气候变化领域集成服务门户(CCPortal): Vorticity Recirculation and Asymmetric Generation at a Small Headland With Broadband Currents

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DOI	10.1029/2020JC016639
	Vorticity Recirculation and Asymmetric Generation at a Small Headland With Broadband Currents
	Kovatch M.; Feddersen F.; Grimes D.J.; MacMahan J.H.
发表日期	2021
ISSN	21699275
卷号	126 期号:3
英文摘要	Fixed acoustic Doppler current profiler (ADCP) velocity measurements are used to investigate headland vorticity generation and recirculation in ∼20 m depth around the small (∼1 km) central California headland Pt. Sal. To reduce vorticity estimation noise, velocities are reconstructed from the first two Empirical Orthogonal Function modes representing ≈73% of the variance. Using fixed ADCPs, depth-averaged vorticity is estimated west and south of Pt. Sal. Only one west-location vorticity component is estimated, leading to negative vorticity bias for northward flow. The south location vorticity is consistent with estimates from parallel vessel transects on one day. The observed depth-averaged flow V was primarily along-bathymetric contours and varied ±0.2 ms−1 across subtidal and tidal frequency bands. The depth-averaged normalized vorticity (Formula presented.) varied ±8 across all frequency bands. Vorticity distributions are skewed with opposite sign at west and south locations, and (Formula presented.) is more likely at the west location. At both locations, depth-averaged vorticity and velocity are inversely related, with relationship asymmetric with sign of V, indicating headland and farther upstream vorticity generation. Binned-mean (Formula presented.) depends on both V and its time-derivative, and indicates vorticity recirculation across the headland. The ∼2 h vorticity adjustment timescale and the associated short excursion distances indicate vorticity generation between south and west locations. Potential vorticity changes across the headland are different for positive and negative V indicating headland asymmetric vorticity generation. Pt. Sal occupies a nondimensional parameter space that is unique relative to other well studied headlands. © 2021. The Authors.
英文关键词	coastal; eddies; headland; inner shelf; nearshore; vorticity
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/186410
作者单位	Scripps Institution of Oceanography, University of California, San Diego, CA, United States; Department of Oceanography, Naval Postgraduate School, Monterey, CA, United States
推荐引用方式 GB/T 7714	Kovatch M.,Feddersen F.,Grimes D.J.,et al. Vorticity Recirculation and Asymmetric Generation at a Small Headland With Broadband Currents[J],2021,126(3).
APA	Kovatch M.,Feddersen F.,Grimes D.J.,&MacMahan J.H..(2021).Vorticity Recirculation and Asymmetric Generation at a Small Headland With Broadband Currents.Journal of Geophysical Research: Oceans,126(3).
MLA	Kovatch M.,et al."Vorticity Recirculation and Asymmetric Generation at a Small Headland With Broadband Currents".Journal of Geophysical Research: Oceans 126.3(2021).