气候变化领域集成服务门户(CCPortal): Self-Aggregation of Convection in Spatially Varying Sea Surface Temperatures

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DOI	10.1029/2019MS001698
	Self-Aggregation of Convection in Spatially Varying Sea Surface Temperatures
	Müller S.K.; Hohenegger C.
发表日期	2020
ISSN	19422466
卷号	12 期号:1
英文摘要	The phenomenon of self-aggregation of convection was first identified in convection-permitting simulations of radiative convective equilibrium, characterized by homogeneous boundary conditions and in the absence of planetary rotation. In this study, we expose self-aggregation of convection to more complex, nonhomogeneous boundary conditions and investigate its interaction with convective aggregation, as forced by large-scale variations in sea surface temperatures (SSTs). We do this by conducting radiative convective equilibrium simulations on a spherical domain, with SST patterns that are zonally homogeneous but meridionally varying. Due to the meridional contrast in SST, a convergence line first forms, mimicking the Intertropical Convergence Zone. We nevertheless find that the convergence line breaks up and contracts zonally as a result of the self-aggregation of convection. The contraction is significant, being here more than 50% of the original extent. The stability of the convergence line is controlled by the strength of the meridional circulation, which depends upon the imposed SST contrast. However, the process of self-aggregation, once it is initiated, is insensitive to the strength of the SST contrast. The zonal contraction is accompanied by a slight meridional expansion and a moistening of the high latitudes, where SSTs are low. The moistening of the high latitudes can be understood from the fact that the convective cluster intensifies and expands its moist meridional low-level outflow when it self-aggregates zonally. Overall, our results suggest that the Intertropical Convergence Zone may be unstable to the self-aggregation of convection, that self-aggregation may serve as a precursor to the formation of atmospheric rivers, and that longer convergence lines are more likely to exist in regimes with strong SST gradients. ©2019. The Authors.
语种	英语
scopus关键词	Atmospheric temperature; Boundary conditions; Oceanography; Submarine geophysics; Surface properties; Surface waters; Homogeneous boundary condition; Intertropical convergence zone; Meridional circulation; Non-homogeneous boundary conditions; Planetary rotation; Radiative-convective equilibrium; Sea surface temperature (SST); Sea surface temperatures; Agglomeration; air-sea interaction; atmospheric convection; boundary condition; intertropical convergence zone; meridional circulation; planetary rotation; sea surface temperature
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/156784
作者单位	Max Planck Institute for Meteorology, Hamburg, Germany
推荐引用方式 GB/T 7714	Müller S.K.,Hohenegger C.. Self-Aggregation of Convection in Spatially Varying Sea Surface Temperatures[J],2020,12(1).
APA	Müller S.K.,&Hohenegger C..(2020).Self-Aggregation of Convection in Spatially Varying Sea Surface Temperatures.Journal of Advances in Modeling Earth Systems,12(1).
MLA	Müller S.K.,et al."Self-Aggregation of Convection in Spatially Varying Sea Surface Temperatures".Journal of Advances in Modeling Earth Systems 12.1(2020).