David Changnon

Research, Grants and Presentations

Recent Refereed Journal Articles

Sandstrom, M., D. Changnon, and B. Flood, 2007: Improving our understanding of H.zea migration in the Midwest : Assessment of Source Populations. Manuscript for Symposium Proceeedings on Helicoverpa zea Susceptibility to Pyrethroids in theMidwest . Online. Plant Health Progress doi:10.1094/PHP-2007-0MDD-01-RV, 9pp.

Changnon, D., and S.A. Changnon, 2006: Unexpected impacts of drought 2005 on Illinois crop yields: Are weather-crop relationships changing? Transactions of the Illinois State Academy of Science , 99, 37-50. Abstract

Changnon , S.A. , D. Changnon, and T.R. Karl, 2006: Temporal and spatial characteristics of snowstorms in the contiguous United States . Journal of Applied Meteorology and Climatology , 45, 1141-1155. Abstract

Changnon , S.A. , and D. Changnon, 2006: A spatial and temporal analysis of damaging snowstorms in the United States . Natural Hazards, 37 , 373-389.

Changnon, D., M. Sandstrom, and M. Bentley, 2006: Midwestern high dew point events 1960-2000. Physical Geography , 27 , 494-504.

Changnon , S.A. and D. Changnon, 2005: Snowstorm catastrophes in the United States. Environmental Hazards, 6, 158-166.

Friedlein, M.T., D. Changnon, E. Musselman, and J. Zielinski, 2005: Using dew points to estimate savings during a planned cooling shutdown. Meteorological Applications , 12 , 319-328.

Changnon, D. and S.A. Changnon, 2005: The pre-Christmas 2004 snowstorm disaster in the Ohio River valley. Weatherwise , 58 , 36-40.

Changnon , S.A. and D. Changnon, 2005: Lessons from the unusual impacts of an abnormal winter. Meteorological Applications , 12 , 187-191.

Changnon , S.A. and D. Changnon, 2005: Importance of sky conditions on the record 2004 Midwestern crop yields. Physical Geography , 26 , 99-111.

Changnon, D., and R. Bigley, 2005: Fluctuations in US freezing rain days. Climatic Change , 69, 229-244. Abstract

Changnon, D., 2004: Improving outreach in atmospheric sciences: Assessment of users of climate products. Bulletin of the American Meteorological Society, 85, 601-606. Abstract

Changnon, S.A., and D. Changnon, 2004: Unusual rainstorms in Illinois produced unusual impacts. Transactions of the Illinois Academy of Science, 97, 45-54. Abstract

Sandstrom, M.A., R.G. Lauritsen, and D. Changnon, 2004: A central U.S. summer extreme dew-point climatology (1949-2000). Physical Geography, 25, 191-207. Abstract

Sparks, J., D. Changnon, and J. Starke, 2002: Changes in the frequency of extreme warm-season surface dew points in northeastern Illinois. Implications for cooling-system design and operation. Journal of Applied Meteorology, 41, 890-898. Abstract

Changnon, D., J. Thompson, T. April, E. Schmidt, M. Falout, J.B. Davis, and M. Russo, 2002: Efforts to improve predictions of urban winter heating anomalies using various climate indices. Meteorological Applications, 9, 105-111. Abstract

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Recent Research Grants:
Analytical Center for Climate and Environmental Change (ACCEC), Department of Geology, NIU. “Bringing Climate Information to Users in Illinois and the Midwest .” Part of a 3-year project funded October 1, 2005-Sept. 30, 2008.

National Science Foundation, Geography and Regional Science, “Changes in the frequency of extreme warm season surface dewpoints in the Midwestern U.S.: Implications for weather-related hazards.” Accepted for funding in January 2004, for period from 2/16/04-2/15/07. Co-P.I. with Mace Bentley and Tony Stallins.

National Oceanic and Atmospheric Administration, Office of Global Programs, and the Midwest Regional Climate Center funded a grant from September 1999-August 2002. "Applications of Climate Information to Solve Weather-Related Problems in a Changing Climate."
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Changnon, D., and S.A. Changnon, 2006: Unexpected impacts of drought 2005 on Illinois crop yields: Are weather-crop relationships changing? Transactions of the Illinois State Academy of Science , 99, 37-50.

Abstract: Rainfall across Illinois was much below normal from March through July 2005, initiating a severe growing season drought. Temperatures from June through September were above normal adding to the potential stress on corn and soybean crops. During the summer, crop experts predicted major yield reductions, and crop quality surveys showed ever growing problems from June through August. However, the 2005 harvest produced statewide corn and soybean yields that were above average, and the soybean yield of 47 bushels per acre was the state's second highest on record. This outcome, in contrast to the dire in-season predictions and crop surveys, raises important questions about the level of understanding about the relationship of weather and crop yields. Genetic improvements and better farming practices likely have altered how weather impacts crop yields.
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Changnon , S.A. , D. Changnon, and T.R. Karl, 2006: Temporal and spatial characteristics of snowstorms in the contiguous United States . Journal of Applied Meteorology and Climatology , 45, 1141-1155.

Abstract: A climatological analysis of snowstorms across the contiguous United States , based on data from 1222 weather stations with data during 1901-2001, defined the spatial and temporal features. The average annual incidence of events creating 15.2 cm or more in 1 or 2 days, which are termed as snowstorms, exhibits great spatial variability. The pattern is latitudinal across most of the eastern half of the United States , averaging 0.1 storm (1 storm per 10 years) in the Deep South , increasing to 2 storms along the Canadian border. This pattern is interrupted by higher averages downwind of the Great Lakes and in the Appalachian Mountains . In the western third of the United States where snow falls, lower-elevation sites average 0.1-2 storms per year, but averages are much higher in the Cascade Range and Rocky Mountains , where 5-30 storms occur per year. Most areas of the United States have had years without snowstorms, but the annual minima are 1 or more storms in high-elevation areas of the West and Northeast. The pattern of annual maxima of storms is similar to the average pattern. The temporal distribution of snowstorms exhibited wide fluctuations during 1901-2000, with downward 100-yr trends in the lower Midwest , South, and West Coast. Upward trends occurred in the upper Midwest , East, and Northeast, and the national trend for the 1901-2000 was upward, corresponding to trends in strong cyclonic activity. The peak periods of storm activity in the United States occurred during 1911-20 and 1971-80, and the lowest frequency was in 1931-40. Snowstorms first occur in September in the Rockies, in October in the high plains, in November across most of the United States , and in December in the Deep South . The month with the season's last storms is December in the South and then shifts northward, with April the last month of snowstorms across most of the United States . Storms occur as late as May and June in the Rockies and Cascades. Snowstorms are most frequent in December downwind of the Great Lakes, with a peak of activity in January for most other areas of the United States .
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Changnon, D., and R. Bigley, 2005: Fluctuations in US freezing rain days. Climatic Change , 69, 229-244.

Abstract: Freezing rain occurrences during a 50-year period, 1949/50-1998/99, derived from carefully examined records of 161 first-order stations distributed across the United States , were assessed for temporal fluctuations and trends. Classification of station fluctuations based on five 10-year periods revealed five unique distribution types in areas east of the Rockies . One of these five distributions, for stations located in the western Great Plains , experienced its greatest 10-year value at the end of the 50-year period. The other four regional distributions experienced their highest 10-year value in either of the first two 10-year periods. Nationally, the 10-year period when the greatest number of stations experienced their maximum value was 1949/50-1958/59, while the period when the greatest number of stations experienced their minimum value fell near the end of the 50-year record 1979/80-1988/89). The 50-yar linear trends defined one region, the western Great Plains, with increasing values, while three areas of decreasing trend were identified; the Great Lakes, the eastern Ohio River valley, and southern New England. These analyses also indicate the need to examine and consider such time-space changes in the frequency of climate variables at various spatial scales when assessing weather risks and developing climate change scenarios.
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Changnon, D., 2004: Improving outreach in atmospheric sciences: Assessment of users of climate products. Bulletin of the American Meteorological Society, 85, 601-606.

Abstract: Over the past six years, 27 projects were conducted involving weather-climate product development by students working with weather-sensitive decision makers in various institutions. Thirteen of these decision makers were interviewed during 2003 to assess the post-product impacts. This assessment revealed that successful integration of climate-related products and information into the decision process depended on four factors: 1) the user’s basic knowledge of atmospheric sciences, 2) their ability to manage risks associated with use of uncertain climate information, 3) their access to climate information and expertise in a timely fashion, and 4) demonstrations of value from use of the project information. These interactive projects, which included a university faculty climatologist, undergraduate meteorology students, and the decision makers, had increased decision makers’ awareness of and interest in climatological information (data, derived products, seasonal outlooks, etc). The projects also identified where climate information and expertise could be obtained, and established a continuing dialogue between the climatologist and users. These projects further demonstrated that most decision makers, even those in the same weather-sensitive sector, often face very different issues that require specialized, value-added information that goes well beyond the generalized information produced by government agencies. Because of this on-going shift in user needs, the atmospheric science community may have to broaden the educational experiences for future students.
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Changnon, S.A., and D. Changnon, 2004: Unusual rainstorms in Illinois produced unusual impacts. Transactions of the Illinois Academy of Science, 97, 45-54.

Abstract: Two intense, short-duration rainstorms occurred in Illinois and adjacent states during mid-August 2002, and many storm characteristics (duration, orientation, rain intensity, and weather conditions) were similar to those of 36 past Illinois-centered rainstorms assessed in detail over the past 50 years. However, the 2002 storms had two features unlike those found in any prior rainstorms assessed. The two storm events occurred just 2.5 days apart and in adjacent areas, and no past storms had occurred in such close time proximity. Slow movement of the stationary front, the focus of the two storms, caused these two storms to occur within a 72-hour period. The other difference concerned the pre-storm summer moisture conditions. Both August storms occurred where antecedent summer rainfall was much below normal and temperatures above normal for 2.5 months, creating much below normal soil moisture conditions. All 36 prior storms studied occurred where pre-storm rainfall was at or above average, and this difference in moisture greatly affected the impacts produced by the August 2002 storms. Neither storm produced the magnitude of flood damages that comparable prior storms had done. The heavy August 2002 rainstorms recharged the soil moisture leading to major increases in soybean yields, representing a gain of $51 million—the first time flash-flood type storms in Illinois have resulted in financial benefits.
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Sandstrom, M.A., R.G. Lauritsen, and D. Changnon, 2004: A central U.S. summer extreme dew-point climatology (1949-2000). Physical Geography, 25, 191-207.

Abstract: Daily average dew points (DADPs) were examined at 68 central United States weather stations from 1949-2000 to identify temporal trends in the occurrence of summer (June-August) extreme surface dew point days (DADP = 22°C). Data homogeneity testing revealed that changes in equipment, station location, and instrument height, in addition to calculated DADPs based on available hourly data caused very few statistically significant changes in the data. Temporal patterns based on four 13-year periods indicated that much of the Midwest experienced a consistent increase in extreme DADPs through time while those along the Gulf Coast remained generally unchanged. Using accumulated DADP departure from the median graphs, the 52-year record was separated into two periods. A comparison of the mean frequency from an earlier (1949-1976) to later (1977-2000) period indicated that the greatest percent increases also occurred in the Midwest. Smaller increases to the south of this area suggest that these increases are not primarily linked to advection from the Gulf of Mexico, rather they are related to changes in a regional moisture source. This moisture source appears to be related to enhanced levels of evapotranspiration from corn and soybean crops, which have experienced a near doubling in total acreage from 1950 to 2000. [Key Words: Midwest, dew point, extreme, climatology.]
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Sparks, J., D. Changnon, and J. Starke, 2002: Changes in the frequency of extreme warm-season surface dew points in northeastern Illinois. Implications for cooling-system design and operation. Journal of Applied Meteorology, 41, 890-898.

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Changnon, D., J. Thompson, T. April, E. Schmidt, M. Falout, J.B. Davis, and M. Russo, 2002: Efforts to improve predictions of urban winter heating anomalies using various climate indices. Meteorological Applications, 9, 105-111.

Abstract: Meteorologists who work in the energy commodities market continue to investigate ways to enhance predictions of seasonal temperature anomalies using oceanic/atmospheric indices. This study examines the relationship of three climate indices-ENSO (El Niño/Southern Oscillation), PNA (Pacific North American) and NAO (North Atlantic Oscillation)-to heating degree day (HDD) totals accumulated in 11 cities in the Midwest and northeastern United States, to determine which, if any, has predictive power. The data covers the 48-year period between 1951/52 and 1998/99, and focuses on two periods either side of 1 January (i.e. the winter months of October-December and January-April). The index most strongly related to the HDD anomalies during both winter periods was NAO. NAO values were negative for cold (above-average HDD) anomalies occurring prior to and after 1 January, while the NAO values were generally positive during warm (below-average HDD) anomalies. During cold anomalies, the PNA values were generally positive in the three months before 1 January and negative afterwards, indicating that different atmospheric teleconnection patterns cause similar temperature anomalies in these regions. The relationship between the equatorial Pacific sea-surface temperatures (SST) data and temperature anomalies was the weakest. Confidence in these relationships increased when the extreme HDD anomaly years were examined. These results indicated that the relationships of climate indices to HDD anomalies exist and that these would be useful in developing and improving seasonal predictions for business applications.
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Invited Talks and Media Interactions:

Enhancing our dialogue with decision makers: A “win-win” situation for climate scientists. Changnon, D., First Climate Working Group Meeting, Argonne National Laboratory, 16 February, 2007.

Integrating basic climate research with applications: What's all the sweat about?” Changnon, D., T. Mylan Stout Lecture Series, Department of Geosciences, University of Nebraska-Lincoln, 26 January, 2007.

The development of an insect migration forecast product for pest management: An example of interaction among atmospheric scientists and the product user. Sandstrom, M., and D. Changnon, WAS*IS session of the 16 th Conference on Applied Climatology, 87 th Annual AMS meeting, San Antonio, TX, 14-18 January, 2007.

Eastern U.S. snowstorms characteristics. Changnon, D., and S.A. Changnon, 16th Conference on Applied Climatology, 87th Annual AMS meeting, San Antonio, TX, 14-18 January, 2007.

Improving our understanding of Corn earworm & insect migration in the Midwest. Changnon, D., Joint meeting of the Chicago and NIU chapters of the AMS at Romeoville, IL, 14 November, 2006.

Improving our understanding of H. zea migration in the Midwest : Assessment of source populations. Symposium: Another Series of Unfortunate Events? Increasing Concerns about Helicoverpa zea Susceptibility to Pyrethroids in the Midwestern U.S. Sandstrom, M.A., D. Changnon, and B. Flood, North Central Branch of the Entomological Society of America. Bloomington, IL, 26-29 March, 2006.

Temporal and spatial variability of large U.S. snowstorms 1950-2000. Changnon, D., and S.A. Changnon, 18th Conference on Climate Variability and Change. AMS 86th Annual Meeting, Atlanta, GA, 29 January-2 February, 2006.

Communicating and Collaborating with Specific User Groups: Focus on Agricultural Users. Changnon, D., Weather and Society Integrated Workshop (WAS*IS) held in Boulder, CO, November 7-11, 2005.

Developing relationships among key players in the Weather Enterprise: User perspectives from the agriculture sector. Changnon, D., National Research Council Committee on “Estimating and Communicating Uncertainty in Weather and Climate Forecasts.” Held at the National Center for Atmospheric Research (NCAR), September 21-23, 2005, in Boulder, CO .

Assessing the temporal and spatial variability of four damaging weather events and their impacts. North American Weather and Climate Extremes: Progress in Monitoring and Research. Changnon, D. and S.A. Changnon, Chairs J. Meehl and T. Karl. Held at the Aspen Global Change Institute, July 15-21, 2005, Aspen, CO .

Characteristics of major snowstorms in the United States, 1949-2000. Changnon, D. and S.A. Changnon, 15th Conference on Applied Climatology. 19-23 June, 2005, Savannah, GA.

"Can changing agricultural practices influence Midwestern dew points?" Dave Changnon, Mike Sandstrom, Ryan Lauritsen, and Mace Bentley. American Meteorological Society's 16th Conference on Climate Variability and Change, San Diego, Jan. 10-13, 2005.

"What can be learned from the Perfect Summer." Dave Changnon and Stan Changnon. Special Session titled "The global earth observation system: Revolutionizing our understanding of how earth works." Panelists included Vice Admiral U.S. Navy (Ret.) Conrad C. Lautenbacher, Ph.D.--NOAA Administrator. The entire Session was taped and shown on C-SPAN. American Meteorological Society's 16th Conference on Climate Variability and Change, San Diego, Jan. 10-13, 2005.

"Climate and business applications: Focused needs in a changing world. Seminar on the Lifelong Work of Stan Changnon", at the American Meteorological Society’s 14th Conference on Applied Climatology, Seattle, WA, January 11-15, 2004.

"Temporal changes in dew point temperature associated with short-duration heat waves in Chicago." Annual Meeting of the American Meteorological Society’s, Seattle, WA, January 11-15, 2004.

"What’s all the sweat about?" Talk given to the central Illinois and Indiana chapters of the American Meteorological Society, Covington, IN, July 22, 2004.

"El Niño and the U.S. Economy." 2002 AAAS Annual Meeting, Session on Visualizing El Niño and How it Influences Society, Boston, MA, February 14-19, 2002.

Interviewed by CNN-TV news February 16, 2002-focused on the impacts related to the upcoming 2002/03 El Niño.

"Developing a "hands-on" applied climate experience for undergraduates." A session for the short course titled "Applied Climatology for Today's Business Applications." 13th Conference on Applied Climatology, Portland, OR, May 12, 2002.

"Societal Impacts-Sorting Out Increased Vulnerability from Changes in Extremes." National Academy of Sciences, National Disasters Roundtable titled "From Climate to Weather: Impacts on Society and Economy." Supported by the Committee on Global Change Research, Washington, D.C., June 28, 2002. Summary published by the National Academy of Sciences (editor James P. Bruce, Global Change Strategies International, Inc.) in August 2002.

Interviewed by Tom Skilling, WGN-TV Meteorologist for an "Ask Tom Why?" segment (aired August 13, 2002)-focused on increased dew point levels in the upper Midwest and how they may be related to minor changes in agricultural practices in the region.

News stories related to higher dew points in Northeast Illinois were printed in the Chicago Sun-Times, the DeKalb Chronicle, and several other Illinois newspapers in late July/early August 2002.

Interviewed by National Public Radio about the upcoming 2002/03 El Niño and its impacts on the United States. Interview aired on October 31, 2002.

Interviewed by Tom Skilling, WGN-TV Meteorologist for an "Ask Tom Why?" segment (aired December 17, 2002)-focused on the results of a MET 431 project (the occurrence of lake effect snow in northeastern Illinois) completed for Mr. Skilling. Both Changnon and undergraduate students involved in the project were interviewed.
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