气候变化领域集成服务门户(CCPortal): Memory effect of the southern atlantic subtropical dipole

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DOI	10.1175/JCLI-D-19-0745.1
	Memory effect of the southern atlantic subtropical dipole
	Santis W.; Castellanos P.; Campos E.
发表日期	2020
ISSN	0894-8755
起始页码	7679
结束页码	7696
卷号	33 期号:17
英文摘要	The South Atlantic subtropical dipole is the dominant mode of coupled variability in the South Atlantic, connecting sea level pressure and sea surface temperature. Previous studies have shown its great relevance to the climate conditions over South America and West Africa. We have used several numerical experiments with the Hybrid Coordinate Ocean Model to investigate the effects that an austral winter–spring dipole asserts on the South Atlantic. We explore the interaction between SST anomalies and the formation of the fossilized mixing region, which preserve temperature anomalies underneath the summer mixed layer, until they feed back to SST after the next autumn. It was found that, through this process, there is a memory effect that restores temperature anomalies from an austral winter–spring dipole back to the austral winter of the following year. The dominant mechanisms are the contribution from entrainment and surface net heat flux (NHF). Entrainment is mostly controlled by vertical temperature gradient anomalies, while surface NHF is controlled by interactions of climatological ocean heat loss and anomalies of mixed layer thickness. Our results suggest that the combined effect of entrainment and surface NHF is different in the southwest and northeast dipole regions, leading to differences in both intensity and timing of SST anomalies. Turbulent and nonlinear processes are most important to reduce entrainment in the southwest dipole region and to increase the memory effect asymmetry. © 2020 American Meteorological Society.
英文关键词	Sea level; Surface waters; Tropics; Climate condition; Dominant mechanism; Hybrid coordinate ocean models; Numerical experiments; Sea level pressure; Sea surface temperature (SST); Temperature anomaly; Vertical temperature gradients; Heat flux; climate conditions; entrainment; heat flux; mixed layer; sea level pressure; sea surface temperature; spring (season); subtropical region; temperature anomaly; temperature gradient; winter; Atlantic Ocean; Atlantic Ocean (South); South America; West Africa
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171137
作者单位	Instituto Oceanográfico da Universidade de São Paulo, São Paulo, Brazil; Marine and Environmental Sciences Centre, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal; College of Arts and Sciences of the American University of Sharjah, Sharjah, United Arab Emirates
推荐引用方式 GB/T 7714	Santis W.,Castellanos P.,Campos E.. Memory effect of the southern atlantic subtropical dipole[J],2020,33(17).
APA	Santis W.,Castellanos P.,&Campos E..(2020).Memory effect of the southern atlantic subtropical dipole.Journal of Climate,33(17).
MLA	Santis W.,et al."Memory effect of the southern atlantic subtropical dipole".Journal of Climate 33.17(2020).