| 1 | May 19, 2004 | last changed June 8, 2004 | 
| 2 |  |  | 
| 3 |  | OBSERVATION SYSTEM SIMULATION EXPERIMENT | 
| 4 |  |  | 
| 5 |  | OSSE is an MITgcm configuration to simulate data assimilation with a | 
| 6 |  | deterministic ensemble Kalman filter and a model of a rotating tank of | 
| 7 |  | water with an ice bucket at the center. | 
| 8 |  |  | 
| 9 |  | INSTALLATION | 
| 10 |  |  | 
| 11 |  | At the time of this writing, the OSSE requires MITgcm checkpoint48 to | 
| 12 |  | compile and run.  MITgcm can be obtained from | 
| 13 |  | <http://mitgcm.org/source_code.html>.  If downloading from the CVS | 
| 14 |  | server, use the command | 
| 15 |  |  | 
| 16 |  | cvs co -r 'checkpoint48' MITgcm | 
| 17 |  |  | 
| 18 |  | in order to specify the correct version.  Read the instructions on the | 
| 19 |  | the webpage before trying to use the CVS server. | 
| 20 |  |  | 
| 21 |  | The OSSE directory tree can be obtained from the MITgcm CVS repository | 
| 22 |  | with the command | 
| 23 |  |  | 
| 24 |  | cvs co MITgcm_contrib/osse | 
| 25 |  |  | 
| 26 |  | The code and its revision history can be browsed at | 
| 27 |  |  | 
| 28 |  | <http://dev.mitgcm.org/cgi-bin/viewcvs.cgi/MITgcm_contrib/osse/> | 
| 29 |  |  | 
| 30 |  | A good place to put the osse directory tree is in MITgcm/verification, | 
| 31 |  | where examples and test examples of MITgcm configurations are kept. | 
| 32 |  |  | 
| 33 |  | CONTENTS | 
| 34 |  |  | 
| 35 |  | code: modifications to MITgcm to run in cyclindrical coordinates.  At | 
| 36 |  | the time of this writing, it requires checkpoint48 to compile and run. | 
| 37 |  |  | 
| 38 |  | input: initialization and input files for MITgcm | 
| 39 |  |  | 
| 40 |  | filter: source and data files to run the data assimilation and Kalman | 
| 41 |  | filter. | 
| 42 |  |  | 
| 43 |  | utils: assorted Matlab m-files | 
| 44 |  |  | 
| 45 |  | EnKF: empty | 
| 46 |  |  | 
| 47 |  | run: empty | 
| 48 |  |  | 
| 49 |  |  | 
| 50 |  | COMPILING AND RUNNING THE MODEL | 
| 51 |  |  | 
| 52 |  | The following series of commands creates the MITgcm executable. | 
| 53 |  |  | 
| 54 |  | From the MITgcm root: | 
| 55 |  |  | 
| 56 |  | cd verification/osse/build | 
| 57 |  | ../../../tools/genmake -mods=../code  # creates makefile | 
| 58 |  | make depend       # contructs Fortran code from model codebase | 
| 59 |  | make              # makes executable mitgcmuv | 
| 60 |  |  | 
| 61 |  | Try a test run, while redirecting the standard output to a file.  The | 
| 62 |  | input directory contains files that should be present in the working | 
| 63 |  | directory when you run mitgcmuv.  It is recommended that you copy the | 
| 64 |  | input contents to a different directory for running -- mitgcmuv does | 
| 65 |  | not change them, but they can be lost in the multitudes of output | 
| 66 |  | files. | 
| 67 |  |  | 
| 68 |  | The data assimilation code is made by typing ``make'' in the filter | 
| 69 |  | directory, which creates an executable named osse. | 
| 70 |  |  | 
| 71 |  | Before running osse, the initial ensemble needs to be set up by | 
| 72 |  | running the mkens script in verification/osse/da.  mkens creates the | 
| 73 |  | directories, symbolically links files necessary to run the model, and | 
| 74 |  | copies in the initial ensemble files.  osse should be run from the | 
| 75 |  | directory verification/osse/da/inits since it expects the ensemble | 
| 76 |  | members to be one directory above.  It also expects to have in its | 
| 77 |  | working directory the file iobsloc-003.txt, which contains the | 
| 78 |  | locations of the observations.  This file is located in | 
| 79 |  | verification/osse/da/inits. | 
| 80 |  |  | 
| 81 |  |  | 
|  | Observation System Simulation Experiment |  | 
| 82 |  |  | 
|  | OSSE is a configuration to simulate running an deterministic |  | 
|  | ensemble Kalman filter on a rotating tank with an ice bucket |  | 
|  | at the center. |  | 
| 83 |  |  | 
|  | code/ contains the modifications to MITgcm to run in cyclindrical |  | 
|  | coordinates.  At the time of this writing, it requires |  | 
|  | checkpoint48 to compile and run. |  | 
| 84 |  |  | 
|  | EnKF/ contains the source and data files to run the Kalman filter. |  | 
| 85 |  |  |