{"action":"created","issue":{"url":"https://api.github.com/repos/StrikeNP/trac_test/issues/386","repository_url":"https://api.github.com/repos/StrikeNP/trac_test","labels_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/386/labels{/name}","comments_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/386/comments","events_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/386/events","html_url":"https://github.com/StrikeNP/trac_test/issues/386","id":330445688,"node_id":"MDU6SXNzdWUzMzA0NDU2ODg=","number":386,"title":"Reduce frequency and magnitude of couplet spikes in wp3 (Trac #386)","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":958042829,"node_id":"MDU6TGFiZWw5NTgwNDI4Mjk=","url":"https://api.github.com/repos/StrikeNP/trac_test/labels/dschanen@uwm.edu","name":"dschanen@uwm.edu","color":"FFFFFF","default":false}],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":36,"created_at":"2018-06-07T21:40:09Z","updated_at":"2018-06-08T22:51:22Z","closed_at":null,"author_association":"OWNER","body":"'''Introduction'''\n\nWe have noticed for some time (see, e.g., http://carson.math.uwm.edu/trac/clubb/ticket/323#comment:15) that occasionally a couplet of spikes forms in wp3.  A zt grid point develops a large, positive spike of wp3, and the grid point above develops a large, negative spike.  At the zm level between, a large positive spike forms in wp2.\n\nAn example occurs at t=3771 (minutes) for the arm_97 case in r4931.  There wp3 goes from small sawtooth noise to values of +-100 in a single timestep.  wp3 is made positive by wp3_ta+wp3_tp (in particular the wp3(n+1) term), and wp2 is made positive by wp2_ta.  The sign of wp3 changes during the timestep at the altitudes of the couplet.  The sign change allows the derivative d(wp3(n)wp3(n+1))/dz to remain large.  Therefore, one might suspect that the sawtooth noise in wp3 is the problem and that smoothing wp3 is the solution.  However, the current discretization already uses wp3_zm, which is a smoothed version of wp3.\n\n'''Technical spec'''\n\nInitially, some additional diagnostics may help.  I think outputting wp3_zm and skewness_velocity = a1*wp3/wp2 may be useful (http://carson.math.uwm.edu/trac/clubb/ticket/182#comment:20).  \n\nLater, we should try new approaches, such as upwinding wp3_ta and wp3_tp, or smoothing skewness_velocity.\n\n'''Tests'''\n\n1.  We would like to prevent the formation any couplet of spikes in wp3 that reaches +-100 in any of our single-column cases, especially arm_97 and twp_ice.\n\n2.  We would like to simulate the VOCA case using WRF-CLUBB without crashes (https://github.com/larson-group/wrf/issues/13).  The crashes may be related to couplet of spikes in wp3.\n\nAttachments:\n\nhttp://carson.math.uwm.edu/trac/clubb/attachment/ticket/386/lwp.png\nhttp://carson.math.uwm.edu/trac/clubb/attachment/ticket/386/lwp_a1_in_deriv.png\n\nMigrated from http://carson.math.uwm.edu/trac/clubb/ticket/386\n```json\n{\n    \"status\": \"closed\", \n    \"changetime\": \"2011-07-27T21:35:58\", \n    \"description\": \"'''Introduction'''\\n\\nWe have noticed for some time (see, e.g., http://carson.math.uwm.edu/trac/clubb/ticket/323#comment:15) that occasionally a couplet of spikes forms in wp3.  A zt grid point develops a large, positive spike of wp3, and the grid point above develops a large, negative spike.  At the zm level between, a large positive spike forms in wp2.\\n\\nAn example occurs at t=3771 (minutes) for the arm_97 case in r4931.  There wp3 goes from small sawtooth noise to values of +-100 in a single timestep.  wp3 is made positive by wp3_ta+wp3_tp (in particular the wp3(n+1) term), and wp2 is made positive by wp2_ta.  The sign of wp3 changes during the timestep at the altitudes of the couplet.  The sign change allows the derivative d(wp3(n)wp3(n+1))/dz to remain large.  Therefore, one might suspect that the sawtooth noise in wp3 is the problem and that smoothing wp3 is the solution.  However, the current discretization already uses wp3_zm, which is a smoothed version of wp3.\\n\\n'''Technical spec'''\\n\\nInitially, some additional diagnostics may help.  I think outputting wp3_zm and skewness_velocity = a1*wp3/wp2 may be useful (http://carson.math.uwm.edu/trac/clubb/ticket/182#comment:20).  \\n\\nLater, we should try new approaches, such as upwinding wp3_ta and wp3_tp, or smoothing skewness_velocity.\\n\\n'''Tests'''\\n\\n1.  We would like to prevent the formation any couplet of spikes in wp3 that reaches +-100 in any of our single-column cases, especially arm_97 and twp_ice.\\n\\n2.  We would like to simulate the VOCA case using WRF-CLUBB without crashes (wrf:ticket:13).  The crashes may be related to couplet of spikes in wp3.\", \n    \"reporter\": \"vlarson@uwm.edu\", \n    \"cc\": \"vlarson@uwm.edu, bmg2@uwm.edu, ldgrant@uwm.edu\", \n    \"resolution\": \"Verified by V. Larson\", \n    \"_ts\": \"1311802558000000\", \n    \"component\": \"clubb_src\", \n    \"summary\": \"Reduce frequency and magnitude of couplet spikes in wp3\", \n    \"priority\": \"critical\", \n    \"keywords\": \"\", \n    \"time\": \"2010-12-27T18:19:31\", \n    \"milestone\": \"\", \n    \"owner\": \"dschanen@uwm.edu\", \n    \"type\": \"defect\"\n}\n```\n"},"comment":{"url":"https://api.github.com/repos/StrikeNP/trac_test/issues/comments/395913292","html_url":"https://github.com/StrikeNP/trac_test/issues/386#issuecomment-395913292","issue_url":"https://api.github.com/repos/StrikeNP/trac_test/issues/386","id":395913292,"node_id":"MDEyOklzc3VlQ29tbWVudDM5NTkxMzI5Mg==","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":"2018-06-08T22:51:22Z","updated_at":"2018-06-08T22:51:22Z","author_association":"OWNER","body":"Trac update at 2011/01/14 at 21:29\n\ndschanen@uwm.edu commented:\n\nReplying to [comment:36 vlarson@…]:\n> Replying to [comment:35 dschanen@…]:\n> > After feeding in the smoothed wp3 / wp2 into the advance_xm_wpxp equations, we looked at some more plots.  The standard resolution plot is [http://www.larson-group.com/dschanen/protected/fluxes_smoothed_plot.maff here], and the 48 level plot is [http://www.larson-group.com/dschanen/protected/fluxes_smoothed_48lev.maff here].\n> > The standard resolution simulations don't have any remarkable features vs. the code where we used the smoothed values for the variances and wp3.  In 48 level plots the intermittency seems to have returned to some degree in the BOMEX simulation, though not as bad as it was prior to adding all this to the code.\n> At 48 grid levels, the code that feeds the smoothed wp3_on_wp2 into wpxp_ta (the new code) produces sawtooth noise in the arm_97 and astex profiles.  However, the profiles and timeseries of ATEX look smoother.  In BOMEX, the profiles look closer to the LES but the timeseries is much more oscillatory.  In RICO, the timeseries look more oscillatory.  \n> \n> Perhaps for now we should just submit the code change that feeds smoothed wp3_on_wp2 into xp2, but not the code change that feeds it into wpxp.  Then we can try to figure out why BOMEX is noisier.  Does the problem have anything to do with the rtp2 trap (ticket:389)?\n\nCommitted in changeset r4964.  I'm not sure about the rtp2 trap, but one thing I noticed is that wpthlp_ta and wprtp_ta are the only terms that always keep a1 in the derivative regardless of flag l_standard_term_ta.  Perhaps this creates some numerical instability that doesn't occur in the other terms.  I'm guessing this was because the results looked bad when a1 was taken outside the derivative?  Maybe Brian has some insight on it?\n\n"}}
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