
VERSION 3 INTERPB PROGRAM (Release 3.3)
(Updated December 23, 2004)

This is the main directory of the INTERPB program in the MM5 modeling 
system Version 3. Everything a user needs to run the INTERPB program 
is contained in this directory.

For questions, please send emails to mesouser@ucar.edu

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What is in V3 INTERPB?

V3 INTERPB takes care of the backend V3 Interp task. It interpolates
MM5 model output data on sigma levels to pressure levels. It creates
pressure level data in two forms: pressure level data for post-processing
(such as for GRAPH job; output file name MMOUTP_DOMAINx), and 
pressure level data that can be used in frontend jobs like 
RAWINS and INTERPF (output file name REGRID_DOMAINx). 

V3 INTERPB works for one domain data at a time. Depending on the 
domain of MM5 output file, INTERPB will create pressure level data
for that domain. It does not do horizontal interpolation.

V3 INTERPB is written in Fortran 90, and requires Fortran 90 compiler.

V3 INTERPB program uses V3 data format, which is different from
that in V2. For details on V3 data format, please see

http://www.mmm.ucar.edu/mm5/mm5v3.html

INTERPB is supported for Cray, Alpha, HP, IBM, SGI, SUN, and Fujitsu with
their native compilers, and PC running Linux using Portland Group Fortran
90 compiler. If your machine isn't one of the ones supported or the
compiler isn't the native one from the vendor, you need to edit the Makefile.

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***************************************************************
Also see the online self-tutorial at
http://www.mmm.ucar.edu/mm5/mm5v3/tutorial/teachyourself.html
(coming soon.)
***************************************************************

To compile INTERPB:

- Type 'make' in the INTERPB directory to compile;

- When make is successful, executable interpb will appear in this
  directory.

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To run INTERPB:

Edit namelist.input, and type ./interpb to execute the program.

Required input file for INTERPB:

MM5 (MMOUT_DOMAINx, where x = 1,2,3,...)

The directory and name of the input file are set in namelist.input.

The output files from INTERPB are

MMOUTP_DOMAINx:   pressure level data for GRAPH/RAWINS/LITTLE_R
REGRID_DOMAINx:   pressure level data for RAWINS/LITTLE_R/INTERPF

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Namelist:

&record0:
 input_file:	path to MM5 model sigma level data.

&record1:
 Date information. Set them similarly as it is in INTERPF.

&record2:
 Pressure level: defines the pressure levels you want to interpolate
 sigma level data to. The data are in Pascals, bottom up, starting
 with 10**5 Pa.

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Other notes about INTERPB:

- In addtional to MM5 model variables, INTERPB only add a couple of
  diagnostic variables in the output: sea-level pressure, geopotential
  height and relative humidity.

- INTERPB uses top half-sigma-level values to fill fields at Ptop level,
  and uses lowest half-sigma-level to fill surface fields.
  This is only an approximation.

- When doing vertical interpolation, INTERPB interpolates wind components
  (u, v, w), moisture variables, perturbation pressure linearly in p. It
  interpolates temperature and height in log p. 

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Trouble shooting:

If the job gets a 'Segmentation fault' immediately at run time, it may mean 
there isn't enough memory to run the job. On some machine, type 'unlimit'
helps.

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Files/directories in this directory:

CHANGES:   description of changes made since 3.0
Makefile:  top-level makefile
README:    general information about how to run INTERPB
configure.rules:   rules for compilation
interpf.deck.cray: not yet available
namelist.input: namelist file requiring user modification
src:       directory of INTERPB source code
