Wind-induced baroclinic response of Lake Constance

Wang, Yongqi; Hutter, Kolumban; Bäuerle, Erich

doi:10.1007/s00585-000-1488-6

Cited by 20 publications

(13 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is previous numerical evidence of internal Poincaré waves being locked to some features of the basin (e.g., Wang et al 2000) and of internal natural modes with a multicellular horizontal structure (Schwab 1977;Lemmin et al 2005); we offer here a dynamical explanation for their occurrence in terms of the dispersion relationships for circular basins developed by Antenucci and Imberger (2001). The structure of the 21ЊC isopycnal velocity of the 10.5-h-period wave (Fig.…”

Section: Discussionmentioning

confidence: 52%

Spatial structure of the dominant basin-scale internal waves in Lake Kinneret

2006

View full text Add to dashboard Cite

Field data and numerical simulations were used to investigate the effects of basin shape, continuous stratification, and rotation on the three-dimensional structure of the dominant natural basin-scale internal-wave modes in Lake Kinneret, a stratified lake large enough so that the earth's rotation influences the wave motion. The structure of the modes was inferred from power spectral density of measured and simulated isotherm vertical displacements and from rotary-power spectral density of isopycnal velocities obtained from numerical simulations. The shape of the lake at the level of the thermocline, in conjunction with the dispersion relationship, determines the horizontal configuration of the natural modes. The dominant response to wind forcing was an azimuthal and vertical mode 1 Kelvin wave with a natural period of 22.6 h that propagated around the entire basin; the second most dominant response was a vertical mode 1 wave with a natural period close to 10.5 h and composed of two counter-rotating Poincaré circular cells. The sloping bottom produced an intensification of vertical displacements and velocities over the slope due to focusing of waves rays after reflection at bottom slopes close to the critical angle. The amplitude of the observed oscillations was very sensitive to the phase of the wind relative to the existing waves; resonance was affected by the cessation time of the wind events because it defines the local forcing period and resets the phase of the observed oscillations.

show abstract

Section: Discussionmentioning

confidence: 52%

Spatial structure of the dominant basin-scale internal waves in Lake Kinneret

2006

View full text Add to dashboard Cite

show abstract

“…S6 and S5 this peak had shifted to a period of 8 h (3.5 ϫ 10 Ϫ5 Hz). This energy peak corresponded to a vertical mode-one Poincaré wave, the period of which Wang et al (2000) has previously shown to be dependent on the station location. The spectra from the model results are also shown in Fig.…”

Section: Basin-scale Internal Wave Fieldmentioning

confidence: 75%

“…Poincaré vertical mode-one waves in Upper Lake Constance have a more local character (Wang et al 2000), with periods in autumn typically around 12 h in the central and eastern main basin (Hollan 1974;Heinz 1995;Wang et al 2000), 9 h at the western end of the main basin (Heinz 1995;Wang et al 2000), and 4 h in Lake Ü berlingen (Hollan 1974;Bäuerle 1994;Wang et al 2000). Little seems to be known about basin-scale internal waves of higher vertical modes.…”

mentioning

confidence: 99%

Basin‐scale motion in stratified Upper Lake Constance

Appt

Imberger

Kobus

2004

Limnology & Oceanography

View full text Add to dashboard Cite

This paper describes experimental and modeled wind-induced oscillations in Upper Lake Constance with an emphasis on a coherent understanding of the basin-scale internal dynamics in this example of a large and stratified lake. Data were collected with eight Lake Diagnostic Systems (LDSs) consisting of thermistor chains and wind anemometers. The isotherm displacements as measured by the LDSs were interpreted using the three-dimensional hydrodynamic Estuary and Lake Computer Model (ELCOM). Three types of basin-scale waves were found to dominate the wave motion: the vertical mode-one Kelvin wave that had an observed period around 90 h, two vertical mode-one Poincaré waves that had periods near 8 h and 12 h, and a vertical mode-two Poincaré wave that had a period near 14 h. After strong westerly winds, upwelling of cold bottom water was observed east of the Sill of Mainau, where the lake's two subbasins connect. The width and length ratios of the subbasins, spatial variations of the wind field, and rotational effects over the lake are shown to play critical roles in the details of the upwelling structure. A sudden fall of the isotherms in Lake Ü berlingen formed a surge. The reflection of the surge from the northwestern boundary induced a vertical mode-two response leading to an intrusion in the metalimnion that caused a three-layer velocity structure in the smaller subbasin.

show abstract

“…In real basins, irregular bathymetry modifies the horizontal structure of a Poincaré wave by localizing the wave (Wang et al 2000) or by introducing an accompanying cyclonic cell (Gó mez-Giraldo et al 2006); whereas the horizontal structure of a Kelvin wave appears to be insensitive to basin irregularities (Mortimer 1974;Gó mez-Giraldo et al 2006). Recently Gó mez- Giraldo et al (2006) analyzed an internal wave consisting of an anticyclonic cell and a cyclonic cell in Lake Kinneret and suggested that the cells were governed by the dispersion relationship of Poincaré and Kelvin waves, respectively, in a circular (or elliptic) basin.…”

mentioning

confidence: 99%

Horizontal structure and excitation of primary motions in a strongly stratified lake

Shimizu

Imberger

Kumagai

2007

Limnology & Oceanography

View full text Add to dashboard Cite

A modal analysis in the horizontal plane was extended to a layer-stratified basin with irregular bathymetry, and the theory was applied to Lake Biwa to investigate the horizontal structure and excitation of the basin-scale internal waves and gyres. The horizontal structure of the basin-scale internal waves consisted of cyclonic and anticyclonic elliptic cells, each of which appeared to follow the dispersion relationship of Kelvin and Poincaré waves in elliptic basins. The internal waves were preferentially excited depending on the arrangement of the cells and the wind direction, but the spatial distribution of wind stress curl over the lake primarily determined the horizontal structure of the ensuing gyres. Decoupled evolutionary equations for the individual modes provided a good approximation for excitation of the internal waves and early stages of excitation of the gyres before nonlinear effects and damping become significant. The modal decomposition of hydrodynamic simulation results also showed that the primary action of the wind was to excite the internal waves; however, these internal waves were damped within a few days, and the dynamics during calm periods were dominated by the gyres, illustrating the importance of internal waves on mixing and gyres on long-term horizontal transport.

show abstract

Wind-induced baroclinic response of Lake Constance

Cited by 20 publications

References 14 publications

Spatial structure of the dominant basin-scale internal waves in Lake Kinneret

Spatial structure of the dominant basin-scale internal waves in Lake Kinneret

Basin‐scale motion in stratified Upper Lake Constance

Horizontal structure and excitation of primary motions in a strongly stratified lake

Contact Info

Product

Resources

About