Lake Hydrodynamic and Ecosystem Response to Weather-related Episodic Events or Changing Climate

Inland Lakes

    Blooms of blue-green algae (i.e. cyanobacteria) are temporally and spatially variable in eutrophic lakes. Algal species that constitute the blooms are also highly variable and sub-species characteristics of algae differ widely (e.g., clumping vs. non-clumping or toxin-producing vs. non-toxin producing genotypes).  Because blue-green algae are often buoyant, hydrodynamic processes result in large intra-lake spatial variability in algal abundance with the potential for high inter-lake spatial correlation in bloom patterns including noxious bloom pile-ups on downwind shorelines. As a result all these factors, the ecological and public health consequences of blue-green algal blooms can be major.
vector  storm
    Blooms of blue-green algae in Madison Lakes                                Lake hydrodynamics processes                                                 Circulation pattern in Lake Mendota                            Transport of effluent under a storm event
   An interdisciplinary approach will be used to characterize spatial/temporal dynamics of bloom development. For remote sensing technologies, we are currently developing a remote controlled model aircraft (DigiDot2) with a high precision CCD camera to sample across the lake. In addition, we are developing a real-time water imaging system (RTWIS) with aerial photogrammetry technique for monitoring water quality in eutrophic lakes under various biophysical environment. At the lake district scale, IKONOS, QuickBird, SPOT, and Landsat will be used to study blooms on lakes. To acquire in-situ and real-time data, a state-of-the-art wireless buoy, vertical profiling buoy, and the BEDS  are used to measure nutrients, phytoplankton and zooplankton species densities, velocity and temperature profiles. Molecular characterization of cyanobacterial taxa are used to detect community change in response to in-situ and remote chemical and physical measurements. Some on-going research progress can be found at the Lake Mendota Environmental Observatory website. Our interdisciplinary approach allows us to assess algal bloom as the synchronicity of bloom development among lakes and the spatial variability of such external drivers as weather or climate change.

    Ongoing research themes address multiple aspects of  water quantity and quality that are of great concerns and interests of the local authorities and Wisconsin citizens. For example one potential strategy for managing the Yahara River watershed is to maintain the hydrological budget by discharging treated effluent released from a water treatment plant. The goal is to evaluate the water levels and examine the fate of hypolimnetic effluent discharges. Specific tasks include: (i) hydrology and hydrodynamics of the lake; (ii) fate and transport of phosphorus in the lake; and (iii) the composition and phosphorus-liberating activity of the lake bacterial communities.  We are developing a three-dimensional non-hydrostatic and stratified flow model (3DNHYS) to examine general circulation pattern, surface and internal waves and their breaking over shoaling bathymetry. The model would take into account of the effects of of temperature stratification, steep bathymetry, and wave-current interactions. In addition, the 3DNYHS model is coupled with a water quality model to examine the environmental impacts of LTER Lakes. The integrated model shows that discharge effluents would be trapped within the hyperlimnion during the summer season but could escape through the thermocline under a storm event.

     Another on-going research is the development of the Integrated Nowcast and Forecast Operation System (INFOS) that provides real-time measured and modeling water information for the Yahara Lakes. The effects of hydrologic, hydrodynamic and wind wave characteristics on environmental impacts of Madison Lakes such as flooding, sediment deposition, and shoreline erosion have been concerns and interests of the local authorities and Wisconsin citizens. INFOS is  a community online web platform that shows real-time data including water level, discharge, temperature, and other meteorological measurements. INFOS integrates observations into models to provide spatial variation of water parameters and transport of sediments and nutrients. The present stage and future stage of lake information will be posted through the web using nowcasting and forecasting models. Our overall goal is to provide managers and researchers to assess the water levels and nutrient management strategies for the Yahara Lakes system. 
Great Lakes

superior Apostle  meteo  INFOS-RC
        Lake Superior circulation in Google-earth                               Wireless real-time buoy and nowcast modeling                                      Generations of meteotsunamis                                                             INFOS-Rip Current

   We have been working several projects on the Laurentian Great Lakes. During the past several years, We attempt to close the carbon budget for one of the Great Lakes using numerical models and data. An interdisciplinary team aims to develop reliable estimates of lake-atmosphere CO2 fluxes on seasonal to decadal timescales and to identify key uncertainties in the carbon budget of Lake Superior. Additionally, this project will contribute to efforts led by terrestrial carbon cycle scientists to understand the regional carbon budget.

     The water environment in the Apostle Islands lakeshore is undoubtedly quite complex and dynamic due to the interaction of Lake Superior processes with the 22 islands at the site. Waves generated in Lake Superior will diffract and reflect when they encounter the islands and may combine to form extreme waves in a process known as geometric focusing.  This process is applied to determine local regions of energetic wave fields for use in wave power generation around the world. When currents are present in a wave field, significant transfers of momentum can occur between the two processes. Laboratory and field measurements have confirmed that waves propagating against a current are more susceptible to extreme wave formation. Current directions through the island network are likely to be highly variable due to different lake-wide processes. Wind shear, seiche, and coastal upwelling have all been documented as important current drivers on Lake Superior. Possible scenarios exist where wind waves generated over the open lake propagate into the islands against currents generated by lake circulation and an upwelling event. The islands greatly complicate wave, current, and temperature fields. Furthermore, shedding eddies, denoted as S, have been found to commonly form when a strong current interacts with an irregular coastline, such as islands, in a process known as flow separation. An eddy is a region of circulating water that is known to contain elevated levels of turbulence and has been found to contribute to the formation of extreme waves in the open ocean. We aim to characterize how the properties of the water environment in the Apostle Islands interact, which will help determine if certain conditions favor the occurrence of dangerous extreme waves and enable the identification of a turbulence threshold for fish habitats in the Great Lakes.    
     Meteotsunamis can pose a serious threat to the Lake Michigan coast, owing to the lake’s characteristics that facilitate the formation of destructive meteotsunamis including frequent fast-moving storm fronts, resonance-promoting bathymetry, and harbors to finally amplify the wave. The most vivid historical meteotsunami on record in the Great Lakes occurred in 1954,  when a squall line-induced longwave wave struck Chicago in Lake Michigan. The coast was inundated up to 50 meters inland and unexpectedly swept many fishermen off of the Montrose Harbor piers, killing seven. While the threat of meteotsunamis in Lake Michigan has been recognized, to date no infrastructure for detecting and warning of a pending meteotsunami disaster is available. Furthermore the potential hot spots in Lake Michigan that can be threatened by meteotsunamis has yet been identified and characterized. In collaboration researchers in Great Lakes Environmental Research Laboratory, we are currently implementing an observation network system to better understand the occurrence of meterotsunamis. An operational meteotsunami forecasting and warning system is also being developed to keep residents safe and avoid dangerous events.

   Rip currents are shore-normal, rapid seaward flows that originate in the surf zone. As a hidden but lethal hazard at Great Lakes beaches, rip currents can quickly sweep swimmers away from the shore out to the open, deep water. It has been estimated by the Great Lakes Current Incident Database that every summer an average 12 fatalities and 26 rescues are related to rip currents during from 2002 to 2012. Rip currents sometimes are incorrectly referred as “undertows” or “rip tides”; however, those are three different phenomena. Undertow is the backwash of breaking waves and in general a weak flow. On the other hand, rip tides are strong offshore currents caused by the constricted tidal flow through barrier beaches. In comparison, rip currents are strong, non-periodical, discretely located, and more dangerous than the other two types of offshore currents. Rip currents are in general caused by spatial difference in wave breaking along the shoreline; however, the mechanism for generation of rip current can be complicated and varies on a beach-to-beach basis. To improve beach hazard rip-current warning, we will  develop an Integrated Nowcast (real-time) Observation and Forecast (future) Operation System (INFOS) and applying the INFOS at three rip-current prone beaches through coordination, communication, and community outreach and education. The three beaches, (i) Park Point Beach, Duluth, MN, (ii) Bradford Beach, Milwaukee, WI, and (iii) North Beach, Port Washington, WI, are identified as high occurrence of bar-gap, headland, and structured-induced rip currents, respectively. The proposed project is an integrated and collaborative effort among many partners: UW-Madison, Minnesota/Wisconsin Sea Grants, Wisconsin Coastal Management Program, National Weather Service at Duluth and Milwaukee/Sullivan, City of Duluth, Milwaukee County, and City of Port Washington,  NOAA-NOS and Great Lakes Environmental Research Laboratory. Several news related to the INFOS-rip current project can be accessed here.


Sponsor :
          Arthur H. Frazier Fellowship
          City of Madison, WI
          Coastal Storm Program, NOAA - Ohio Sea Grant College Program
          Cooperative Institute for Limnology and Ecosystems Research
          Dane County Land and Water Resources Department

          Gordon and Betty Moore Foundation
          Hilldale Undergraduate/Faculty Research Fellowships
Madison Metropolitan Sewerage District
          NOAA-Ocean and Human Health
          NSF-North Temperate Lakes Long-Term Ecological Research
          NSF-Ocean Sciences
          NSF-Environmental Biology
          Office of Sustainability SIRE Award Program
          University of Wisconsin Sea Grant Institute, NOAA
          UW-Madison/UW-Milwaukee Intercampus Research Incentive Grants Program
University of Wisconsin Water Resources Institute
          Wisconsin Alumni Research Foundation
          Wisconsin Coastal Management Program, NOAA

Status :  
Student Investigators: 
John Reimer (PhD), Yuli Liu (PhD), Wei Wang (PhD), Michael Meyer (MS), Chen Jin (MS)

Graduated: Josh Anderson (PhD), Madeline Magee (PhD),  Adam Bechle (PhD), Jordan Read (PhD), Yi-Fang Hsieh (PhD), C.C. Jay Young (PhD),
                      Nobuaki  Kimura (PhD), Henry Yuan (PhD), Dong Yong Choi (PhD),
                      Prashansa Shrivastava (MS), Biyun Sheng (MS), Anastasia Gunawan (MS), Hoi Lai Tseung (MS), Sen Yan (MS),
                      Khurran Khan (MS), John Reimer (MS), Theresa Possley (MS)

Dr. Eric Anderson, NOAA, Great Lakes Environmental Research Laboratory
Mr. Todd Breiby, Wisconsin Coastal Management Program
Professor Steven Carpenter, Center of Limnology, UW-Madison
Mr. Gene Clark, Coastal Engineering Specialist, NOAA-UW Sea Grant Institute
Professor Ankur Desai, AOS, UW-Madison
Professor  Paul Hanson, Center of Limnology, UW-Madison
Dr. Jane Harrison, Social Science Specialist, NOAA-UW Sea Grant Institute
Dr. John Kelley, NOAA/National Ocean Service
Dr. Tim Kratz, Center of Limnology, UW-Madison
Professor David Hamilton, University of Waikato, New Zealand
Dr. Richard (Dick) Lathrop, WDNR/Center of Limnology, UW-Madison
Professor Trina McMahon, CEE/Bacteriology, UW-Madison
Dr. Alexander B. Rabinovich, P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences
Professor Galen Mckinley, AOS, UW-Madison
Dr. Dale Robertson, USGS, Wisconsin
Mr. Jesse Schomberg, Minnesota Sea Grant
Dr. David Schwab, Graham Sustainability Institute, University of Michigan
Dr. Joseph Zhang, Virginia Institute of Marine Science


  • Liu, Y and Wu, C.H., Lifeguarding Operational Camera Kiosk System (LOCKS) for Flash Rip Warning: Development and Application, Coastal Engineeringdoi:10.1016/j.coastaleng.2019.103537, 2019
  • Linares, A., Wu, C.H., Bechle, A.J., Anderson, J.A., and Kristovich, D.A, Unexpected rip currents induced by a meteotsunami, Scientific Reports, doi:10.1038/s41598-019-38716-2, 2019.
  • Magee, M.R, McIntyre, P.B., Hanson, P.C., and Wu, C.H., Drivers and management implications of long-term cisco oxythermal habitat decline in Lake Mendota, WI.  Environmental Management, doi:10.1007/s00267-018-01134-7, 2019.
  • Kimura, N. and Wu, C.H., Using a nowcasting system to understand lake water dynamics, Lakes & Reservoirs: Science, Policy and Management for Sustainable Use, 23(4), 367-380, doi:10.1111/lre.12239, 2018.
  • Anderson, J.D. and Wu, C.H., Development and Application of a real-time water environment cyber-infrastructure for kayaker safety in the Apostle Islands, Lake Superior, Lake Superior. J. of Great Lakes Research, 44 (5), 990-1001,, 2018.
  • Magee, M., McIntyre, P.B., and Wu, C.H., 2018, Modeling oxythermal stress for cool-water fishes in lakes using a cumulative dosage approach, Canadian Journal of Fisheries and Aquatic Sciences, 75(8), 1303-1312,
  • Linares, A., Wu, C.H., Anderson, J.A., Chu, P.Y.,  Role of meteorologically-induced water level oscillations on bottom shear stress in freshwater estuaries in the Great Lakes, J. Geophysical Research-Oceans, 123 (7), 4970-4987,, 2018.
  • Hamilton, D.P., Magee, M.R., Wu, C.H., Kratz, T. K., Ice cover and thermal regime in a dimictic seepage lake under climate change, Inland Waters, 8(3), 381-398,  doi/full/10.1080/20442041.2018.1505372, 2018.
  • Magee, M. and Wu, C.H., Response of water temperatures and stratification to changing climate in three lakes with different morphometry, Hydrology and Earth System Sciences, 21(12), 6253-6274, 2017
  • Magee, M. and Wu, C.H., Effects of changing climate on ice cover in three morphometrically different lakes, Hydrological Processes,  31(2), 308-323, 2017.
  • Bechle, A.J., Wu, C.H., David A.R. Kristovich, D.A., Anderson, E.J., Schwab, D.J., Rabinovich, A.B., Meteotsunamis in the Laurentian Great Lakes, Scientific Reports, 6, 37832, doi:10.1038/srep37832, 2016.
  • Linares, A., Bechle, A.J., and Wu,C.H., Characterization and Assessment of the meteotsunami hazard in northern Lake Michigan, J. Geophysical Research-Oceans, 121(9), 7141–7158 DOI: 10.1002/2016JC011979, 2016.
  • Kimura, N., Wu, C.H., Hoopes, J.A., and Tai, A. Diurnal thermal dynamic processes in a small and shallow lake under non-uniform wind and weak stratification, Journal of Hydraulic Engineering-ASCE, 142(11), 04016047, 10.1061/(ASCE)HY.1943-7900.0001190, 2016.
  • Magee, M.R., Wu, C.H., Robertson, D.M., Lathrop, R.C., and Hamilton, D.P. Trends and abrupt changes in 104-years of ice cover and water temperature in a dimictic lake in response to air temperature, wind speed, and water clarity drivers, Hydrology and Earth System Sciences, 20(5), 1681-1702, 2016.
  • Bechle, A.J., Kristovich, D.A, and Wu, C.H., Meteotsunami Occurrences and Causes in Lake Michigan, J. Geophysical Research-Oceans, 120, 8422–8438, 2015.
  • Anderson, E.J., Bechle, A.J., Wu, C.H., Schwab, D.J., Mann, G., Lombardy, K., Reconstruction of a Meteotsunami in Lake Erie on May 27, 2012: Roles of Atmospheric Conditions on Hydrodynamic Response in Enclosed Basins, J. Geophysical Research-Oceans, 120, 8020–8038, 2015.
  • Anderson, J.D., Wu, C.H., and Schwab, D.J., Wave climatology in the Apostle Islands, Lake Superior, J. Geophysical Research-Oceans, 120(7), 4869-4890, 2015.
  • Zhang, Y.J., Ateljevichb, E., Yu, H.C., Wu, C.H., and Yu, J.C.S. A new vertical coordinate system for a 3D unstructured-grid model, Ocean Modelling, 85(1), 16-31, 2015.
  • Lin. Y.T. and Wu, C.H., Response of bottom sediment stability after carp removal in a small lake, Annales de Limnologie - International Journal of Limnology, 49 (03), 157-168, 2013.
  • Lathrop, R.C., Reimer, J.R., Sorsa, K.K., Steinhorst, G.M., Wu, C.H., Madison's lake beaches - results of a three-year pilot study, Lakeline, 33(3), 31-38, 2013.
  • Shade, A.,  Read, J.S. ; Youngblut, N.D., Fierer, N., Knight, R., Kratz, T.K., Lottig, N.R., Roden, E.E., Stanley, E.H., Stombaugh, J., Whitaker, R.J., Wu, C.H., McMahon, K.D., Lake microbial communities are resilient after a whole-ecosystem disturbance, ISME 6(12), 2153-2167, 2012.
  • Read, J.S., Hamilton, D.P., Desai, A.R., Rose, K.C., MacIntyre, S., Lenters, J.D.,  Smyth, R.L., Hanson, P.C., Cole, J.J., Staehr, P.A., Rusak, J.A., Pierson, D.C., Brookes, J.D., Laas, A., Wu, C.H., Lake-size dependency of wind shear and convection as controls on gas exchange, Geophysical Research Letters, 39, L09405, doi:10.1029/2012GL051886, 2012.
  • Kara, E.L., Hanson P, Hamilton, D.P., Hipsey, M.R., McMahon, K.D., Read, J.S., Winslow, L., Dedrick, J., Rose, K., Carey, C.C., Bertilsson, S., Motta Marques, D.D., Beversdorf, L., Miller, T., Wu, C., Hsieh, Y.F., Gaiser, E., Kratz, T., Time-scale dependence in numerical simulations: Assessment of physical, chemical, and biological predictions in a stratified lake at temporal scales of hours to months, Environmental Modeling and Software, 35, 104-121, 2012.
  • Shade, A., Read, J.S., Welkie, D., Kratz, T.K., Wu, C.H., and McMahon, K.D., Resistance, resilience, and recovery: aquatic bacterial dynamics after water column disturbance. Environmental Microbiology, 13(10), 2752-2767, 2011.
  • Read, J.S., Hamilton, D.P., Jones, I.D., Kohji Muraoka, K., Winslow, L.A., Kroiss R., Wu, C.H., and Gaiser, E., Derivation of lake mixing and stratification indices from high-resolution lake buoy data using 'Lake Analyzer', Environmental Modelling & Software, 1325-1336, 2011.
  • Read, J.S., Shade A., Wu, C.H., Gorzalski, A., and McMahon, K.D., Gradual Entrainment Lake Inverter (GELI): A novel device for experimental lake mixing, Limnology and Oceanography: Methods, 9:14-28, 2011.
  • Atilla, N., McKinley, G.A., Bennington, V. Baehr, M., Urban, N., DeGrandpre, M., Desai, A.R., Wu, C.H., Observed variability of Lake Superior pCO2, Limnology and Oceanography, 56(3), 775-786, 2011.
  • Bennington V., McKinley, G.A., Kimura, N., and Wu, C.H., The general circulation of Lake Superior: mean, variability, and trends from 1979-2006, J. Geophysical Research-Oceans, 115, C12015, 1-14, 2010.
  • Kamarainen, A., Yuan, H.L, Wu, C.H., and Carpenter, S.R., Estimates of phosphorus entrainment in Lake Mendota: A comparison of one-dimensional and three-dimensional approaches, Limnology and Oceanography: Methods, 7, 553-567, 2009..
  • Hanson, P.C. Carpenter, S.R., Kimura, N., Wu, C.H., Cornelius, S.P., Kratz, T.K., Evaluation of metabolism models for free-water dissolved oxygen methods in lakes,  Limnology and Oceanography: Methods, 6, 454-465, 2008.
  • Carpenter, S.R., Benson, B.J., Biggs, R., Chipman, J.W., Foley, J.A. Foley, Golding, S.A., Hammer, R.B., Hanson, P.C., Johnson, P.T.J., Kamarainen,A.M., Kratz, T.K., Lathrop, R.C., McMahon, K.D., Provencher, B., Rusak, J.A., Solomon, C.T., Stanley, E.H., Turner, M.G., Vander Zanden, M.J., Wu, C.H. and Yuan, H., Understanding regional change: Comparison of two lake districts. BioScience, 57(4), 323-335, 2007.
  • Yuan, H.L. and Wu, C.H., Fully non-hydrostatic modeling of surface waves,  J. of Engineering Mechanics - ASCE, T132 (4), 447-456, 2006.
  • Wu, C.H. and Wanek, J.M., A low-cost, ground-based, oblique, multi-spectral imaging system for chlorophyll concentration measurements, 2006.
  • Yuan, H.L. and Wu, C.H., An implicit 3D fully non-hydrostatic model for free-surface flows, International J. for Numerical Methods in Fluids, 46, 709-733, 2004.
  • Yuan, H.L. and Wu, C.H., A two-dimensional vertical non-hydrostatic model with an implicit method for free-surface flows, International J. for Numerical Methods in Fluids. 44, 811-835, 2004.
  • Wu, C.H. and Yuan, H., Efficiency and Accuracy of Non-hydrostatic modeling of free-surface flows, 434-447, 9th Estuarine and Coastal Modeling, ASCE, 2006.
  • Wu, C.H. and Yuan, H.L., A fully non-hydrostatic three-dimensional model with implicit algorithm, ASCE, 8th Estuarine and Coastal Modeling, ASCE, 8th Coastal and Estuarine Modeling, ISBN: 0784407347, 2004.