GLERL Publication Abstracts: 1994

Buchberger, S.G. Covariance properties of annual net basin supplies to the Great Lakes. NOAA Technical Memorandum ERL GLERL-85, Great Lakes Environmental Research Laboratory, Ann Arbor, MI (PB94-204732/XAB) 29 pp. (1994).

The cross correlation function (CCF) and autocorrelation function (ACF) for Great Lakes annual net basin supplies are derived under the assumptions that annual lake outflows and water levels are autoregressive lag-1 processes, and that each lake behaves as a linear reservoir. Except for the pairing between Lakes Superior and Michigan-Huron, there is reasonable agreement between the sample and predicted CCFs, especially among net basin supplies to the small lower basin lakes. The derived ACFs reduce to an expression identical in form to the ACF for an Auto Regressive Moving Average (ARMA)(1,1) process at all the Great Lakes except Lake Michigan-Huron. At the upper basin lakes, sample and predicted ACFs drop to zero rapidly. At the lower basin lakes, the ACFs exhibit a much more gradual decay suggesting the presence of long-term persistence. Prominent tails in the ACFs of the annual net basin supplies have been attributed to historical shifts in the precipitation regime at the lower basin lakes. Results from this study show that the residual method currently used to estimate net basin supplies can also induce a similar artificial long tail in the ACF. This observation has important ramifications in efforts to simulate Great Lakes water levels, since simulation results are quite sensitive to the covariance structure of the annual net basin supplies.

Cooperative Institute for Limnology and Ecosystem Research and the Great Lakes Environmental Research Laboratory. Forming an Initiative: Coastal Zone Management and the Laurentian Great Lakes. The Great Lakes - Coastal Ocean Program Workshop, Ypsilanti, MI, November 5-6, 1992. Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 74 pp. (1994).

No abstract.

CROLEY, T.E. II. Great Lakes climate scenarios and physical response. Proceedings, Global Climate Change ProjectResearch Priorities for Assessing the Impacts of Climate Change in the Great Lakes Basin, C.M. Ryan, F. H. Quinn, and M.J. Donahue, Ypsilanti, MI, December 6-8, 1993. NOAA, CILER, and the Great Lakes Commission, Ann Arbor, MI, 80-95 (1994).

Climate change impacts on the Great Lakes may be understood by considering atmospheric scenarios with hydrologic models. Scenarios are traditionally generated as general circulation model (GCM) simulations of the earth's atmosphere. Typically, researchers change historical meteorology to match mean changes observed in the atmospheric scenarios, observe changed process model outputs, and compare to model results from unchanged data. This method keeps spatial and temporal variability the same in the adjusted data sets as in the historical base period. Changes are made independently to each historical meteorological variable, ignoring their interdependencies. GCM simulations are over grids that are coarse compared to the scale of interest of the Great Lakes. Recently, scenarios were taken from other climes and transposed to the Great Lakes to preserve reasonable spatial and temporal variations and to avoid the other problems. In all methods, the linkage between the atmospheric scenarios and the hydrology models allows no feedback between the surface and the atmosphere in scenario development and hydrologic impact estimation. Now, mesoscale atmospheric models are embedded within GCMs and coupled to relevant surface hydrology models. This allows more relevant scales for regional impact estimation and dynamic linkages between the atmosphere and the surface. We must link atmospheric models to existing large-scale irregular-area surface models to adequately portray the hydrology and lake thermodynamics of the Great Lakes. Only as sufficiently fine grids become available for surface hydrology models in the next few years will hydrological impacts be directly estimable from purely gridded models.

CROLEY, T.E.II. Probabilistic Great Lakes hydrology outlooks. Water Resources Bulletin 29(5):741-753 (1993).

The Great Lakes Environmental Research Laboratory developed a semiautomatic software package for making hydrological outlooks for the Great Lakes. These include basin moisture storages, basin runoff, lake heat storage, lake evaporation, heat fluxes, and net lake supplies, one or more full months into the future. The package combines GLERL's rainfall-runoff and lake evaporation models with near real-time data reduction techniques to represent current system states. Users select historical meteorologic record segments as candidate future scenarios to generate deterministic near real-time hydrological outlooks. GLERL has extended the package to make probabilistic outlooks for a decision-maker who must estimate the risk associated with his decisions. GLERL matches National Weather Service meteorologic outlook probabilities by selecting groups of historical meteorologic sequences, and constructs embedded outlook intervals for each hydrologic variable of interest. Interval probabilities are assigned from comparisons over a recent evaluation period. This physically-based approach for generating outlooks offers the ability, as compared to other statistically-based approaches, to incorporate improvements in the understanding of process dynamics as they occur in the future and to respond reasonably to conditions initial to a forecast (such as heat and moisture storages), not observed in the past.

CROLEY, T.E.II, and R.A. ASSEL. A one-dimensional ice thermodynamics model for the Laurentian Great Lakes. Water Resources Research 30(3):625-639 (1994).

Great Lakes hydrologic research requires the use of continuous-simulation daily ice cover models over long time periods in the absence of field observations. They must be physically based, rather than statistically based, for use under conditions different than those under which they were derived. But they also must match existing conditions for which data exist. A review discloses that existing ice dynamics models do not meet all of these criteria; a new one that does is based here on a prismatic ice pack heat balance, ice growth and temperature constraints, and thermodynamic flux terms from companion water heat balance and storage equations. The prismatic ice model is a good first step to understanding complex geometries and is supportable through the use of lake-averaged energy fluxes. The ice model is integrated into an existing lake thermodynamics and one-dimensional heat storage model, and the resulting combination is calibrated for Laurentian Great Lakes applications. Simulation experiments are used to analyze the model's strengths and limitations and to explore its relevance. Comparisons between model output and existing data allow consideration of the ice climatology of the Great Lakes; the climatology description is extended through use of the new model. Promising potential model extensions include spatial extension, additional parameterizations for wind-ice movement, snow, and albedo, and inclusions of remotely sensed data.

CROLEY, T.E., II, and T.S. HUNTER. Great Lakes monthly hydrologic data. NOAA Technical Memorandum ERL GLERL-83, Great Lakes Environmental Research Laboratory, Ann Arbor, MI (PB95-173076/XAB) 83 pp. (1994).

Accurate hydrologic data (over-land precipitation, over-lake precipitation, runoff, lake evaporation, net basin supplies, connecting channel flows, diversion flows, beginning-of-month lake levels, and changes in storage) are required for simulation, forecasting, and water resource studies on the Laurentian Great Lakes and their basins. This report is an update of an earlier report presenting Great Lakes monthly hydrologic data (Quinn and Kelley, 1983). It has been expanded and revised to include all available data through 1990 and to reflect improved computational techniques. The data and a program for combining the data are available on a companion diskette.

CROLEY, T.E., II, and B.M. LOFGREN. Coupled Hydrologic Atmospheric Research Model (CHARM). Proceedings, Effects of Human-Induced Changes on Hydrologic Systems, Jackson Hole, WY, June 26-29, 1994. American Water Research Association, 109-118 (1994).

Atmospheric impacts on surface hydrology have been explored by using general circulation models (GCMs) to drive surface hydrology models with no dynamic feedback between them. However, embedding mesoscale atmospheric models within GCMs and coupling relevant surface hydrology models to the mesoscale models, allows more relevant scales for regional impact estimation and the consideration of dynamic linkages between the atmosphere and the surface. Still, large-scale parameter changes, such as lake levels, can only be estimated indirectly by using these model outputs as inputs to hydrologic models. The Great Lakes Environmental Research Laboratory (GLERL) estimates large-scale surface hydrological parameters by using models developed for the Great Lakes. Likewise, further refinement of the Regional Atmospheric Modeling System (RAMS) is ongoing at Colorado State University, ASTeR, Inc., and other institutions. To enable direct dynamic estimation of large-scale parameter changes, GLERL is integrating these models into a Coupled Hydrosphere Atmosphere Research Model (CHARM). This paper concentrates on the formulation of CHARM. Results of preliminary testing show that CHARM produces features in the temperature, humidity, and precipitation fields which cannot be resolved by GCMs and may be attributed to the Great Lakes. Careful validation of these results against observed data is in progress.

Dinnel, S.P., and A.W. BRATKOVICH. Water discharge, nitrate concentration and nitrate flux in the lower Mississippi River. Journal of Marine Science 4(1993):315-326 (1993).

Thirty-five years of monthly lower Mississippi River water discharge, nitrate concentration, and nitrate flux have been analyzed. The potential predictability of these quantities has been evaluated. Results indicate a large amplitude, long-term cycle in the nitrate concentration that is not observed in the water discharge. A decrease in average nitrate concentration from a peak in 1983 to the present confirms that this variability is more cyclic than trend-like. River-water discharge variation was greatest in association with the annual cycle. The annual water discharge and nitrate concentration cycles were similar; high nitrate concentrations usually occurred near the vernal freshet, and low concentrations usually occurred along with autumnal low-flow conditions. Nitrate flux variations exhibited a low amplitude, long-term modulation of a dominant, annual cycle. A predictor-hindcast analysis indicates that truly skilled forecasts of all three fields are feasible.

DONG, D.Y., A.W. BRATKOVICH, and S.P. Dinnel. Nutrient Enhanced Coastal Ocean Productivity (NECOP): CTD observations from R/V Longhorn cruise July 1-12, 1993. NOAA Technical Memorandum ERL GLERL-82, Great Lakes Environmental Research Laboratory, Ann Arbor, MI (PB94-181872/XAB) 144 pp. (1994).

As part of NOAA's Nutrient Enhanced Coastal Ocean Productivity (NECOP) program, scientists working on the University of Texas R/V Longhorn surveyed shelf waters of the Gulf of Mexico from Port Aransas, Texas to east of the Mississippi River delta. The study began July 1 and ended July 12, 1993. Using the onboard CTD (conductivity, temperature, and depth) sampling system, vertical water profiles were obtained for temperature, salinity, density, light transmission (beam c), oxygen, and fluorescence. This technical memorandum describes the data and the methods used for data collection and processing.

FAHNENSTIEL, G.L., D.G. Redalje, and S.E. Lohrenz. Has the importance of photoautotrophic picoplankton been overestimated? Limnology and Oceanography 39(2):432-438 (1994).

Post-incubation differential filtration (PIDF), pre-incubation differential filtration (Pre IDF), and track autoradiography (TA) were compared for estimating cell-specific and total photoautotrophic picoplankton production. Experiments were performed in Lakes Michigan and Huron and in the Gulf of Mexico. When Synechococcus dominated the photoautotrophic picoplankton community (>70% of total picoplankton abundance), PIDF estimates of cell-specific and total picoplankton production were ~3.0 x (range, 2.0-3.8 x) higher than TA estimates, PreIDF estimates of cell-specific and total picoplankton production, however, were only slightly higher than TA estimates (mean, 1.4 x; range, 1.4-1.5 x). The higher PIDF estimates were attributable to breakage and damage of larger photoautotrophs during post-incubation filtration and to retention of this labeled material on the smaller (0.2 mm) pore-size filter. Results from PIDF experiments must be viewed with caution and previous estimates of picoplankton production, cell-specific or total, based solely on PIDF may need to be re-evaluated.

GARDNER, W.S., E.E. Briones, E.C. Kaegi, and G.T. Rowe. Ammonium excretion by benthic invertebrates and sediment-water nitrogen flux in the Gulf of Mexico near the Mississippi River outflow. Estuaries 16(4):799-808 (1993).

Benthic macroinvertebrate biomass and ammonium excretion rates were measured at four stations in the Gulf of Mexico near the Mississippi River mouth. Calculated areal excretion rates were then compared to sediment-water nitrogen fluxes measured in benthic bottom lander chambers at similar stations to estimate the potential importance of macroinvertebrate excretion to sediment nitrogen mineralization. Excretion rates for individual crustaceans (amphipods and decapods) was 2-21 nmoles NH4+ (mg dry weight)-1h-1. The mean excretion rates for the polychaetes (Paraprionaspio pinnata [6-12 nmoles NH4+ (mg dry weight)-1h-1] and Magelona sp. [27-53 nmoles NH4+(mg dry weight)-1h-1], were comparable or higher than previous measurements for similar size benthic or pelagic invertebrates incubated at the same temperature (22±1oC). Although the relatively high rates of excretion by these selective feeders may have been partially caused by experimental handling effects (e.g., removal from sediment substrates), they probably reflected the availability of nitrogen-rich food supplies in the Mississippi River plume. When the measured weight-specific rates were extrapolated to total areal biomass, areal macroinvertebrate excretion estimates ranged from 7 mmole NH4+ m-2h-1 at a 40-m deep station near the river mouth to 18 mmole NH4+m-2h-1 at a shallower (28-m deep) station further from the river mouth. The net flux of ammonium and nitrate from the sediments to the water measured in bottom lander chambers in the same region were 15-53 mmole NH4+m-2h-1 and -25-21 mmole NO3-m-2h-1 . These results suggest that excretion of NH4+ by macroinvertebrates could be a potentially important component of benthic nitrogen regeneration in the Mississippi River plume-Gulf shelf region.

Gbah, M.B., G.A. Meadows, and S.J. Jacobs. A thermal front circulation model. NOAA Technical Memorandum ERL GLERL-84, Great Lakes Environmental Research Laboratory, Ann Arbor, MI (PB95-17290/XAB) 9 pp. (1994).

A model of the thermal bar circulation in a large lake, of small aspect ratio is presented. Unlike models that use prescribed values of the eddy viscosity and diffusivity, this model utilizes a second order turbulence-closure scheme to compute flow variables and turbulence properties as part of the overall solution.

GREAT LAKES ENVIRONMENTAL RESEARCH LABORATORY. Publications by the Staff of the Great Lakes Environmental Research Laboratory. C.M. Darnell (ed.). Great Lakes Environmental Research Laboratory, Ann Arbor, MI, 88 pp. (1994).

No abstract.

Hamelink, J.L., P.F. LANDRUM, H.L. Bergman, and W.H. Benson (Editors). Bioavailability: Physical, Chemical, and Biological Interactions. Society of Environmental Toxicology and Chemistry, CRC Press, Lewis Publishers, Boca Raton, FL, 239 pp. (1994).

No abstract.

Hamelink, J.L., P.F. LANDRUM, H.L. Bergman, and W.H. Benson. Session 1. Introduction. In Bioavailability: Physical, Chemical, and Biological Interactions, Society of Environmental Toxicology and Chemistry, Lewis Publishers, Inc., (1994).

No abstract.

HARKEY, G.A. Investigation of the bioavailability of sediment-associated hydrophobic organic contaminants. Ph.D. Dissertation, Clemson University, Clemson, SC, 158 pp. (1994).

Bioassays have frequently been used as tools to simulate exposure of benthos to sediment-associated contaminants in hazard assessments. Due to the problems involved with diluting and estimating bioavailability in whole sediment bioassays, aqueous fractions, such as porewater and elutriates, have been substituted for whole sediment exposures. The objective of this research was to compare and evaluate the bioavailability of neutral hydrophobic contaminants in whole sediment and in aqueous extracts of whole sediment (elutriate and porewater) in simultaneous extracts of whole sediment, in most cases, underexposed organisms compared to whole sediment, even after adjusting accumulation to the fraction of organic carbon contained in the test media. Bioaccumulation relationships among the media varied with sampling time and with the species used. Subsequent experiments were conducted to identify the factors responsible for the observed bioaccumulation differences. Partitioning studies showed differential partitioning of the contaminants in porewater, elutriate, and dosed, filtered Lake Michigan water. The percentage of freely dissolved, bioavailable contaminant in these experiments was dependent on the method of separation, the media tested, the amount of sediment/contaminant contact time, and chemical and physical properties of the individual contaminants studied. Thus, an accurate estimation of the bioavailable fraction of contaminant could not be based on simple partitioning of individual compounds. Selective feeding habits of one indicator species, Diporeia spp., were examined in a series of experiments that determined the influence of sediment particle sizes on assimilation and accumulation of contaminants represented by two classes of hydrophobic contaminants. Accumulation of hexachlorobiphenyl (HCBP) was consistently greater than benzo(a)pyrene (BaP), suggesting a greater bioavailability of the polychlorinated biphenyl to Diporeia. Sediment analysis indicated that BaP and HCBP were associated with different particle size fractions, and that these contaminants did not partition similarly to organic carbon. These data indicate that simple organic carbon partitioning models cannot be applied to hydrophobic contaminants possessing approximately the same octanol-water partition coefficients.

HARKEY, G.A., P.F. LANDRUM, and S.J. Klaine. Comparison of whole-sediment, elutriate, and pore-water exposures for use in assessing sediment-associated organic contaminants in bioassays. Environmental Toxicology and Chemistry 13(8):1315-1329 (1994).

Bioassays have frequently been used as tools to simulate exposure of benthos to sediment-associated contaminants in hazard assessments. Due to the problems involved with estimating bioavailability in whole-sediment bioassays, aqueous fractions such as elutriates and pore water have been substituted for whole-sediment exposures. The objective of this research was to compare and evaluate the bioavailability of representative neutral hydrophobic contaminants in whole sediments and in aqueous extracts of whole sediment (elutriate and pore water) in simultaneous bioasssys, using three representative indicator species, Diporeia spp., Chironomus riparius larvae, and Lumbriculus variegatus. Aqueous extracts of whole sediment did not accurately represent the exposure observed in whole sediment. Generally, the aqueous extracts underexposed organisms compared to whole sediment, even after adjusting accumulation to the fraction of organic carbon in the test media. Accumulation comparisons among whole-sediment, elutriate, and pore-water exposures depended on sampling time. At some sampling times for some contaminants, differences in accumulation between a particular aqueous extract and whole sediment were not significant; however, these similarities were not observed for all species at the particular sampling time. Bioaccumulation and contaminant clearance data suggest that a number of factors such as the indicator species, exposure media, and chemical/physical properties of individual contaminants are responsible for the accumulation differences observed among the tested media. Normalizing bioaccumulation to the amount of organic carbon in a source compartment adjusted for bioavailability differences of only some contaminants. We suggest that the bioavailability of contaminants such as those tested cannot be accurately predicted in bioassays that expose organisms to aqueous representation of whole sediment.

HARKEY, G.A., P.F. LANDRUM, and S.J. Klaine. Partition coefficients of hydrophobic contaminants in natural water, porewater, and elutriates obtained from dosed sediment: A comparison of methodologies. Chemosphere 28(3):583-596 (1994).

Partitioning of organic contaminants in elutriates, porewater, and lake water was compared using four methods: AX-4 resin columns, equilibrium dialysis, and centrifugation and filtration with subsequent C-18 reverse phase column separation. In addition, possible changes in partitioning with sediment aging and during bioaccumulation assays were examined. Centrifugation with C-18 separation produced the most consistent partition coefficients. Partition coefficients from filtration and centrifugation methods compared favorably with previously published data. Contaminant partitioning did not change during 96-h exposures in bioassays, and partitioning of contaminants in porewater and elutriates did not follow a linear trend with the amount of sediment aging or manipulation. The contaminant partitioning apparently depends on characteristics of the contaminant as well as contaminant-associated media composition.

HARKEY, G.A., P.F. LANDRUM, and S.J. Klaine. Preliminary studies on the effect of feeding during whole sediment bioassays using Chironomus riparius larvae. Chemosphere 28(3):597-606 (1994).

Current protocols for freshwater sediment bioassays require feeding, which will likely alter the exposure to sediment-associated contaminants. To determine the potential change in exposure brought about by adding uncontaminated food, whole sediment contaminant bioaccumulation by the midge, Chironomus riparius, was determined in the presence and absence of added food. Lake Michigan sediment was dosed with radiolabeled polycyclic aromatic hydrocarbons (PAHs) and/or DDT and trans-chlordane. Three groups of organisms (Feeding Levels I and II plus a control) were exposed in static assays. After two-, four-, seven-, and ten-day exposures, individual larvae were analyzed for contaminant concentration, mass, and total lipid content. After 7 to 10 days, accumulation of pyrene and benzo(a)pyrene was significantly greater with feeding, while larvae exposed to chrysene accumulated significantly less contaminant when fed, compared to controls. No feeding-related differences in accumulation of the two insecticides were observed. Significant differences in larval mass between test animals and controls were observed only with pyrene-dosed sediment. Larval lipid content tended to remain constant throughout the exposures and did not differ between fed and unfed organisms. Thus, it appears that contaminant bioavailability can be altered by the addition of uncontaminated food. However, this phenomenon appears to be compound-specific and not broadly predictable.

HARKEY, G.A., M.J. LYDY, J. KUKKONEN, and P.F. LANDRUM. Feeding selectivity and assimilation of PAH and PCB in Diporeia spp. Environmental Toxicology and Chemistry 13(9):1445-1455 (1994).

A series of experiments were conducted to estimate assimilation efficiencies of two hydrophobic organic contaminants and the influence of particle sizes on the selective sediment ingester, Diporeia spp. Florissant soil was divided into particle-size fractions consisting of 0 to 63 mm, 0 to 20 mm, and 20 to 63 mm and dosed with radiolabeled 2,2',4,4',5,5'-hexachlorobiphenyl (HCBP) and/or benzo[a]pyrene (BaP) to which animals were exposed for individual assays. At the end of timed exposure intervals, individual Diporeia and any fecal pellets they produced were removed from the sediment and analyzed for contaminant content. Assimilation efficiency was estimated via a selectivity index based on organic carbon. Assimilation efficiency of BaP (5.6-32.7%) was comparable to previous studies. However, HCBP did not correlate with organic carbon over a range of particle sizes. Accumulation of both contaminants was greatest when animals were exposed to the 20- to 63-mm size fraction, suggesting that Diporeia selectively fed within this particle-size range. Accumulation of HCBP was consistently greater than BaP in all dual-labeled assays, suggesting a greater bioavailability of the PCB to Diporeia. Sediment analysis indicated that BaP and HCBP were associated with different particle-size fractions possessing different amounts of organic carbon, with BaP having the greater tendency to associate with TOC.

Kelley, J.G., C.J. Yen, K.W. Bedford, J.S. Hobgood, and D.J. SCHWAB. Coupled Lake Erie air-sea, storm resolving forecasts and predictions, the Viento project. Proceedings, 3rd Conference on Estuarine and Coastal Modeling, M.L. Spaulding, K. W. Bedford, A. Blumberg, R. Cheng, and C. Swanson (eds.), Oak Brook, IL, September 8-10, 1993. American Society of Civil Engineers, New York, NY, 202-215 (1994).

The Viento Project is a collaborative effort to generate storm-scale predictions for Lake Erie by coupling a mesoscale atmospheric model with a coastal ocean model. The project will employ the Pennsylvania State University/National Center for Atmospheric Research (NCAR) mesoscale atmospheric prediction system, version 5 and the Great Lakes Forecasting System (GLFS). The two prediction systems will be run on separate supercomputers located at NCAR in Boulder, CO and at the Ohio Supercomputer Center in Columbus, OH. Boundary conditions for the two models will be exchanged in real-time via the National Aeronautics and Space Administration's Advanced Communications Technology Satellite (ACTS). ACTS will also allow for shared visualization and video conferencing during the execution of the models. One- and two-way coupling model runs will be conducted in 1994 after the launch of ACTS in the Fall of 1993. A demonstration of a one-way coupled model run was conducted for Lake Erie using archived forecast output from the Penn State/NCAR model in GLFS.

KUKKONEN, J., and P.F. LANDRUM. Toxicokinetics and toxicity of sediment-associated pyrene to Lumbriculus variegatus (oligochaeta). Environmental Toxicology and Chemistry 13(9):1457-1468 (1994).

The oligochaete Lumbriculus variegatus has been proposed for whole-sediment bioassays to assess sediment contamination. Our work examines Lumbriculus variegatus exposure to pyrene-dosed Lake Michigan sediment at 0.4 ng g-1 and 64, 132, 206, and 269 mg g-1. Both bioaccumulation and survival were followed to enhance Lumbriculus variegatus development as a bioassay organism. Lumbriculus variegatus accumulated sediment-associated pyrene rapidly and achieved apparent steady state within 48 to 168 h. The pyrene uptake clearances (ks, g sed g-1 animal h-1) ranged from 0.039 to 0.132 and decreased with increasing pyrene concentration. At high pyrene concentrations, the worms avoided the sediment, which reduced accumulation and likely minimized the mortality response. In addition, the effect or organism loading on bioaccumulation was determined at different animal densities, 1:10, 1:50, and 1:100 g dry weight Lumbriculus variegatus: g sediment organic carbon, and a sediment pyrene concentration of 0.4 ng g-1. Surprisingly, the bioaccumulation declined as organism density decreased. Pyrene elimination was rapid in clean sediment (ke=0.026 ± 0.002 h-1) but was much slower in water (ke=0.0043 ± 0.0007 h-1). Bioavailability apparently declined for exposures in sediment stored 1.5 months, based on the estimate of ke from nonlinear regression compared to direct measures of elimination. The apparent decline was attributed to both a decline in lipid content during the experiment and changes in pyrene bioavailability. Finally, for bioaccumulation studies, gut purging at a set time (e.g., 24 h) may result in an understanding of contaminant concentrations in organisms. An elimination study with extrapolation to the initial body burden can ensure that biases due to incomplete elimination of gut contents and body burden losses during the purging process are minimized.

LANDRUM, P.F., W.L. Hayton, H. Lee, L.S. McCarty, D. Mackay, and J.M. McKim. Synopsis of discussion session on the kinetics behind environmental bioavailability. In Bioavailability: Physical, Chemical, and Biological Interactions, J.L. Hamelink, P. F. Landrum, H.L. Bergman, and W.H. Benson (eds.). Boca Raton, FL, Lewis Publishers, 203-219 (1994).

No abstract.

LANSING, M.B., W.S. GARDNER, and B.J. EADIE. Catecholamines as potential sub-lethal stress indicators in Great Lakes macrobenthic invertebrates. Journal of Great Lakes Research 19(3):569-581 (1993).

Concentrations of the catecholamines [dopamine (D), and norepinephrine (NE)] were measured in representative Great Lakes macrobenthic invertebrates to determine the feasibility of using these compounds as indicators of sub-lethal stress. Epinephrine [E] was not detected in most of these invertebrates. A high performance liquid chromatographic procedure was modified for use with aquatic invertebrates. Chironomids and oligochaetes contained D concentrations that were similar, averaging 1 pmole/mg wet wt. Crustacean D levels were lower, averaging 0.2 pmole/mg wet wt. NE averaged 0.2 pmole/mg wet wt. for chironomids and 0.57 pmole/mg wet wt. for oligochaetes. NE was not detected in the crustaceans. Individual chironomids contained detectable levels of catecholamines; all other invertebrates required pooled homogenates. The chironomid group was targeted for laboratory stress experiments. Cultured midge larvae (Chironomus tentans) subjected to acute thermal stress (35oC) exhibited D concentrations significantly lower than controls (23oC). Animals exposed to lindane concentrations 0.5 mg/L - 8.0 mg/L contained D concentrations significantly higher than controls. NE and E were not detected in either stress experiment. Demonstration of dramatic catecholamine concentration changes in response to stressors suggests that these compounds could potentially be indicators of sublethal stress.

LEE, D.H., K.W. Bedford, and C.-CJ. Yen. Storm and entrainment effects on tributary sediment loads. Journal of Hydraulic Engineering 120(1):81-103 (1994).

A two-dimensional, multiclass-size sediment transport model with source/sink terms for erosion and deposition, and a sediment bed model were developed and applied to Sandusky Bay, Ohio to study the transport of fine sand, silt, and clay through the bay for June 1 to June 30, 1981. During this period, a flood carried high sediment loads from the Sandusky River to the bay. The model's simulation showed that 79.3% of the flood's sediment loads were deposited in the upper bay. Areas of net deposition and erosion compare favorably to other published results. This study showed that the dominant sediment size transported to Lake Erie is clay, and the sediment load to Lake Erie is significantly different from that measured at the U.S. Geological Survey gage at Fremont, Ohio, located upstream of the bay. Weaknesses in state-of-the-art sediment transport modeling and field measurements are discussed.

LEE, D.H., F.H. QUINN, D. Sparks, and J.C. Rassam. Modification of Great Lakes regulation plans for simulation of maximum Lake Ontario outflows. Journal of Great Lakes Research 20(3):569-582 (1994).

Nearly 50,000 years of Lake Ontario outflows were simulated and analyzed as a part of the Hydro-Quebec Beauharnois-Les Cedres spillway rehabilitation study. Historical Lake Ontario outflows could not be used for the study because of anthropogenic effects reflected in the data, the statistically short record length, and autocorrelation of the data. Stochastically generated Great Lakes net basin supplies were used in a Great Lakes hydrologic response model to obtain Lake Ontario levels and outflows. A significant problem was the lack of robustness in the Lake Superior and Lake Ontario regulation plans during simulations with extreme water supplies. The regulation plans were modified consistent with the International Joint Commission's regulation criteria and past operational actions to give reasonable results under these conditions. The simulated Lake Ontario levels and flows had a greater range than those resulting from historical water supplies. The maximum simulated Lake Ontario quarter-monthly level was 76.41 m (IGLD 55), and the maximum simulated quarter-monthly outflow was 14,160 m3s-1. The maximum-flow limitation of Lake Ontario's regulation plan, 8,780 m3s-1, was exceeded 0.27% of the time. The upper lake-level regulation limit, 75.22 m, was exceeded 0.15% of the time. It was found that some of the regulation criteria cannot be met simultaneously under extreme conditions. Historical water supplies, the current standard for the design and evaluation of modifications to the operational regulation plans, should no longer be the sole test of the plans.

LEE, D.H., and C. Southam. Effect and implications of differential isostatic rebound on Lake Superior's regulation limits. Journal of Great Lakes Research 20(2):407-415 (1994).

In 1902, U.S. federal authorities established water level limits for Lake Superior as part of the requirements permitting hydropower water diversions from the lake's outlet, the St. Marys River. The vertical datum to which these limits are referenced must be adjusted every 25 to 30 years due to differential isostatic rebound (i.e., crustal movement). Because crustal movement unequally changes the land-to-water relationship along Lake Superior's shoreline, the method by which the limits are established on a new datum could accelerate the natural effects of crustal movement with adverse effects on shoreline flood levels, navigation depths, and lake outflows. With the implementation of the new International Great Lakes Datum of 1985, a study was undertaken 1) to review the methods used to establish the limits on previous datums; and 2) to quantify the changed land-to-water relationship between the limits established in 1902 and those referenced to the new datum. Rates of differential crustal uplift, determined from linearly regressing water level differences between gauge pairs with time, were used. The study shows that although the numerical values of the upper and flow reduction threshold limits have changed due to subsequent datum adjustments and different reference gauge locations, the relationship of the limits with respect to the lake's outlet and the lake-wide average has not changed from that established in 1902. The present method of regulating Lake Superior based on a lake-wide average water level is shown to maintain the natural changes in the land-to-water relationship around the lake due to crustal movement. Due to these natural changes, the upper regulation limit is now 0.21 m higher at Duluth, Minnesota and 0.26 m lower at Michipicoten, Ontario, than in 1902. By 2050, these differences will be a much as 0.34 m higher and 0.43 m lower, respectively. Thus, the implications of crustal movement should be considered in long-term planning, particularly with respect to establishing flood levels along Lake Superior's southwestern shore and navigation depths along the northeastern shore.

LESHKEVICH, G.A., W. Pichel, and P. Clemente-Colon. Great Lakes SAR ice research application demonstration. Second ERS-1 SymposiumSpace at the Service of our Environment, Hamburg, Germany, October 11-14, 1993. European Space Agency (ESA SP-361), 675-679 (1994).

As part of the NOAA CoastWatch synthetic aperture radar (SAR) applications demonstration, the Great Lakes SAR ice research applications demonstration was developed to assess the utility of satellite SAR data for Great Lakes ice analysis. The primary applications to be studied are ice classification and mapping and ice jam monitoring. A data set for selected areas on the Great Lakes was established covering the period from 18 to 24 February 1993 and includes ERS-1 SAR scenes, AVHRR imagery, side looking airborne radar (SLAR), and ground data consisting of aerial photographs, video, and ice charts. Preliminary analysis using computer aided comparison and statistical techniques indicates that different ice types can be identified and mapped in the digital SAR imagery. The all-weather, day/night viewing capability of satellite SAR make it a valuable tool for Great Lakes ice analysis and monitoring.

LIU, P.C. Estimating breaking wave statistics from wind-wave time series data. Annales Geophysicae 11:970-972 (1993).

Wave breaking is a familiar phenomenon which occurs intermittently and ubiquitously on the ocean surface. It is instantly visible from the usual appearance of the whitecaps, yet it is not amenable for routine measurement with customary instruments. Wave breaking has been recognized as playing a crucial role in accurate estimations of the exchange of gases between the ocean and the atmosphere (Wallace and Wirick, 1992) and in the transfer of momentum from wind to the ocean surface (Agrawal et al., 1992). Most of the practical works on wave breaking (Banner and Peregrine, 1993), both in the laboratory and in the field, have been done with specialized methods based on radar reflectivity, optical contrast, or acoustic output of the ocean surface. In this letter I report an application of the wavelet transform analysis (Combes et al., 1989 and Daubechies, 1992) to conventional wave gauge measured time-series data which facilitates the use of classical criterion for distinguishing breaking from non-breaking waves. This simple and fairly efficient approach can be readily applied for an indirect estimation of wave breaking statistics from all available time-series data of wind-generated waves.

LIU, P.C. Wavelet spectrum analysis and ocean wind waves. In Wavelets in Geophysics, E. Foufoula-Georgiou, and P. Kumar (eds.). Academic Press, San Diego, 151-166 (1994).

Wavelet spectrum analysis is applied to a set of measured ocean wind waves data collected during the 1990 SWADE (Surface Wave Dynamics Experiment) program. The results reveal significantly new and previously unexplored insights on wave grouping parameterizations, phase relations during wind wave growth, and detecting wave breaking characteristics. These insights are due to the nature of the wavelet transform that would not be immediately evident using a traditional Fourier transform approach.

Lohrenz, S.E., D.G. Redalje, G.L. FAHNENSTIEL, M.J. McCORMICK, G.A. LANG, K. Prasad, X. Chen, D.A. Arwood, and B. Chen. Phytoplankton rate processes in coastal waters of the northern Gulf of Mexico and relationships to environmental conditions. Proceedings, Nutrient Enhanced Coastal Ocean Productivity Workshop, Baton Rouge, LA, April 26-27, 1994. Louisiana Sea Grant, Baton Rouge, LA, 56-66 (1994).

No abstract.

McCORMICK, M.J. Mixed layer models and their application to water quality problems. Water Pollution Research Journal of Canada 29(2/3):221-232 (1994).

Four one-dimensional models which have been used to characterize surface mixed layer (ML) processes and the thermal structure are described. Although most any model can be calibrated to mimic surface water temperatures, it does not imply that the corresponding mixing processes are well described. Eddy diffusion of "K" models can exhibit this problem. If a ML model is to be useful for water quality applications, then it must be able to resolve storm events and, therefore, be able to simulate the ML depth, h, and its time rate of change, dh/dt. A general water quality model is derived from mass conservation principles to demonstrate how ML models can be used in a physically meaningful way to address water quality issues.

McCORMICK, M.J., and J.D. PAZDALSKI. Monitoring midlake water temperature in southern Lake Michigan for climate change studies. Climatic Change 25:119-125 (1993).

Recent studies of potential climatic change on Great Lakes fisheries (e.g. Meisner, 1987; Magnuson, 1990; Regier et al., 1990) and our general ignorance of the natural variability of the basic physical properties of the Great Lakes (McCormick, 1990) have demonstrated the need for a long-term observation program which is representative of the lake-wide environment. In April 1990, a site was established in Lake Michigan to continuously monitor the offshore thermal structure and vertical velocity profile. The site is located near the center of the lake's southern basin in 160 m of water. Temperature is measured at 16 depths (winter) to 28 depths (summer), and the horizontal velocity components are measured at 5 levels which allows us to characterize the offshore environment with high temporal resolution. The goals of this effort are to provide basic physical measurements to better describe the flow of energy through the lake ecosystem and to provide a basis against which future change can be better gauged.

MILLER, G.S., and J.H. SAYLOR. Comparison of acoustic doppler current profiler and vector averaging current meter measurements in a stratified, freshwater bay. Marine Technology Society Journal 27(3):15-20 (1994).

The performance of a moored, upward-looking acoustic Doppler current profiler was compared with vector averaging current meters at three depths in a shallow, stratified bay during a 142-day period. Mean current speeds during the period agreed to better than 0.2 cms-1 and 5 degrees in direction. Scatter plots showed instantaneous differences of up to 10 cms-1 which were related to the active internal oscillations and episodes of large wind-induced temperature changes together with the 0.5 km separation of the two moorings.

NALEPA, T.F., J.F. CAVALETTO, M. FORD, W.M. GORDON, and M. WIMMER. Seasonal and annual variation in weight and biochemical content of the zebra mussel, Dreissena polymorpha, in Lake St. Clair. Journal of Great Lakes Research 19(3):541-552 (1993).

Zebra mussels, Dreissena polymorpha, were collected monthly from April/May to November in 1990 and 1991 from two sites in Lake St. Clair. The sites were characterized by relatively high and low mussel densities. The following variables were measured: ash-free dry weight (AFDW) per unit shell length (SL), lipid content and classes, carbon content, and nitrogen content. Mussels from the high-density site had a lower AFDW:SL relationship, lower lipid content, and a lower C:N ratio than mussels from the low-density site. Seasonal trends in these variables were consistent between sites and years. AFDW:SL, lipid, and carbon content were highest in the spring and then declined to minimum levels in late summer/fall. The mean seasonal decline in weight from spring to late summer for a standard 15-mm mussel was 60%. This decline was greater than might be expected from gamete release alone and was likely a result of nutritional stress from warm summer temperatures and limited food supplies. Between 1990 and 1991, the mean AFDW of a 15-mm mussel declined 34% and 50% at the high- and low-density site, respectively. However, when C:N ratios and lipid levels in 1990 and 1991 were compared, C:N ratios were only lower in fall 1991 compared to fall 1990, and lipid levels for the 2 years were generally similar.

Nelson, M.K., P.F. LANDRUM, G.A. Burton, S.J. Klaine, E.A. Crecelius, T.D. Byl, D.C. GOSSIAUX, V.N. Tsymbal, L. Cleveland, C.G. Ingersoll, and G. Sasson-Brickson. Toxicity of contaminated sediments in dilution series with control sediments. Chemosphere 27(9):1789-1812 (1993).

The use of dilutions has been the foundation of our approach for assessing contaminated water, and accordingly, it may be important to establish similar or parallel approaches for sediment dilutions. Test organism responses to dilution gradients can identify the degree of necessary sediment alteration to reduce the toxicity. Using whole sediment dilutions to represent the complex interactions of in situ sediments can identify the toxicity, but the selection of the appropriate diluent for the contaminated sediment may affect the results and conclusions drawn. Contaminated whole sediments were examined to evaluate the toxicity of dilutions of sediments with a diversity of test organisms. Dilutions of the contaminated sediments were prepared with differing diluents that varied in organic carbon content, particle size distribution, and volatile solids. Studies were conducted using four macroinvertebrates and a vascular, rooted plant. Responses by some test organisms followed a sigmoidal dose response curve, but others followed a U-shaped curve. Initial dilutions reduced toxicity as expected, but further dilution resulted in an increase in toxicity. This type of diluent used was an important factor in assessing the sediment toxicity, because the control solid reduced toxicity more effectively than sand as a diluent of the same sediment. Using sediment chemical and physical characteristics as an indicator of sediment dilution may not be as useful as chemical analysis of contaminants, but warrants further investigation.

NORTON, D.C., and S.J. BOLSENGA. Spatiotemporal trends in lake effect and continental snowfall in the Laurentian Great Lakes, 1951-1980. Journal of Climate 6(10):1943-1956 (1993).

A new raster-based monthly snowfall climatology was derived from 1951-1980 snowfall station data for the Laurentian Great Lakes. An automated methodology was used to obtain higher spatial resolution than previously obtained. The increase in resolution was attained by using all available monthly snowfall data from over 1230 stations per year combined with a monthly time step to produce high-resolution grids. These monthly grids were combined to produce snow-year grids. Multiyear average grids were created and compared. This technique minimizes traditional problems associated with missing data and variable length station records. The three 10-year average distribution maps presented here indicate a period of increasing snowfall. Windowing of the 30 seasonal grids revealed that increasing snowfall was attributable to an increase in lake effect snowfall and not to continental snowfall. The Great Lakes drainage basin was evaluated for trends within and between monthly and seasonal average snowfall through windowing of all 240 monthly grids. The graphical and statistical evaluation of these trends indicates a strong natural variation in the region's snowfall and reveals an increasing trend during the study period.

O'CONNOR, W.P., and D.J. SCHWAB. Sensitivity of Great Lakes Forecasting System nowcasts to meteorological fields and model parameters. Proceedings, 3rd International Conference on Estuarine and Coastal Modeling, M.L. Spaulding, K. Bedford , A. Blumberg, R. Cheng, and C. Swanson (eds.), Oak Brook, IL, September 8-10, 1993. ASCE, New York, NY, 149-157 (1994).

The Great Lakes Forecasting System is being developed by the NOAA Great Lakes Environmental Research Laboratory and Ohio State University. It uses meteorological fields as input to a numerical ocean model to produce nowcasts and forecasts of lake temperature, currents, and water levels. In this study, the Princeton model, a fully three-dimensional, nonlinear, primitive equation model that solves both the barotropic (free surface) mode, and the baroclinic (internal) mode, is evaluated for use in the Great Lakes Forecasting System. Observational wind data is used to test the sensitivity of this model to initial conditions and model parameters. The model is set up for Lake Erie which is represented by a Cartesian grid with 5 km grid spacing aligned along the greater lake axis. The model uses a terrain following (s) vertical coordinate with 13 levels. The model uses a split mode calculation with a barotropic time step of 1 minute and a baroclinic time step of 30 minutes.

Pichel, W., P. Clemente-Colon, G. Hufford, G.A. LESHKEVICH, G. Wohl, F. Kniskern, J. Sapper, and R. Carey. CoastWatch SAR applications demonstration development phase. Proceedings, Second ERS-1 Symposium, Space at the Service of our Environment, B. Kaldeich, Hamburg, Germany, October 11-14, 1993. European Space Agency, Paris, France, 669-674 (1994).

An applications demonstration of the use of synthetic aperture radar (SAR) data in an operational setting is being conducted by the NOAA CoastWatch program. The first phase, the development phase, of this demonstration has been completed. Case studies have been carried out to assess the utility of SAR data for monitoring (1) coastal ice, (2) river ice jams and flooding, (3) ocean fronts, current boundaries, and eddies, and (4) lake ice in straits and channels. The all-weather, day/night viewing capabilities of the SAR make it a unique and valuable tool for monitoring coastal, river, and lake ice as well as ice-free coastal ocean features.

QUINN, F.H., J.A. DERECKI, and C.E. SELLINGER. Pre-1900 St. Clair River flow regime. Journal of Great Lakes Research 19(4):660-664 (1993).

The St. Clair River is the outlet channel for Lakes Michigan and Huron to the lower Great Lakes. The river's hydraulic characteristics naturally regulate Lakes Michigan-Huron's water levels by controlling the amount of water that flows out of the lakes. Accurate determinations of the outflows are necessary, in conjunction with the St. Marys River flows and lake levels data, to determine the water supplies to Lakes Michigan-Huron. The hydraulic regime of the river has been changed many times since the mid-1800s primarily due to dredging for deeper draft navigation and sand and gravel mining. In addition there have also been minor effects due to shipwrecks at the head of the river. For water resource studies of the Great Lakes system it would be highly desirable to determine Lakes Michigan-Huron's water supplies for the period 1860-1900. Additional water supply values would extend the available period of study by 40 years or approximately 45 percent. This period is also particularly important as it contains extreme high water supplies that led to record Lakes Michigan-Huron water levels. This study comprised an analysis of the existing discharge and dredging data for the 1860-1902 period to determine if discharge equations could be developed with sufficient accuracy to compute monthly St. Clair River flows. The analysis demonstrated that it is not possible to quantify St. Clair River flows prior to 1900, thus limiting the period available for determining Lakes Michigan-Huron water supplies to this century. The study also confirmed the previously determined 0.18 m lowering of Lakes Michigan-Huron between 1900 and present due to channel dredging in the upper river.

REID, D.F., J. Bidwell, J. Carlton, L. Johnson, E. Marsden, and S.J. Nichols (Editors). Zebra Mussel-Specific Containment Protocols. Aquatic Nuisance Species Task Force, Research Protocol Committee, 72 pp. (1993).

The Nonindigenoue Aquatic Nuisance Prevention and Control Act of 1990 (Act; Public Law 101-646, 104 STAT. 4671, 16 U.S.C. 4701-4741 approved Nov. 29, 1990) requires that an intergovernmental Aquatic Nuisance Speciee Taek Force (Taek Force) develop and implement a protocol to eneure that reeearch carried out under Subtitle C of the Act doee not reeult in the introduction or dispersal of nonindigenous aquatic nuisance epeciee to the watere of the United States. This protocol fulfills the requirements of the Act. The Taek Force intends to develop the research protocol further baeed on experience gained through implementation of this protocol. Thie prot0~01 will supplement other existing Federal protocols eetablished to control activities with specific major claesee of organisms, such ae thoee already eetabliehed for plants and ineecte under the Plant Quarantine Act of 1912 and the Federal Plant Pest Act of 1952, and for reeearch involving recombinant DNA molecules -under the Public Health Service Act of 1944. This protocol must be used when research is carried out under Subtitle C of the Nonindigenoue Aquatic Nuisance Prevention and Control Act of 1990. Individuals, statlee, corporations, and inetitutione not required by the Act to follow this protocol are encouraged to do so to prevent introductions and dispersal of nonindigenous aquatic nuisance speciee through reeearch activities. Prevention of unintentional introductione through means other than research is addressed in the Task Force's proposed Aquatic Nuisance Species Program (which addresees prevention, detection, monitoring, and control of nonindigenous aquatic nuisance epeciee). Intentional introductione are addreeeed in the Task Force's Report to Congreee entitled "Findinge, Conclueione, and Recommendations of the Intentional Introductions Policy

ROBBINS, J.A., and L.R. HERCHE. Models and uncertainty in 210Pb dating of sediments. Verhandlugen-Internationale Vereinigung Fur Theoretische und Angewandte Limnologie 25:217-222 (1993).

The idea of using the long-lived decay product of radium, 210Pb (t1/2 = 22.3 yr), as a geochronological tool originated with Goldberg (1963) who successfully dated a core from the Greenland ice sheet. The first sediment cores, from lakes in Europe and India, were dated 8 years later by Krishnaswami et al. (1971). About the same time Kodie et al. (1972) showed that 210Pb could establish recent chronologies in coastal marine sediments as well. In the intervening 20 years, the method has been used with ever-increasing frequency in a wide variety of aquatic systems: the world's largest lakes, small ponds, water bodies with extreme and contrasting physical, chemical, and biological characteristics, pristine and impacted reservoirs, peat bogs, rivers, fjords, estuaries, and open coastal marine waters. At the present time over 2000 published articles have dealt with some aspect of sedimentary lead-210 and mostly in terms of its use as a geochronological tool. In many cases, the method has been shown to be useful for dating sediments accumulated over the past 100 years especially in circumstances where annual laminae or other unambiguous stratigraphic indicators are absent and the use of "direct" dating methods are precluded. The following sections offer comments on some recent development in 210Pb dating.

Ryan, C.M., F.H. QUINN, and M.J. Donahue. Great Lakes Climate ChangeResearch Priorities for Assessing the Impacts of Climate Change in the Great Lakes Basin. Proceedings, Great Lakes Climate Change Workshop, Ypsilanti, MI, December 6-8, 1993. NOAA, CILER, and GLC, Ann Arbor, MI, 159 (1994).

No abstract.

SAYLOR, J.H. Studies of bottom Ekman layer processes and mid-lake upwelling in the Laurentian Great Lakes. Water Pollution Research Journal 29(2/3):233-246 (1994).

Profiles of horizontal current velocity have been measured over long time intervals across bottom Ekman layers in Lake Michigan. Measurements at offshore locations in water depths greater than 100 m have disclosed current speeds exceeding 25 cms-1 at 1 m above the lake floor during winter storms when the lake water is unstratified. Counterclockwise veering of the current velocity vector occurs as the bottom is approached, with the veering being most rapid close to the bottom. Measurements of currents during winter and spring have shown prevailing cyclonic circulation at all water depths. This is true of the other deep Great Lakes as well. Mass conservation calculations with the current meter data yield upwelling velocities on the order of 1 m day-1 in the center of the lake during winter. Water temperature data have been obtained from thermistor strings attached to meteorological buoys moored in the center of the lake by the National Data Buoy Center, Bay St. Louis, Mississippi. Simulations of the temperature data with four different one-dimensional mixed-layer models were all premature in timing the onset of stratification. Additional simulations of the temperature data were made with a constant upwelling velocity imposed through late spring. Results of the new simulations were significantly improved over those neglecting upwelling. These results emphasize the importance of Ekman pumping in retarding the start of stratification in large lake basins.

SCHNEIDER, K., R.A. ASSEL, and T.E. CROLEY. Normal water temperature and ice cover of the Laurentian Great Lakes: A computer animation, data base, and analysis tool. NOAA Technical Memorandum ERL GLERL-81, Great Lakes Environmental Research Laboratory, Ann Arbor, MI (PB95-171203/XAB) 47 pp. (1993).

A long-term temperature and ice cover data base was created together with a computer program to display and analyze different aspects of normal temperature and ice cover in the Great Lakes. "Normal" refers to long-term averages over the annual cycle. The daily normal surface temperature of each of the Great Lakes was derived from remotely sensed data acquired by the Canadian Atmospheric Environment Service (AES) and by NOAA. Normal ice cover maps, from the NOAA Great Lakes Ice Atlas, were interpolated to yield daily patterns and converted to a Mercator projection with a 2.5-km grid resolution used for the satellite-derived surface temperature maps. The two-dimensional surface temperature and ice data, bathymetry maps, and normal daily vertical temperature profiles (interpolated from thermodynamic models) were combined into a data base for an analysis and animation program. This interactive, menu-driven computer program, for an IBM-compatible PC with color VGA graphics, has 4 main modules for data presentation: a) normal daily surface temperature and ice patterns, b) horizontal surface temperature profiles, c) normal daily vertical temperature depth profiles, and d) surface temperature and ice cover versus bathymetry. All modules display daily normal values in animated sequences. Online documentation of the program and the dataset is provided. The two-dimensional data (module a) are presented in color-coded maps, and modules b, c, and d provide line drawings. The animations can be manipulated interactively and temperature and ice values, along with geographical location or depth, can be accessed and displayed numerically with a mouse-driven cursor. The dependence of temperature and ice cover on bathymetry can be investigated in two ways: 1) by toggling between the spatial temperature pattern and bathymetry, and 2) by viewing plots of temperature or ice versus depth. The two-dimensional surface temperature data for each lake are stored in a documented data base with 0.1oC resolution. Ice cover data are stored in 10% ice cover concentration steps. Modeled normal vertical temperature profiles are stored in 0.01oC steps.

SCHNEIDER, K., R.A. ASSEL, and T.E. CROLEY. Normal temperature and ice cover of the Great Lakes. Second Thematic Conference on Remote Sensing for Marine and Coastal Environments, New Orleans, LA, January 31-February 2, 1994. 325-335 (1994).

A long-term average (normal) temperature and ice cover data base was created together with a computer program to display and analyze different aspects of temperature and ice cover in the Great Lakes. The daily normal surface temperature of each of the Great Lakes was derived from remotely sensed data acquired between 1966 and 1993. Normal ice cover maps, from the NOAA Great Lakes Ice Atlas, were interpolated to yield daily patterns and converted to a Mercator projection with a 2.5 km grid resolution. Two-dimensional surface temperature and ice data, bathymetry maps, and normal daily vertical temperature profiles were combined into a database for an analysis and animation program. This interactive, menu-driven computer program has four main modules: a) two-dimensional normal daily surface temperature and ice patterns, b) horizontal surface temperature profiles, c) normal daily vertical temperature depth profiles, and d) surface temperature and ice cover versus bathymetry.

Schneider, K., and T.E. CROLEY. Temperature and energy flux patterns at the Great Lakes water surface. Proceedings, Second Thematic Conference on Remote Sensing for Marine and Coastal Environments, New Orleans, LA, January 31-February 2, 1994. 313-324 (1994).

A two-dimensional thermodynamic model was developed that uses meteorological measurements and satellite-derived surface temperatures to estimate energy flux patterns at the water surface. The model is used in either a simulation mode or a real-time mode. The simulation mode uses the two-dimensional model in combination with GLERL's one-dimensional lumped evaporation and heat storage model to simulate past daily energy flux patterns. The real-time mode uses daily surface temperature patterns derived from cloud-free NOAA/AVHRR satellite images. The model was tested in the simulation mode for a 30-year period. The energy fluxes (shortwave radiation, net longwave radiation, latent and sensible heat flux, and advection) were calculated for each day and gridpoint, and an average value for each day of the year was calculated from the 30-year period. Long-term energy fluxes should balance; indeed the 30-year average is within ± 5.0 W/m2 on lakes, except Superior (-11.3 W/m2).

SCHWAB, D.J., and K.W. Bedford. Initial implementation of the Great Lakes Forecasting System: A real-time system for predicting lake circulation and thermal structure. Water Pollution Research Journal of Canada 29(2/3):203-220 (1994).

The Great Lakes Forecasting System is a real-time coastal prediction system for forecasting, on a daily basis, the physical state of each of the Great Lakes for the next two days. Forecast variables include the surface water level fluctuation, horizontal and vertical structure of temperature and currents, and turbulence. The system uses meteorological observations, satellite data, and forecasts from numerical weather prediction models as input. Lake circulation and thermal structure are calculated using a three-dimensional hydrodynamic prediction model. Output from the model is used to provide information on the current state of the lake and to predict changes for the next two days. This information is used by scientists, government agencies, commercial operations, and the public for enhancement of commercial and recreational activity, resource management, and hazard avoidance. This paper describes system design, data acquisition and analysis procedures, the hydrodynamic model, and sample model output. The initial implementation of the system provides daily nowcasts of system variables for one lake, Lake Erie. Requirements for implementing actual lake forecasts are discussed.

Suffet, I.H., C.T. Jafvert, J. KUKKONEN, M.R. Servos, A. Spacie, L.L. Williams, and J.A. Noblet. Synopsis of discussion session: Influences of particulate and dissolved material on the bioavailability of organic compounds. Thirteenth Pellston Workshop, J.L. Hamelink, P. F. Landrum, H.L. Bergman, and W.H. Benson (eds.), Pellston, MI, August 17-22, 1992. Society of Environmental Toxicology and Chemistry, Lewis Publishers, Inc., Boca Raton, FL, 93-108 (1994).

No abstract.

VANDERPLOEG, H.A. Zooplankton particle selection and feeding mechanisms. In The Biology of Particles in Aquatic Systems, R.S. Wotton (ed.). Lewis Publishers, Ann Arbor, MI, 205-234 (1994).

No abstract.

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