Search

The influence of climate conditions in the agricultural environment is important in evapotranspiration, water availability for plants and roots, and other processes. This research focuses on two aspects: (1) the effects of climate change on the occurrence of extreme events that may affect agricultural processes in a region in Illinois (USA), and (2) the effects of climate change on the soil water dynamics in a corn crop. Different climate scenarios developed by the Institut Pierre Simon Laplace, using a climate model with medium resolution-IPSL(CM5MR), provided input to simulate soil water dynamics in two fields with different drainage system layouts. The Hydrus model simulated surface flux and runoff. Results indicate that the variation of precipitation and temperature in the future may increase extreme events, representing a risk for agriculture. Hydrus simulations indicate different results accordingly to the drainage layout, suggesting that it may be necessary to make adjustments in drainage systems in the future. In general, surface flux and runoff will increase over time, and these changes are more related to extreme events than average values. Extreme event indices show vulnerability in agriculture and will be reflected in changes in the soil water dynamics, and may increase the climatic risk of corn production.

In this paper, we examine how surface runoff affects public safety and urban infrastructure worldwide and how human activity has significantly altered the frequency and magnitude of these events. We investigate this issue in Ferson Creek, IL, USA. Our study focuses on three specific areas of impact: (1) the primary reasons for a considerable increase in average runoff peaks, using annual maximum runoff discharge and annual maximum precipitation and temperature to evaluate the role of climate variability; (2) the effect of land use change on runoff peaks by coupling dominant land use categories with annual maximum runoff discharge; and (3) the use of return level plots as a reference to explore the watershed's sensitivity to land use change. Our findings indicate that land use change has a greater effect on runoff peak values than climate variability in our region of interest. The agricultural areas of Ferson Creek have been most affected by the rapid transformation of about 20% of their land into developed areas. Although agricultural areas can sometimes intensify runoff peaks, their reduction has led to excessive runoff discharges in Ferson Creek, as they have higher relative infiltration capacity than developed areas. We conclude that each watershed has its own fingerprint in terms of the connection between its land use types and hydrological patterns and that the region is most sensitive to the percentage of forests. These results are essential for improving infrastructure design and risk estimation methods in the region of interest. [ABSTRACT FROM AUTHOR]

This paper assesses the effect of climate change on crop yield from a soil water balance perspective. The uncertainties of regional-scale climate models, local-scale climate variability, emissions scenarios, and crop growth models are combined to explore the possible range of climate change effects on rainfed corn yield in central Illinois in 2055. The results show that a drier and warmer summer during the corn growth season and wetter and warmer precrop and postcrop seasons will likely occur. Greater temperature and precipitation variability may lead to more variable soil moisture and crop yield, and larger soil moisture deficit and crop yield reduction are likely to occur more frequently. The increased water stress is likely to be most pronounced during the flowering and yield formation stages. The expected rainfed corn yield in 2055 is likely to decline by 23%–34%, and the probability that the yield may not reach 50% of the potential yield ranges from 32% to 70% if no adaptation measures are instituted. Among the multiple uncertainty sources, the greenhouse gas emissions projection may have the strongest effect on the risk estimate of crop yield reduction. The effects from the various uncertainties can be offset to some degree when the uncertainties are considered jointly. An ensemble of GCMs with an equal weight may overestimate the risk of soil moisture deficits and crop yield reduction in comparison with an ensemble of GCMs with different weight determined by the root-mean-square error minimization method. The risk estimate presented in this paper implies that climate change adaptation is needed to avoid reduced corn yields and the resulting profit losses in central Illinois. [ABSTRACT FROM AUTHOR]

The interaction of global climate change and urban heat islands (UHI) is expected to have far-reaching impacts on the sustainability of the world's rapidly growing urban population centers. Given that a wide range of spatiotemporal scales contributed by meteorological forcing and complex surface heterogeneity complicates UHI, a multimodel nested approach is used in this paper to study climate-change impacts on the Chicago, Illinois, UHI, covering a range of relevant scales. One-way dynamical downscaling is used with a model chain consisting of global climate (Community Atmosphere Model), regional climate (Weather Research and Forecasting Model), and microscale ('ENVI-met') models. Nested mesoscale and microscale models are evaluated against the present-day observations (including a dedicated urban miniature field study), and the results favorably demonstrate the fidelity of the downscaling techniques that were used. A simple building-energy model is developed and used in conjunction with microscale-model output to calculate future energy demands for a building, and a substantial increase (as much as 26% during daytime) is noted for future (~2080) climate. Although winds and lake-breeze circulation for future climate are favorable for reducing energy usage by 7%, the benefits are outweighed by such factors as exacerbated UHI and air temperature. An adverse change in human-comfort indicators is also noted in the future climate, with 92% of the population experiencing thermal discomfort. The model chain that was used has general applicability for evaluating climate-change impacts on city centers and, hence, for urban-sustainability studies. [ABSTRACT FROM AUTHOR]

Climate change could have impacts on hydrologic systems threatening, availability of water supply resources. In Illinois, regional water supply planning efforts are attempting to better understand potential impacts on low flow and surface water availability through analysis of hydrologic sensitivity to a range of climate scenarios. This paper explores the development, calibration and validation of Fox River watershed model using the soil and water assessment tool (SWAT) and the model’s application to assess impacts of potential climate change. The watershed model is calibrated and validated using daily flow records at three gauging stations. Automatic model calibration followed by manual refinement of parameter values was performed. Calibration results were generally good for monthly and annual time step but only satisfactory for daily simulations. Based on simulations of global climate models produced for IPCC fourth assessment report, climate scenarios were prepared by the Illinois State Water Survey for water supply planning initiatives in north-east and east-central Illinois. These scenarios showed ranges of temperature change between 0°C to +3.3°C and annual precipitation changes between −127 to +127 mm in the next 50 years, excluding the 5% extreme ends of those climate model simulations considered. Changes in climate were reflected using adjustments to the historical record, instead of using direct outputs from individual climate models. The watershed model was used to assess the impact of potential climate change. Application results indicate that annual precipitation change of 127 mm on average increases annual water yield and 7-day low flows by 28% and 19%, respectively. In contrast, a temperature change of +3.3°C results in average reductions of annual water yield by 13% and 7-day low flows by 10%. Seasonal effects were investigated through evaluation of changes in average monthly flows. Increasing precipitation resulted in significant changes in streamflows in late summer and fall months where as increasing temperature greatly affects winter flows due to snowmelt. The key implication is that climate change-induced variability of streamflows could have major impacts on water supply availability in the Fox River watershed and in particular, increased periods of drought could result in deficit of supplies during seasons of peak water use. It must be noted that this analysis does not examine the potential impacts of population growth and water use on water supply availability, which are also expected to have substantial influences in the region. [ABSTRACT FROM AUTHOR]

Wind power is becoming an increasingly attractive method of electric power generation due to concerns with global climate change, increasing uncertainty of future oil supplies, and energy security. While most large-scale wind turbines are part of wind farms, which help states meet state renewable energy standards, several colleges and universities in the United States have purchased wind turbines for financial and educational purposes. This paper gives details of a cost-benefit analysis completed for a small liberal arts college in Illinois, Principia College, which is considering buying a single large-scale turbine. The process set forth here can easily be adapted to any college, university, or school. It is found that the project has a positive net present value for both a 20-year scenario and a 30-year scenario. Assuming the project did not receive any grants, Principia College would need to have an annual real return rate of about 6% on its initial investment to gain the same economic benefits. [ABSTRACT FROM AUTHOR]

Trend analysis of annual flood peaks on 12 small urbanizing watersheds in northeastern Illinois indicated that annual peaks, and thus frequency and impact of flooding, increased over the past several decades. An increase in flood peaks could be attributed to intensive urbanization and increasing incidences of heavy rainfall. Average urbanization of the 12 watersheds increased significantly from 10.6% in 1954 to 61.8% in 1996. In addition, numerous studies have reported increasing frequency and intensity of heavy rainfall in the region. This outcome is consistent with lower design rainfall estimates produced by older studies, such as U.S. Weather Bureau Technical Paper No. 40 (TP-40), compared to more recent sources, such as National Oceanic and Atmospheric Administration Atlas-14. This study used a design storm approach and the Hydrologic Engineering Center for Hydrologic Modeling System (HEC-HMS) model to calculate design flood peaks. Hydrologic model parameters were calibrated using hourly rainfall-runoff data of two large regional floods, observed in 1954 and 1996 at 12 small urbanizing watersheds in the metropolitan Chicago area. A sensitivity analysis was performed to evaluate the effects of urbanization and climate variability on increasing flood peaks. Results indicated that, on average, urbanization caused a 34% greater increase in peak flows than climate variability. In addition, this study indicated that present discharges are, on average, at least 19% larger than regulatory discharges. Ongoing urbanization may cause flood peaks to become even higher. The proposed framework can be used to provide input for flood study prioritization by comparing published regulatory discharges and flood discharges computed for current conditions, and investigating potential impacts of future land use changes and precipitation on flood peaks. [ABSTRACT FROM AUTHOR]

This paper describes a method to detect the impact of rainfall anomalies on vegetation phenology, in terms of timing (phase) and greenness, by using Fourier series to fit a time series of Normalized Difference Vegetation Index (NDVI) observations. The study was conducted in the northern semiarid region of Argentina, where rainfall is the driving factor of vegetation phenology. A 9-year time series of monthly NDVI Global Area Coverage (GAC) images, obtained with the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR), was split into nine series of 12-monthly images, each corresponding to a yearly growth cycle. A Fast Fourier Transform (FFT) algorithm was applied to each cycle, and derived parameters were analysed according to rainfall anomalies for irrigated and rainfed crops, grasslands and native forest. Derived Fourier parameters were: mean NDVI, amplitude and phase. Both negative and positive rainfall anomalies had a significant impact on the Fourier parameters. Amplitude and phase were the most sensitive parameters. Droughts modified the monomodal structure of the yearly cycle by decreasing the contribution of the 12-month periodic component and increasing the contribution of the 6-month component. The impact of drought on the Fourier parameters was highest for rainfed crops. Yearly values of Fourier parameters for grasslands and native forest were affected by prevailing hydrological conditions over the previous year. [ABSTRACT FROM AUTHOR]

The concept of soil health is increasingly being used as an indicator for sustainable soil management and even includes legislative actions. Current applications of soil health often lack geospatial and monetary analyses of damages (e.g., land development), which can degrade soil health through loss of carbon (C) and productive soils. This study aims to evaluate the damages to soil health (e.g., soil C, the primary soil health indicator) attributed to land developments within the state of Illinois (IL) in the United States of America (USA). All land developments in IL can be associated with damages to soil health, with 13,361.0 km2 developed, resulting in midpoint losses of 2.5 × 1011 of total soil carbon (TSC) and a midpoint social cost of carbon dioxide emissions (SC-CO2) of $41.8B (where B = billion = 109, USD). More recently developed land area (721.8 km2) between 2001 and 2016 likely caused the midpoint loss of 1.6 × 1010 kg of TSC and a corresponding midpoint of $2.7B in SC-CO2. New developments occurred adjacent to current urban areas near the capital cities of Springfield, Chicago, and St. Louis (the border city between the states of Missouri and IL). Results of this study reveal several types of damage to soil health from developments: soil C loss, associated "realized" soil C social costs (SC-CO2), and loss of soil C sequestration potential from developments. The innovation of this study has several aspects. Geospatial analysis of land cover combined with corresponding soil types can identify changes in the soil health continuum at the landscape level. Because soil C is a primary soil health indicator, land conversions caused by developments reduce soil health and the availability of productive soils for agriculture, forestry, and C sequestration. Current IL soil health legislation can benefit from this landscape level data on soil C loss with GHG emissions and associated SC-CO2 costs by providing insight into the soil health continuum and its dynamics. These techniques and data can also be used to expand IL's GHG emissions reduction efforts from being solely focused on the energy sector to include soil-based emissions from developments. Current soil health legislation does not recognize that soil's health is harmed by disturbance from land developments and that this disturbance results in GHG emissions. Soil health programs could be broadened to encourage less disturbance of soil types that release high levels of GHG and set binding targets based on losses in the soil health continuum. [ABSTRACT FROM AUTHOR]

For several decades, green treefrogs (Hyla cinerea) have been undergoing rapid range expansion northward and eastward in Illinois, Indiana, and Kentucky. While range expansion of green treefrogs in these states may be linked to climate change, a recent study suggested this expansion could be facilitated by parasites, given that expanded range populations of green treefrogs from Kentucky and Indiana exhibited significant decreases in helminth species diversity compared to those examined from historical locations of Kentucky. Because rapid range expansion may lead to hosts escaping their parasites (= parasite release), a reprieve from parasitic infection could allocate additional resources to growth and reproduction and thus facilitate the expansion. The present study compares patterns of helminth diversity for green treefrogs from historical and 2 types (early and late expansion) of expanded range locations of southern Illinois to test whether these range-expansion populations are also experiencing a reduction in parasitism due to parasite release. The results of this study did not find significant differences in helminth diversity when helminth communities of green treefrogs from their historical and expanded ranges were compared. These results appear to downplay the putative role of parasite release in the northward range expansion of H. cinerea in Illinois. Studies are underway to determine whether local factors, including abiotic conditions and amphibian host diversity, play a more prominent role in influencing helminth diversity of green treefrogs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Current land management can lead to more severe BAP conditions. • Regulating fertilizer application rate can offset HAB risks from extreme climate. • Regulating P was more effective in reducing HAB risks in freshwater watersheds. • Regulating N was more effective in controlling HAB downstream of watershed. This paper was aimed at assessing the risk of HAB occurrence in a highly cultivated watershed and evaluating the effectiveness of N and P fertilizer reduction practices in mitigating this risk under future climate projections. To achieve this objective, a modelling framework was developed for HAB risk assessment under different environmental stressors including climate changes and different land management practices. The modelling framework used a fully distributed physical-based hydrologic model, MIKE SHE, and a hydrodynamic river model, MIKE 11, coupled with ECO-Lab to simulate the fate and transport of different forms of N and P in the Upper Sangamon River Basin (USRB), a highly cultivated watershed in central Illinois. Three different land management scenarios based on the N and P reduction target in "The Gulf Hypoxia Action Plan" were simulated to assess the P nonpoint source behavior and HAB risk level in the USRB from 2020 to 2050 under extreme climate projections. Our results predicted that the HAB risk in USRB is relatively low even with increased bioavailable P (BAP) concentration and longer duration with high BAP concentration due to low water temperature. Reducing N or P application rates by 50% was able to offset the negative effects on HAB occurrence from extreme climate projections apart from spring. Within P and N, regulating P was found to be more effective in reducing HAB risks in the USRB while regulating N was more effective in controlling HAB downstream. Understanding the dynamics of N and P in causing the occurrence of HAB was expected to improve the mitigation measures that we implement at the field level. [ABSTRACT FROM AUTHOR]

Seed sourcing decisions affect short‐ and long‐term restoration outcomes. Seeds sourced closer to restoration sites are likely to be better adapted to local conditions and therefore may perform better than those sourced farther away, following assumptions of local adaptation. However, plants may not be adapted to future conditions under climate change; hence, managers are considering a predictive provenancing approach, where plant materials adapted to predicted conditions are used at a site. Currently, there is little empirical evidence available to inform this approach. To address this, we evaluate predictive provenancing using three species of forbs used in tallgrass prairie restorations (Allium cernuum, Chamaecrista fasciculata, and Rudbeckia hirta) in a common garden experiment in northeastern Illinois, U.S.A. We compared the fitness in plants sourced from three regional zones across a latitudinal gradient that represents different climate projections, relative to the planting site. Data were analyzed using Aster life‐history models and generalized linear models. We found that source affected overall fitness in all three species, but no climate proxy had the highest fitness across all species. The performance at each life stage had different effects on overall fitness, which varied by source. We observed later reproductive phenology in southern‐sourced plants for all three species, possibly due to adaptation to longer growing seasons. The mixed results of this study suggest that climate proxy alone would not be sufficient to determine an effective and accurate predictive provenancing strategy. Long‐term tests are needed to pursue such a strategy for high‐priority species. [ABSTRACT FROM AUTHOR]

This paper examines how the Kishwaukee River basin located between Chicago and Rockford, Illinois, would respond to various climate-land use combined scenarios. The Hydrological Simulation Program—Fortran was calibrated and repeatedly run with eight climate—land-use combined scenarios generated from a general circulation model (HadCM3) and a dynamic urban growth model. The climate scenarios were based on two IPCC SRES emission scenarios (A2 and B2) and the land-use scenarios were based on four economic growth scenarios. The results of the study indicate that total runoff is predicted to decrease noticeably to moderate climate change but shows little sensitivity to land-use change. What is sensitive to land-use change is surface runoff, which is predicted to change from -9.9% to +29.2% depending on land-use scenarios under the A2 emission scenario. Runoff during summer and the low-flow season is projected to undergo the most severe decrease, up to 41.4% under the B2 emission scenario. Finally, it was found that simply combining climate and land-use scenarios is not enough to show the compounding effect of climate change and land-use change. [ABSTRACT FROM AUTHOR]

Despite increasing concern regarding broad-scale declines in insects, there are few published long-term, systematic butterfly surveys in North America, and fewer still that have incorporated the influence of changing climate and landscape variables. In this study, we analyzed 20 years of citizen science data at seven consistently monitored protected areas in Illinois, U.S.A. We used mixed models and PERMANOVA to evaluate trends in butterfly abundance, richness, and composition while also evaluating the effects of temperature and land use. Overall butterfly richness, but not abundance, increased in warmer years. Surprisingly, richness also was positively related to percent impervious surface (at the 2 km radius scale), highlighting the conservation value of protected areas in urban landscapes (or alternately, the potential negative aspects of agriculture). Precipitation had a significant and variable influence through time on overall butterfly abundance and abundance of resident species, larval host plant specialists, and univoltine species. Importantly, models incorporating the influence of changing temperature, precipitation, and impervious surface indicated a significant overall decline in both butterfly abundance and species richness, with an estimated abundance decrease of 3.8%/year and richness decrease of 1.6%/year (52.5% and 27.1% cumulatively from 1999 to 2018). Abundance and richness declines were also noted across all investigated functional groups except non-resident (migratory) species. Butterfly community composition changed through time, but we did not find evidence of systematic biotic homogenization, perhaps because declines were occurring in nearly all functional groups. Finally, at the site-level, declines in either richness or abundance occurred at five of seven locations, with only the two largest locations (>300 Ha) not exhibiting declines. Our results mirror those of other long-term butterfly studies predominantly in Europe and North America that have found associations of butterflies with climate variables and general declines in butterfly richness and abundance. [ABSTRACT FROM AUTHOR]

Copyright of Review of Policy Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Climate change has been concerned as a trigger of hydrologic changes around the world. Budyko framework was widely used in hydrologic sensitivity analyses on the steady‐state water balance. The unsteady‐state responses, for example the inter‐annual hydrologic sensitivity, were not well investigated, especially for catchments influenced by croplands as that exist in Illinois in the United States. We propose a new hydrologic sensitivity framework for the unsteady‐state condition, together with a new hydrological model, to investigate the impact of croplands on the hydrologic sensitivity. In addition to the Budyko‐type relationship between the annual evapotranspiration ratio (E/P) and the aridity index (Ep/P), this framework incorporates the empirical relationship between the annual storage change ratio (ΔS/P) and Ep/P into sensitivity coefficients. The required data of annual E/P and ΔS/P could be obtained from observation and hydrological models. In particular, the bcd‐αK model is newly developed from the existing bcd model in considering croplands in Illinois, which includes only five parameters while capturing major hydrological processes for catchments with croplands. Results show that the annual E/P, ΔS/P and Q/P in 12 studied catchments have significant linear relationships with Ep/P. The annual runoff is much more sensitive to the change in precipitation than to the change in potential evapotranspiration. The traditional steady‐state analysis overestimates the sensitivity of the evapotranspiration to the change in the precipitation for the unsteady‐state condition and underestimates the variability of sensitivity coefficients among catchments. Plain Language Summary: With the changing climate, frequent disasters of floods and droughts, shortage of water resources, and water quality deterioration, the importance of studying water cycle is increasingly recognized. Moreover, human activities have seriously changed the processes of hydrological cycle. Therefore, it makes no sense to only study the natural water cycle in which intensive and extensive human activities occur, such as agricultural development. In this study, we develop a new method for hydrologic sensitivity analysis on catchments bearing the changes in climate and land use. Case studies are undertaken for 12 catchments in Illinois, USA. Results show that the annual runoff is much more sensitive to the change in the precipitation than to the change in the potential evapotranspiration. Key Points: Empirical relationships of multiple hydrologic ratios versus the aridity index are jointly used to estimate sensitive coefficientsA new hydrological model is developed to incorporate the impact of croplands with minimum additional parametersThe steady‐state analysis misestimates the sensitivity and underestimate the variability of sensitivity for the unsteady‐state condition [ABSTRACT FROM AUTHOR]

Recurring drying and wetting events are likely to increase in frequency and intensity in predicted future droughts in the central USA and alter the regeneration potential of species. We explored the resistance of seed banks to successive droughts in 53 sites across the nine locations in baldcypress swamps in the southeastern USA. Along the Mississippi River Alluvial Valley and northern Gulf of Mexico, we investigated the capacity of seed banks to retain viable seeds after successive periods of drying and wetting in a greenhouse study. Mean differences in species richness and seed density were compared to examine the interactions of successive droughts, geographical location and water regime. The results showed that both species richness and total density of germinating seedlings decreased over repeated drought trials. These responses were more pronounced in geographical areas with higher annual mean temperature. In seed banks across the southeastern swamp region, most species were exhausted after Trial 2 or 3, except for semiaquatic species in Illinois and Tennessee, and aquatic species in Texas. Distinct geographical trends in seed bank resistance to drought demonstrate that climate-induced drying of baldcypress swamps could influence the regeneration of species differently across their ranges. Despite the health of adult individuals, lack of regeneration may push ecosystems into a relict status. Seed bank depletion by germination without replenishment may be a major conservation threat in a future with recurring droughts far less severe than megadrought. Nevertheless, the protection of moist refugia might aid conservation. [ABSTRACT FROM AUTHOR]

New cap-and-trade (CT) programs (e.g., Regional Greenhouse Gas Initiative) to mitigate climate change have created the need for decision support in investment, bidding, and oversight in electricity markets. This need is critical for practicing engineering managers in restructured electricity markets operating under market-based competition. In this research we develop a bi-level game-theoretic model to obtain optimal bidding strategies for power generating companies in restructured markets under a CT program. We demonstrate the applicability of our model on data from Northern Illinois electricity market and discuss managerial implications. Detailed sensitivity analyses show how CT programs can impact electricity and allowance prices. [ABSTRACT FROM AUTHOR]

Between June 2006 and September 2009, an instrumented light aircraft measured over 400 vertical profiles of aerosol and trace gas properties over eastern and central Illinois. The primary objectives of this program were to (1) measure the in situ aerosol properties and determine their vertical and temporal variability and (2) relate these aircraft measurements to concurrent surface and satellite measurements. The primary profile location was within 15 km of the NOAA/ESRL surface aerosol monitoring station near Bondville, Illinois. Identical instruments at the surface and on the aircraft ensured that the data from both platforms would be directly comparable and permitted a determination of how representative surface aerosol properties were of the lower column. Aircraft profiles were also conducted occasionally at two other nearby locations to increase the frequency of A-Train satellite underflights for the purpose of comparing in situ and satellite-retrieved aerosol data. Measurements of aerosol properties conducted at low relative humidity over the Bondville site compare well with the analogous surface aerosol data and do not indicate any major sampling issues or that the aerosol is radically different at the surface compared with the lowest flyby altitude of ~240m above ground level. Statistical analyses of the in situ vertical profile data indicate that aerosol light scattering and absorption (related to aerosol amount) decreases substantially with increasing altitude. Parameters related to the nature of the aerosol (e.g.,single-scattering albedo, ° Angstr¨om exponent, etc.), however, are relatively constant throughout the mixed layer, and do not vary as much as the aerosol amount throughout the profile. While individual profiles often showed more variability, the median in situ single-scattering albedo was 0.93-0.95 for all sampled altitudes. Several parameters (e.g., submicrometer scattering fraction, hemispheric backscattering fraction, and scattering ° Angstr¨om exponent) suggest that the fraction of smaller particles in the aerosol is larger near the surface than at high altitudes. The observed dependence of scattering on size, wavelength, angular integration range, and relative humidity, together with the spectral dependence of absorption, show that the aerosol at higher altitudes is larger, less hygroscopic, and more strongly absorbing at shorter wavelengths, suggesting an increased contribution from dust or organic aerosols. The aerosol profiles show significant differences among seasons. The largest amounts of aerosol (as determined by median light extinction profile measurements) throughout most of the sampled column were observed during summer, with the lowest amounts in the winter and intermediate values in the spring and fall. The highest three profile levels (3.1, 3.7, 4.6 km), however, showed larger median extinction values in the spring, which could reflect long-range transport of dust or smoke aerosols. The aerosols in the mixed layer were darkest (i.e., lowest single-scattering albedo) in the fall, in agreement with surface measurements at Bondville and other continental sites in the US. In situ profiles of aerosol radiative forcing efficiency showed little seasonal or vertical variability. Underflights of the CALIPSO satellite show reasonable agreement in a majority of retrieved profiles between aircraft-measured extinction at 532 nm (adjusted to ambient relative humidity) and CALIPSO-retrieved extinction, and suggest that routine aircraft profiling programs can be used to better understand and validate satellite retrieval algorithms. CALIPSO tended to overestimate the aerosol extinction at this location in some boundary layer flight segments when scattered or broken clouds were present, which could be related to problems with CALIPSO cloud screening methods. The in situ aircraft-collected aerosol data suggest extinction thresholds for the likelihood of aerosol layers being detected by the CALIOP lidar. In this study, aerosol layers with light extinction (532 nm) values >50Mm-1 were detected by CALIPSO ~95% of the time, while aerosol layers with extinction values lower than 10Mm-1 had a detection efficiency of <2 %. For all collocated comparison cases, a 50% probability of detection falls at an in situ extinction level of 20-25Mm-1. These statistical data offer guidance as to the likelihood of CALIPSO's ability to retrieve aerosol extinction at various locations around the globe. [ABSTRACT FROM AUTHOR]

Potential effects of climate change on streamflow and soil moisture in Vermilion basin, Illinois, are investigated using a spatial distributed hydrological model (WetSpa). The model results show good agreement between observed and simulated discharges at the Leonore gauge station and soil moisture at the Stelle soil moisture recording site. Climate scenarios are derived by statistical downscaling of regional climate predictor variables for two climate scenarios and four time periods. The downscaled local climate variables are used as inputs to the WetSpa model. The results of the hydrological simulations show that streamflow in the Vermilion basin may decrease substantially, especially in summer, as a result of less precipitation but primarily due to increased evapotranspiration. Predictions also indicate that reduced precipitation in summer combined with a substantial increase in evaporative demand may lead to soil moisture deficits in the fall, which could have a negative impact on the natural vegetation and rainfed crop growth. [ABSTRACT FROM AUTHOR]

Although ecologists have long recognized that certain mammalian species exhibit high-amplitude, often multiannual, fluctuations in abundance, their causes have remained poorly understood and the subject of intense debate. A key contention has been the relative role of density-dependent and density-independent processes in governing population dynamics. We applied capture-mark-recapture analysis to 25 years of monthly trapping data from a fluctuating prairie vole Microtus ochrogaster population in Illinois, USA, to estimate realized population growth rates and associated vital rates (survival and recruitment) and modeled them as a function of vole density and density-independent climatic variation. We also tested for phase dependence and seasonality in the effects of the above processes. Variation in the realized population growth rate was best explained by phase-specific changes in vole density lagged by one month and mean monthly temperatures with no time lags. The underlying vital rates, survival and recruitment, were influenced by the additive and interactive effects of phase, vole density, and mean monthly temperatures. Our results are consistent with the observation that large-scale population fluctuations are characterized by phase-specific changes in demographic and physiological characteristics. Our findings also support the growing realization that the interaction between climatic variables and density-dependent factors may be a widespread phenomenon, and they suggest that the direction and magnitude of such interactive effects may be phase specific. We conclude that density-dependent and density-independent climatic variables work in tandem during each phase of density fluctuations to drive the dynamics of fluctuating populations. [ABSTRACT FROM AUTHOR]

The Advanced Research version of the Weather Research and Forecasting Model (ARW) coupled with an urban canopy model is used to investigate the potential of vegetative (green) roof technology to mitigate against ongoing climate warming and continued urban sprawl for a day representing average summer conditions in late-twenty-first-century Chicago, Illinois. Effects related particularly to human health hazards resulting from excessive heat and high pollution concentrations are emphasized. Continued expansion of the urban environment over the next century is shown to lead to an expansion of the warming signal across the metropolitan region. Widespread adoption of vegetative rooftops, through increased albedo and evapotranspiration, reduces temperatures in the urban environment by as much as 3°°C, an effect similar to the simpler but less appealing alternative of employing painted or other reflective rooftop structures (e.g., white roofs). A significant limitation to the green roof approach for the case studied is that the increase in moisture resulting from transpiration leads to only marginal cooling when apparent temperatures are considered. An additional complication arises in that the reduced temperatures alter the lake-breeze circulation, potentially reducing circulation of pollutants into the city core, but also reducing natural cooling in the most urbanized areas during the climatologically warmest hours. Future work that evaluates these impacts over a broader range of synoptic settings, documents changes in the planetary boundary layer structure and attendant pollution, and considers the multiple-day dependence of these effects is needed. [ABSTRACT FROM AUTHOR]

The present study examines the effects of historic climate variability on cold-season processes, including soil temperature, frost depth, and the number of frost days and freeze–thaw cycles. Considering the importance of spatial and temporal variability in cold-season processes, the study was conducted in the midwestern United States using both observations and model simulations. Model simulations used the Variable Infiltration Capacity (VIC) land surface model (LSM) to reconstruct and to analyze changes in the long-term (i.e., 1917–2006) means of soil frost variables. The VIC model was calibrated using observed streamflow records and near-surface soil temperatures and then evaluated for streamflow, soil temperature, frost depth, and soil moisture before its application at the regional scale. Soil frost indicators—such as the number of frost days and freeze–thaw cycles—were determined from observed records and were tested for the presence of significant trends. Overall trends in extreme and mean seasonal soil temperature from 1967 onward indicated a warming of soil temperatures at a depth of 10 cm—specifically in northwest Indiana, north-central Illinois, and southeast Minnesota—leading to a reduction in the number of soil frost days. Model simulations indicated that by the late-century period (1977–2006), soil frost duration decreased by as much as 36 days compared to the midcentury period (1947–76). Spatial averages for the study area in warm years indicated shallower frost penetration by 15 cm and greater soil temperatures by about 3°C at 10-cm soil depth than in the cold years. [ABSTRACT FROM AUTHOR]

Strong climate-related secular trends are apparent in a 52-yr long (1947–1998) uninterrupted series of monthly temperature profiles from Lake Zurich, a large, deep (136 m), temperate lake on the Swiss Plateau. Decadal mean water temperatures have undergone a secular increase at all depths, reflecting the high degree of regional warming that occurred in the European Alpine area during the 20th century. From the 1950s to the 1990s, high warming rates (~ 0.24 K per decade) in the uppermost 20 m of the lake (i.e., the epi/metalimnion) combined with lower warming rates (~ 0.13 K per decade) below 20 m (i.e., in the hypolimnion), have resulted in a 20% increase in thermal stability and a consequent extension of 2–3 weeks in the stratification period. In common with many other parts of the world, 20th-century climate change on the Swiss Plateau has involved a steep secular increase in daily minimum (nighttime) air temperatures, but not in daily maximum (daytime) air temperatures. With respect to both secular change and decadal-scale variability, the temporal structure of the temperature of the surface mixed layer of Lake Zurich faithfully reflects that of the regional daily minimum air temperature, but not that of the daily maximum. The processes responsible for longer-term changes in the temperature structure of the lake therefore act during the night, presumably by suppressing nighttime convective cooling of the surface mixed layer. Application of a one-box heat exchange model suggests that the observed secular changes in thermal structure are due to shifts in the nighttime rate of emission of infrared radiation from the atmosphere and in the nighttime rates of latent and sensible heat exchange at the air-water interface. The increase in hypolimnetic temperatures is mainly a result of the increased prevalence of warm winters in Europe. [ABSTRACT FROM AUTHOR]

Focuses on the 64-year period deep soil temperature data which assessed the long-term changes in surface temperatures in Illinois. Details on the collected data; Trends in temperature in Illinois from 1889 to 1952; Factors that influence the temperature changes.

Switchgrass (Panicum virgatum L.) is a C4, warm season, perennial native grass that has been strongly recommended as an ideal biofuel feedstock. Accurate forecasting of switchgrass yield across a geographically diverse region and under future climate conditions is essential for determining realistic future ethanol production from switchgrass. This study compiled a switchgrass database through reviewing the existing literature from field trials across the U.S. Using observed switchgrass data, a process-based model (ALMANAC) was developed. The ALMANAC simulation results showed that crop management had more effect on yield than location. The ALMANAC model consists of functional relationships that provide a better understanding of interactions among plant physiological processes and environmental factors (water, soil, climate, and nutrients) giving realistic predictions in different climate conditions. This model was used to quantify the impacts of climate change on switchgrass yields. Simulated lowland switchgrass would have more yield increases between Illinois and Ohio in future (2021–2050) under both Representative Concentration Pathway (RCP) 4.5 and 8.5 pathways with low N fertilizer inputs than high N fertilizer inputs. There was no significant effect of climate variability on upland simulated yields, which means that N fertilization is a key factor in controlling upland switchgrass yields under future climate conditions. [ABSTRACT FROM AUTHOR]