2-D Modeling and Simulation of Ozone Distribution, Depletion, and Holes

• Other Authors: Alelmi, Ibraheem (Author), The Catholic University of America (Degree granting institution), Nieh, Sen (Thesis advisor), Massoudieh, Arash (Committee member), Tongele, Tongele (Committee member), Omar, Mohamed (Committee member)
• Format: Doctoral or Postdoctoral Thesis
• Language: unknown
• Published: The Catholic University of America 2024
• Subjects: 2-D Model; Convection Diffusion Reaction; Latitudinal Changes; Ozone-Depleting Reactions; Sensitivity Analysis; Stratospheric Ozone; South pole
• Online Access: https://cuislandora.wrlc.org/islandora/object/cuislandora%3A321465

This dissertation presents a systematic engineering system approach to modeling and analyzing the complex dynamics of stratospheric ozone. A 2-D cylindrical model that incorporates mass balance calculations, convection, diffusion, and all fourteen photolysis, ozone-generating, and ozone-depleting chemical reactions was developed, validated, and extensively tested. The model accurately reproduces ozone concentrations, profiles, and peak values observed in the stratosphere, with less than 1% deviation from measured data for average concentrations and within 14% deviation for distributions at the equator, and less than 19% deviation at higher latitudes such as 60°S. Investigation into latitudinal variations revealed significant shifts in peak ozone concentrations attributed to solar radiation intensity and latitudinal positioning. For instance, at the equator, peak ozone concentrations reached 9.41 ppm at an altitude of 30 km in the mid-stratosphere, while at 40°S the peak concentration was 7.81 ppm at 34.5 km altitude, and at the South Pole it decreased to 5.78 ppm at 39 km altitude. Furthermore, total ozone abundances at the strategic latitudes of 0°S, 20°S, 40°S, 60°S, and 90°S remained relatively stable, ranging from 305 DU to 335 DU, except for a smaller value of 288 DU at the South Pole. Monthly evolution analysis provided insights into seasonal variations, with calculated values closely matching measured data. Exploration of the influence of slow air movement in both vertical and radial directions highlighted its impact on ozone distribution, with variations in wind speed correlating with shifts in ozone concentration profiles. Parametric studies on mass diffusivities of ozone (DO3) and active atomic oxygen gases (DO) elucidated their roles in shaping ozone distribution, with atomic oxygen diffusivity (DO) identified as a critical factor due to its higher sensitivity compared to ozone diffusivity (DO3). Sensitivity analyses demonstrate that chlorine exhibits higher sensitivity when compared to other ...