https://doi.org/10.4081/jlimnol.2020.1983
Moored observations of turbulent mixing events in deep Lake Garda, Italy
Submitted: 15 August 2020
Accepted: 26 October 2020
Published: 3 November 2020
Accepted: 26 October 2020
Abstract Views: 2767
PDF: 781
HTML: 13
HTML: 13
Publisher's note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Authors
Deep water circulation and mixing processes are responsible for the transport of matter, nutrients and pollutants in deep lakes. Nevertheless, detailed continuous observations are rarely available. To overcome some of these deficiencies and with the aim of improving our understanding of deep mixing processes, a dedicated yearlong mooring comprising 100 high-resolution temperature sensors and a single current meter were located in the deeper half of the 344 m deepest point of the subalpine Lake Garda, Italy. The observations show peaks and calms of turbulent exchange, besides ubiquitous internal wave activity. In late winter, northerly winds activate episodic deep convective overturning, the dense water being subsequently advected along the lake-floor. Besides deep convection, such winds also set-up seiches and inertial waves that are associated with about 100 times larger turbulence dissipation rates than that by semidiurnal internal wave breaking observed in summer. In the lower 60 m above the lake-floor, however, the average turbulence dissipation rate is approximately constant in value year-around, being about 10 times larger than open-ocean values, except during deep convection episodes.
Amadori M, Piccolroaz S, Giovannini L, Zardi D, Toffolon M, 2018. Wind variability and Earth’s rotation as drivers of transport in a deep, elongated subalpine lake: the case of Lake Garda. J. Limnol. 77:1814.
DOI: https://doi.org/10.4081/jlimnol.2018.1814
Ambrosetti W, Barbanti L, 1999. Deep water warming in lakes: an indicator of climatic change. J. Limnol. 58:1.
DOI: https://doi.org/10.4081/jlimnol.1999.1
Antenucci J, Imberger J, 2003. The Seasonal Evolution of Wind/Internal Wave Resonance in Lake Kineret. Limnol. Oceanogr. 48:2055-2061.
DOI: https://doi.org/10.4319/lo.2003.48.5.2055
Berger SA, Diehl S, Stibor H, Trommer G, Ruhenstroth M, Wild A, Weigert A, Gerald Jäger C, Striebel M, 2007. Water temperature and mixing depth affect timing and magnitude of events during spring succession of the plankton. Oecologia 150:643-654.
DOI: https://doi.org/10.1007/s00442-006-0550-9
Boegman L, Imberger J, Ivey GN, Antenucci JP, 2003. High-frequency internal waves in large stratified lakes. Limnol. Oceanogr. 46:895-919.
DOI: https://doi.org/10.4319/lo.2003.48.2.0895
Boehrer B, Fukuyama R, Chikita K, 2008. Stratification of very deep, thermally stratified lakes. Geophys. Res. Lett. 35:L16405.
DOI: https://doi.org/10.1029/2008GL034519
Chalamalla VK, Sarkar S, 2015. Mixing, dissipation rate, and their overturn-based estimates in a near-bottom turbulent flow driven by internal tides. J. Phys. Oceanogr. 45:1969-1983.
DOI: https://doi.org/10.1175/JPO-D-14-0057.1
Copetti D, Guyennon N, Buzzi F, 2020. Generation and dispersion of chemical and biological gradients in a large-deep multi-basin lake (Lake Como, north Italy): The joint effect of external drivers and internal wave motions. Sci. Tot. Env. 749:141587.
DOI: https://doi.org/10.1016/j.scitotenv.2020.141587
Dauxois T, Didier A, Falcon E, 2004. Observations of near-critical reflection of internal waves in a stably stratified fluid. Phys. Fluids 16:1936-1941.
DOI: https://doi.org/10.1063/1.1711814
Dillon TM, 1982. Vertical overturns: a comparison of Thorpe and Ozmidov length scales. J. Geophys. Res. 87:9601-9613.
DOI: https://doi.org/10.1029/JC087iC12p09601
Dokulil MT, 2014. Impact of climate warming on European inland waters. Inland Wat. 4:27-40.
DOI: https://doi.org/10.5268/IW-4.1.705
Ekman VW, 1905. On the influence of the Earth’s rotation on ocean-currents. Ark Math Astron Fys 2:1-52.
Eriksen CC, 1982. Observations of internal wave reflection off sloping bottoms. J. Geophys. Res. 87:525-538.
DOI: https://doi.org/10.1029/JC087iC01p00525
Farmer DM, 1978. Observations of long nonlinear internal waves in a lake. J. Phys. Oceanogr. 8:63-73.
DOI: https://doi.org/10.1175/1520-0485(1978)008<0063:OOLNIW>2.0.CO;2
Fer I, Lemmin U, Thorpe SA, 2002. Winter cascading of cold water in Lake Geneva. J. Geophys. Res. 107:C6.
DOI: https://doi.org/10.1029/2001JC000828
Galbraith PS, Kelley DE, 1996. Identifying overturns in CTD profiles. J. Atmos. Ocean. Tech. 13:688-702.
DOI: https://doi.org/10.1175/1520-0426(1996)013<0688:IOICP>2.0.CO;2
Garanaik A, Venayagamoorthy SK, 2019. On the inference of the state of turbulence and mixing efficiency in stably stratified flows. J. Fluid Mech. 867:323-333.
DOI: https://doi.org/10.1017/jfm.2019.142
Garrett CJR, Munk WH, 1972. Space-time scales of internal waves. Geophys. Fluid Dyn. 3:225-264.
DOI: https://doi.org/10.1080/03091927208236082
Gill AE, 1982. Atmosphere-ocean dynamics. Academic Press: 682 pp.
Giovannini L, Laiti L, Zardi D, de Franceschi M, 2015. Climatological characteristics of the Ora del Garda wind in the Alps. Int. J. Clim. 35:4103-4115.
DOI: https://doi.org/10.1002/joc.4270
Gloor M, Wüest A, Münnich M, 1994. Benthic boundary mixing and resuspension induced by internal seiches. Hydrobiol. 284:59-68.
DOI: https://doi.org/10.1007/BF00005731
Goudsmit G-H, Peeters F, Gloor M, Wüest A, 1997. Boundary versus internal diapycnal mixing in stratified natural waters. J. Geophys. Res. 102:27903-27914.
DOI: https://doi.org/10.1029/97JC01861
Goudsmit G‐H, Burchard H, Peeters F, Wüest A, 2002. Application of k‐ϵ turbulence models to enclosed basins: The role of internal seiches. J. Geophys. Res. 107:3230.
DOI: https://doi.org/10.1029/2001JC000954
Gregg MC, 1989. Scaling turbulent dissipation in the thermocline. J. Geophys. Res. 94:9686-9698.
DOI: https://doi.org/10.1029/JC094iC07p09686
Gregg MC, D’Asaro EA, Riley JJ, Kunze E, 2018. Mixing efficiency in the ocean. Annu. Rev. Mar. Sci. 10:443-473.
DOI: https://doi.org/10.1146/annurev-marine-121916-063643
Guyennon N, Valerio G, Salerno F, Pilotti M, Tartari G, Copetti D, 2014. Internal wave weather heterogeneity in a deep multi-basin subalpine lake resulting from wavelet transform and numerical analysis. Adv. Water Res. 71:149-161.
DOI: https://doi.org/10.1016/j.advwatres.2014.06.013
Imboden DM, Wüest A, 1995. Mixing mechanisms in lakes, p. 83-138. In: A. Lerman, D.M. Imboden and J.R. Gat (eds.), Physics and chemistry of lakes. Cham, Springer.
DOI: https://doi.org/10.1007/978-3-642-85132-2_4
IOC, SCOR, IAPSO, 2010. The international thermodynamic equation of seawater – 2010: Calculation and use of thermodynamic properties. Intergovernmental Oceanographic Commission, Manuals and Guides No. 56, UNESCO.
LeBlond PH, Mysak LA, 1978. Waves in the ocean. Elsevier: 602 pp.
Lemmin U, Mortimer CH, Bäuerle E, 2005. Internal seiche dynamics in Lake Geneva. Limnol. Oceanogr. 50:207-216.
DOI: https://doi.org/10.4319/lo.2005.50.1.0207
Leoni B, Garibaldi L, Gulati R, 2014. How does interannual trophic variability caused by vertical water mixing affect reproduction and population density of the Daphnia longispina group in Lake Iseo, a deep stratified lake in Italy. Inland Wat. 4:193-203.
DOI: https://doi.org/10.5268/IW-4.2.663
Li S, Li H, 2006. Parallel AMR code for compressible MHD and HD equations. T-7, MS B284, Theoretical division, Los Alamos National Laboratory. Available from: http://math.lanl.gov/Research/Highlights/amrmhd.shtml
Lorke A, Peeters F, Bäuerle E, 2006. High-frequency internal waves in the littoral zone of a large lake. Limnol. Oceanogr. 51: 1935-1939.
DOI: https://doi.org/10.4319/lo.2006.51.4.1935
Lorke A, 2007. Boundary mixing in the thermocline of a large lake. J. Geophys. Res. 112:C09019. doi:10.1029/2006JC004008
DOI: https://doi.org/10.1029/2006JC004008
Lorrai C, Umlauf L, Becherer JK, Lorke A, Wüest A, 2011. Boundary mixing in lakes: 2. Combined effects of shear-and convectively induced turbulence on basin-scale mixing. J. Geophys. Res. 116:C10018.
DOI: https://doi.org/10.1029/2011JC007121
Mater BD, Venayagamoorthy SK, St. Laurent L, Moum JN, 2015. Biases in Thorpe scale estimation of turbulence dissipation. Part I: Assessments from large-scale overturns in oceanographic data. J. Phys. Oceanogr. 45:2497-2521.
DOI: https://doi.org/10.1175/JPO-D-14-0128.1
Matsumoto Y, Hoshino M, 2004. Onset of turbulence by a Kelvin-Helmholtz vortex. Geophys. Res. Lett. 31:L02807.
DOI: https://doi.org/10.1029/2003GL018195
Oakey NS, 1982. Determination of the rate of dissipation of turbulent energy from simultaneous temperature and velocity shear microstructure measurements. J. Phys. Oceanogr. 12:256-271.
DOI: https://doi.org/10.1175/1520-0485(1982)012<0256:DOTROD>2.0.CO;2
Osborn TR, 1980. Estimates of the local rate of vertical diffusion from dissipation measurements. J. Phys. Oceanogr. 10:83-89.
DOI: https://doi.org/10.1175/1520-0485(1980)010<0083:EOTLRO>2.0.CO;2
Perroud M, Goyette S, Martynov A, Beniston M, Anneville O, 2009. Simulation of multiannual thermal profiles in deep Lake Geneva: A comparison of one-dimensional lake models. Limnol. Oceanogr. 54:1574-594.
DOI: https://doi.org/10.4319/lo.2009.54.5.1574
Phillips OM, 1971. On spectra measured in an undulating layered medium. J. Phys. Oceanogr. 1:1-6.
DOI: https://doi.org/10.1175/1520-0485(1971)001<0001:OSMIAU>2.0.CO;2
Piccolroaz S, Amadori M, Toffolon M, Dijkstra HA, 2019. Importance of planetary rotation for ventilation processes in deep elongated lakes: Evidence from Lake Garda (Italy). Sci. Rep. 9:8290.
DOI: https://doi.org/10.1038/s41598-019-44730-1
Polzin K L, Toole JM, Ledwell JR, Schmitt RW, 1997. Spatial variability of turbulent mixing in the abyssal ocean. Science 276:93-96.
DOI: https://doi.org/10.1126/science.276.5309.93
Portwood GD, de Bruyn Kops SM, Caulfield CP, 2019. Asymptotic dynamics of high dynamic range stratified turbulence. Phys. Rev. Lett. 122:194504.
DOI: https://doi.org/10.1103/PhysRevLett.122.194504
Preusse M, 2012. Properties of internal solitary waves in deep temperate lakes. Ph.D. Thesis University of Konstanz.
DOI: https://doi.org/10.1371/journal.pone.0041674
Ravens TM, Kocsis O, Wüest A, Granin N, 2000. Small-scale turbulence and vertical mixing in Lake Baikal. Limnol. Oceanogr. 45:159-173.
DOI: https://doi.org/10.4319/lo.2000.45.1.0159
Salmaso N, Decet F, 1998. Interactions of physical, chemical and biological processes affecting the seasonality of mineral composition and nutrient cycling in the water column of a deep subalpine lake (Lake Garda, Northern Italy). Arch. Hydrobiol. 142:385-414.
DOI: https://doi.org/10.1127/archiv-hydrobiol/142/1998/385
Salmaso N, Morabito G, Mosello R, Garibaldi L, Simona M, Buzzi F, Ruggiu D, 2003. A synoptic study of phytoplankton in the deep lakes south of the Alps (lakes Garda, Iseo, Como, Lugano, and Maggiore). J. Limnol. 62:207.
DOI: https://doi.org/10.4081/jlimnol.2003.207
Salmaso N, 2005. Effects of climatic fluctuations and vertical mixing on the interannual trophic variability of Lake Garda, Italy. Limnol. Oceanogr. 50:553-565.
DOI: https://doi.org/10.4319/lo.2005.50.2.0553
Sarkar S, Scotti A, 2017. From topographic internal gravity waves to turbulence. Ann. Rev. Fluid Mech. 49:195-220.
DOI: https://doi.org/10.1146/annurev-fluid-010816-060013
Swann GEA, Panizzo VN, Piccolroaz S, Pashley V, Horstwood MSA, Roberts S, Vologina E, Piotrowska N, Sturm M, Zhdanov A, Granin N, Norman V, McGowan S, Mackay AS, 2020. Changing nutrient cycling in Lake Baikal, the world’s oldest lake. Proc. Natl. Acad. Sci. USA 117:27211-27217.
DOI: https://doi.org/10.1073/pnas.2013181117
Tennekes H, Lumley JL, 1972. A first in turbulence. MIT Press: 300 pp.
DOI: https://doi.org/10.7551/mitpress/3014.001.0001
Thorpe SA, 1977. Turbulence and mixing in a Scottish loch. Phil. Trans. Roy. Soc. Lond. A 286: 25-181.
DOI: https://doi.org/10.1098/rsta.1977.0112
Thorpe SA, Keen JM, Jiang R, Lemmin U, 1996. High frequencu internal waves in Lake Geneva. Phil. Trans. R. Soc. Lond. A 354 237-257.
DOI: https://doi.org/10.1098/rsta.1996.0008
Toffolon M, Piccolroaz S, Dijkstra HA, 2017. A plunge into the depths of Italy’s Lake Garda. Eos 98. Available from: https://eos.org/meeting-reports/a-plunge-into-the-depths-of-italys-lake-garda
DOI: https://doi.org/10.1029/2017EO074499
Valerio G, Pilotti M, Clelia M, Imberger J, 2012. The structure of basin scale internal waves in a stratified lake in response to lake bathymetry and wind spatial and temporal distribution: Lake Iseo, Italy. Limnol. Oceanogr. 57:772-786.
DOI: https://doi.org/10.4319/lo.2012.57.3.0772
Valerio G, Pilotti M, Lau M, Hupfer M, 2019. Oxycline oscillations induced by internal waves in deep Lake Iseo. Hydrol. Earth Syst. Sci. 23:1763-1777.
DOI: https://doi.org/10.5194/hess-23-1763-2019
van Haren H, 2017. Exploring the vertical extent of breaking internal wave turbulence above deep-sea topography. Dyn. Atmos. Oc. 77:89-99.
DOI: https://doi.org/10.1016/j.dynatmoce.2017.01.002
van Haren H, 2018. Philosophy and application of high-resolution temperature sensors for stratified waters. Sensors 18:3184.
DOI: https://doi.org/10.3390/s18103184
van Haren H, 2019. Open-ocean interior moored sensor turbulence estimates, below a Meddy. Deep-Sea Res. I 144:75-84.
DOI: https://doi.org/10.1016/j.dsr.2019.01.005
van Haren H, Gostiaux L, 2012. Detailed internal wave mixing above a deep-ocean slope. J. Mar. Res. 70:173-197.
DOI: https://doi.org/10.1357/002224012800502363
van Haren H, Maas L, Zimmerman JTF, Ridderinkhof H, Malschaert H, 1999. Strong inertial currents and marginal internal wave stability in the central North Sea. Geophys. Res. Lett. 26:2993-2996.
DOI: https://doi.org/10.1029/1999GL002352
van Haren H, Cimatoribus AA, Gostiaux L, 2015. Where large deep-ocean waves break. Geophys. Res. Lett. 42:2351-2357.
DOI: https://doi.org/10.1002/2015GL063329
Wang Y, Hutter C, Bäuerle E, 2000. Wind-induced baroclinic response of Lake Constance. Ann. Geophys. 18:1488-1501.
DOI: https://doi.org/10.1007/s00585-000-1488-6
Warhaft Z, 2000. Passive scalars in turbulent flows. Ann. Rev. Fluid Mech. 32:203-240.
DOI: https://doi.org/10.1146/annurev.fluid.32.1.203
Wetzel RG, 2001. Limnology: Lake and river ecosystems. Academic Press, San Diego: 1006 pp.
Winters KB, 2015. Tidally driven mixing and dissipation in the boundary layer above steep submarine topography. Geophys. Res. Lett. 42:7123-7130.
DOI: https://doi.org/10.1002/2015GL064676
Wüest A, Lorke A, 2003. Small-scale hydrodynamics in lakes. Ann. Rev. Fluid Mech. 35:373-412.
DOI: https://doi.org/10.1146/annurev.fluid.35.101101.161220
Edited by
Aldo Marchetto, CNR-IRSA Verbania, ItalyHow to Cite
van Haren, Hans, Sebastiano Piccolroaz, Marina Amadori, Marco Toffolon, and Henk A. Dijkstra. 2020. “Moored Observations of Turbulent Mixing Events in Deep Lake Garda, Italy”. Journal of Limnology 80 (1). https://doi.org/10.4081/jlimnol.2020.1983.
Copyright (c) 2020 The Author(s)
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Similar Articles
- Muhammed Shikhani, Chenxi Mi, Artur Gevorgyan, Gor Gevorgyan, Amalya Misakyan, Levon Azizyan, Klemens Barfus, Martin Schulze, Tom Shatwell, Karsten Rinke, Simulating thermal dynamics of the largest lake in the Caucasus region: The mountain Lake Sevan , Journal of Limnology: Vol. 81 No. s1 (2022): Lake Sevan. Past, present, and future state of a unique alpine lake
- Bouke Biemond, Marina Amadori, Marco Toffolon, Sebastiano Piccolroaz, Hans van Haren, Henk A. Dijkstra, Deep-mixing and deep-cooling events in Lake Garda: Simulation and mechanisms , Journal of Limnology: Vol. 80 No. 2 (2021)
- Claudia Dresti, Andrea Fenocchi, Diego Copetti, Modelling physical and ecological processes in medium-to-large deep European perialpine lakes: a review , Journal of Limnology: Vol. 80 No. 3 (2021): Celebratory Issue - 80th Anniversary of the Journal of Limnology
- Ali Oveisy, Leon Boegman, One-dimensional simulation of lake and ice dynamics during winter , Journal of Limnology: Vol. 73 No. 3 (2014)
- Franco Tassi, Dmitri Rouwet, An overview of the structure, hazards, and methods of investigation of Nyos-type lakes from the geochemical perspective , Journal of Limnology: Vol. 73 No. 1 (2014)
- Armine Hayrapetyan, Gor Gevorgyan , Martin Schultze, Muhammed Shikhani, Termine Khachikyan, Aleksandr Krylov, Karsten Rinke, Contemporary community composition, spatial distribution patterns, and biodiversity characteristics of zooplankton in large alpine Lake Sevan, Armenia , Journal of Limnology: Vol. 81 No. s1 (2022): Lake Sevan. Past, present, and future state of a unique alpine lake
- Luigi Hinegk, Luca Adami, Sebastiano Piccolroaz, Marina Amadori, Marcello Moretti, Marco Tubino, Marco Toffolon, Multidecadal analysis of Lake Garda water balance , Journal of Limnology: Vol. 82 (2023)
- Marco Pilotti, Giulia Valerio, Luca Gregorini, Luca Milanesi, Charlie A.R. Hogg, Study of tributary inflows in Lake Iseo with a rotating physical model , Journal of Limnology: Vol. 73 No. 1 (2014)
- María del Carmen Hernández, Javier Alcocer, Luis A. Oseguera, Elva Escobar, Profundal benthic invertebrates in an oligotrophic tropical lake: different strategies for coping with anoxia , Journal of Limnology: Vol. 73 No. 2 (2014)
- Tiina Nõges, Orlane Anneville, Jean Guillard, Juta Haberman, Ain Järvalt, Marina Manca, Giuseppe Morabito, Michela Rogora, Stephen J. Thackeray, Pietro Volta, Ian J. Winfield, Peeter Nõges, Fisheries impacts on lake ecosystem structure in the context of a changing climate and trophic state , Journal of Limnology: Vol. 77 No. 1 (2018)
You may also start an advanced similarity search for this article.
List of Cited By :
