ALBERT

Description: Numerical methods are used to simulate the double-diffusion driven convective pore-fluid flow and rock alteration in three-dimensional fluid-saturated geological fault zones. The double diffusion is caused by a combination of both the positive upward temperature gradient and the positive downward salinity concentration gradient within a three-dimensional fluid-saturated geological fault zone, which is assumed to be more permeable than its surrounding rocks. In order to ensure the physical meaningfulness of the obtained numerical solutions, the numerical method used in this study is validated by a benchmark problem, for which the analytical solution to the critical Rayleigh number of the system is available. The theoretical value of the critical Rayleigh number of a three-dimensional fluid-saturated geological fault zone system can be used to judge whether or not the double-diffusion driven convective pore-fluid flow can take place within the system. After the possibility of triggering the double-diffusion driven convective pore-fluid flow is theoretically validated for the numerical model of a three-dimensional fluid-saturated geological fault zone system, the corresponding numerical solutions for the convective flow and temperature are directly coupled with a geochemical system. Through the numerical simulation of the coupled system between the convective fluid flow, heat transfer, mass transport and chemical reactions, we have investigated the effect of the double-diffusion driven convective pore-fluid flow on the rock alteration, which is the direct consequence of mineral redistribution due to its dissolution, transportation and precipitation, within the three-dimensional fluid-saturated geological fault zone system.

Description: The use of groundbased GPS network (e.g., Suominet, [Ware et al., 2000]) and spaceborne GPS-to-Low-Earth-Orbiter (LEO) GPS limb-sounding techniques for retrieving atmospheric profiles have been demonstrated [e.g., Rocken et al., 1997]. GPS has also been used as a water level measurement [e.g., Parke et al., 1997] and for radar altimeter calibration. In this paper, we will discuss the use of the proposed Ohio State University continuous GPS stations (located in Columbus, Lake Erie, and Gulf of Mexico offshore oil platform) and buoy equipped GPS receivers as a measurement system of atmospheric water vapor, sea level, and for absolute calibrations of spaceborne radar altimeters. Furthermore, water vapor measurements sampled in space and time will be discussed using the groundbased stations and the current and future spaceborne measurements for the potential of near-real time retrieval of atmospheric profiles to improve regional weather forecasting.