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.
Blooms of blue-green
algae in Madison LakesLake
hydrodynamics processes
Circulation
pattern
in Lake MendotaTransport
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.
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 : Active
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) Openings
Zhang, Y.J.,Wu, C.H., Anderson, J.D., Danilov, S.,
Wang, Q., Liu, Y., Qang, Q., Lake ice simulation using a
3D unstructured grid model, Ocean Dynamics, 73, 219-230,
https://doi.org/10.1007/s10236-023-01549-9,
2023.
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, doi.org/10.1016/j.jglr.2018.07.006,
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, doi.org/10.1139/cjfas-2017-0260.
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, doi.org/10.1029/2017JC013741,
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), 7141–7158DOI: 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.