README.greg	Greg O'Donnell [tempgd@hydro.washington.edu] June 2000

**********************
INTRO
**********************

This document contains details of code changes to the core VIC [ie as
used at UW] for application to the LDAS project.
The starting version of the code is VIC_4.0.0.

All routines changed are detailed below. Changes to standard VIC files
are enclosed by the following:

/** Start of changes - NGMOD **/
/** End of changes - NGMOD **/

or

/** Start of changes - JS **/
/** End of changes - JS **/

Note: there are in addition new VIC routines added.


**********************
LDAS SPECIFIC CHANGES
**********************

The following provides changes on modifications made to the VIC
routine to run for LDAS.

Met data changes
----------------

The met data for the LDAS data is provided by NCEP in grib files. The
preprocessor ncep_forcing_pp should be run to convert these grib files
to a format suitable for VIC.

1) make_in_outfiles.c removed from vicNl.c
   No longer open files on a cell by cell basis.

2) open_ldas_files.c
   Opens the met input files and the output files.

3) get_ldas_global_param.c 
   Get the LDAS required data from the global file.

4) initialize_ldas_atmos.c
   Replace initialize_atmos.c

5) put_data_ldas
   Replace put_data. write_data function call changes.

The following have the rewind statement commented out.
read_vegparam.c
read_snowband.c

Header Files
------------

An additional header file 'vicNl_ldas.h' is now included.

Input Files
------------

Beyond the obvious changes to the met data files the following changes
were implemented:

1) soil file
   The first column should be cell number, ie copy col2 to col1.
   This is used to determine whether the cell is to be computed.

**********************
GENERAL BUGS
**********************

Below are general bug fixes - these should be applied to all versions
of the code.

1) In initialize_atmos_data.c
   
   if(atmos[rec].air_temp[i]>min) min = atmos[rec].air_temp[i];

   should be replaced by

   if(atmos[rec].air_temp[i]<min) min = atmos[rec].air_temp[i];

   [ie the > sign is incorrect.]

2) In make_in_outfiles.c the following lines should be commented out

  /** Initial Model State Variables Read from File **/
  if(options.INIT_STATE) {
    infp->statefile = open_file(fnames.init_state, "r");
  }

  The opening of this file is dealt with in check_state_file.c.