Ocean region mask

Files: 

  • /models/ocn/pop2/input_templates/gx1v6_region_ids
  • region_mask_gx1v6_myrun.DATE.ieeei4

 

region_mask_gx1v6

The region_mask_gx1v6 file defines the ocean regions in CESM1 POP2.  If you change the land/ocean mask from the present day configuration you must also modify the region_mask.ieeei4 file to match your KMT land/ocean definitions.  The tool 'change_kmt.ncl' will automatically create a binary region_mask file that matches your binary kmt file. 

gx1v6_region_ids

If you make significant changes to your land/ocean mask you may also need to adjust the gx1v6_region_ids file, which divides the oceans into numbered regions; negatively numbered regions denote inland or marginal seas.

Deep Time:  Since deep time simulations have ocean configurations that differ profoundly from current day, deep time modelers will need to define their own ocean regions.  Typically we recommend that they define two simple regions, Northern and Southern Hemisphere.

Quaternary:  Quaternary modelers can usually use the default ocean region mask as long as they retain at least one active ocean grid cell within each default region.   However, if you remove an entire ocean basin or marginal sea,  you will need to reorder all subsequent regions. 

gx1v6_region_ids - present day
1 'Sothern Ocean ' 0.0 0.0
2 'Pacific Ocean ' 0.0 0.0
3 'Indian Ocean ' 0.0  0.0
4 'Persian Gulf ' 22.0 60.0
-5 'Red Sea ' 14.0 47.0
6 'Atlantic Ocean ' 0.0 0.0
7 'Mediterranean Sea ' 36.0 354.0
8 'Labrador Sea ' 0.0 0.0
9 'GIN Sea ' 0.0 0.0
10 'Arctic Ocean ' 0.0 0.0
11 'Hudson Bay ' 61.0 295.0
-12 'Baltic Sea ' 56.0 8.0
-13 'Black Sea ' 40.0 25.0
-14 'Caspian Sea ' 70.0 65.0

 

gx1v6_region_ids - modified to remove Mediterranean Sea
1 'Sothern Ocean ' 0.0 0.0
2 'Pacific Ocean ' 0.0 0.0
3 'Indian Ocean ' 0.0  0.0
4 'Persian Gulf ' 22.0 60.0
-5 'Red Sea ' 14.0 47.0
6 'Atlantic Ocean ' 0.0 0.0
7 'Labrador Sea ' 0.0 0.0
8 'GIN Sea ' 0.0 0.0
9 'Arctic Ocean ' 0.0 0.0
10 'Hudson Bay ' 61.0 295.0
-11 'Baltic Sea ' 56.0 8.0
-12 'Black Sea ' 40.0 25.0
-13 'Caspian Sea ' 70.0 65.0

 

LGM:  Here is an example of the region mask we used for our CCSM4/CESM1 Last Glacial Maximum simulation.  Note the changes to the IDs of the Black and Caspian Seas, and the removal of the Baltic Sea and Hudson Bay.  We also changed the location of the Caspian Sea slightly.

gx1v6_region_ids - modified for the LGM
1 'Sothern Ocean ' 0.0 0.0
2 'Pacific Ocean ' 0.0 0.0
3 'Indian Ocean ' 0.0  0.0
4 'Persian Gulf ' 22.0 60.0
-5 'Red Sea ' 14.0 47.0
6 'Atlantic Ocean ' 0.0 0.0
7 'Mediterranean Sea ' 36.0 354.0
8 'Labrador Sea ' 0.0 0.0
9 'GIN Sea ' 0.0 0.0
10 'Arctic Ocean ' 0.0 0.0
-11 'Black Sea ' 40.0 25.0
-12 'Caspian Sea ' 82.0 72.0