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Full-Text Articles in Engineering
A Data-Driven Approach For Winter Precipitation Classification Using Weather Radar And Nwp Data, Bong Chul Seo
A Data-Driven Approach For Winter Precipitation Classification Using Weather Radar And Nwp Data, Bong Chul Seo
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study describes a framework that provides qualitative weather information on winter precipitation types using a data-driven approach. The framework incorporates the data retrieved from weather radars and the numerical weather prediction (NWP) model to account for relevant precipitation microphysics. To enable multimodel-based ensemble classification, we selected six supervised machine learning models: k-nearest neighbors, logistic regression, support vector machine, decision tree, random forest, and multi-layer perceptron. Our model training and cross-validation results based on Monte Carlo Simulation (MCS) showed that all the models performed better than our baseline method, which applies two thresholds (surface temperature and atmospheric layer thickness) for …
Utility Of Vertically Integrated Liquid Water Content For Radar-Rainfall Estimation: Quality Control And Precipitation Type Classification, Bong Chul Seo, Witold F. Krajewski, Youcun Qi
Utility Of Vertically Integrated Liquid Water Content For Radar-Rainfall Estimation: Quality Control And Precipitation Type Classification, Bong Chul Seo, Witold F. Krajewski, Youcun Qi
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study proposes a new estimation method for vertically integrated liquid water content (VIL) using radar reflectivity volume data and temperature sounding retrieved from the numerical weather model analysis. This method addresses uncertainty factors in conventional VIL estimation associated with the effects from the bright band (BB) and radar beam geometry near the radar site. The new VIL is then used for precipitation classification (convective/stratiform) and wind turbine clutter detection in the hope that the estimated VIL indicating vertical activities or development of precipitation systems will account for the two independent subjects together, in opposite ways. The non-precipitation radar echoes …
Weak Magnetic Field Accelerates Chromate Removal By Zero-Valent Iron, Pian Feng, Xiaohong Guan, Yuankui Sun, Wonyong Choi, Hejie Qin, Jianmin Wang, Junlian Qiao, Lina Li
Weak Magnetic Field Accelerates Chromate Removal By Zero-Valent Iron, Pian Feng, Xiaohong Guan, Yuankui Sun, Wonyong Choi, Hejie Qin, Jianmin Wang, Junlian Qiao, Lina Li
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Weak magnetic field (WMF) was employed to improve the removal of Cr(VI) by zero-valent iron (ZVI) for the first time. The removal rate of Cr(VI) was elevated by a factor of 1.12-5.89 due to the application of a WMF, and the WMF-induced improvement was more remarkable at higher Cr(VI) concentration and higher pH. Fe2+ was not detected until Cr(VI) was exhausted, and there was a positive correlation between the WMF-induced promotion factor of Cr(VI) removal rate and that of Fe2+ release rate in the absence of Cr(VI) at pH 4.0-5.5. These phenomena imply that ZVI corrosion with Fe2+ …
Nexrad Nws Polarimetric Precipitation Product Evaluation For Ifloods, Luciana K. Cunha, James A. Smith, Witold F. Krajewski, Mary Lynn Baeck, Bong Chul Seo
Nexrad Nws Polarimetric Precipitation Product Evaluation For Ifloods, Luciana K. Cunha, James A. Smith, Witold F. Krajewski, Mary Lynn Baeck, Bong Chul Seo
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The NEXRAD program has recently upgraded the WSR-88D network observational capability with dual polarization (DP). In this study, DP quantitative precipitation estimates (QPEs) provided by the current version of the NWS system are evaluated using a dense rain gauge network and two other single-polarization (SP) rainfall products. The analyses are performed for the period and spatial domain of the Iowa Flood Studies (IFloodS) campaign. It is demonstrated that the current version (2014) of QPE from DP is not superior to that from SP mainly because DP QPE equations introduce larger bias than the conventional rainfall- reflectivity [i.e., R(Z)] relationship for …
Uncertainty In Radar-Rainfall Composite And Its Impact On Hydrologic Prediction For The Eastern Iowa Flood Of 2008, Bong Chul Seo, Luciana K. Cunha, Witold F. Krajewski
Uncertainty In Radar-Rainfall Composite And Its Impact On Hydrologic Prediction For The Eastern Iowa Flood Of 2008, Bong Chul Seo, Luciana K. Cunha, Witold F. Krajewski
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Key Points A significant potential source of error exists in mosaicked radar-rainfall maps. Different radar calibration offsets lead to misestimation of rainfall amounts. Systematic error in rainfall significantly affects hydrologic predictions. This study addresses a significant potential source of error that exists in radar-rainfall maps that are combined using data from multiple WSR-88D radars of the Next Generation Radar (NEXRAD) national network in the United States. This error stems from different radar calibration offsets that create a border within discontinuous rainfall fields at the equidistance zone among radars. The discontinuity in rainfall fields could lead to misestimation of rainfall over …
Radar-Rainfall Estimation Algorithms Of Hydro-Nexrad, Bong Chul Seo, Witold F. Krajewski, Anton Kruger, Piotr Domaszczynski, James A. Smith, Matthias Steiner
Radar-Rainfall Estimation Algorithms Of Hydro-Nexrad, Bong Chul Seo, Witold F. Krajewski, Anton Kruger, Piotr Domaszczynski, James A. Smith, Matthias Steiner
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Hydro-NEXRAD is a prototype software system that provides hydrology and water resource communities with ready access to the vast data archives of the U.S. weather radar network known as NEXRAD (Next Generation Weather Radar). This paper describes radar-rainfall estimation algorithms and their modular components used in the Hydro-NEXRAD system to generate rainfall products to be delivered to users. A variety of customized modules implemented in Hydro-NEXRAD perform radar-reflectivity data processing, produce radar-rainfall maps with user-requested space and time resolution, and combine multiple radar data for basins covered by multiple radars. System users can select rainfall estimation algorithms that range from …