000014061 001__ 14061 000014061 005__ 20241121095730.0 000014061 02470 $$2doi$$ahttps://doi.org/10.1002/2017MS001162 000014061 037__ $$aTEXTUAL 000014061 037__ $$bArticle 000014061 041__ $$aeng 000014061 245__ $$aAn Extended Eddy-Diffusivity Mass-Flux Scheme for Unified Representation of Subgrid-Scale Turbulence and Convection 000014061 269__ $$a2018-02-06 000014061 336__ $$aArticle 000014061 520__ $$aLarge-scale weather forecasting and climate models are beginning to reach horizontal resolutions of kilometers, at which common assumptions made in existing parameterization schemes of subgrid-scale turbulence and convection—such as that they adjust instantaneously to changes in resolved-scale dynamics—cease to be justifiable. Additionally, the common practice of representing boundary-layer turbulence, shallow convection, and deep convection by discontinuously different parameterizations schemes, each with its own set of parameters, has contributed to the proliferation of adjustable parameters in large-scale models. Here we lay the theoretical foundations for an extended eddy-diffusivity mass-flux (EDMF) scheme that has explicit time-dependence and memory of subgrid-scale variables and is designed to represent all subgrid-scale turbulence and convection, from boundary layer dynamics to deep convection, in a unified manner. Coherent up and downdrafts in the scheme are represented as prognostic plumes that interact with their environment and potentially with each other through entrainment and detrainment. The more isotropic turbulence in their environment is represented through diffusive fluxes, with diffusivities obtained from a turbulence kinetic energy budget that consistently partitions turbulence kinetic energy between plumes and environment. The cross-sectional area of up and downdrafts satisfies a prognostic continuity equation, which allows the plumes to cover variable and arbitrarily large fractions of a large-scale grid box and to have life cycles governed by their own internal dynamics. Relatively simple preliminary proposals for closure parameters are presented and are shown to lead to a successful simulation of shallow convection, including a time-dependent life cycle. 000014061 536__ $$oNational Science Foundation$$cCCF-1048575 000014061 536__ $$oSwiss National Science Foundation$$c200021_156109 000014061 536__ $$oCaltech and the Jet Propulsion Laboratory$$aPresident's and Director's Fund 000014061 540__ $$a<p>© 2018. The Authors.</p> <p>This is an open access article under the terms of the <a href="http://creativecommons.org/licenses/by-nc-nd/4.0/">Creative Commons Attribution-NonCommercial-NoDerivs</a> License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.</p> 000014061 542__ $$fCC BY-NC-ND 000014061 6531_ $$aturbulence 000014061 6531_ $$aconvection 000014061 6531_ $$aparameterization 000014061 6531_ $$aeddy diffusivity/mass flux scheme 000014061 6531_ $$aclimate modeling 000014061 690__ $$aPhysical Sciences Division 000014061 691__ $$aGeophysical Sciences 000014061 7001_ $$1http://orcid.org/0000-0002-7422-3317$$2ORCID$$aTan, Zhihong$$uUniversity of Chicago 000014061 7001_ $$1http://orcid.org/0000-0002-4462-0987$$2ORCID$$aKaul, Colleen M.$$uCalifornia Institute of Technology 000014061 7001_ $$1https://orcid.org/0000-0002-4538-3055$$2ORCID$$aPressel, Kyle G.$$uCalifornia Institute of Technology 000014061 7001_ $$1http://orcid.org/0000-0002-9615-2476$$2ORCID$$aCohen, Yair$$uCalifornia Institute of Technology 000014061 7001_ $$1http://orcid.org/0000-0001-5687-2287$$2ORCID$$aSchneider, Tapio$$uCalifornia Institute of Technology 000014061 7001_ $$aTeixeira, João$$uCalifornia Institute of Technology 000014061 773__ $$tJournal of Advances in Modeling Earth Systems 000014061 8564_ $$uhttps://knowledge.uchicago.edu/record/14061/files/J%20Adv%20Model%20Earth%20Syst%20-%202018%20-%20Tan%20-%20An%20Extended%20Eddy%E2%80%90Diffusivity%20Mass%E2%80%90Flux%20Scheme%20for%20Unified%20Representation%20of.pdf$$9072c5b54-8ea8-41aa-8cc3-8c1760da45c6$$s1755804$$ePublic 000014061 908__ $$aI agree 000014061 909CO $$ooai:uchicago.tind.io:14061$$pGLOBAL_SET 000014061 983__ $$aArticle