EEWR Brown Bag Seminar with Graduate Students Xinwo Huang and Wang Zhan
Speaker: Xinwo Huang and Wang Zhan, Graduate Students
Series: EEWR Brown Bag Seminars
Location: Engineering Quad E225
Date/Time: Friday, March 29, 2013, 12:00 p.m. - 1:00 p.m.
Speaker: Xinwo Huang
Title: Basin-scale modeling of CO2 storage using a cascade of models of varying complexity
Geological carbon storage can contribute to climate-change mitigation only if it is deployed at a very large scale. This means that injection scenarios must occur, and be analyzed, at the basin scale. Various mathematical models of different complexity have been developed to assess the fate of injected CO2 and/or resident brine, spanning the range from multi-dimensional, multi-phase numerical simulators to simple single-phase analytical solutions. In this study, we consider a range of models, all based on vertically-integrated governing equations, to predict the basin-scale pressure response to given injection scenarios. The Canadian section of the Basal Aquifer is used as a test site to compare the different modeling approaches. The model domain covers an area of approximately 811,000 km2, and the total injection rate is 63 Mt/yr, corresponding to 9 locations where large point sources have been identified. The predicted areas of critical pressure exceedance of the injection sites are used as a comparison metric among the different modeling approaches. The comparison of results shows that singlephase numerical models may be good enough to quickly predict the pressure response over a large aquifer; however, a simple superposition of the semi-analytical or analytical solutions is not a sufficiently accurate tool because spatial variability of formation properties plays an important role in the problem. We consider two different injection scenarios: injection at the source locations and injection at locations with more suitable aquifer properties. In formations with significant spatial variability in properties, strong variations in injectivity among the different source locations can be expected to lead to the need to transport the captured CO2 to suitable injection locations, thereby necessitating development of a pipeline network.
Speaker: Wang Zhan
Title: Adjusting TRMM Multi-Satellite Precipitation Analysis (TMPA) Real-Time Precipitation over the Contiguous United States
Droughts and floods are pervasive natural hazards and are responsible for significant loss of lives and property each year. With the availability of satellite-based precipitation estimates and upgrades to the precipitation algorithms, it has become possible to improve current hydrologic monitor and prediction capability at global scale. However, significant concern has been expressed regarding the ability of real-time satellite-based precipitation products such as the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis estimates (TMPA) real-time products for flood and drought monitor. This paper addresses these concerns by firstly evaluating TMPA 3B42 real-time (3B42RT) rainfall estimates against the North American Land Data Assimilation System (NLDAS) rainfall products with a focus on its ability to detect patterns of heavy rainfall that may lead to flood events. Analysis shows that bias exists in TMPA 3B42RT rainfall estimates in terms of frequency, intensity, duration, and timing. Following the evaluation, a methodology is developed to adjust TMPA 3B42RT products utilizing satellite-based soil moisture retrievals based on AMSR-E soil moisture retrievals. Particle filter is used in data assimilation to enhance real-time satellite-based rainfall estimates. Using ground streamflow measurements and a river routing model for validation, the approach is evaluated over the contiguous United States. Results demonstrate that, the method of assimilating soil moisture retrievals are capable of improving satellite-based realtime rainfall products. The adjustment method developed in this study can be further applied in demanding areas lacking ground-based observations such as Africa.