AGW Observer

Observations of anthropogenic global warming

Papers on lake effect and climate

Posted by Ari Jokimäki on December 10, 2010

This is a list of papers on the lake effect and how climate affects it. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.

A New Look at Lake-Effect Snowfall Trends in the Laurentian Great Lakes Using a Temporally Homogeneous Data Set – Kunkel et al. (2009) “Snowfall data are subject to quality issues that affect their usefulness for detection of climate trends. A new analysis of lake-effect snowfall trends utilizes a restricted set of stations identified as suitable for trends analysis based on a careful quality assessment of long-term observation stations in the lake-effect snowbelts of the Laurentian Great Lakes. An upward trend in snowfall was found in two (Superior and Michigan) of the four snowbelt areas. The trends for Lakes Erie and Ontario depended on the period of analysis. Although these results are qualitatively similar to outcomes of other recent studies, the magnitude of the upward trend is about half as large as trends in previous findings. The upward trend in snowfall was accompanied by an upward trend in liquid water equivalent for Superior and Michigan, while no trend was observed for Erie and Ontario. Air temperature has also trended upward for Superior and Michigan, suggesting that warmer surface waters and less ice cover are contributing to the upward snowfall trends by enhancing lake heat and moisture fluxes during cold air outbreaks. However, a more comprehensive study is needed to definitely determine cause and effect. Overall, this study finds that trends in lake-effect snowfall are not as large as was believed based on prior research.” Kenneth E. Kunkel, Leslie Ensor, Michael Palecki, David Easterling, David Robinson, Kenneth G. Hubbard, Kelly Redmond, Journal of Great Lakes Research 35(1):23-29. 2009, doi: 10.1016/j.jglr.2008.11.003. [Full text]

Climatology of Lake-Effect Precipitation Events over Lake Champlain – Laird et al. (2009) “This study provides the first long-term climatological analysis of lake-effect precipitation events that developed in relation to a small lake (having a surface area of ≤1500 km2). The frequency and environmental conditions favorable for Lake Champlain lake-effect precipitation were examined for the nine winters (October–March) from 1997/98 through 2005/06. Weather Surveillance Radar-1988 Doppler (WSR-88D) data from Burlington, Vermont, were used to identify 67 lake-effect events. Events occurred as 1) well-defined, isolated lake-effect bands over and downwind of the lake, independent of larger-scale precipitating systems (LC events), 2) quasi-stationary lake-effect bands over the lake embedded within extensive regional precipitation from a synoptic weather system (SYNOP events), or 3) a transition from SYNOP and LC lake-effect precipitation. The LC events were found to occur under either a northerly or a southerly wind regime. An examination of the characteristics of these lake-effect events provides several unique findings that are useful for comparison with known lake-effect environments for larger lakes. January was the most active month with an average of nearly four lake-effect events per winter, and approximately one of every four LC events occurred with southerly winds. Event initiation and dissipation occurred on a diurnal time scale with an average duration of 12.1 h. In general, Lake Champlain lake-effect events 1) typically yielded snowfall, with surface air temperatures rarely above 0°C, 2) frequently had an overlake mesolow present with a sea level pressure departure of 3–5 hPa, 3) occurred in a very stable environment with a surface inversion frequently present outside the Lake Champlain Valley, and 4) averaged a surface lake–air temperature difference of 14.4°C and a lake–850-hPa temperature difference of 18.2°C. Lake Champlain lake-effect events occur within a limited range of wind and temperature conditions, thus providing events that are more sensitive to small changes in environmental conditions than are large-lake lake-effect events and offering a more responsive system for subsequent investigation of connections between mesoscale processes and climate variability.” Laird, Neil F., Jared Desrochers, Melissa Payer, 2009, J. Appl. Meteor. Climatol., 48, 232–250, doi: 10.1175/2008JAMC1923.1. [Full text]

Climate teleconnections related to El Niño winters in a lake-effect region of west-central New York – Grimaldi (2008) “A 64-year climatological record for the cold season in Syracuse, New York is analyzed for temperature and snowfall. Evidence suggests that El Niño winters are characterized by warmer temperatures and below normal snowfall during the first month of winter followed by colder temperatures and above normal snowfall for the second month of winter. Major snow events were more than five times more likely to occur for El Niño winters compared to climatology. It is suggested that the greater frequency of heavy snowfalls is related to both favorable dynamics and warmer lake/ocean temperatures which follow the mild early winter period.” Richard Grimaldi, Atmospheric Science Letters, Volume 9, Issue 1, pages 18–25, January/March 2008, DOI: 10.1002/asl.166. [Full text]

Hydroclimatic Analysis of Snowfall Trends Associated with the North American Great Lakes – Ellis & Johnson (2004) “Research over the past several decades has indicated that snowfall has increased dramatically over portions of the past century across those areas of the Great Lakes region of North America that are subject to lake-effect snowfall. Within this study, time series of annual midwinter snowfall within lake-effect areas show evidence of a clear increase in both snowfall and snowfall frequency through a 40-yr period beginning in the early 1930s and ending in the early 1970s. The goal of the work presented here is to determine to what extent the apparent increases in lake-effect snowfall actually modified the winter hydroclimate of the areas. Simple hydroclimatic analysis of midwinter precipitation to the lee of Lakes Erie and Ontario for the period of significant snowfall increases suggests that the changes were a product of 1) a shift toward more precipitation events that were snowfall rather than rainfall, 2) an associated decrease in midwinter rainfall, 3) an increase in the intensity of individual snowfall events, and 4) an increase in the snowfall/snow water equivalence ratio. The balance was a small increase in total precipitation confined to areas in close proximity to the lakes across northeastern Ohio and western New York, while areas outside the regions generally experienced an overall decrease in midwinter precipitation. While the cause(s) of the snowfall trends remains elusive, the results of the work presented here suggest that no great long-term regional change occurred in the true wintertime seasonal hydroclimate of the lake-effect areas. Rather, much of the touted snowfall increase simply came at the expense of rainfall events to produce only small changes in total precipitation over the time period of significant snowfall increase.” Ellis, Andrew W., Jennifer J. Johnson, 2004, J. Hydrometeor, 5, 471–486. [Full text]

Increasing Great Lake–Effect Snowfall during the Twentieth Century: A Regional Response to Global Warming? – Burnett et al. (2003) “The influence of the Laurentian Great Lakes on the climate of surrounding regions is significant, especially in leeward settings where lake-effect snowfall occurs. Heavy lake-effect snow represents a potential natural hazard and plays important roles in winter recreational activities, agriculture, and regional hydrology. Changes in lake-effect snowfall may represent a regional-scale manifestation of hemispheric-scale climate change, such as that associated with global warming. This study examines records of snowfall from several lake-effect and non-lake-effect sites throughout most of the twentieth century in order to 1) determine whether differences in snowfall trends exist between these settings and 2) offer possible linkages between lake-effect snow trends and records of air temperature, water temperature, and ice cover. A new, historic record of oxygen isotope [δ18O(CaCO3)] data from the sediments of three eastern Finger Lakes in central New York is presented as a means of independently assessing changes in Great Lakes lake-effect snowfall. Results reveal a statistically significant increasing trend in snowfall for the lake-effect sites, whereas no trend is observed in the non-lake-effect settings. The Finger Lake oxygen isotope record reflects this increase in lake-effect snow through a statistically significant trend toward lower δ18O(CaCO3) values. Records of air temperature, water temperature, and lake ice suggest that the observed lake-effect snow increase during the twentieth century may be the result of warmer Great Lakes surface waters and decreased ice cover, both of which are consistent with the historic upward trend in Northern Hemispheric temperature due to global warming. Given projected increases in future global temperature, areas downwind of the Great Lakes may experience increased lake-effect snowfall for the foreseeable future.” Burnett, Adam W., Matthew E. Kirby, Henry T. Mullins, William P. Patterson, 2003, J. Climate, 16, 3535–3542. [Full text]

Assessment of Potential Effects of Climate Change on Heavy Lake-Effect Snowstorms Near Lake Erie – Kunkel et al. (2002) “The potential effects of future climate change on the frequency of heavy lake-effect snowstorms in the Lake Erie snowbelt were assessed using recent transient simulations from two General Circulation Models (GCMs): the second-generation Hadley Centre (HadCM2) and the first generation Canadian Climate Centre (CGCM1) coupled ocean-atmosphere models. An analysis of historical heavy lake-effect snowstorms identified six weather conditions to be closely related to heavy lake-effect snowstorm occurrence: surface wind speed > 6 m/s, surface wind direction of south southwest to west northwest, surface air temperature in the range of −10°C to 0°C, lake surface to air temperature difference > 7°C, lower tropospheric stability (Tlake − 850 >15°C), and a highly amplified middle tropospheric wave train. These criteria were applied to daily grid point data from the GCMs for two periods, the late 20th Century and the late 21st Century, to determine the relative frequency with which heavy lake-effect conditions were predicted. Surface conditions favorable for heavy lake-effect snow decreased in frequency by 50% and 90% for the HadCM2 and CGCM1, respectively, by the late 21st Century. This reduction was due almost entirely to a decrease in the number of occurrences of surface air temperature in the range of −10 to 0°C, which in turn was the result of an increase in average winter air temperatures. Other surface conditions favorable for lake-effect snow occurred at about the same frequency in the late 21st Century as in the late 20th Century, suggesting that lake-effect rain events may replace lake-effect snow events. Changes in the middle tropospheric wave train were also noted in both models. However, there were sizable biases in the simulation of the present-day climate, raising questions about the validity of the future projections.” Kenneth E. Kunkel, Nancy E. Westcott and David A.R. Kristovich, Journal of Great Lakes Research, Volume 28, Issue 4, 2002, Pages 521-536, doi:10.1016/S0380-1330(02)70603-5.

Synoptic mechanisms associated with snowfall increases to the lee of Lakes Erie and Ontario – Leathers & Ellis (1996) “Snowfall is a cyrospheric variable that impacts nearly every sector of society. Because of its societal importance, snowfall is a logical variable to be used as an indicator of potential global environmental change. This study investigates the mechanisms responsible for large observed snowfall increases across the eastern Great Lakes region of the USA. Results indicate that mean snowfall amounts across sections of western New York and north-western Pennsylvania have increased by up to 100 cm over the 60-year period encompassing the snowfall seasons 1930–1931 through to 1989–1990. A synoptic climatological approach is utilized to identify consistent synoptic-scale atmospheric patterns responsible for snowfall across the region. Nine synoptic types are identified as producing significan t snowfall in the study area; five with synoptic characteristics indicative of lake-effect snowfall and four evidencing characteristics of snowfall associated with cyclonic influence. An examination of the seasonal frequency of the nine synoptic types indicates a substantial increase in the frequency of the five lake-effect synoptic types and a long-term decrease in the numbers of cyclone synoptic types over the period 1950–1951 through to 1981–1982. Information concerning trends in the frequency and the intensity of each of the nine snowfall-producing synoptic types was combined to produce a modelled snowfall change due to frequency and intensity variations over the period. Trends in the frequency and intensity of the synoptic patterns associated with lake- effect snowfall explain the majority of the observed snowfall increase across the region. Variations in the synoptic types associated with cyclonically induced snowfall are shown to be unimportant to snowfall changes across the eastern Great Lakes area. Possible reasons for increases in the frequency and the intensity of the lake-effect synoptic types are discussed.” Daniel J. Leathers, Andrew W. Ellis, International Journal of Climatology, Volume 16, Issue 10, pages 1117–1135, October 1996, DOI: 10.1002/(SICI)1097-0088(199610)16:103.0.CO;2-4.

Temporal characteristics of USA snowfall 1945–1946 through to 1984–1985 – Leathers et al. (1993) “The temporal variability of USA snowfall is investigated for the period 1945–1946 through to 1984–1985 using linear trend and principal components analyses. The results of the linear trend analysis indicate that two regions of the USA evidence significant changes in monthly snowfall over the period. These areas include the Great Lakes/upper mid-west and high plains regions of the USA. In the Great Lakes/upper mid-west sector, positive linear trends are found in monthly snowfall totals for the mid-winter months (December, January, February). For the high plains region, positive linear trends are found for the month of December. Principal components analysis (PCA) is used with seasonal snowfall data in order to better understand the spatial and temporal nature of seasonal snowfall variations across the USA. The PCA isolates six spatially coherent regions in which seasonal snowfall varied similarly over the 40-year period. Only one of these regions, centred on the Great Lakes and upper mid-west, displays any long-term change in seasonal snowfall, a positive trend during the period 1945–1946 through to 1984–1985. These results are discussed in the context of man-induced and natural environmental changes.” Daniel J. Leathers, Thomas L. Mote, Karl C. Kuivinen, Stuart McFeeters, Douglas R. Kluck, International Journal of Climatology, Volume 13, Issue 1, pages 65–76, January/February 1993, DOI: 10.1002/joc.3370130105.

Spatiotemporal Trends in Lake Effect and Continental Snowfall in the Laurentian Great Lakes, 1951–1980 – Norton & Bolsenga (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 lime 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.” Norton, D. C., S. J. Bolsenga, 1993, J. Climate, 6, 1943–1956. [Full text]

Numerical Study of the Influence of Environmental Conditions on Lake-Effect Snowstorms over Lake Michigan – Hjelmfelt (1990) “Numerical simulations are used to examine the influence of environmental parameters on the morphology of lake effect snowstorms over Lake Michigan. A series of model sensitivity studies are performed using the Colorado State University mesoscale model to examine the effects of lake–land temperature difference, surface roughness, atmospheric boundary layer stability, humidity, and wind speed and direction on the morphology of simulated storms. Four morphological types of lake effect snowstorms have been identified: (i) Broad area coverage, which may become organized into wind parallel bands or cellular convection; (ii) shoreline bands with a line of convection roughly parallel to the lee shore and a well developed land breeze on the lee shore; (iii) midlake band with low-level convergence centered over the lake; and (iv) mesoscale vortices with a well-developed cyclonic flow pattern in the boundary layer. The model is able to reproduce all four morphological types. Simulations varying environmental parameters independently define the thermodynamic and wind conditions for the occurrence of each morphological type. In particular, the limiting conditions of lake–land temperature difference, upwind wind speed stability, and humidity for development of a land breeze on the east side of Lake Michigan are defined for lake snow conditions. The effects of wind direction, surface roughness, and latent heat release are also described.” Hjelmfelt, Mark R., 1990, Mon. Wea. Rev., 118, 138–150. [Full text]

Quantitative Estimates of the Effect of Lake Michigan on Snowfall – Braham & Dungey (1984) “A climatological study of snowfall in the snowbelts of Michigan shows that decade-average amounts varied by a factor of 2 during the period from 1909/10 through 1980/81. The effect of Lake Michigan on total winter snowfall along its shores has been estimated. A long-term average effect of +10% is found for the Wisconsin shore south of Sheboygan, and an average of +60% for the Michigan shore, south of Hart, with a minimum effect in the 1930s and a maximum in the 1960s.” Braham, Roscoe R., Maureen J. Dungey, 1984, J. Climate Appl. Meteor., 23, 940–949. [Full text]

Lake Effect Snowfall to the Lee of the Great Lakes: Its Role in Michigan – Eichenlaub (1970) “Lake effect snowfalls contribute a significant proportion of the total winter snowfall in areas to the lee of the Great Lakes. In Michigan during the seasons 1957–58 through 1961–62 at least 30% of the seasonal snowfall in lee areas was derived from lake-atmosphere interactions. Evidence suggests that lake effect snowfall has significantly increased during the past several decades, particularly in southwestern Michigan and northern Indiana. While the observed changes cannot be definitely ascribed to any single factor, it seems likely that a general cooling of winter temperatures may be partially responsible for this climatic change.” Eichenlaub, Val L., 1970, Bull. Amer. Meteor. Soc., 51, 403–412. [Full text]

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