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ABSTRACT Lake whitefish (Coregonus clupeaformis) is an ecologically, culturally, and economically important species in the Laurentian Great Lakes. Lake Whitefish have been a staple food source for thousands of years and, since 1980, have... more
ABSTRACT Lake whitefish (Coregonus clupeaformis) is an ecologically, culturally, and economically important species in the Laurentian Great Lakes. Lake Whitefish have been a staple food source for thousands of years and, since 1980, have supported the most economically valuable (annual catch value ≈ US$16.6 million) and productive (annual harvest ≈ 15 million lbs.) commercial fishery in the upper Great Lakes (Lakes Huron, Michigan, and Superior). Climate change, specifically change in temperature, wind, and ice cover, is expected to impact the ecology, production dynamics, and value of this fishery, because recruitment to the fishery has been linked with these climatic factors. We used linear regression to determine the relationship between fall and spring temperature indices, fall wind speed, winter ice cover, and Lake Whitefish recruitment in 13 management units located in the 1836 Treaty Waters, a culturally and commercially important region for Lake Whitefish. Corrected Akaike’s Information Criterion comparisons indicated that selected climate variables significantly improved model fit in eight of the 13 management units evaluated. Isolating the climate-recruitment relationship and projecting recruitment using the Coupled Hydrosphere-Atmosphere Research Model (CHARM) suggested increased Lake Whitefish recruitment in the majority of the 1836 Treaty Waters management units given projected changes in climate.
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Seasonal and interannual variability of lake ice cover in the Great Lakes is investigated using historical and satellite measurements for the period 1973-2010. After climatology of the seasonal cycle is derived for lake ice season, large... more
Seasonal and interannual variability of lake ice cover in the Great Lakes is investigated using historical and satellite measurements for the period 1973-2010. After climatology of the seasonal cycle is derived for lake ice season, large anomalous interannual variability is found in response to atmospheric teleconnection patterns. Nevertheless, spatial variability of ice cover in the five Great Lakes shows regional differences and characteristics. A principal-component or EOF (empirical orthogonal function) analysis is applied to lake ice anomalies to derive major spatial and temporal patterns, which can be explained by major atmospheric variability controlled by well-known climate patterns: Arctic Oscillation (AO) and ENSO (El Nino and Southern Oscillation). Thus, a normalized ice anomaly index is derived by combined five Great Lakes ice normalized by its individual standard deviation, which can be used to be regressed atmospheric forcing field. Lake ice reduction rate over the las...
Research Interests: Environmental Science, Oceanography, Climatology, Climate variability, Principal Component Analysis, and 15 moreGlobal change, Seasonality, Standard Deviation, Spatial Variability, Great Salt Lake, El Nino-Southern Oscillation, Indexation, Southern Oscillation, Force Field Analysis, El Nino, Interannual Variability, Arctic Oscillation, Seasonal Cycle, Regional Climate Change, and Regional Difference
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ABSTRACT We used a bioenergetics modeling approach to investigate potential effects of climate change on the growth of two economically important native fishes: yellow perch (Perca flavescens), a cool-water fish, and lake whitefish... more
ABSTRACT We used a bioenergetics modeling approach to investigate potential effects of climate change on the growth of two economically important native fishes: yellow perch (Perca flavescens), a cool-water fish, and lake whitefish (Coregonus clupeaformis), a cold-water fish, in deep and oligotrophic Lakes Michigan and Huron. For assessing potential changes in fish growth, we contrasted simulated fish growth in the projected future climate regime during the period 2043–2070 under different prey availability scenarios with the simulated growth during the baseline (historical reference) period 1964–1993. Results showed that effects of climate change on the growth of these two fishes are jointly controlled by behavioral thermoregulation and prey availability. With the ability of behavioral thermoregulation, temperatures experienced by yellow perch in the projected future climate regime increased more than those experienced by lake whitefish. Thus simulated future growth decreased more for yellow perch than for lake whitefish under scenarios where prey availability remains constant into the future. Under high prey availability scenarios, simulated future growth of these two fishes both increased but yellow perch could not maintain the baseline efficiency of converting prey consumption into body weight. We contended that thermal guild should not be the only factor used to predict effects of climate change on the growth of a fish, and that ecosystem responses to climate change should be also taken into account.
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Proper modeling of the turbulent heat fluxes over lakes is critical for accurate predictions of lake-effect snowfall (LES). However, model evaluation of such a process has not been possible because of the lack of direct flux measurements... more
Proper modeling of the turbulent heat fluxes over lakes is critical for accurate predictions of lake-effect snowfall (LES). However, model evaluation of such a process has not been possible because of the lack of direct flux measurements over lakes. The authors conducted the first-ever comparison of the turbulent latent and sensible heat fluxes between state-of-the-art numerical models and direct flux measurements over Lake Erie, focusing on a record LES event in southwest New York in November 2014. The model suite consisted of numerical models that were operationally and experimentally used to provide nowcasts and forecasts of weather and lake conditions. The models captured the rise of the observed turbulent heat fluxes, while the peak values varied significantly. This variation resulted in an increased spread of simulated lake temperature and cumulative evaporation as the representation of the model uncertainty. The water budget analysis of the atmospheric model results showed th...
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Research Interests: Geology, Climatology, East Asia, Science, China, and 3 moreSubtropics, Polar Front, and Winter climate
ABSTRACTBoth land‐cover/land‐use change (LCLUC) and greenhouse gas (GHG) concentrations have been shown to influence regional climate, albeit at different spatial scales. In East Africa, climate changes due to changing GHG concentrations... more
ABSTRACTBoth land‐cover/land‐use change (LCLUC) and greenhouse gas (GHG) concentrations have been shown to influence regional climate, albeit at different spatial scales. In East Africa, climate changes due to changing GHG concentrations are broadly projected to be warmer and wetter. LCLUC projections include trends towards both agricultural intensification and agricultural expansion into savannas, which may result in complex climate interactions and impacts. The primary objective of this study was to examine the regional responses to future GHG, LCLUC, and their combined effects in East Africa, and to better understand how hydrometeorological mechanisms might be altered by LCLUC in future scenarios. In this study, we present high‐resolution decadal simulations from a regional climate model that compare the relative and combined effects of projected LCLUC and GHG. This research suggests that taken separately, these two climate forcings may significantly alter regional precipitation ...
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The Midwest is home to over 60 million people, and its active economy represents 18% of the U.S. gross domestic product. The region is probably best known for agricultural production. Increases in growingseason temperature in the Midwest... more
The Midwest is home to over 60 million people, and its active economy represents 18% of the U.S. gross domestic product. The region is probably best known for agricultural production. Increases in growingseason temperature in the Midwest are projected to be the largest contributing factor to declines in the productivity of U.S. agriculture. Increases in humidity in spring through mid-century are expected to increase rainfall, which will increase the potential for soil erosion and further reduce planting-season workdays due to waterlogged soil
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East African food security as influenced by future climate change and land use change at local to regional scales
In this study, decadal variability of ice cover in the Great Lakes is investigated using historical airborne and satellite measurements from 1963 to 2017. It was found that Great Lakes ice cover has 1) a linear relationship with the... more
In this study, decadal variability of ice cover in the Great Lakes is investigated using historical airborne and satellite measurements from 1963 to 2017. It was found that Great Lakes ice cover has 1) a linear relationship with the Atlantic multidecadal oscillation (AMO), similar to the relationship of lake ice cover with the North Atlantic Oscillation (NAO), but with stronger impact than NAO; 2) a quadratic relationship with the Pacific decadal oscillation (PDO), which is similar to the relationship of lake ice cover to Niño-3.4, but with opposite curvature; and 3) decadal variability with a positive (warming) trend in AMO contributes to the decreasing trend in lake ice cover. Composite analyses show that during the positive (negative) phase of AMO, the Great Lakes experience a warm (cold) anomaly in surface air temperature (SAT) and lake surface temperature (LST), leading to less (more) ice cover. During the positive (negative) phase of PDO, the Great Lakes experience a cold (war...
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Projections of regional climate, net basin supply (NBS), and water levels are developed for the mid- and late twenty-first century across the Laurentian Great Lakes basin. Two state-of-the-art global climate models (GCMs) are dynamically... more
Projections of regional climate, net basin supply (NBS), and water levels are developed for the mid- and late twenty-first century across the Laurentian Great Lakes basin. Two state-of-the-art global climate models (GCMs) are dynamically downscaled using a regional climate model (RCM) interactively coupled to a one-dimensional lake model, and then a hydrologic routing model is forced with time series of perturbed NBS. The dynamical downscaling and coupling with a lake model to represent the Great Lakes create added value beyond the parent GCM in terms of simulated seasonal cycles of temperature, precipitation, and surface fluxes. However, limitations related to this rudimentary treatment of the Great Lakes result in warm summer biases in lake temperatures, excessive ice cover, and an abnormally early peak in lake evaporation. While the downscaling of both GCMs led to consistent projections of increases in annual air temperature, precipitation, and all NBS components (overlake precip...
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The question of the net effect of global warm- ing, and of other changes in climate on water re- sources can often be more complex than is indi- cated by individual simple measures. * The dimen- sions of total precipitation,... more
The question of the net effect of global warm- ing, and of other changes in climate on water re- sources can often be more complex than is indi- cated by individual simple measures. * The dimen- sions of total precipitation, evapotranspiration, soil moisture, runoff, and net basin supply can interact in ways that are not related at a simple intuitive
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Research Interests: Environmental Engineering, Environmental Science, Great Lakes, Surface Water, Heat Flux, and 15 moreSatellite, Seasonal variation, Atmospheric Boundary Layer, Spatial Distribution, Great Salt Lake, Free Surface, Energy Budget, Spatial Variation, Annual Cycle, Surface Energy, Sensible Heat Flux, Shallow Water, ENVIRONMENTAL SCIENCE AND MANAGEMENT, surface temperature, and Seasonal Cycle
Research Interests: Environmental Science, Convection, Climate Change, Climatology, Climate, and 15 moreGlobal change, Atmosphere, Land Cover, Classification, Land Use, Climate Models, Land cover classification, Land cover change, Accuracy, Climate Model, Geophysical, Land Use Cover Change, Accuracy Assessment, Forcing, and Classification Accuracy
Research Interests: Environmental Science, Climate Change, Climatology, Climate variability, Modeling, and 15 moreEast Africa, Data Assimilation, Climate modeling, Global change, global Climate change, Land Cover, Land Surface Temperature, Climate Models, Leaf Area Index, Land cover change, Climate Model, Intertropical Convergence Zone, Geophysical, Land Use Cover Change, and Diurnal Cycle
Research Interests: Geography, Climate Change, Decision Making, Research Design, Modeling, and 15 moreEast Africa, Multidisciplinary, Land Use Change, Global change, Livelihood, Environmental Resource Management, Land Cover, Land Use, Scientific Discovery, Vegetation dynamics, Feedback loop, Physical Properties, Quantitative Method, Land Use Land Cover, and Driving force
Climate change due to anthropogenic greenhouse gases (GHG) is expected to have important impacts on water resources, with a variety of societal impacts. Recent research has shown that applying different methodologies to assess hydrologic... more
Climate change due to anthropogenic greenhouse gases (GHG) is expected to have important impacts on water resources, with a variety of societal impacts. Recent research has shown that applying different methodologies to assess hydrologic impacts can lead to widely diverging projections of water resources. The authors classify methods of projecting hydrologic impacts of climate change into those that estimate potential evapotranspiration (PET) based on air temperature and those that estimate PET based on components of the surface energy budget. In general, air temperature–based methods more frequently show reductions in measures of water resources (e.g., water yield or soil moisture) and greater sensitivity than those using energy budget–based methods. There are significant trade-offs between these two methods in terms of ease of use, input data required, applicability to specific locales, and adherence to fundamental physical constraints: namely, conservation of energy at the surfac...
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Research Interests: Environmental Science, Climate Change, East Africa, Multidisciplinary, Food Security, and 15 moreLand Use Change, Seasonality, Land Cover, Regional scale, Climatic Change, Spatial Distribution, Spatial Variability, Climate change impact, Greenhouse gases, First Order Logic, Climate impacts, Soil Type, Food Products, Crop Yield, and Simulation Model
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The Climate-Land Interactions Project (CLIP) is studying climate impacts coupled to land use/land cover (LULC) change in East Africa. Accompanying dramatic shifts in population distribution and economic drivers in eastern Africa are... more
The Climate-Land Interactions Project (CLIP) is studying climate impacts coupled to land use/land cover (LULC) change in East Africa. Accompanying dramatic shifts in population distribution and economic drivers in eastern Africa are changes in global climate forcings; eg the melting of Kilimanjaro's glaciers, shifts in the Indian Ocean Dipole periodicity, and greater drought frequency. These socioeconomic factors can alter the surface energy balance, thereby influencing climate, and climate shifts can in turn ...
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A method for projecting the water levels of the Laurentian Great Lakes under scenarios of human-caused climate change, used almost to the exclusion of other methods in the past, relies very heavily on the large basin runoff model (LBRM)... more
A method for projecting the water levels of the Laurentian Great Lakes under scenarios of human-caused climate change, used almost to the exclusion of other methods in the past, relies very heavily on the large basin runoff model (LBRM) as a component for determining the water budget for the lake system. This model uses near-surface air temperature as a primary predictor of evapotranspiration (ET); as in previous published work, it is shown here that the model’s very high sensitivity to temperature causes it to overestimate ET in a way that is greatly at variance with the fundamental principle of conservation of energy at the land surface. The traditional formulation is characterized here as being equivalent to having several suns in the virtual sky created by LBRM. More physically based methods show, relative to the traditional method, often astoundingly less potential ET and less ET, more runoff from the land and net basin supply for the lake basins, and higher lake water levels i...