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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Three Dimensional Hydrodynamic Modelling of Lake Erie: Kelvin Wave Propagation and Potential Effects of Climate Change on Thermal Structure and Dissolved Oxygen

Liu, Wentao 07 1900 (has links)
This thesis investigates physical processes in Lake Erie, a large, shallow mid-latitude lake, from two perspectives: climate change impacts on the thermal structure and dissolved oxygen concentration and small-scale eddy dynamics generated by internal Kelvin wave propagation. A three-dimensional hydrodynamic and aquatic ecological coupled model ELCOM-CAEDYM, validated by the field data collected in 2008, is first used to investigate the responses of the thermal structure and dissolved oxygen concentration in Lake Erie to potential changes in air temperature and wind speed. A new method is presented to define spatially and temporally varying regions for the epilimnion, thermocline, and hypolimnion. Four metrics are selected to quantify the characteristics of the thermal structure: mean epilimnion temperature, mean hypolimnion temperature, onset and breakdown of stratification, and thermocline depth. Exploiting the power of the three dimensional model to provide a more authentic characterization of thermal structure in such large lakes, it is shown that patterns inferred from simple isotherm dynamics, as typically done with one dimensional models, are not always accurate. In the dissolved oxygen studies similar analyses are presented. Three factors related to lake hydrodynamics have strong influences on hypolimnetic hypoxia: water temperature, stratification duration, and hypolimnion thickness. The present results show the potential for complicated and interactive effects of climate forcing on important biogeochemical processes in Lake Erie as well as other large mid-latitude lakes. Taking advantage of high performance computing, the generation of eddies when a baroclinic Kelvin wave propagates past a peninsula is studied using the MITgcm. The grid resolution can be refined from 2 km to 200 m in the parallel computing environment. With the finer resolution small-scale processes which cannot be resolved in the coarse resolution applied previously are able to be explored. The eddy dynamics are studied in detail in both an idealized lake and in Lake Erie. This work presents a first attempt at simulating small-scale hydrodynamic processes in large lakes and contributes to our understanding of how energy is moved from large scales (the scale of the basins in Lake Erie) to smaller scales (the scale of the peninsula or Point Pelee).
52

Soil testing and nutrient application practices of agricultural retailers in the Great Lakes Region

Sisung, Theresa January 1900 (has links)
Master of Agribusiness / Agricultural Economics / Terry Griffin / Agricultural runoff containing phosphorus is believed to be a major contributor of algae blooms in the Western Lake Erie Basin. However, the implementation of best management practices (BMPs) can be used to help reduce the runoff of phosphorus. This research involved conducting surveys to analyze the current implementation of BMPs in Michigan and Indiana. The hypothesis is that the survey results are similar between the two states. An additional hypothesis is that the Michigan and Indiana results are similar to results from two other studies that were previously conducted. The results from this research generally support the hypothesis that a similar number of farmers in Michigan and Indiana are already implementing best management practices on their farms. In addition to the results being similar across Michigan and Indiana, there is also some evidence that shows that the results are similar to studies from the Ohio State University (LaBarge and Prochaska 2014), CropLife magazine (Erickson and Widmar 2015) and NRCS (U.S. Department of Agriculture, Natural Resources Conservation Service 2016); however upon further investigation there are distinct differences before and after media mentions of ramifications from the Lake Erie algal blooms. While it is difficult to force farmers to implement BMPs, the results of this study may help to educate them, which may cause them to add these practices to their operations.
53

Instream processes alter the bioavailability of P exports from agricultural watersheds during high flow events.

King, Whitney M. January 2020 (has links)
No description available.
54

Quantification of gene expression from metatranscriptomic analysis of a Lake Erie spring diatom bloom

Shupe, Kari L. 24 May 2022 (has links)
No description available.
55

Evaluating sediments as an ecosystem service in western Lake Erie through quantification of nitrogen cycling pathways

Boedecker, Ashlynn Rose January 2018 (has links)
No description available.
56

Identification and Characterization of Microfibers in Wastewater Discharging into Lake Erie

Houck, Blane 10 May 2019 (has links)
No description available.
57

Coupling Ecosystem Rehabilitation to Water Quality Improvements in the Wolf Creek Watershed

Jackwood, Ryan W. 05 September 2019 (has links)
No description available.
58

Modeling and Understanding Groundwater Contamination Caused by Cyanotoxins from Harmful Algal Blooms in Lake Erie

Abesh, Bidisha Faruque 09 August 2019 (has links)
No description available.
59

Implication Of Inorganic Nitrogen And Phosphorous Species As A Cause Of A Harmful Algal Bloom Event In Caesar Creek Lake, Ohio And Its Tributaries

Foskuhl, Baxter Jeffrey January 2019 (has links)
No description available.
60

The Fate of Anthropogenic Nitrogen Along Hydrologic Continuums: Patterns of Transformation and Recycling in a Eutrophic Lake and Coastal Marine Sediments

Hoffman, Daniel K. 15 September 2020 (has links)
No description available.

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