Using The Storm Water Management Model To Predict Urban Headwater Stream Hydrological Response To Climate And Land Cover Change, J. Y. Wu, Janette R. Thompson, R. K. Kolka, Kristie J. Franz, Timothy W. Stewart
Timothy W. Stewart
Streams are natural features in urban landscapes that can provide ecosystem services for urban residents. However, urban streams are under increasing pressure caused by multiple anthropogenic impacts, including increases in human population and associated impervious surface area, and accelerated climate change. The ability to anticipate these changes and better understand their effects on streams is important for developing and implementing strategies to mitigate potentially negative effects. In this study, stream flow was monitored during April-November (2011 and 2012), and the data were used to apply the Storm Water Management Model (SWMM) for five urban watersheds in central Iowa, USA, representing ...
Composites Of Heavy Rain Producing Elevated Thunderstorms In The Central United States, 2017 University of Missouri
Composites Of Heavy Rain Producing Elevated Thunderstorms In The Central United States, Laurel P. Mccoy, Patrick S. Market, Chad M. Gravelle, Charles E. Graves, Neil I. Fox, Scott M. Rochette, Joshua S. Kastman, Bohumil Svoma
Earth Sciences Faculty Publications
Composite analyses of the atmosphere over the central United States during elevated thunderstorms producing heavy rainfall are presented. Composites were created for five National Weather Service County Warning Areas (CWAs) in the region. Events studied occurred during the warm season (April–September) during 1979–2012. These CWAs encompass the region determined previously to experience the greatest frequency of elevated thunderstorms in the United States. Composited events produced rainfall of >50 mm 24 hr−1 within the selected CWA. Composites were generated for the 0–3 hr period prior to the heaviest rainfall, 6–9 hours prior to it, and 12 ...
Observations And Regional Climate Model Simulations Of Heavy Precipitation Events And Seasonal Anomalies: A Comparison, 2017 Illinois State Water Survey
Observations And Regional Climate Model Simulations Of Heavy Precipitation Events And Seasonal Anomalies: A Comparison, Kenneth E. Kunkel, Karen Andsager, Xin-Zhong Liang, Raymond W. Arritt, Eugene S. Takle, William J. Gutowski Jr., Zaitao Pan
A regional climate model simulation of the period of 1979–88 over the contiguous United States, driven by lateral boundary conditions from the National Centers for Environmental Prediction–National Center for Atmospheric Research reanalysis, was analyzed to assess the ability of the model to simulate heavy precipitation events and seasonal precipitation anomalies. Heavy events were defined by precipitation totals that exceed the threshold value for a specified return period and duration. The model magnitudes of the thresholds for 1-day heavy precipitation events were in good agreement with observed thresholds for much of the central United States. Model thresholds were greater ...
Will Climate Change Impact The Sustainability Of Iowa Farms?, 2017 Iowa State University
Will Climate Change Impact The Sustainability Of Iowa Farms?, Eugene S. Takle
Overheads from the 2011 Shivvers Memorial Lecture Series.
Temporal–Spatial Scales Of Observed And Simulated Precipitation In Central U.S. Climate, 2017 Iowa State University
Temporal–Spatial Scales Of Observed And Simulated Precipitation In Central U.S. Climate, William J. Gutowski Jr., Steven G. Decker, Rodney A. Donavon, Zaitao Pan, Raymond W. Arritt, Eugene S. Takle
Precipitation intensity spectra for a central U.S. region in a 10-yr regional climate simulation are compared to corresponding observed spectra for precipitation accumulation periods ranging from 6 h to 10 days. Model agreement with observations depends on the length of the precipitation accumulation period, with similar results for both warm and cold halves of the year. For 6- and 12-h accumulation periods, simulated and observed spectra show little overlap. For daily and longer accumulation periods, the spectra are similar for moderate precipitation rates, though the model produces too many low-intensity precipitation events and too few high-intensity precipitation events for ...
Hydrological Processes In Regional Climate Model Simulations Of The Central United States Flood Of June–July 1993, Christopher J. Anderson, Raymond W. Arritt, Zaitao Pan, Eugene S. Takle, William J. Gutowski Jr., Francis O. Otieno, Renato Da Silva, Daniel Caya, Jens H. Christensen, Daniel Lüthi, Miguel A. Gaertner, Clemente Gallardo, Filippo Giorgi, René Laprise, Soung-You Hong, Colin Jones, H.-M. H. Juang, J. J. Katzfey, John L. Mcgregor, William M. Lapenta, Jay W. Larson, John A. Taylor, Glen E. Liston, Roger A. Pielke Sr., John Roads
Thirteen regional climate model (RCM) simulations of June–July 1993 were compared with each other and observations. Water vapor conservation and precipitation characteristics in each RCM were examined for a 10° × 10° subregion of the upper Mississippi River basin, containing the region of maximum 60-day accumulated precipitation in all RCMs and station reports. All RCMs produced positive precipitation minus evapotranspiration (P − E > 0), though most RCMs produced P − Ebelow the observed range. RCM recycling ratios were within the range estimated from observations. No evidence of common errors of E was found. In contrast, common dry bias of P was found ...
Soil Moisture In A Regional Climate Model: Simulation And Projection, 2017 Iowa State University
Soil Moisture In A Regional Climate Model: Simulation And Projection, Zaitao Pan, Raymond W. Arritt, William J. Gutowski Jr., Eugene S. Takle
Regional climate simulations driven by three sets of initial and lateral boundary conditions—analyzed observations, GCM control climate, and GCM enhanced greenhouse-gas scenario climate—are used to assess model accuracy in predicting soil moisture and to examine changes in soil moisture in the scenario climate. Simulated soil moisture does not show noticeable drift during the 10-year simulations. Observed and simulated soil moisture for Illinois and Iowa correspond reasonably well for the top 10 cm soil layer but a consistent low bias is present in the top 1 m. Growing season depletion of soil water is simulated well but recharge after ...
Transferability Intercomparison: An Opportunity For New Insight On The Global Water Cycle And Energy Budget, 2017 Iowa State University
Transferability Intercomparison: An Opportunity For New Insight On The Global Water Cycle And Energy Budget, Eugene S. Takle, W. J. Gutowski Jr., R. W. Arritt, J. Roads, I. Meinke, C. G. Jones, A. Zadra
A new approach, called transferability intercomparisons, is described for advancing both understanding and modeling of the global water cycle and energy budget. Under this approach, individual regional climate models perform simulations with all modeling parameters and parameterizations held constant over a specific period on several prescribed domains representing different climatic regions. The transferability framework goes beyond previous regional climate model intercomparisons to provide a global method for testing and improving model parameterizations by constraining the simulations within analyzed boundaries for several domains. Transferability intercomparisons expose the limits of our current regional modeling capacity by examining model accuracy on a wide ...
Hydrological Responses To Dynamically And Statistically Downscaled Climate Model Output, 2017 University of Derby
Hydrological Responses To Dynamically And Statistically Downscaled Climate Model Output, Robert L. Wilby, Lauren E. Hay, William J. Gutowski Jr., Raymond W. Arritt, Eugene S. Takle, Zaitao Pan, George H. Leavesley, Martyn P. Clark
Daily rainfall and surface temperature series were simulated for the Animas River basin, Colorado using dynamically and statistically downscaled output from the National Center for Environmental Prediction/ National Center for Atmospheric Research (NCEP/NCAR) re-analysis. A distributed hydrological model was then applied to the downscaled data. Relative to raw NCEP output, downscaled climate variables provided more realistic simulations of basin scale hydrology. However, the results highlight the sensitivity of modeled processes to the choice of downscaling technique, and point to the need for caution when interpreting future hydrological scenarios.
Use Of Regional Climate Model Output For Hydrologic Simulations, 2017 United States Geological Survey
Use Of Regional Climate Model Output For Hydrologic Simulations, L. E. Hay, M. P. Clark, R. L. Wilby, W. J. Gutowski Jr., G. H. Leavesley, Z. Pan, R. W. Arritt, E. S. Takle
Daily precipitation and maximum and minimum temperature time series from a regional climate model (RegCM2) configured using the continental United States as a domain and run on a 52-km (approximately) spatial resolution were used as input to a distributed hydrologic model for one rainfall-dominated basin (Alapaha River at Statenville, Georgia) and three snowmelt-dominated basins (Animas River at Durango, Colorado; east fork of the Carson River near Gardnerville, Nevada; and Cle Elum River near Roslyn, Washington). For comparison purposes, spatially averaged daily datasets of precipitation and maximum and minimum temperature were developed from measured data for each basin. These datasets included ...
A Possible Constraint On Regional Precipitation Intensity Changes Under Global Warming, 2017 Iowa State University
A Possible Constraint On Regional Precipitation Intensity Changes Under Global Warming, W. J. Gutowski Jr., E. S. Takle, K. A. Kozak, J. C. Patton, R. W. Arritt, J. H. Christensen
Changes in daily precipitation versus intensity under a global warming scenario in two regional climate simulations of the United States show a well-recognized feature of more intense precipitation. More important, by resolving the precipitation intensity spectrum, the changes show a relatively simple pattern for nearly all regions and seasons examined whereby nearly all high-intensity daily precipitation contributes a larger fraction of the total precipitation, and nearly all low-intensity precipitation contributes a reduced fraction. The percentile separating relative decrease from relative increase occurs around the 70th percentile of cumulative precipitation, irrespective of the governing precipitation processes or which model produced the ...
A Wrf Ensemble For Improved Wind Speed Forecasts At Turbine Height, 2017 Iowa State University
A Wrf Ensemble For Improved Wind Speed Forecasts At Turbine Height, Adam Joshua Deppe, William A. Gallus Jr., Eugene S. Takle
The Weather Research and Forecasting Model (WRF) with 10-km horizontal grid spacing was used to explore improvements in wind speed forecasts at a typical wind turbine hub height (80 m). An ensemble consisting of WRF model simulations with different planetary boundary layer (PBL) schemes showed little spread among the individual ensemble members for forecasting wind speed. A second configuration using three random perturbations of the Global Forecast System model produced more spread in the wind speed forecasts, but the ensemble mean possessed a higher mean absolute error (MAE). A third ensemble of different initialization times showed larger model spread, but ...
Altered Hydrologic Feedback In A Warming Climate Introduces A “Warming Hole”, 2017 St. Louis University
Altered Hydrologic Feedback In A Warming Climate Introduces A “Warming Hole”, Zaitao Pan, Raymond W. Arritt, Eugene S. Takle, William J. Gutowski Jr., Christopher J. Anderson, Moti Segal
In the last 25 years of the 20th century most major land regions experienced a summer warming trend, but the central U.S. cooled by 0.2–0.8 K. In contrast most climate projections using GCMs show warming for all continental interiors including North America. We examined this discrepancy by using a regional climate model and found a circulation-precipitation coupling under enhanced greenhouse gas concentrations that occurs on scales too small for current GCMs to resolve well. Results show a local minimum of warming in the central U.S. (a “warming hole”) associated with changes in low-level circulations that ...
Characteristics Of 50–200-M Winds And Temperatures Derived From An Iowa Tall-Tower Network, 2017 Iowa State University
Characteristics Of 50–200-M Winds And Temperatures Derived From An Iowa Tall-Tower Network, Renee A. Walton, Eugene S. Takle, William A. Gallus Jr.
Limitations in skill of wind speed forecasts lead to conservative bids of wind-plant production in the dayahead energy market and usually to an underutilization of wind resources. Improvements are needed in understanding wind characteristics in the turbine-rotor layer (40–120 m) for developing refined forecast models. The seasonal and diurnal behavior of wind speed, wind direction, and temperature were analyzed from data taken on five tall meteorological towers across Iowa. Several significant high-shear events, which would have the potential to cause problems by inducing substantial stress on the infrastructure of the wind turbine, were observed, with vertical shear up to ...
Conceptual And Scaling Evaluation Of Vehicle Traffic Thermal Effects On Snow/Ice-Covered Roads, 2017 Iowa State University
Conceptual And Scaling Evaluation Of Vehicle Traffic Thermal Effects On Snow/Ice-Covered Roads, Joseph M. Prusa, Moti Segal, Bradley R. Temeyer, William A. Gallus Jr., Eugene S. Takle
The potential thermal effects of traffic on road surface thermal energy balance under frost/snow cover conditions have been largely ignored in meteorological evaluations of road ice deposit conditions. Preliminary exploration of these effects, particularly for heavy traffic scenarios with calm wind conditions and an ambient temperature of 0Â°C, is provided in this study using a conceptual model. Observational data were used to constrain the model, and parameterizations were employed to estimate the various heat transfer processes involved. The results indicate that, for heavy traffic situations, as well as for stopped traffic at intersections, the traffic thermal flux contribution ...
Diagnosis And Attribution Of A Seasonal Precipitation Deficit In A U.S. Regional Climate Simulation, 2017 Iowa State University
Diagnosis And Attribution Of A Seasonal Precipitation Deficit In A U.S. Regional Climate Simulation, William J. Gutowski Jr., Francis O. Otieno, Raymond W. Arritt, Eugene S. Takle, Zaitao Pan
Precipitation from a 10-yr regional climate simulation is evaluated using three complementary analyses: self-organizing maps, bias scores, and arithmetic bias. Collectively, the three reveal a precipitation deficit in the south-central United States that emerges in September and lingers through February. Deficient precipitation for this region and time of year is also evident in other simulations, indicating a generic problem in climate simulation. Analysis of terrestrial and atmospheric water balances shows that the 10-yr average precipitation error for the region results primarily from a deficit in horizontal water vapor convergence. However, the 10-yr average for fall only suggests that the primary ...
Evaluation Of Uncertainties In Regional Climate Change Simulations, 2017 Iowa State University
Evaluation Of Uncertainties In Regional Climate Change Simulations, Z. Pan, J. H. Christensen, R. W. Arritt, W. J. Gutowski Jr., E. S. Takle, F. Otieno
We have run two regional climate models (RCMs) forced by three sets of initial and boundary conditions to form a 2×3 suite of 10-year climate simulations for the continental United States at approximately 50 km horizontal resolution. The three sets of driving boundary conditions are a reanalysis, an atmosphere-ocean coupled general circulation model (GCM) current climate, and a future scenario of transient climate change. Common precipitation climatology features simulated by both models included realistic orographic precipitation, east-west transcontinental gradients, and reasonable annual cycles over different geographic locations. However, both models missed heavy cool-season precipitation in the lower Mississippi River ...
Seasonal Temperature Changes With Elevation On Mount Washington, 2017 Meteorology
Seasonal Temperature Changes With Elevation On Mount Washington, Meghan Wells
Student Showcase of Excellence
The summit of Mount Washington is warming more slowly than surrounding lower elevations of the Northeast, which is opposite to climate model projections and observations in other mountain ranges. A looming scientific question is: why? A hypothesis is that the exposure of the summit to the “free troposphere”, an air mass that sits above the ground-based "boundary layer”, for approximately half the year is imparting a slower warming at the summit. This research project takes a preliminary first step toward answering this question by finding methods to determine when Mount Washington is in the boundary layer. Temperature readings from the ...
Direct Comparisons Of Ice Cloud Macro- And Microphysical Properties Simulated By The Community Atmosphere Model Version 5 With Hippo Aircraft Observations, Chenglai Wu, Xiaohong Liu, Minghui Diao, Kai Zhang, Andrew Gettelman, Zheng Lu, Joyce Penner, Zhaohui Lin
In this study we evaluate cloud properties simulated by the Community Atmosphere Model version 5 (CAM5) using in situ measurements from the HIAPER Pole-to-Pole Observations (HIPPO) campaign for the period of 2009 to 2011. The modeled wind and temperature are nudged towards reanalysis. Model results collocated with HIPPO flight tracks are directly compared with the observations, and model sensitivities to the representations of ice nucleation and growth are also examined. Generally, CAM5 is able to capture specific cloud systems in terms of vertical configuration and horizontal extension. In total, the model reproduces 79.8 % of observed cloud occurrences inside model ...