Download or read book Simulation of Surface Water Temperature and Ice Extent in Lake Ontario and Lake Erie Using a Dynamic Reservoir Simulation Model DYRESM written by R. C. McCrimmon and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Year round Water Temperature and Dissolved Oxygen Simulation Model for Lakes with Winter Ice Cover written by and published by . This book was released on 1994 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Ice Cover and Water Temperature of Lake Mendota written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this work is to build lake physical templates, i.e., ice cover, thermal structure, and transport processes through modeling approaches. Knowledge of lake physics can be further used for ecosystem and climate change studies. Specifically, the following two science questions are addressed using the lake physical template developed in this study: (1) How do lake temperate and ice cover vary in response to long-term (~ 100 years) changing climate, and what are physical drivers. (2) At a short-term scale (~ less than 1 year), what is the spatial and temporal variation when lake experiencing natural (e.g. meteorological inputs) and/or manmade (e.g. effluent discharge) disturbances. Both one-dimensional (1D) and three-dimensional (3D) lake hydrodynamic-ice models were developed to have continuous simulations over the course of the year. The study lake of this thesis, on which all the field experiments and model simulations are focused, is Lake Mendota, located in Madison, Wisconsin, USA (43o40'N, 89o24'W). In summary, Chapter 2 presents validation and application of a 1-D hydrodynamic-ice model in simulating a continuous 100-year period (1911-2010) of ice cover and water temperature. Influences of three important drivers (air temperature, wind speed, and water clarity) on ice cover and thermal structure during the past century was investigated. Also, with the knowledge of lake responses to the past climatic conditions, some suggestions about how the lake might respond to changes in these three important drivers associated with future climate changes were presented. In Chapter 3, the 1D-version ice module was extended to a 3D framework and coupled with an existing three dimensional (3D) hydrodynamic model. The coupled 3D hydrodynamic-ice model was applied to simulate the temporal and spatial variations of ice cover. Besides, some features of under-ice hydrodynamics were discussed. In Chapter 4, modeling transport of buoyant effluent plume during the summer stratified season was presented. In closing, conclusions and some recommendations for future study are summarized in Chapter 5.

Download or read book Simulation of Lake Erie Water Quality Responses to Loading and Weather Variations written by David C. L. Lam and published by Burlington, Ont. : Environment Canada. This book was released on 1983 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This report presents simulation results and observational data relating to the water quality conditions of Lake Erie for the twelve-year period from 1967 to 1978"--Abstract.

Download or read book Modeling Climate Change Impacts on the Thermodynamics of Oneida Lake written by Amy Lee Hetherington and published by . This book was released on 2013 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was the grandest and most majestic sight I had seen. It was exquisitely beautiful. The sun in its full splendor at the western horizon gilding the enlightened clouds, the islands, the shores, the woods, and all seemed to vie with each other for preference. The evening was serene and delightful; a soft breeze curled the waves and fringed them with white while the sun, sinking toward the west beautified the whole scene. Description of Oneida Lake Francis Adrian VanderKemp (1792) ABSTRACT Substantial change in climate is predicted to occur across the globe this century. Understanding climatic impacts on lake ecosystems is highly relevant as they will have important effects on eutrophication, ecosystem processes, and aquatic biodiversity. Field-based monitoring and modeling were used to evaluate the impacts of predicted climate change on Oneida Lake temperature profiles and stratification. Oneida Lake is a 207 km2 shallow, polymictic lake located in the center of an extensive 3,579 km2 watershed in Central New York. Field data were collected on stream and groundwater temperature loading, weather, and lake temperatures at varying depths to calibrate and validate the Oneida Lake thermodynamics model. Downscaled climate data from three general circulation models and two emissions scenarios provided by the Northeast Regional Climate Center and maximum projections were used to assess the impacts of different anticipated climate scenarios on the lake for 2050 and 2099. Lake temperature profiles under current and anticipated conditions were modeled using a deterministic, one-dimensional model, Dynamic Reservoir Simulation Model (DYRESM), from the University of Western Australia Centre for Water Research. The sensitivity analysis confirmed the importance of meteorological variables, including solar radiation and wind speed, as drivers to the thermal regime of the lake. A best fit model was obtained by decreasing wind speed by 25%, mean albedo to 1%, and minimum layer thickness to 0.5 m. By the end of the century, the predicted increase in air temperatures and precipitation associated with the higher emissions scenario will be paralleled by an average increase in 2 m and 10 m water temperatures (April - November) of 2.47°C (SD 1.08) and 2.01°C (SD 1.43), respectively. Additionally, the higher emissions scenario indicated an increase of 15 consecutive days of stratification in Oneida Lake. This study contributes to our understanding of the thermal regime of polymictic lakes in a warmer world and provides broad-scale predictions of the effects of climate change on the thermal structure of the majority of global freshwater lakes.

Download or read book The Use of Lake Water Temperature and Ice Cover as Climatic Indicators written by Dale Martin Robertson and published by . This book was released on 1989 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermal Simulation of Lakes written by and published by . This book was released on 1977 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of Lake Thermal Structure Ice Cover and Fish Habitat in Response to Changing Climate written by Madeline Rosalie Magee and published by . This book was released on 2016 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical, chemical, and biological properties in lakes are all sensitive to changes in climate, but the interaction and response of these properties to climate changes is not yet fully understood. This dissertation has two main objectives: (1) characterize the role of lake depth and lake surface area on the physical response of water temperature and ice cover to air temperature (AT) and wind speed (WS) changes and (2) determine the response fish habitat to climate-caused changes in the physical parameter of temperature chemical parameter of dissolved oxygen. To fulfill these objectives, a one-dimensional lake hydrodynamic, ice, and water quality model is utilized on three lakes near Madison, WI. Chapter 2 investigates the response of lake water temperatures and stratification to AT increases and WS decreases for three Madison area lakes. Results indicate that surface area is more important than depth when determining the response of water temperature, stratification, and stability and increasing AT and decreasing WS have a cumulative effect for all variables except hypolimnion temperature, where they have opposing influences. Chapter 3 investigates the response of ice cover duration and ice thickness to AT increases for the same three lakes, and results show that lake depth is the greater influence on ice cover response, with shallow lakes being more resilient to changes in AT. Chapter 4 investigates the role of meteorological drivers and water quality drivers on oxythermal habitat of cisco. Results show that summer AT, spring phosphorus load, and spring inflow volume drive habitat loss, but effects of AT increases can be offset by decreases in phosphorus loading. Finally, Chapter 5 develops a novel metric, cumulative oxythermal stress dosage (COSD), to quantify oxythermal habitat of yellow perch in Fish Lake, WI. Results show that COSD is a good predictor of fish declines, COSD values are closely tied to the July -- September AT, and perturbation scenarios identify 3°C AT increase as a possible threshold for yellow perch extirpation.

Download or read book Lake Erie Regional Ice Cover Analysis written by Raymond A. Assel and published by . This book was released on 1983 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling the Impacts of Climate Change on the Hydrodynamics and Biogeochemistry of Lake Simcoe Hamilton Harbour and the Bay of Qunite written by and published by . This book was released on 2014 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on 3 Ontario water bodies (Hamilton Harbour, the Bay of Quinte and Lake Simcoe), which are vital for economic and recreational activities, yet are threatened by eutrophication, which leads to low dissolved oxygen concentrations (hypoxia) and harmful algae blooms. Among them, Hamilton Harbour and Bay of Quinte are listed as Great Lakes Areas of Concerns (AOCs). To develop effective Remedial Action Plans (RAPs) the potential impacts of climate change on the water quality problems must be assessed. The main objective of this study is to predict the effects of future climate change on the water quality and the implications for lake restoration through computational modeling. A vertical one-dimensional (1D) computational model, Dynamic Reservoir Simulation Model (DYRESM) coupled to Computational Aquatic Ecosystem Dynamics Model (CAEDYM) was applied to Lake Simcoe and Hamilton Harbour. We forecasted the response of the Lake to two greenhouse gas GCM emissions scenarios (A2 and B1). There is a relatively small difference between A2 and B1 predictions. According to the simulations, Lake Simcoe will be stratified 4.5 days per decade longer until 2100 and the length of hypoxia will increase from 55 days to ~100 days. Hamilton Harbor, will be stratified approximately 6 days per decade longer by 2100 and the hypoxic period is projected to increase from 150 days to 200 days. In Lake Simcoe, the mean surface cyanobacteria biomass during the stratified season is simulated to increase from ~ 0.2 ugL-1 to ~1 ug L-1 by 2066 as a consequence of a warming climate. The three-dimensional (3D) hydrodynamic Estuary and Lake Computer Model (ELCOM) combined with CAEDYM was applied to Bay of Quinte. The model results were comprehensively validated against the observed physical (temperature), chemical (nutrients) and biological (phytoplankton biomass) parameters. The model was then forced for the periods of 2000-2004 and 2066-2070, with North American Regional Climate Change Assessment Program (NARCCAP) meteorological data. The simulations show an increase in surface temperature of 2-3.5· C with minimal simulated effects on cyanobacteria. The average May-October TP concentrations in present and future simulations are higher than the RAP target (~0.1 mg L-1), from loads to the upper Bay, and biomass is consistently below the RAP target range (

Download or read book Simulation of Atmospheric and Lake Conditions in the Laurentian Great Lakes Region Using the Coupled Hydrosphere Atmosphere Research Model CHARM written by Brent Melvin Lofgren and published by . This book was released on 2014 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Greenhouse gas-induced climate change will have notable effects on the Great Lakes region, in the atmosphere, land surfaces, and lakes themselves. Simulations of these effects were carried out using the Coupled Hydrosphere-Atmosphere Research Model (CHARM), driven by output from the Canadian General Circulation Model version 3 (CRCM3) for past and future time periods. This results in increased downward longwave radiation and near-surface air temperature. The air temperature increases during summer have strong spatial minima directly over the lakes that are limited to the lowest model layer and seem to be associated with frequent fog depicted by CHARM. Precipitation is also generally increased, with the most spatially coherent, and among the strongest, increases occurring in the near-shore lake effect zones during winter. Evapotranspiration is generally increased, although only weakly over land, but very strongly over the lakes during winter. Water temperatures are increased and the summer stratification pattern (warmer water overlying colder) is established earlier in the year. Ice cover is diminished and limited to shallow parts of the lakes. Several bugs and shortcomings in CHARM are identified for correction in future development and use.

Download or read book Evaporation from Lake Erie written by Jan A. Derecki and published by . This book was released on 1975 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of a Thermodynamic Simulation Model for the Ice Regime of Lake Erie written by Akio Wake and published by . This book was released on 1977 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Water Temperature Characteristics of Lakes Subjected to Climate Change written by Midhat Hondzo and published by . This book was released on 1992 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: A deterministic, one dimensional, unsteady lake water temperature model was modified and validated to simulate the seasonal (spring to fall) temperature statification structure over a wide range of lake morphometries, trophic and meteorological conditions. Model coefficients related to hypolimnetic eddy diffusivity, light attenuation, wind sheltering, ad convective heat transfer were generalized using theoretical and empirical extensions. Propagation of uncertainty in the lake temperature model was studied using a vector state-space method. The output uncertainty was defined as the result of deviations of meteorological variables from their mean values. Surface water temperatures were affected by uncertain meteorological forcing. Air temperture and dew point temperature fluctuations had significant effects on lake temperature uncertainty. The method presents a useful alternative for studying long-term averages and variability of the water temperature structure in lakes due to variable meteorological forcing. The lake water temperature model was linked to a daily meteorological data base to simulate daily water temperature in several specific lakes as well as 27 lake classes characteristic for the north central US. Case studies of lake water temperature and stratification response to variable climate were made in a particulary warm year (1988) and a more normal one (1971). A regional analysis was conducted for 27 lake classes over a period of twenty-five years (1955-1979). Output from a global climate model (GISS) was used to modify te meteorological data base to account for a doubling of atmospheric CO2. The simulations predict that after climate change: 1) epilimnetic water temperatures will be higher but will increase less than air temperature, 2) hypolimnetic temperatures in seasonally stratified dimictic lakes will be largely unchanged and in some cases lower than at present, 3) evaporative water loss will be increased by as much as 300 mm for the open water season, 4) onset of stratification will occur earlier and overturn will occur later in the season, and 5) overall lake stability will become greater in spring and sumer.

Download or read book Modelling Lake Ice Cover Under Contemporary and Future Climate Conditions written by Laura Claire Brown and published by . This book was released on 2012 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lakes comprise a large portion of the surface cover in northern North America, forming an important part of the cryosphere. Further alterations to the present day ice regime could result in major ecosystem changes, such as species shifts and the disappearance of perennial ice cover. Lake ice has been shown to both respond to, and play a role in the local/regional climate. The timing of lake ice phenological events (e.g. break-up/freeze-up) is a useful indicator of climate variability and change. Trends in ice phenology have typically been associated with variations in air temperatures while trends found in ice thickness tend to be associated more with changes in snow cover. The inclusion of lakes and lake ice in climate modelling is an area of increased attention in recent studies and the ability to accurately represent ice cover on lakes will be an important step in the improvement of global circulation models, regional climate models and numerical weather forecasting. This thesis aimed to further our understanding of lake ice and climate interactions, with an emphasis on ice cover modelling. The Canadian Lake Ice Model (CLIMo) was used throughout for lake ice simulations. To validate and improve the model results, in situ measurements of the ice cover for two seasons in Churchill, MB were obtained using an upward-looking sonar device Shallow Water Ice Profiler (SWIP) installed on the bottom of the lake. The SWIP identified the ice-on/off dates as well as collected ice thickness measurements. In addition, a digital camera was installed on shore to capture images of the ice cover through the seasons and field measurements were obtained of snow depth on the ice, and both the thickness of snow ice (if present) and total ice cover. Altering the amounts of snow cover on the ice surface to represent potential snow redistribution affected simulated freeze-up dates by a maximum of 22 days and break-up dates by a maximum of 12 days, highlighting the importance of accurately representing the snowpack for lake ice modelling. The late season ice thickness tended to be underestimated by the simulations with break-up occurring too early, however, the evolution of the ice cover was simulated to fall between the range of the full snow and no snow scenario, with the thickness being dependent on the amount of snow cover on the ice surface. CLIMo was then used to simulate lake ice phenology across the North American Arctic from 1961-2100 using two climate scenarios produced by the Canadian Regional Climate Model (CRCM). Results from the 1961-1990 time period were validated using 15 locations across the Canadian Arctic, with both in situ ice cover observations from the Canadian Ice Database as well as additional ice cover simulations using nearby weather station data. Projected changes to the ice cover using the 30-year mean data between 1961-1990 and 2041-2070 suggest a shift in break-up and freeze-up dates for most areas ranging from 10-25 days earlier (break-up) and 0-15 days later (freeze-up). The resulting ice cover durations show mainly a 10-25 day reduction for the shallower lakes (3 and 10 m) and 10-30 day reduction for the deeper lakes (30 m). More extreme reductions of up to 60 days (excluding the loss of perennial ice cover) were shown in the coastal regions compared to the interior continental areas. The mean maximum ice thickness was shown to decrease by 10-60 cm with no snow cover and 5-50 cm with snow cover on the ice. Snow ice was also shown to increase through most of the study area with the exception of the Alaskan coastal areas. While the most suitable way to undertake wide scale lake ice modeling is to force the models with climate model output or reanalysis data, a variety of different lake morphometric conditions could exist within a given grid cell leading to different durations of ice cover within the grid cell. Both the daily IMS product (4 km) and the MODIS snow product (500 m) were assessed for their utility at determining lake ice phenology at the sub-grid cell level throughout the province of Quebec. Both products were useful for detecting ice-off, however, the MODIS product was advantageous for detecting ice-on, mainly due to the finer resolution and resulting spatial detail of the lake ice. The sub-grid cell variability was typically less than 2%, although it ranged as high as 10% for some grid cells. An indication of whether or not the simulated ice-on/off dates were within the sub-grid cell variability was determined and on average across the entire province, were found to be within the variability 62% of the time for ice-off and 80% of the time for ice-on. Forcing the model with the future climate scenarios from CRCM predicts ice cover durations throughout the region will decrease by up to 50 days from the current 1981-2010 means to the 2041-2070 means, and decrease from 15 to nearly 100 days shorter between the contemporary and 2071-2100 means. Overall, this work examined the climate-lake-ice interactions under both contemporary and future climate conditions, as well as provided new insight into sub-grid cell variability of lake ice.

Download or read book Thermal Simulation of Lakes with Winter Ice Cover written by J. C. Patterson and published by . This book was released on 1984 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of the Formation and Propagation of the Thermal Bar on Lake Ontario written by Dilkushi Anuja de Alwis and published by . This book was released on 1999 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Computer-based, mathematical models that simulate spatially distributed and time dependent environmental processes are increasingly recognized to provide diagnostic and productive outputs for the assessments of environmental factors. Mathematical models have been utilized since 60's to study the water quality, the circulation structure and the seasonal changes of large water bodies such as the Great Lakes. Analysis of changes in water quality related to seasonal cycles such as the formation and the propagation of the thermal bar requires spatial and temporal models, with high resolution. The overall objective of this study was to integrate geo-referenced site-specific spatial data to a 3D hydrodynamic model (ALGE) and compare the outputs with geo-referenced remotely sensed thermal imagery. The motivation of this work is based on the idea that the spatial data provides a significant advantage of equipping the model with site specific data to manipulate site specific circulation patterns. Further since the input is geo-referenced and site specific, the output can be directly compared to geo-referenced remotely sensed imagery for model validation. Thus, the aspect of integration of spatial data to hydrodynamic models is an obvious and promising approach to study lake-wide hydrodynamic processors and seasonal changes. A specific objective of the study was to examine how different spatial patterns and weather conditions influence the formation and the propagation of the thermal bar temporally and spatially. Several preliminary studies were conducted on square lakes and lakes with false bathymetric profiles, and compared with the results of laboratory studies and field surveys. Since the outputs compared well with the literature, bathymetric data of Lake Ontario was integrated to the 3D hydrodynamic model with real time surface and atmospheric weather data. The formation and the propagation of the thermal bar was simulated for the years 1997, 1998, 1999 and 1997 (winter) through 1998(fall). The model was fine tuned by changing the initial conditions and weather data to obtain a good approximation to the surface temperature derived from satellite imagery using the split and dual window technique. The lake was also subjected to different weather conditions to study its influences on the formation and propagation of the thermal bar. The model outputs from case studies as well as comparisons of the model output with satellite imagery and the NOAA forecasting model are discussed."--Abstract.