Great Lakes Levels Research Articles

Developing new sources of proxy climate data from historical structures in the Lake Michigan-Huron Basin

Abstract The need to understand lake level variability in the Great Lakes is underscored by record low stands in 2012 followed by a quick shift back to the historic averages by 2014 in the Michigan-Huron basins. These rapid changes have important implications for near-shore ecology, sedimentology, water management, tourism, and industrial commerce throughout the Great Lakes region. Attempts to reconstruct climatic controls of lake level variability from tree rings have either been based on spatially and temporally limited tree-ring data sets or tree-ring records from sites in the Pacific Northwest teleconnected to Great Lakes climate. The necessary local tree-ring chronologies to develop more robust reconstructions of climate and its relation to Great Lakes levels simply do not exist. A particularly evident gap in available data exists in Lower Michigan, where logging in the 1800s removed most old growth forests. Here we report the development of three new tree-ring chronologies derived from a pier near the mouth of the Kalamazoo River that was constructed ca. 1871. The new chronologies include multi-century Pinus resinosa (1673–1878), Quercus spp. (1628–1847), and Tsuga canadensis (1643–1864) tree-ring data that exhibit patterns of correlation among reference chronologies of the same species indicative of origins within the Great Lakes Region, and possibly Lower Michigan. Our results illustrate the excellent potential to develop a more complete network of sites with tree-ring data throughout the Michigan-Huron Basin by utilizing wood incorporated into historical structures.

Present and future Laurentian Great Lakes hydroclimatic conditions as simulated by regional climate models with an emphasis on Lake Michigan-Huron

Regional climate modelling represents an appealing approach to projecting Great Lakes water supplies under a changing climate. In this study, we investigate the response of the Great Lakes Basin to increasing greenhouse gas and aerosols emissions using an ensemble of sixteen climate change simulations generated by three different Regional Climate Models (RCMs): CRCM4, HadRM3 and WRFG. Annual and monthly means of simulated hydro-meteorological variables that affect Great Lakes levels are first compared to observation-based estimates. The climate change signal is then assessed by computing differences between simulated future (2041–2070) and present (1971–1999) climates. Finally, an analysis of the annual minima and maxima of the Net Basin Supply (NBS), derived from the simulated NBS components, is conducted using Generalized Extreme Value distribution. Results reveal notable model differences in simulated water budget components throughout the year, especially for the lake evaporation component. These differences are reflected in the resulting NBS. Although uncertainties in observation-based estimates are quite large, our analysis indicates that all three RCMs tend to underestimate NBS in late summer and fall, which is related to biases in simulated runoff, lake evaporation, and over-lake precipitation. The climate change signal derived from the total ensemble mean indicates no change in future mean annual NBS. However, our analysis suggests an amplification of the NBS annual cycle and an intensification of the annual NBS minima in future climate. This emphasizes the need for an adaptive management of water to minimize potential negative implications associated with more severe and frequent NBS minima.

Analysis of changes in the Great Lakes hydro-climatic variables

A study of changes in hydro-climatology of the Great Lakes was performed incorporating the nonparametric Mann–Kendall trend detection test and a recently developed Bayesian multiple change point detection model. The Component Net Basin Supply (C-NBS) and its components (runoff, precipitation, evaporation) as well as water levels of Great Lakes were analyzed for gradual (i.e. trend type) and abrupt (i.e. shift type) nonstationary behaviors at seasonal and annual scales. It was found that the C-NBS experienced significant upward trends only in the lower Great Lakes (Erie, Ontario) during the summer portion of the year. At an annual scale upward trends were observed only in Lake Ontario. Change point analysis suggested an upward shift in Great Lakes C-NBS in the late 1960s and early 1970s. A combination of gradual and abrupt change analysis of Great Lakes water levels indicated a common upward shift along with a change in trend direction around the early 1970s. It was also found that precipitation and runoff are on a plateau and in some cases on a decreasing course following an increasing trend in the early twentieth century. Results obtained from this study show that the hydro-climatology of Great Lakes is characterized by nonstationary behavior. Changes in this behavior have caused the Great Lakes water levels to decrease during the last few decades. This study provides valuable insights into the nature of the nonstationary behavior of hydro-climatic variables of Great Lakes and contributes useful information to the future water management planning.

Periodic structures of Great Lakes levels using wavelet analysis

Periodic structures of Great Lakes levels using wavelet analysisThe recently advanced approach of wavelet transforms is applied to the analysis of lake levels. The aim of this study is to investigate the variability of lake levels in four lakes in the Great Lakes region where the method of continuous wavelet transform and global spectra are used. The analysis of lake-level variations in the time-scale domain incorporates the method of continuous wavelet transform and the global spectrum. Four lake levels, Lake Erie, Lake Michigan, Lake Ontario, and Lake Superior in the Great Lakes region were selected for the analysis. Monthly lake level records at selected locations were analyzed by wavelet transform for the period 1919 to 2004. The periodic structures of the Great Lakes levels revealed a spectrum between the 1-year and 43- year scale level. It is found that major lake levels periodicities are generally the annual cycle. Lake Michigan levels show different periodicities from Lake Erie and Lake Superior and Lake Ontario levels. Lake Michigan showed generally long-term (more than 10 years) periodicities. It was shown that the Michigan Lake shows much stronger influences of inter-annual atmospheric variability than the other three lakes. The other result was that some interesting correlations between global spectrums of the lake levels from the same climatic region were found.

Holocene climatic change and the development of the lake-effect snowbelt in Michigan, USA

Lake-effect snow is an important constraint on ecological and socio-economic systems near the North American Great Lakes. Little is known about the Holocene history of lake-effect snowbelts, and it is difficult to decipher how lake-effect snowfall abundance affected ecosystem development. We conducted oxygen-isotope analysis of calcite in lake-sediment cores from northern Lower Michigan to infer Holocene climatic variation and assess snowbelt development. The two lakes experience the same synoptic-scale climatic systems, but only one of them (Huffman Lake) receives a significant amount of lake-effect snow. A 177-cm difference in annual snowfall causes groundwater inflow at Huffman Lake to be 18O-depleted by 2.3‰ relative to O'Brien Lake. To assess when the lake-effect snowbelt became established, we compared calcite-δ18O profiles of the last 11,500 years from these two sites. The chronologies are based on accelerator-mass-spectrometry 14C ages of 11 and 17 terrestrial-plant samples from Huffman and O'Brien lakes, respectively. The values of δ18O are low at both sites from 11,500 to 9500 cal yr BP when the Laurentide Ice Sheet (LIS) exerted a dominant control over the regional climate and provided periodic pulses of meltwater to the Great Lakes basin. Carbonate δ18O increases by 2.6‰ at O'Brien Lake and by 1.4‰ at Huffman Lake between 9500 and 7000 cal yr BP, suggesting a regional decline in the proportion of runoff derived from winter precipitation. The Great Lakes snowbelt probably developed between 9500 and 5500 cal yr BP as inferred from the progressive 18O-depletion at Huffman Lake relative to O'Brien Lake, with the largest increase of lake-effect snow around 7000 cal yr BP. Lake-effect snow became possible at this time because of increasing contact between the Great Lakes and frigid arctic air. These changes resulted from enhanced westerly flow over the Great Lakes as the LIS collapsed, and from rapidly rising Great Lakes levels during the Nipissing Transgression. The δ18O difference between Huffman and O'Brien lakes declines after 5500 cal yr BP, probably because of a northward shift of the polar vortex that brought increasing winter precipitation to the entire region. However, δ18O remains depleted at Huffman Lake relative to O'Brien Lake because of the continued production of lake-effect snow.

Climate Change Impacts on the Hydrology of the Great Lakes-St. Lawrence System

A review of the current state of knowledge on climate change due to an ’enhanced greenhouse effect’ and the response of the climate and hydrologic systems to a changing atmosphere is provided. In particular, the survey presents historic trends in and the impacts of climate change on temperature, precipitation, evapotranspiration, runoff and Great Lakes levels. While much of the impacts research in the Great Lakes-St. Lawrence basin has used equilibrium 2 × CO2 scenarios, the transient scenarios for 2030 and 2050 from the Canadian Centre for Climate Modelling and Analysis and the United Kingdom Hadley Centre coupled atmosphere-ocean global circulation models are also described. If the significant declines in runoff and lakes levels suggested by climate change scenarios are realized, there could be serious supply-demand mismatches and water allocation issues. The issue of climate change reinforces the need for continued cooperative planning and management of the water resources of the Great Lakes-St. Lawrence basin.

Coping with the Effects of High Water Levels on Property Hazards: North Shore of Lake Superior

Property hazards associated with the 1985–86 high-water levels on the north shore of Lake Superior between Duluth, Minnesota, and Thunder Bay, Ontario, are examined. Data on composition of bluff/shore materials, recession rates, property setbacks, and existing shore protection structures were obtained from questionnaire surveys. Estimated long-term bluff/shoreline recession rates vary from less than 3 m to more than 15 m over a minimum period of 5 years, with a substantial amount of erosion occurring during the 1985–86 high water period. Approximately 39 percent of the respondents protected their properties with structural devices, but many were ineffective. Many respondents perceived lower water levels as a higher priority than providing shore protection structures. However, human ability to manipulate the levels of Great Lakes is limited, since lake levels are dependent primarily on climatic cycles. Because of the limitations on controlling water levels, master plans for land use regulations should be developed to prevent or minimize future encroachment of properties upon flood- and erosion-prone reaches of the shoreline.

Climatic change and great lakes levels the impact on shipping

This paper represents an attempt to combine the output of several models that deal with future climatic, hydrologic and economic conditions in the Great Lakes and makes some predictions about the possible impact of one scenario of 2 × CO2 climate on Great Lakes shipping. It is realized that there is a great deal of uncertainty in all the models and that improvements are continually being made. Data from a General Circulation Model of future temperature and precipitation in the Great Lakes basin, a Great Lakes levels and flows model from the Canada Centre for Inland Waters and an International Joint Commision's Great Lakes economic model modified by the University of Wisconsin were used. The 1900–1976 period of lake levels and flows was used. The hydrologic model indicated that future mean lake levels may be reduced by one-half meter, and that the extreme low levels of the mid 1960's could occur 77% of the time in the future. No ice cover is predicted for any lake except Erie, permitting an eleven month shipping season. Five scenarios of future impact on shipping were evaluated. It was found that mean annual shipping costs may increase by 30% and the frequency of years when costs exceed those of the period of low lake levels (1963–65) could rise to 97%. Possible policy options in a future with climatically induced lower lake levels could include regulation to keep levels artificially high by diversions into the system, or increased dredging of the connecting channels.

Great Lakes Levels and Flows: Past and Future

The many analyses of the more than 100 years’ record of Great Lakes levels and of precipitation in the basin are generally assumed to provide a reasonable basis for predicting, statistically, future lake levels. The usefulness of this assumption is questioned because of increasing consumptive use of Great Lakes waters, and probable climatic change over the next century. The International Joint Commission's 1981 report on consumptive use and diversions gives as its most likely scenario an annual growth of 2.7% in consumptive uses. By the year 2035, this would reduce Great Lakes outflows by about 708 m 3 (25,000 cfs), with an estimated loss of “$200 million per year in hydro power production.” The climatic effects of the inexorable increases in atmospheric carbon dioxide (CO 2) due mainly to burning of fossil fuels are still difficult to predict. However, the best predictions available suggest that in the next 70 years or so, the mean air temperature in the Great Lakes basin will rise by approximately 3C° and may well be accompanied by slightly less precipitation. Increases in evaporation from the Great Lakes would be equivalent to 7–8% of the mean annual flow of the St. Lawrence. These two factors — increased evaporation and increased consumptive uses — suggest that significantly lower lake levels and flows of interconnecting channels and the St. Lawrence River are likely in the next century.

Reproductive Parameters and Egg Contaminant Levels of Great Lakes Herring Gulls

Poor reproductive success and declines in colony size of herring gulls (Larus argentatus) have occurred in Lake Ontario at a time that dramatic increases of this species have been reported on the Atlantic seaboard. In 1975 herring gull productivity on Scotch Bonnet Island, Lake Ontario, was 0.15 chicks per pair of adults, one-tenth the productivity of colonies studied on Lakes Erie, Huron and Superior. Reduced nest site defense and decreases in eggs found, egg hatchability and chick survival were observed in the Lake Ontario colony. The major causes of egg failure were disappearance and embryonic death. Hatching success of Lake Ontario eggs by artificial incubation was 23-26 percent compared to 5379 percent for eggs from other areas. Analyses of eggs from 9 gull colonies for organochlorine contaminants indicated that the pattern of relative contamination was: Lakes Ontario > Michigan > Superior > Huron > Erie. Mirex levels were nearly 10 times higher in Lake Ontario than in the other lakes. Movements of herring gulls within the Great Lakes basin are offered as an explanation of variation in individual egg residues in each colony and the moderately high levels of chemical residues in some Lake Superior eggs. J. WILDL. MANAGE. 41(3):458-468 Recent declines have been noted in several herring gull colonies in Lake Ontario (Quilliam 1973, Canadian Wildlife Service unpublished data) and Lake Michigan (Ludwig and Ludwig 1969, J. J. Hickey personal communication). In contrast, herring gull populations have increased since the early 1900's along the eastern seaboard of both the United States (Kadlec and Drury 1968) and Canada (Haycock and Threlfall 1975). Reproductive success (the number of chicks fledged per pair of breeding adults) in 6 Lake Ontario herring gull colonies between 1972 and 1974 was reported as 0.1 to 0.44 (Gilbertson 1974, Teeple 1977, R. D. Morris personal communication). This is in contrast to the range in herring gull productivity (0.5-1.5) reported from other areas (reviewed by Kadlec and Drury 1968). The poor reproductive success of Lake Ontario herring gulls is the result of excessive embryonic mortality and egg disappearance, and poor survival of hatched chicks. Attention has been focused on organochlorine contaminants as causative a ents (Keith 1966, Ludwig and Tomoff 1966, Gilbertson 1974, Teeple 1977). The herring gull consumes a large variety of foods including fish and other aquatic organisms, insects, garbage, small rodents, and the young of other birds. Its capacity for accumulating organochlorine compounds has been well documented (Hickey et al. 1966, Anderson and Hickey 1976). Reproductive success and eggshell quality of herring gulls nesting in Lakes Superior, Huron, Erie and Ontario are reported in this paper. Seasonal movements and levels of several environmental contaminants in eggs are presented for herring gulls nesting in all 5 Great Lakes. In addition, the 458 J. Wildl. Manage. 41(3):1977 This content downloaded from 207.46.13.106 on Wed, 15 Mar 2017 18:01:31 UTC All use subject to http://about.jstor.org/terms REPRODUCTION AND CONTAMINANTS OF HERRING GULLS Gilman et al. 459

Regulation of Great Lakes Water Levels: the Public Speaks Out

The Great Lakes water levels fluctuate around a long-term average; these fluctuations are largely beyond man's control. Most lake users have adjusted to a narrow range of levels but when extremes of stage occur, lake users are affected in different and opposite ways. In 1964, the problem of fluctuating levels was referred to the International Joint Commission (I.J.C). As an integral part of the reference procedure, the I.J.C. holds public hearings. Three sets of hearings were held on the Great Lakes Levels Reference (1964, 1973, 1974). The first part of this paper discusses the I.J.C. Reference and reviews the I.J.C.’s public participation process. The second part of the paper reviews various methods for analysing and summarizing public input; content analysis not only makes possible numerical summaries but also yields quantitative data for further analysis. The major section of the paper focuses on the 1974 transcripts (13 volumes) which were subjected to content/contingency analysis in order to provide objective summaries of public input and to reveal statistically significant associations between pairs of variables with particular reference to the affiliation of the participants. The study suggests that participants who are consulted during the study (federal/state/provincial government participants) make submissions that differ from those of other participants (municipal governments, interest groups and individuals).

RESIDENTS’ UTILIZATION OF COASTAL HAZARD ASSISTANCE PROGRAMS THE LONG POINT AREA, LAKE ERIE

This paper evaluates how adequately residents have utilized and benefitted from Ontario coastal-hazard assistance programs during the 1972 to 1976 Great Lakes high-water period. Four programs are described and their effectiveness in helping shore-dwellers in the Long Point Bay area of Lake Erie is examined. Data are obtained from a field survey measuring residents’ attitudes toward coastal hazard responsibility and government financial aid, as well as their knowledge about, and utilization of, assistance programs. The study reveals that a majority of residents are: poorly informed about coastal ecological processes, misinformed about lake level fluctuations, and uninformed about assistance programs. As a result, they disregard adverse effects of structural adjustments, blame government for regulating Great Lakes levels, and fail to utilize hazard assistance programs. The programs, while benefitting some residents, encourage expensive structural devices, piecemeal shoreline protection, and stop-gap repair works. Suggestions to help overcome these deficiencies and general approaches to ensure wider and more effective utilization of assistance programs are recommended.

VARIATION IN GREAT LAKES LEVELS IN RELATION TO ENGINEERING PROBLEMS

Throughout the recorded history of the Great Lakes, the fluctuation in their water levels has created engineering problems generally unique in relation to coastal engineering. In periods of low water, demands are heard from navigation and power interests to raise the levels. In periods of high water appeals are made by shore property owners to lower the levels. Such conflicting interests present major engineering problems, the nature of which during a given period of time reflect the long-range upward and downward trend in lake levels due to natural phenomena.