The scripts in this directory are for adding tidal boundary condition 
to a regional configuration of MITgcm.  

The scripts are tested for Pine Island Model   
and also for verification/seaice_obcs using specified tidal boundary file.

Steps  to add tide boundary conditions  to regional MITgcm 
0) Download the Circum-Antarctic Tide (CATS) Solution (Padman et al. 2002)
   from Earth and Space Research,   http://www.esr.org/~padman/cats2008b/ 
   Modify CATS directory in test_tide_bc.m   
   Download the TMD2.03 software for extracting the tidal solution from 
   http://www.esr.org. 
   Modifications  are needed in the original /TMD2.03/tmd_extract_HC.m in order 
   to have the correct path of tidal solution as shown in the sample_tmd_extract_HC.m.  
   Use CATS2008b not CAT2008a since CATS200a is not on north-south east-west coordinate 


1) use create_bc_grid.m (called by test_bc_grid.m) to generate bc grid files. 
   create_bc_grid.m will generate files with names like 
   bdry_grid_[snwe].mat for south, north, west, and east boundary.  
   This script needs a directory path for MITgcm domain related files, 
   specifically  YC.data, XC.data, hFacC.data, AngleCS.data, AngleSN.data. 

2) use test_tide_bc.m to generate tidal bc files which calls 
   create_tide_bc_second.m 
   or dummy tidal bc files (zero amplitude and phase, tide_bc_empty.m) 
   for land boundary if there is such a need. 

   create_tide_bc_second.m will generate tidal boundary files with names 
   like OB[SNWE]{am ph}.seaice_obcs.  
   The tidal current and phase will be used in  obcs_add_tides.F.    

3) Modify MITgcm configuration 
   3.1) ALLOW_OBCS_TIDES in OBCS_OPTIONS.h  
   3.2) OBCS_PARAMS.h  (tidalComponents = ??, number of tidal constituent to be included.) 
   3.3) data.obcs as following
   The number of tidal constituents to be included and their period and 
   order should be consistent with their order in tidal current amplitude 
   and phase files,  OB?amFile and OB?phFile.
   useOBCStides = .TRUE.
   tidalperiod = ...
   OBSamFile =  ...
   OBNamFile =  ...
   OBWamFile = ...
   OBEamFile = ...
   OBSphFile = ...
   OBNphFile = ...
   OBWphFile = ...
   OBEphFile = ...



CAT Reference 
Padman, L., H. A. Fricker, R. Coleman, S. Howard, and S. Erofeeva, 2002: A new tidal model for the
Antarctic ice shelves and seas, Ann. Glaciol., 34, 247-254.


XC WANG 02 Apr  2013 
XC WANG 25 Mar  2013 
XC WANG 07 Feb. 2013 
XC WANG 20 Dec. 2012 
xiaochun.wang@jpl.nasa.gov