{"action":"created","issue":{"url":"https://api.github.com/repos/StrikeNP/trac_test/issues/867","repository_url":"https://api.github.com/repos/StrikeNP/trac_test","labels_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/867/labels{/name}","comments_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/867/comments","events_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/867/events","html_url":"https://github.com/StrikeNP/trac_test/issues/867","id":328665283,"node_id":"MDU6SXNzdWUzMjg2NjUyODM=","number":867,"title":"SAM_CLUBB ARM9707 develops large tke near the surface and crashes (Trac #9)","user":{"login":"StrikeNP","id":2577059,"node_id":"MDQ6VXNlcjI1NzcwNTk=","avatar_url":"https://avatars0.githubusercontent.com/u/2577059?v=4","gravatar_id":"","url":"https://api.github.com/users/StrikeNP","html_url":"https://github.com/StrikeNP","followers_url":"https://api.github.com/users/StrikeNP/followers","following_url":"https://api.github.com/users/StrikeNP/following{/other_user}","gists_url":"https://api.github.com/users/StrikeNP/gists{/gist_id}","starred_url":"https://api.github.com/users/StrikeNP/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/StrikeNP/subscriptions","organizations_url":"https://api.github.com/users/StrikeNP/orgs","repos_url":"https://api.github.com/users/StrikeNP/repos","events_url":"https://api.github.com/users/StrikeNP/events{/privacy}","received_events_url":"https://api.github.com/users/StrikeNP/received_events","type":"User","site_admin":false},"labels":[{"id":950816635,"node_id":"MDU6TGFiZWw5NTA4MTY2MzU=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/Migrated%20from%20Trac","name":"Migrated from Trac","color":"FFFFFF","default":false},{"id":950816732,"node_id":"MDU6TGFiZWw5NTA4MTY3MzI=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/clubb_src","name":"clubb_src","color":"FFFFFF","default":false},{"id":950816644,"node_id":"MDU6TGFiZWw5NTA4MTY2NDQ=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/defect","name":"defect","color":"FFFFFF","default":false},{"id":950816791,"node_id":"MDU6TGFiZWw5NTA4MTY3OTE=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/vlarson@uwm.edu","name":"vlarson@uwm.edu","color":"FFFFFF","default":false}],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":13,"created_at":"2018-06-01T21:24:08Z","updated_at":"2018-06-01T21:44:24Z","closed_at":null,"author_association":"OWNER","body":"Set up:\nSAM_CLUBB, 128 vertical levels, dt = 10 s or dt = 2 s, Morrison microphysics, CAM radiation, dx = 16 km, 4 grid columns.\n\nnrad is immaterial.  The difference in set-up from the nightly plots is that the nightly plots uses only 30 vertical levels or so.\n\nSymptom: u2 is very large ( 50,000 (m/s)**2 ) near the ground.  However, all other fields look fine, including SAM's u and CLUBB's up2 and um. \n\nPossible cause: CLUBB's eddy diffusivity has a large gradient near the ground.  Perhaps then CLUBB's contribution to SAM's momentum (u_tndcy in advance_clubb_sgs) is too large, causing a CFL violation.  However, if this is the case, it seems strange that u and um are small and smooth, and do not exhibit sawtooth noise.\n\nNext step: Perhaps reduce the coefficient in u_tndcy from 0.4 to some smaller number, e.g. 0.2.\n\nMigrated from http://carson.math.uwm.edu/trac/clubb/ticket/9\n```json\n{\n    \"status\": \"closed\", \n    \"changetime\": \"2012-02-14T19:52:10\", \n    \"description\": \"Set up:\\nSAM_CLUBB, 128 vertical levels, dt = 10 s or dt = 2 s, Morrison microphysics, CAM radiation, dx = 16 km, 4 grid columns.\\n\\nnrad is immaterial.  The difference in set-up from the nightly plots is that the nightly plots uses only 30 vertical levels or so.\\n\\nSymptom: u2 is very large ( 50,000 (m/s)**2 ) near the ground.  However, all other fields look fine, including SAM's u and CLUBB's up2 and um. \\n\\nPossible cause: CLUBB's eddy diffusivity has a large gradient near the ground.  Perhaps then CLUBB's contribution to SAM's momentum (u_tndcy in advance_clubb_sgs) is too large, causing a CFL violation.  However, if this is the case, it seems strange that u and um are small and smooth, and do not exhibit sawtooth noise.\\n\\nNext step: Perhaps reduce the coefficient in u_tndcy from 0.4 to some smaller number, e.g. 0.2.\", \n    \"reporter\": \"vlarson@uwm.edu\", \n    \"cc\": \"\", \n    \"resolution\": \"Verified by V. Larson\", \n    \"_ts\": \"1329249130000000\", \n    \"component\": \"clubb_src\", \n    \"summary\": \"SAM_CLUBB ARM9707 develops large tke near the surface and crashes\", \n    \"priority\": \"major\", \n    \"keywords\": \"ARM9707, arm_97, SAM_CLUBB, crash, horizontal winds\", \n    \"time\": \"2009-05-05T21:21:33\", \n    \"milestone\": \"\", \n    \"owner\": \"vlarson@uwm.edu\", \n    \"type\": \"defect\"\n}\n```\n"},"comment":{"url":"https://api.github.com/repos/StrikeNP/trac_test/issues/comments/394017318","html_url":"https://github.com/StrikeNP/trac_test/issues/867#issuecomment-394017318","issue_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/867","id":394017318,"node_id":"MDEyOklzc3VlQ29tbWVudDM5NDAxNzMxOA==","user":{"login":"StrikeNP","id":2577059,"node_id":"MDQ6VXNlcjI1NzcwNTk=","avatar_url":"https://avatars0.githubusercontent.com/u/2577059?v=4","gravatar_id":"","url":"https://api.github.com/users/StrikeNP","html_url":"https://github.com/StrikeNP","followers_url":"https://api.github.com/users/StrikeNP/followers","following_url":"https://api.github.com/users/StrikeNP/following{/other_user}","gists_url":"https://api.github.com/users/StrikeNP/gists{/gist_id}","starred_url":"https://api.github.com/users/StrikeNP/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/StrikeNP/subscriptions","organizations_url":"https://api.github.com/users/StrikeNP/orgs","repos_url":"https://api.github.com/users/StrikeNP/repos","events_url":"https://api.github.com/users/StrikeNP/events{/privacy}","received_events_url":"https://api.github.com/users/StrikeNP/received_events","type":"User","site_admin":false},"created_at":"2018-06-01T21:44:24Z","updated_at":"2018-06-01T21:44:24Z","author_association":"OWNER","body":"Trac update at 20090514T19:25:48: vlarson@uwm.edu commented:\n\n> Replying to [comment:12 dschanen@…]:\n> > Replying to [comment:11 vlarson@…]:\n> > > I don't know why this change was made.  The formula looks completely different.  \n> > > \n> > > Probably we should impose uniformity between CLUBB and SAM for ease of comparison.  Should we change SAM's formula to that of CLUBB, and enclose the change in the #ifdef CLUBB preprocessor flag so that we can revert easily?\n> > \n> > This could be done fairly easily I think.  I have determined a couple of things since yesterday.  The formula in the original ARM paper [http://www.knmi.nl/samenw/eurocs/ARM/ here] appears to the one found in SAM. Based on archived tarballs the diag_ustar in HOC/CLUBB has been as it is now since at least February of 2005.\n> \n> That's interesting; nice job, Dave.  I'm not sure whether or not we should change CLUBB to use SAM's formula, or change SAM to use CLUBB's formula.  I don't recall why we would have changed diag_ustar in CLUBB.  Perhaps a later GCSS case used the formula in CLUBB.  Could you please check some of the references for GCSS cases from, say, 2006 and before that use diag_ustar?  If references (i.e. URL and papers in the literature) are missing from CLUBB could you please add them to the relevant header comments? \n> \n> Also, it might be worth doing a run_standalone_all/plotgen using CLUBB w/ CLUBB's standard diag_ustar and w/ SAM's standard diag_ustar.\n> \n> > \n> > Furthermore, ARM9707 can run to completion if we use the CEM mode.  I think this is because in LES mode surface.f90 uses the horizontally averaged u values (u0), which would be small for surface values we see before the crash, while CEM uses the local value of u.  Of course this doesn't tell us what the ultimate source of the high u2 we see is.\n> \n> That's interesting too.  Perhaps in CEM mode the surface momentum flux can impose a local drag that damps the sawtooth noise, whereas in LES mode the surface momentum flux can't impose any such drag, resulting in a free-slip lower boundary where perturbations can grow.  Perhaps one lesson is that we should use CEM mode in SAM/SAM_CLUBB for any horizontal grid spacing coarser than 500 m.\n> \n> If you run ARM9707 using SAM_CLUBB in CEM mode (say 4 columns at 16-km horz grid spacing and 128 vertical grid points), then does the simulation crash?\n\n"}}
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