fields set to zero if < 1.e-10

  This prevents very small or negative hydrometeo variables
  going into model's initial and boundary conditions.

- Fixed masked interpolation for LSM

  If the input to nestdown has LSM data, such as sea ice, and
  water equivalent depth of snow, Nestdown now will properly
  interpolate them across land-water boundary.

Updated 08/12/99:

- Added OpenMP parallel directives.
