气候变化领域集成服务门户(CCPortal): Oxycline oscillations induced by internal waves in deep Lake Iseo

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DOI	10.5194/hess-23-1763-2019
	Oxycline oscillations induced by internal waves in deep Lake Iseo
	Valerio G.; Pilotti M.; Lau M.P.; Hupfer M.
发表日期	2019
ISSN	1027-5606
起始页码	1763
结束页码	1777
卷号	23 期号:3
英文摘要	Lake Iseo is undergoing a dramatic deoxygenation of the hypolimnion, representing an emblematic example among the deep lakes of the pre-alpine area that are, to a different extent, undergoing reduced deep-water mixing. In the anoxic deep waters, the release and accumulation of reduced substances and phosphorus from the sediments are a major concern. Because the hydrodynamics of this lake was shown to be dominated by internal waves, in this study we investigated, for the first time, the role of these oscillatory motions on the vertical fluctuations of the oxycline, currently situated at a depth of approximately 95 m, where a permanent chemocline inhibits deep mixing via convection. Temperature and dissolved oxygen data measured at moored stations show large and periodic oscillations of the oxycline, with an amplitude of up to 20m and periods ranging from 1 to 4 days. Deep motions characterized by larger amplitudes at lower frequencies are favored by the excitation of second vertical modes in strongly thermally stratified periods and of first vertical modes in weakly thermally stratified periods, when the deep chemical gradient can support baroclinicity regardless. These basin-scale internal waves cause a fluctuation in the oxygen concentration between 0 and 3 mg L-1 in the water layer between 85 and 105m in depth, changing the redox condition at the sediment surface. This forcing, involving approximately 3% of the lake's sediment area, can have major implications for the biogeochemical processes at the sediment-water interface and for the internal matter cycle. ©2019 Author(s).
语种	英语
scopus关键词	Biochemical oxygen demand; Lakes; Mixing; Sediments; Biogeochemical process; Chemical gradients; Oscillatory motion; Oxygen concentrations; Periodic oscillation; Sediment water interface; Thermally stratified; Vertical fluctuations; Dissolved oxygen; deep water; dissolved oxygen; hydrodynamics; hypolimnion; internal wave; lacustrine deposit; oscillation; phosphorus; sediment chemistry; sediment-water interface; Italy; Lake Iseo; Lombardy
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159709
作者单位	Valerio, G., DICATAM, Università degli Studi di Brescia, via Branze 43, Brescia, 25123, Italy; Pilotti, M., DICATAM, Università degli Studi di Brescia, via Branze 43, Brescia, 25123, Italy, Civil and Environmental Engineering Department, Tufts University, Medford, MA 02155, United States; Lau, M.P., Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin, 12587, Germany, Université du Quebec À Montréal (UQAM), Department of Biological Sciences, Montréal, QC H2X 3Y7, Canada; Hupfer, M., Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin, 12587, Germany
推荐引用方式 GB/T 7714	Valerio G.,Pilotti M.,Lau M.P.,et al. Oxycline oscillations induced by internal waves in deep Lake Iseo[J],2019,23(3).
APA	Valerio G.,Pilotti M.,Lau M.P.,&Hupfer M..(2019).Oxycline oscillations induced by internal waves in deep Lake Iseo.Hydrology and Earth System Sciences,23(3).
MLA	Valerio G.,et al."Oxycline oscillations induced by internal waves in deep Lake Iseo".Hydrology and Earth System Sciences 23.3(2019).