气候变化领域集成服务门户(CCPortal): Multiple states and transport properties of double-diffusive convection turbulence

CCPortal

DOI	10.1073/pnas.2005669117
	Multiple states and transport properties of double-diffusive convection turbulence
	Yang Y.; Chen W.; Verzicco R.; Lohse D.
发表日期	2020
ISSN	0027-8424
起始页码	14676
结束页码	14681
卷号	117 期号:26
英文摘要	When fluid stratification is induced by the vertical gradients of two scalars with different diffusivities, double-diffusive convection (DDC) may occur and play a crucial role in mixing. Such a process exists in many natural and engineering environments. Especially in the ocean, DDC is omnipresent since the seawater density is affected by temperature and salinity. The most intriguing phenomenon caused by DDC is the thermohaline staircase, i.e., a stack of alternating well-mixed convection layers and sharp interfaces with very large gradients in both temperature and salinity. Here we investigate DDC and thermohaline staircases in the salt finger regime, which happens when warm saltier water lies above cold fresher water and is commonly observed in the (sub)tropic regions. By conducting direct numerical simulations over a large range of parameters, we reveal that multiple equilibrium states exist in fingering DDC and staircases even for the same control parameters. Different states can be established from different initial scalar distributions or different evolution histories of the flow parameters. Hysteresis appears during the transition from a staircase to a single salt finger interface. For the same local density ratio, salt finger interfaces in the single-layer state generate very different fluxes compared to those within staircases. However, the salinity flux for all salt finger interfaces follows the same dependence on the salinity Rayleigh number of the layer and can be described by an effective power law scaling. Our findings have direct applications to oceanic thermohaline staircases. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Double-diffusive convection; Thermohaline staircase; Turbulence
语种	英语
scopus关键词	fresh water; salt water; Article; body equilibrium; calculation; density; double diffusive convection turbulence; electrolyte transport; hysteresis; morphology; pH; priority journal; salinity; subtropic; thermohaline circulation; tropics
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160896
作者单位	Yang, Y., State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, 100871, China, Beijing Innovation Center for Engineering Science and Advanced Technology, Peking University, Beijing, 100871, China, Institute of Ocean Research, Peking University, Beijing, 100871, China; Chen, W., State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, 100871, China; Verzicco, R., Physics of Fluids Group, Max Planck Center Twente for Complex Fluid Dynamics and J. M. Burgers Centre for Fluid Mechanics, MESA+ Institute for Nanotechnology, University of Twente, Enschede, 7500 AE, Netherlands, Dipartimento di Ingegneria Industriale, University of Rome “Tor Vergata,, Rome, 00133, Italy, Maths Division, Gran Sasso Science Institute, L’Aquila, 67100, Italy; Lohse, D., Physics of Fluids Group, Max Planck Center Twente for Complex ...
推荐引用方式 GB/T 7714	Yang Y.,Chen W.,Verzicco R.,et al. Multiple states and transport properties of double-diffusive convection turbulence[J],2020,117(26).
APA	Yang Y.,Chen W.,Verzicco R.,&Lohse D..(2020).Multiple states and transport properties of double-diffusive convection turbulence.Proceedings of the National Academy of Sciences of the United States of America,117(26).
MLA	Yang Y.,et al."Multiple states and transport properties of double-diffusive convection turbulence".Proceedings of the National Academy of Sciences of the United States of America 117.26(2020).