{"action":"created","issue":{"url":"https://api.github.com/repos/StrikeNP/trac_test/issues/452","repository_url":"https://api.github.com/repos/StrikeNP/trac_test","labels_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/452/labels{/name}","comments_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/452/comments","events_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/452/events","html_url":"https://github.com/StrikeNP/trac_test/issues/452","id":330446988,"node_id":"MDU6SXNzdWUzMzA0NDY5ODg=","number":452,"title":"Why is CLUBB sensitive to small changes at coarse resolution? (Trac #452)","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":958019852,"node_id":"MDU6TGFiZWw5NTgwMTk4NTI=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/Migrated%20from%20Trac","name":"Migrated from Trac","color":"FFFFFF","default":false},{"id":958042830,"node_id":"MDU6TGFiZWw5NTgwNDI4MzA=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/clubb_src","name":"clubb_src","color":"FFFFFF","default":false},{"id":958019855,"node_id":"MDU6TGFiZWw5NTgwMTk4NTU=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/defect","name":"defect","color":"FFFFFF","default":false},{"id":958043921,"node_id":"MDU6TGFiZWw5NTgwNDM5MjE=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/meyern@uwm.edu","name":"meyern@uwm.edu","color":"FFFFFF","default":false}],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":{"url":"https://api.github.com/repos/StrikeNP/trac_test/milestones/7","html_url":"https://github.com/StrikeNP/trac_test/milestone/7","labels_url":"https://api.github.com/repos/StrikeNP/trac_test/milestones/7/labels","id":3408874,"node_id":"MDk6TWlsZXN0b25lMzQwODg3NA==","number":7,"title":"Improve CLUBB's accuracy at coarse vertical grid spacing","description":null,"creator":{"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},"open_issues":22,"closed_issues":14,"state":"open","created_at":"2018-06-07T19:57:53Z","updated_at":"2018-06-09T03:10:54Z","due_on":null,"closed_at":null},"comments":14,"created_at":"2018-06-07T21:44:48Z","updated_at":"2018-06-09T03:13:06Z","closed_at":null,"author_association":"OWNER","body":"CLUBB appears to be more sensitive to small perturbations at coarse resolution than fine resolution.  This is partly to be expected, but perhaps part of CLUBB's equations tend to diverge to very different solution depending on slight differences in the initial conditions.  For instance, the rtp2 trap (e.g. ticket:389 and https://github.com/larson-group/clubb/issues/386) might send rtp2 to zero or keep it at large values depending on small background perturbations.\n\nAs a first step, we should go through old plots linked on Trac and find cases with extreme sensitivity to small changes. \n\nOne example is that ATEX changes when we use upwind differencing on the mean fields (see the 30-level plot in https://github.com/larson-group/clubb/issues/344).\n\nAnother example is that RF01 changes when we let the background diffusivity vary with grid spacing (see the 128-level plot in https://github.com/larson-group/clubb/issues/286)\n\nThen we should go back and see if there are any common behaviors or flaws in these cases.  That might point to an area of the code that is sensitive.\n\n\nAttachments:\n\n\nMigrated from http://carson.math.uwm.edu/trac/clubb/ticket/452\n```json\n{\n    \"status\": \"closed\", \n    \"changetime\": \"2012-02-16T21:37:04\", \n    \"description\": \"CLUBB appears to be more sensitive to small perturbations at coarse resolution than fine resolution.  This is partly to be expected, but perhaps part of CLUBB's equations tend to diverge to very different solution depending on slight differences in the initial conditions.  For instance, the rtp2 trap (e.g. ticket:389 and comment:38:ticket:386) might send rtp2 to zero or keep it at large values depending on small background perturbations.\\n\\nAs a first step, we should go through old plots linked on Trac and find cases with extreme sensitivity to small changes. \\n\\nOne example is that ATEX changes when we use upwind differencing on the mean fields (see the 30-level plot in comment:7:ticket:344).\\n\\nAnother example is that RF01 changes when we let the background diffusivity vary with grid spacing (see the 128-level plot in comment:10:ticket:286)\\n\\nThen we should go back and see if there are any common behaviors or flaws in these cases.  That might point to an area of the code that is sensitive.\\n\", \n    \"reporter\": \"vlarson@uwm.edu\", \n    \"cc\": \"vlarson@uwm.edu, dschanen@uwm.edu\", \n    \"resolution\": \"fixed\", \n    \"_ts\": \"1329428224000000\", \n    \"component\": \"clubb_src\", \n    \"summary\": \"Why is CLUBB sensitive to small changes at coarse resolution?\", \n    \"priority\": \"major\", \n    \"keywords\": \"\", \n    \"time\": \"2011-08-25T22:44:15\", \n    \"milestone\": \"Improve CLUBB's accuracy at coarse vertical grid spacing\", \n    \"owner\": \"meyern@uwm.edu\", \n    \"type\": \"defect\"\n}\n```\n"},"comment":{"url":"https://api.github.com/repos/StrikeNP/trac_test/issues/comments/395935293","html_url":"https://github.com/StrikeNP/trac_test/issues/452#issuecomment-395935293","issue_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/452","id":395935293,"node_id":"MDEyOklzc3VlQ29tbWVudDM5NTkzNTI5Mw==","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":"2018-06-09T03:13:06Z","updated_at":"2018-06-09T03:13:06Z","author_association":"OWNER","body":"Trac update at 2012/01/11 at 18:27\n\nmeyern@uwm.edu commented:\n\nLooking into the differences between 1 minute and 5 minute simulations of s6 where the 1 minute begins to form more of an anvil, I did a couple high resolution runs using a 20 m grid spacing and a 10 second and 5 min timestep.  Even between these runs, it's difficult to say which is better.  The 10 second run produces a high, thin cloud at 5000 m and has a large cloud fraction between 500m and 3000m.  The 5 min run produces about 11% cloud at 500m and quickly drops to around 2-3% cloud up to 3500m.\n\nWhat's interesting is that the 10 second run shows skewness more like a Sc near the base and gets more cumulus-like at the top of the domain while the 5 min run has cumulus-like skewness through the cloud layer with Sc skewness at the bottom and top of the domain.  This may stem from differing wp3 profiles.\n\n"}}
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