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Simulating Tvashtar's Plume Observed During the 2007 New Horizons Io Flyby
Simulating Tvashtar's Plume Observed During the 2007 New Horizons Io Flyby
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260311091501.5
- ISBN
- 9798270228972
- DDC
- 515.35
- 서명/저자
- Simulating Tvashtars Plume Observed During the 2007 New Horizons Io Flyby / Aanuoluwapo Olorunfemi Adeloye
- 발행사항
- [Sl] : The University of Texas at Austin, 2025
- 형태사항
- 1 electronic resource (208 pages)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-06, Section: B.
- 주기사항
- Advisors: Goldstein, David; Varghese, Philip L. Committee members: Trafton, Laurence M.; Clemens, Noel T.; Lopes, Rosaly.
- 학위논문주기
- - Ph.D. : The University of Texas at Austin, 2025.
- 초록/해제
- 요약During the 2007 New Horizons (NH) flyby, Io's Tvashtar Catena region exhibited a remarkable ~350 km high Pele-type volcanic plume whose canopy radiance unexpectedly surged by an order of magnitude as the solar phase angle between the Sun, Io, and NH increased from ~40° to 150°. High-resolution LOng-Range Reconnaissance Imager (LORRI) images captured the plume's evolution, prompting an investigation into the underlying causes of this brightness anomaly. Initial analyses using Direct Simulation Monte Carlo (DSMC) simulations revealed that variations in basic vent parameters-such as stagnation temperature, vent area, mass flow rate, and grain mass loading-alone could not account for the observed radiance increase. To elucidate the factors influencing the plume's brightness, a comprehensive sensitivity study was conducted, focusing on Tvashtar's vent properties and the optical scattering behavior of entrained basaltic grains. The study employed axisymmetric DSMC simulations integrated with both gas and grain radiation modeling, alongside Mie theory to characterize light scattering from a log-normal grain size distribution. A robust method was developed to constrain vent parameters by fitting DSMC-generated plume canopies to canopy spatial coordinates extracted from each LORRI image using a Levenberg-Marquardt optimization algorithm. This approach identified vent stagnation temperature and area as the most influential parameters on the plume's canopy characteristics, suggesting an asymmetric source region consistent with prior research. However, the fitting process indicated that changes in vent conditions during the flyby did not correlate with the brightness surge. Instead, the surge was primarily attributed to the optical scattering properties of the plume particulates, influenced by observational geometry and grain mass loading. Further integrating fractal aggregate theory, the study modeled the microphysical structure of entrained grains, deriving a fractal dimension of D=1.88±0.01 and a z-average aggregate radius of R_(g,z)=0.22±0.01 μm. These results are consistent with diffusion-limited cluster aggregation (DLCA) observed in terrestrial volcanic aerosols, suggesting similar aggregation processes on Io. Furthermore, an analysis of cluster polydispersity indicates that the grains in Tvashtar's plume canopy exhibit behavior more characteristic of a monodisperse population. This interdisciplinary approach, combining DSMC modeling, fractal aggregate theory, and Mie scattering analyses, provides a comprehensive framework for understanding Io's volcanic plume dynamics. The insights gained not only enhance the interpretation of NH's Tvashtar observations but also offer a robust diagnostic tool for investigating particle-gas interactions in extreme environments, informing future planetary science missions and remote-sensing strategies.
- 언어주기
- English
- 일반주제명
- Physics
- 일반주제명
- Planetology
- 일반주제명
- Atmospheric sciences
- 기타저자
- The University of Texas at Austin Aerospace Engineering
- 기본자료저록
- Dissertations Abstracts International. 87-06B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■007cr|nu||||||||
■020 ▼a9798270228972
■040 ▼aMiAaPQD▼beng▼cMiAaPQD▼erda
■082 ▼a515.35
■1001 ▼aAdeloye, Aanuoluwapo Olorunfemi▼eauthor.
■24510▼aSimulating Tvashtar's Plume Observed During the 2007 New Horizons Io Flyby ▼cAanuoluwapo Olorunfemi Adeloye
■260 ▼a[Sl]▼bThe University of Texas at Austin▼c2025
■264 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a1 electronic resource (208 pages)
■336 ▼atext▼btxt▼2rdacontent
■337 ▼acomputer▼bc▼2rdamedia
■338 ▼aonline resource▼bcr▼2rdacarrier
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-06, Section: B.
■500 ▼aAdvisors: Goldstein, David; Varghese, Philip L. Committee members: Trafton, Laurence M.; Clemens, Noel T.; Lopes, Rosaly.
■5021 ▼bPh.D.▼cThe University of Texas at Austin▼d2025.
■520 ▼aDuring the 2007 New Horizons (NH) flyby, Io's Tvashtar Catena region exhibited a remarkable ~350 km high Pele-type volcanic plume whose canopy radiance unexpectedly surged by an order of magnitude as the solar phase angle between the Sun, Io, and NH increased from ~40° to 150°. High-resolution LOng-Range Reconnaissance Imager (LORRI) images captured the plume's evolution, prompting an investigation into the underlying causes of this brightness anomaly. Initial analyses using Direct Simulation Monte Carlo (DSMC) simulations revealed that variations in basic vent parameters-such as stagnation temperature, vent area, mass flow rate, and grain mass loading-alone could not account for the observed radiance increase. To elucidate the factors influencing the plume's brightness, a comprehensive sensitivity study was conducted, focusing on Tvashtar's vent properties and the optical scattering behavior of entrained basaltic grains. The study employed axisymmetric DSMC simulations integrated with both gas and grain radiation modeling, alongside Mie theory to characterize light scattering from a log-normal grain size distribution. A robust method was developed to constrain vent parameters by fitting DSMC-generated plume canopies to canopy spatial coordinates extracted from each LORRI image using a Levenberg-Marquardt optimization algorithm. This approach identified vent stagnation temperature and area as the most influential parameters on the plume's canopy characteristics, suggesting an asymmetric source region consistent with prior research. However, the fitting process indicated that changes in vent conditions during the flyby did not correlate with the brightness surge. Instead, the surge was primarily attributed to the optical scattering properties of the plume particulates, influenced by observational geometry and grain mass loading. Further integrating fractal aggregate theory, the study modeled the microphysical structure of entrained grains, deriving a fractal dimension of D=1.88±0.01 and a z-average aggregate radius of R_(g,z)=0.22±0.01 μm. These results are consistent with diffusion-limited cluster aggregation (DLCA) observed in terrestrial volcanic aerosols, suggesting similar aggregation processes on Io. Furthermore, an analysis of cluster polydispersity indicates that the grains in Tvashtar's plume canopy exhibit behavior more characteristic of a monodisperse population. This interdisciplinary approach, combining DSMC modeling, fractal aggregate theory, and Mie scattering analyses, provides a comprehensive framework for understanding Io's volcanic plume dynamics. The insights gained not only enhance the interpretation of NH's Tvashtar observations but also offer a robust diagnostic tool for investigating particle-gas interactions in extreme environments, informing future planetary science missions and remote-sensing strategies.
■546 ▼aEnglish
■590 ▼aSchool code: 0227
■650 4▼aPhysics
■650 4▼aPlanetology
■650 4▼aAtmospheric sciences
■653 ▼aVolcanic plume dynamics
■653 ▼aDirect Simulation Monte Carlo
■653 ▼aFractal aggregate theory
■7102 ▼aThe University of Texas at Austin▼bAerospace Engineering.▼edegree granting institution.
■7201 ▼aGoldstein, David▼edegree supervisor.
■7201 ▼aVarghese, Philip L.▼edegree supervisor.
■7730 ▼tDissertations Abstracts International▼g87-06B.
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17361113▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
