{"id":4622,"date":"2019-12-12T10:31:22","date_gmt":"2019-12-12T09:31:22","guid":{"rendered":"https:\/\/www.mi.uni-koeln.de\/NumSim\/?p=4622"},"modified":"2019-12-12T10:49:09","modified_gmt":"2019-12-12T09:49:09","slug":"talk-almut-gassmann-leibnitz-institute-of-atmospheric-physics","status":"publish","type":"post","link":"https:\/\/www.mi.uni-koeln.de\/NumSim\/2019\/12\/12\/talk-almut-gassmann-leibnitz-institute-of-atmospheric-physics\/","title":{"rendered":"Talk: Almut Gassmann, Leibnitz-Institute of Atmospheric Physics, University Rostock"},"content":{"rendered":"<p><strong>On Friday, 13 December 2019 at 14.00\u00a0Almut Gassman will talk on the topic \u201cEntropy production in numerical modeling of a moist atmosphere\u201d<\/strong><\/p>\n<p><strong>Location:\u00a0<\/strong>Weyertal 86 &#8211; 90, Seminar room 1 (ground floor),\u00a050931 Cologne<\/p>\n<p><strong>Abstract:\u00a0<\/strong>Atmospheric models are based on basic physical laws, like mass conservation, momentum conservation or sometimes energy conservation. In this talk, another law is inspected, namely the second law of thermodynamics which says that the internal entropy production has to be positive. This law has hardly been checked by modellers. But this law determines the direction (but not the strength) of subgrid-scale parameterized fluxes. Furthermore, the choice of numerical schemes for advection is also limited, because the inherent diffusion of those schemes must be downgradient with respect to the gradients of special measures, which are determined by the second law.\u00a0The formulation of energetically and entropically consistent numerical schemes will be outlined. Examples of failure of contemporary schemes with respect to the second law will be shown. For instance, conventional (non-entropy-consistent) heat flux parameterizations in the mesosphere will amplify waves instead of allowing them to break and dissipate. Or, as another example, entropy-law-inconsistent higher order or TVD advection schemes for temperature might give rise to accelerations of the wind in the wrong direction.\u00a0When inspecting the different entropy production (or dissipation) rates in the atmosphere, four types of those rates are distinguished, namely (i) dissipation due to friction, (ii) dissipation due to heat fluxes, (iii) dissipation due to mixing of constituents, and (iv) dissipation due to phase changes. The most important among them are the dissipation due to friction and the dissipation due to falling rain, which can be seen as a special case of mixing of moist air and precipitation.<\/p>\n<hr \/>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>On Friday, 13 December 2019 at 14.00\u00a0Almut Gassman will talk on the topic \u201cEntropy production in numerical modeling of a moist atmosphere\u201d Location:\u00a0Weyertal 86 &#8211; 90, Seminar room 1 (ground floor),\u00a050931 Cologne Abstract:\u00a0Atmospheric models are based on basic physical laws, &hellip; <a href=\"https:\/\/www.mi.uni-koeln.de\/NumSim\/2019\/12\/12\/talk-almut-gassmann-leibnitz-institute-of-atmospheric-physics\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[48],"tags":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/posts\/4622"}],"collection":[{"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/comments?post=4622"}],"version-history":[{"count":6,"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/posts\/4622\/revisions"}],"predecessor-version":[{"id":4628,"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/posts\/4622\/revisions\/4628"}],"wp:attachment":[{"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/media?parent=4622"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/categories?post=4622"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mi.uni-koeln.de\/NumSim\/wp-json\/wp\/v2\/tags?post=4622"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}