Browsing OU - Theses by Author "Wang, Xuguang"
Now showing items 1-20 of 26
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African Easterly Wave Tracks as Simulated by CMIP5 Models
Brannan, Allison (2017-08)African Easterly Waves (AEWs) impact Sahel rainfall and serve as trigger disturbances for tropical cyclones (TCs) in the North Atlantic Ocean. So far, there has been very little investigation into future changes in intensity ... -
Assessing scanning strategies with all-digital phased array weather radars for characterization and detection of microbursts
Pearson, Connor (2022-05-13)Microbursts are a rapidly evolving, vertically oriented meteorological phenomena that can be extremely hazardous to aviation, and other human activities, if left undetected. The temporal resolution and vertical sampling ... -
Assessing the impact of non-conventional observation types on high-resolution 3DVAR analyses and ARW-WRF forecasts
Osborne, Andrew (2016-12)This work looks at the impact on high-resolution analyses and forecasts of several non-conventional data types available within the Dallas Fort Worth (DFW) Urban Testbed. A major focus is an evaluation of the added value ... -
Assessing the Impact of Non-Conventional Observations on High-Resolution Analyses and Forecasts
Morris, Matthew (2017-05)A key recommendation of a 2009 report by the National Research Council (NRC) was for new mesoscale networks to be integrated with existing ones to form a nationwide “network of networks”. This recommendation originated ... -
A Comparative Convective Study Between the Ensemble Kalman Filter and the Local Particle Filter Using the Gridpoint Statistical Interpolation System
McAuliffe, Joel (2020-07-30)The localized particle filter (LPF) is a recent advance in ensemble data assimilation for numerical weather prediction. Derived from the original particle filter used for highly nonlinear state variables, the LPF incorporates ... -
A Comparison of Hybrid-4DEnVar and Hourly Hybrid-3DEnVar Assimilation of Tail Doppler Radar Observations on the Prediction of Rapidly Evolving Hurricanes
Davis, Benjamin (2019-08-01)Beginning in the summer of 2017 the National Weather Service upgraded the operational Hurricane WRF (HWRF) to a continuously cycled Gridpoint Statistical Interpolation (GSI) based, 6-hourly, Hybrid 3-dimensional (3D) ... -
Constraint of Vegetation Photosynthesis and Respiration Model (VPRM) Parameter Uncertainty Using a Markov Chain Monte Carlo (MCMC) Technique
Jester, Steven (2023-05-12)Modeling the changes to the carbon cycle and their effects on the atmosphere is a key area of research for understanding climate change. The Vegetation Photosynthesis and Respiration Model (VPRM) is a light-use efficiency ... -
Evaluation of the experimental warn-on-forecast system and WoF-hybrid 3DEnVar system on short-term forecasts for 2021 real-time cases
Carpenter, Noah (2022-12-16)Over the last few decades, it has become more important than ever to provide accurate forecasts for severe hazards that have become more common due to climate change effects. Over this time, several forecasting experiments ... -
Flow Dependent Evaluation and Training of Random Forest based Probabilistic Forecasts of Severe Weather Hazards
Shearer, Andrew (2023-12-15)There has been an increasing interest over the past ten years in the use of Machine Learning (ML) algorithms such as Random Forests (RF) in the context of severe weather prediction. RF-based methods have even been shown ... -
Impact of Assimilating Ground-Based and Airborne Radar Observations for the Analysis and Prediction of the Eyewall Replacement Cycle of Hurricane Matthew (2016) Using HWRF Hybrid 3DEnVar System
Green, Tyler (2021-08-05)Eyewall replacement cycles (ERC) are common dynamical processes in mature tropical cyclones (TCs) that can result in quick changes to the storm’s intensity and wind field size. As the resolution of TC models increases, ... -
Impact of data assimilation and model physics on the predictability of the 2012 Great Arctic Cyclone
Chen, Zhihong (2022-08-04)Impact of data assimilation and model physics on the predictability of the 2012 Great Arctic Cyclone A case study of the Great Arctic Cyclone 2012 (AC12) is used to understand the role of initial condition errors and model ... -
Impact of Microphysics Parameterization Schemes on the Assimilation of GOES-16 All-Sky Infrared Radiances for a Bow Echo Analysis and Prediction
Kim, Yu-Shin (2023-08-04)Assimilating infrared brightness temperature (BT) from the water vapor sensitive channels of the GOES-16 Advanced Baseline Imager (ABI) has been shown by past studies to improve the analysis and prediction of severe weather ... -
Impacts of Multiscale Predictors on Random Forest Based Probabilistic Forecasts of Severe Weather Hazards
Kubalek, Daniel (2024-05-10)Machine learning (ML) algorithms utilized for post-processing of convection-allowing model/ensemble (CAM/CAE) output has been a major area of research to handle limitations with CAM/CAE forecasts. ML has been used to correct ... -
Investigating Arctic Cyclone-Tropopause Polar Vortex Interactions with Observing System Simulation Experiments
Bray, Matthew (2023-05-12)Tropopause polar vortices (TPVs) are upper-level cyclonic circulations that are common in high latitudes. TPVs most directly impact weather at the surface by providing baroclinic forcing for the development of Arctic ... -
A Multi-Resolution Ensemble Hybrid 4DEnVar with Variable Ensemble Sizes to Improve Global and Tropical Cyclone Track Numerical Prediction
Jones, Erin (2022-05)One challenge associated with ensemble-based data assimilation (DA) is the quantitative estimation of the background error covariances. In the current global operational DA system, a reduced resolution background ensemble ... -
Multi-scale object-based probabilistic forecast evaluation of WRF-based CAM ensemble configurations
Wilkins, Andrew (2020)Recent developments in numerical weather prediction have included increased usage of ensemble forecasts in contrast to single, deterministic forecasts. In particular, convection-allowing model (CAM) ensembles have been ... -
Observations of Tropical Cyclone Vortex Rossby Waves and Their Role in Inner Core Rainbands
Alford, Austin (2016-08-12)Vortex Rossby Waves (VRWs) are hypothesized to exist in tropical cyclones (TCs), acting as an axisymmetrizing mechanism to the inner core TC flow and restored by the radial gradient of storm vorticity. In addition, they ... -
Observing System Simulation Experiments on Assimilation of Multistatic Passive Radar Network Observations into the Warn-On Forecast System to Improve Short-Term Prediction of Thunderstorm Hazards
Mose, Angela (2022-12-16)The Warn-on-Forecast System (WoFS) assimilates radar and satellite observations to produce initial conditions for short-term forecasts of individual convective storms. The accuracy of the WoFS analysis is a function of the ... -
Scale-dependent Inflation for Multiscale Ensemble based Data Assimilation
Xu, Naicheng (2023-12-15)The degree of the background ensemble deficiency, often manifested as ensemble underdispersion, can vary at different scales in the ensemble-based data assimilation. This study develops the new scale-dependent inflation ... -
SIMULTANEOUS ASSIMILATION OF RADAR AND SATELLITE DATA FOR CONVECTIVE SCALE NWP USING HYBRID ENSEMBLE VARIATIONAL DATA ASSIMILATION APPROACH
Pan, Sijie (2017)Recently, an ensemble of the three-dimensional variational data assimilation (En3DA) system has been developed based on Advanced Regional Prediction System (ARPS) three-dimensional variational (3DVar) data assimilation ...