2004 Experiment:

EC: Ram Yerubandi, M. Charlton, W. Schertzer, M. SkafelV. Richardson, D. Lam, M. Neilson

Collaborators:

NOAA-GLERL: N. Hawley, D. Schwab, D. BeletskyU. Windsor: J. Cibrowski, U Waterloo: R. SmithOMNR: T. Johnson

2005 IFYLE:EC: Ram Yerubandi, M. Charlton, V. Richardson

Currents and Temperature in Lake Erie

SupportTech Ops & Eng Services (NWRI)Data Processing: Bob Rowsel, J. Milne

L=388 kmB=93 kmTr=2.7 yr

BackgroundNutrient management plans started in 70s reduced

- Eutrophication, Hypoxia & TP in the central basin90s Issues

- Warmer temperatures, alteration in the ecosystem due to zebra mussel invasion etc.

- Re-emergence of some 70s issues (Cladophora, Increased TP, Low DO levels never went away in the CB)

Need to revisit nutrient management plans of the lake?

Recent Model SimulationsWater Quality Simulations (Lam et al. 2002)

Lake Erie water quality model simulations (post zebra mussel scenarios) indicated that

• Mussels can affect the phosphorous concentrations in the Lake

• Simulations have not shown any affect of Mussels on the DO in the central basin

• DO variability is related to the interannual variability of the meteorological conditions.

Limitations and future needs (gaps) of these simulations

•Substantial experimental data such as circulations, thermal structure, horizontal and vertical exchanges and biochemical data need to be incorporated in models to improve the predictions.

•Increased understanding of nearshore-offshore exchanges is needed & incorporate these effects in models

•Recalibration of water quality model parameters (for eg. sedimentation and resuspension) in the present conditions

•The models require better tributary loading estimatesPrevious experiments

Project Hypo (1970) & Bi-National Program (1979-80)

Objective

To conduct intensive measurements in Lake Erie for providinghydrodynamic and thermal observations required to assess/predictchanges in water quality and aquatic ecosystem components concurrentlywith the cooperative monitoring in 2004.

Sub-objectives•Develop a data base for calibration and verification of hydrodynamicmodel and 9 Box Model.

• Estimate Water residence times• Estimate Inter basin transports on daily scale for model input• Study bottom currents and dissolved oxygen in the hypolimnion of the

central basin •Estimate onshore-offshore exchanges during summer episodicevents (upwelling) along the north shore of the central basin

9 6 9

9 7 48 8 2

9 7 3

9 7 2

8 8 1

9 7 0

9 6 8

9 7 13 5 8

8 8 5 9 6 5 9 6 4

9 6 3

9 6 7

9 6 6

9 6 2

9 6 19 6 1

9 6 0

9 5 9

9 5 8

9 5 7

8 8 0

9 5 6

9 5 5

9 4 8

8 8 99 4 6

8 8 8

9 5 4

9 5 39 4 9

9 5 2

9 5 1

9 5 0

9 4 7

9 4 5

9 4 4

9 4 3

9 3 7

9 4 2

9 4 1

9 4 0

8 7 9

9 3 98 8 6

9 3 6

9 3 59 3 8 8 8 7

9 3 4

9 3 3 9 3 29 3 1

Figure 2. Station locations for the Lake Erie surveillance program 1994-1998.

Great Lakes Surveillance Program•8 CCGS LIMNOS surveys•Spring sampling = surface

•Summer sampling a. 1 m below water surface, plusb. 1 m above the thermocline, plusc. mid-thermocline, plusd. 1 m below the thermocline, pluse. bottom minus 10 and 2 meters.

1. The linear slope shows a depletion of 0.07 mg/L/d.2. Some stations show anoxic conditions from mid-July to the middle of August.

Mar Apr May Jun Jul Aug Sep02468

101214161820222426

Slope=-0.07 m g/L/dayDO

mg/

L &

Hypo

Thi

ckne

ss (m

)

2004

W inklers Profiles Hypo Thickness

(M. Charlton & J. Milne)

25

20

15

10

5

0

0 2 4 6 8 10 12 14 16 18 20 22 24 0 2 4 6 8 10 12 14 16 18 20 22 24 0 2 4 6 8 10 12 14 16 18 20 22 24

25

20

15

10

5

0

0 2 4 6 8 10 12 14 16 18 20 22 24 0 2 4 6 8 10 12 14 16 18 20 22 24 0 2 4 6 8 10 12 14 16 18 20 22 24

25

20

15

10

5

0

0 2 4 6 8 10 12 14 16 18 20 22 24 0 2 4 6 8 10 12 14 16 18 20 22 24 0 2 4 6 8 10 12 14 16 18 20 22 24

25

20

15

10

5

0

0 2 4 6 8 10 12 14 16 18 20 22 24

Lake ErieCentral BasinGLNPO stnsJuly 21, 2004

Temp & DO

Dept

h (m

)

'896o '896p '896w '896t

'897do '897p '897w '897t

'898do '898p '898w '898t

Dept

h (m

)

'899do '899p '899w '899t

Temp & DO

'915do '915p '915w '915t

'916do '916p '916w '916t

Dept

h (m

)

'918do '918p '918w '918t

Temp & DO

'919do '919p '919w '919t

'920do '920p '920w '920t

Temp & DO

Dept

h (m

)

'980do '980p '980w '980t

(M. Charlton & J. Milne)

TemperatureDO

Experimental Set-up (Physical measurements)

Penn. Ridge Box

W. Basin box

RT

RT

OMEE

Jeff Reuter’s buoys

OMNR & UW

Currents• 6 RDI-ADCPs for inter-basin transports, • Sontek Hydra station (+75 cm above bottom)

in the central basin for studying the hypolimnion characteristics.• 5 NOBSKA MAVs for Coastal exchange processesTemperature

Thermistor chain moorings near all ADCP and Met stations.Meteorology

3 Meteorological buoys in three basins with Radiation sensorsWater Quality

2 Stations with transmissometers at two depths3 YSI 6600 (2 in the central basin) Hydrolab stations in the western basin

Deployed:12-16 April 2004Refurbished: July & August 2004Retrieved: First week of October

Meteorology

Central basin buoy

Wind stress and Heat flux in the east basin

Thermal structure in the east basin

Thermocline formation

Relaxation/thermocline oscillations

SE wind storm

Temperature and DO in the central Basin

1. Stratification started from middle of June2. Hypo depth & Low DO3. Effects of physical processes on DO

0.37 mg/L/d

-0.3 mg/L/d -0.4 mg/L/d

-0.082 mg/L/d

(CPH)

6-7 day

Currents: Spectral Characteristics

1. 6-7 day period2. Near-inertial

Rotary Spectra

Stn: Penn Channel

Wind and current vectors (low-pass filtered in EB)

1104

hrs

, 200

4/10

/27

-83.5 -83 -82.5 -82 -81.5 -81 -80.5 -80 -79.5 -79

41

41.5

42

42.5

43

43.5

Stn 84

Longitude [°]

Latit

ude

[ °]

A B

Lake Erie Stn84 2004 Hyrda deploy. A and B

A: major: 3.3 cm/s, 80.8°T; minor: 2.6 cm/s. For B: major: 4.1 cm/s, 85.4°T, minor: 2.9 cm/s

Near Bottom Currents

Currents are not very weak as typical parameterizations assumecurrent fluctuations were some times as high as 8 -10 cm/sBBL processes- resuspension processes needs more data and analysis

Deployed in the central and west basins

Cross-validation of DO and temperaturedata is being carried out in Hamilton Harbour

Water Quality time series

Lake Erie Central Basin B at 23.2 m04B0263_AB

0

5

10

15

20

25

200 220 240 260 280 300 320

Julian Day 2004

Temp C pH Depth m

Lake Erie Western Basin B at 23.2 m04B0263_AB

200

220

240

260

280

300

320

340

200 220 240 260 280 300 320

Julian Day 2004

SpCond uS/cm

Lake Erie Western Basin B at 23.2 m04B0263_AB

0

20

40

60

80

100

120

200 220 240 260 280 300 320

Julian Day 2004

DOsat %

Lake Erie Western Basin B at 23.2 m04B0263_AB

0

4

8

12

16

20

200 220 240 260 280 300 320

Julian Day 2004

Turbidity NTU

recalibrated

DO is practically zero?, and sudden recovery due to easterly storm

Inter-basin Exchanges

1. Correlation with along-the-lake wind2. Return flow3. Thermocline depth

230 235 240 245 250 255 260 265 270 275 280

-20

-15

-10

-5

Dep

th (m

)

230 235 240 245 250 255 260 265 270 275 280

-20

-15

-10

-5D

epth

(m)

-0.18

-0.12

-0.06

0

0.06

0.12

-0.45

-0.3

-0.15

0

0.15

0.3

a)

b)

Low-pass filtered Penn. Channel ADCP currents

Cross-lake

Along-lake

+ towards the eastTowards the CB

Mean currents

Currents in Penn. Ridge

-20

-15

-10

-5

0

-50 -45 -40 -35 -30 -25 -20 -15 -10 -5

cmC/s

Dep

th

<u'T'> <v'T'>

Fluxes13 14 15 16 17 18 19 20 21

Temp

Temp

Mean heat fluxes are towards the CB

Transports & exchanges are being calculatedHydrodynamic modeling work in progress

N-Penn Ridge

S-Penn Ridge

Both alongshore & Crosshore exchanges are episodic

0 20 40 60 80 100-20-10

01020

cm/s

Days from April 16, 2004

cross-shore722

-20-10

01020

cm/s

721

-20-10

01020

cm/s

720

-20-10

01020

cm/s

723xx

xx

May 26Jul 5

Currents during spring deployment

Horizontal exchanges in the coastal zone

Lake wide forcings;meteorology- nearshore/offshore accelerations-well-known

Summary

2004 Measurements:

• Large experiment after 20 years in the lake• Physical limnology and surface meteorology parameters• Extensive lake-wide surveys• Data analysis & Hydrodynamic and water quality

modeling (In progress)

2005 Measurements with IFYLE:

• ADCP, Temp, Met moorings • Higher resolution in the thermocline and BBL• Long-term deployments of YSI at four stations in the

central basin

International Field Year on Lake Erie

2005- GLERL & NWRI Collaborative Moorings