气候变化领域集成服务门户(CCPortal): Growth and Decay of Northwestern Tropical Atlantic Barrier Layers

CCPortal

DOI	10.1029/2020JC016956
	Growth and Decay of Northwestern Tropical Atlantic Barrier Layers
	Saha A.; Serra N.; Stammer D.
发表日期	2021
ISSN	21699275
卷号	126 期号:5
英文摘要	The growth and decay mechanisms of barrier layers in the northwestern tropical Atlantic are studied by investigating small-scale processes embedded in the regional circulation of the tropical Atlantic using output from an eddy-resolving numerical simulation at 4 km resolution forced by an atmospheric reanalysis. The simulation reproduces well the temporal and spatial patterns of barrier layer thickness (BLT) estimated with Argo and CTD in situ profiles. As seen from an analysis of the salinity and temperature vertical gradient balances, localized large barrier layers form inside North Brazil Current rings during late-June to July because of a thickening of the isothermal layer in the rings due to horizontal temperature advection, stretching of isotherms and tilting of temperature fronts. These barrier layers decay when the isothermal layer reduces again due to the above mechanisms. Further to the north, along the North Equatorial Current, the seasonal variability of BLT is highly pronounced. Thick winter (January to early March) barrier layers locally grow as the base of the mixed layer shoals mainly due to a tilting of the salinity fronts and partly due to stretching of the isohalines, horizontal salt advection and vertical turbulent mixing. The short-term barrier layers in this case decay due to a deepening of the mixed layer, whereas they get completely eroded in spring by a shoaling of the isothermal layer due to surface temperature stratification. This work highlights that barrier layers are localized phenomena at times growing solely due to ocean dynamics, without a surface freshwater influx. © 2021. The Authors.
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186328
作者单位	Institute of Oceanography, Centrum für Erdsystemforschung und Nachhaltigkeit (CEN), Universität Hamburg, Hamburg, Germany
推荐引用方式 GB/T 7714	Saha A.,Serra N.,Stammer D.. Growth and Decay of Northwestern Tropical Atlantic Barrier Layers[J],2021,126(5).
APA	Saha A.,Serra N.,&Stammer D..(2021).Growth and Decay of Northwestern Tropical Atlantic Barrier Layers.Journal of Geophysical Research: Oceans,126(5).
MLA	Saha A.,et al."Growth and Decay of Northwestern Tropical Atlantic Barrier Layers".Journal of Geophysical Research: Oceans 126.5(2021).