• Login
    View Item 
    •   Home
    • University of Alaska Fairbanks
    • UAF Graduate School
    • Physics
    • View Item
    •   Home
    • University of Alaska Fairbanks
    • UAF Graduate School
    • Physics
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of Scholarworks@UACommunitiesPublication DateAuthorsTitlesSubjectsTypeThis CollectionPublication DateAuthorsTitlesSubjectsType

    My Account

    Login

    First Time Submitters, Register Here

    Register

    Statistics

    Display statistics

    Exospheric neutral density study using XMM-Newton soft x-ray observations and MHD-based magnetosheath model

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Jung_J_2022.pdf
    Size:
    6.512Mb
    Format:
    PDF
    Download
    Author
    Jung, Jaewoong
    Chair
    Zhang, Hui
    Committee
    Connor, Hyunju K.
    Carter, Jennifer A.
    Sibeck, David G.
    Newman, David
    Keyword
    Solar wind
    Exosphere
    X-rays
    Metadata
    Show full item record
    URI
    http://hdl.handle.net/11122/13084
    Abstract
    Studying interactions between the solar wind and the Earth is important, and one future satellite mission, called Solar wind Magnetosphere Ionosphere Link Explorer (SMILE), will be launched in late 2024 or early 2025 to study these interactions. SMILE will image the magnetosheath using the charge exchange process and extract the location and motion of the bow shock and magnetopause. The subsolar magnetopause is typically around 10 Earth radii, and neutral density in this outer exosphere is poorly understood. For that reason, we study the neutral density around 10 Earth radii. We estimated the exospheric density at 10 Earth radii using XMM-Newton astrophysics observations, one taken during solar minimum and five taken during solar maximum. For the solar minimum case study, the lower limit of the exospheric density was estimated to be 36.8 ± 11.7 cm⁻³ at 10 Earth radii subsolar point. For solar maximum case studies, we estimated neutral density to be in the range of 42.5 - 65.1 cm⁻³ at 10 Earth radii subsolar point. This suggests weak dependence of neutral density on solar activity but more statistical analysis is needed. The neutral density behavior of the outer exosphere will help us understand the Earth's atmospheric loss due to the dynamic space environment and thus, infer the entire evolutionary history of the Earth's atmosphere as well as of other planetary atmospheres. Along with neutral density, plasma number density, velocity, and temperature in the magnetosheath are key parameters for predicting soft X-ray images. We developed a user-friendly model of magnetosheath parameters to help derivation of these parameters in future wide field-of-view soft X-ray missions. The model parameterizes number density, velocity, magnetic field, and temperature, by using OpenGGCM MHD simulation results as seed data. We made a suite of magnetosheath models, by compiling pre-existing magnetosheath models (analytic, gas-dynamic) with our MHD-based model. This parameterized model is expected to enable researchers to reconstruct expected soft X-ray images and also use these images for analysis of observed images from future satellite missions including SMILE.
    Description
    Dissertation (Ph.D.) University of Alaska Fairbanks, 2022
    Table of Contents
    Chapter 1: Introduction -- 1.1. Solar wind and magnetospheric regions -- 1.2. Solar wind charge exchange -- 1.3. Basic SWCX flux modeling -- 1.4. Exosphere -- 1.5. References. Chapter 2. Solar minimum exospheric neutral density near the subsolar magnetopause estimated from the XMM soft X-ray observations on 12 November 2008 -- 2.1. Introduction -- 2.2. Data and model -- 2.2.1. XMM data -- 2.2.2. OpenGGCM model -- 2.3. Methodology -- 2.4. Event selection -- 2.5. Case study of the 12-Nov-2008 event -- 2.5.1. Extraction of the near-earth SWCX counts -- 2.5.2. Neutral density estimation -- 2.5.3. Error analysis -- 2.6. Discussion -- 2.7. Summary -- 2.8. References. Chapter 3. Exospheric neutral density during solar maximum estimated from the XMM soft X-ray observations -- 3.1. Introduction -- 3.2. Methodology -- 3.3. SWCX observation -- 3.4. Discussion -- 3.5. Conclusion -- 3.6. References. Chapter 4. A user-friendly, parameterized model of magnetosheath conditions -- 4.1. Introduction -- 4.2. MHD-based magnetosheath model -- 4.2.1. Coordinates and boundaries -- 4.2.2. Parameterization of MHD model -- 4.2.3. Comparison with THEMIS statistics -- 4.3. Compilation of magnetosheath models -- 4.3.1. Additional models -- 4.3.2. Comparison With satellite magnetosheath crossing -- 4.3.3. Modeling of soft X-ray image -- 4.4. Discussion -- 4.5. Summary -- 4.6. References. Chapter 5. Summary and future work -- 5.1. Summary of results -- 5.1.1. Solar minimum exospheric neutral density near the subsolar magnetopause estimated from the XMM soft X-ray observations on 12 November 2008 -- 5.1.2. Exospheric neutral density during solar maximum estimated from the XMM soft X-ray observations -- 5.1.3. A user-friendly, parameterized model of magnetosheath conditions -- 5.2. Future work -- 5.3. References. Appendix.
    Date
    2022-08
    Type
    Dissertation
    Collections
    Physics

    entitlement

     
    ABOUT US|HELP|BROWSE|ADVANCED SEARCH

    The University of Alaska is an affirmative action/equal opportunity employer, educational institution and provider and prohibits illegal discrimination against any individual.

    Learn more about UA’s notice of nondiscrimination.

    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.