气候变化领域集成服务门户(CCPortal): Toward a Stochastic Relaxation for the Quasi-Equilibrium Theory of Cumulus Parameterization: Multicloud Instability, Multiple Equilibria, and Chaotic Dynamics

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DOI	10.1029/2019MS001627
	Toward a Stochastic Relaxation for the Quasi-Equilibrium Theory of Cumulus Parameterization: Multicloud Instability, Multiple Equilibria, and Chaotic Dynamics
	Khouider B.; Leclerc E.
发表日期	2019
ISSN	19422466
起始页码	2474
结束页码	2502
卷号	11 期号:8
英文摘要	The representation of clouds and organized tropical convection remains one of the biggest sources of uncertainties in climate and long-term weather prediction models. Some of the most common cumulus parameterization schemes, namely, mass-flux schemes, rely on the quasi-equilibrium (QE) closure, which assumes that convection consumes the large-scale instability and restores large-scale equilibrium instantaneously. However, the QE hypothesis has been challenged both conceptually and in practice. Subsequently, the QE assumption was relaxed, and instead, prognostic equations for the cloud work function (CWF) and the cumulus kinetic energy (CKE) were derived and used. It was shown that even if the CWF kernel serves to damp the CWF, the prognostic system exhibits damped oscillations on a timescale of a few hours, giving parameterized-cumulus-clouds enough memory to interact with each other, with the environment, and with stratiform anvils in particular. Herein, we show that when cloud-cloud interactions are reintroduced into the CWF-CKE equations, the coupled system becomes unstable. Moreover, we couple the CWF-CKE prognostic equations to dynamical equations for the cloud area fractions, based on the mean field limit of a stochastic multicloud model. Qualitative analysis and numerical simulations show that the CKE-CWF-cloud area fraction equations exhibit interesting dynamics including multiple equilibria, limit cycles, and chaotic behavior both when the large-scale forcing is held fixed and when it oscillates with various frequencies. This is representative of cumulus convection variability, and its capability to transition between various regimes of organization at multiple scales and regimes of scattered convection, in an intermittent and chaotic fashion. ©2019. The Authors.
英文关键词	chaotic dynamics; cloud area fraction; cumulus parameterization; mass flux; multiple equilibria; prognostic closure
语种	英语
scopus关键词	Climate models; Clouds; Kinetic energy; Kinetics; Mass transfer; Parameterization; Stochastic systems; Area fraction; Chaotic dynamics; Cumulus parameterization; Multiple equilibrium; prognostic closure; Stochastic models; chaotic dynamics; convection; cumulus; kinetic energy; mass transfer; numerical model; parameterization; qualitative analysis; stochasticity
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156883
作者单位	Department of Mathematics and Statistics, University of Victoria, Victoria, BC, Canada
推荐引用方式 GB/T 7714	Khouider B.,Leclerc E.. Toward a Stochastic Relaxation for the Quasi-Equilibrium Theory of Cumulus Parameterization: Multicloud Instability, Multiple Equilibria, and Chaotic Dynamics[J],2019,11(8).
APA	Khouider B.,&Leclerc E..(2019).Toward a Stochastic Relaxation for the Quasi-Equilibrium Theory of Cumulus Parameterization: Multicloud Instability, Multiple Equilibria, and Chaotic Dynamics.Journal of Advances in Modeling Earth Systems,11(8).
MLA	Khouider B.,et al."Toward a Stochastic Relaxation for the Quasi-Equilibrium Theory of Cumulus Parameterization: Multicloud Instability, Multiple Equilibria, and Chaotic Dynamics".Journal of Advances in Modeling Earth Systems 11.8(2019).