東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Energetic Electron Precipitation Int...

Capannolo, Luisa.

Linked to FindBook

Google Book

Amazon

博客來

Energetic Electron Precipitation Into the Earth's Upper Atmosphere Driven by Electromagnetic Ion Cyclotron Waves.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Energetic Electron Precipitation Into the Earth's Upper Atmosphere Driven by Electromagnetic Ion Cyclotron Waves./
Author:	Capannolo, Luisa.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2020,
Description:	209 p.
Notes:	Source: Dissertations Abstracts International, Volume: 81-10, Section: B.
Contained By:	Dissertations Abstracts International81-10B.
Subject:	Astronomy. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=27833277
ISBN:	9798641803814

Energetic Electron Precipitation Into the Earth's Upper Atmosphere Driven by Electromagnetic Ion Cyclotron Waves.
Capannolo, Luisa.

Energetic Electron Precipitation Into the Earth's Upper Atmosphere Driven by Electromagnetic Ion Cyclotron Waves. - Ann Arbor : ProQuest Dissertations & Theses, 2020 - 209 p.

Source: Dissertations Abstracts International, Volume: 81-10, Section: B.

Thesis (Ph.D.)--Boston University, 2020.

This item must not be sold to any third party vendors.

Energetic electrons undergo significant flux variations in the Earth's outer radiation belt, where magnetospheric waves play an important role in changing the energetic electron dynamics. In particular, electromagnetic ion cyclotron (EMIC) waves are suggested to drive efficient pitch angle scattering of relativistic electrons, which results in relativistic electron precipitation into the upper atmosphere. Such precipitation provides an important source of energy input into the upper atmosphere, where precipitating electrons can affect atmospheric chemistry and ionization. However, the quantitative role of EMIC waves in energetic electron precipitation in various regions of the magnetosphere is not fully understood. This dissertation aims to answer outstanding open questions on the characteristics and quantification of EMIC-driven precipitation, such as the spatial extent and the energy range of electron precipitation. The relationship between EMIC waves and electron precipitation is evaluated by analyzing magnetic conjunction events when EMIC waves are detected in the magnetosphere by near-equatorial satellites (Van Allen Probes, GOES) and precipitating electrons are measured by Low-Earth-Orbiting satellites (POES, FIREBIRD). Quasi-linear theory is used to quantify the role of various observed magnetospheric waves (e.g., EMIC waves, plasmaspheric hiss, magnetosonic waves) in the electron precipitation. Several in-depth case analyses show that EMIC waves are the main driver of the observed relativistic electron precipitation, while other waves play a minor role. The precipitation events were clearly identified within L shell of ~7.5, favorably near the dusk and night sectors. The analysis shows that each precipitation event was localized on average spatial scales of ~0.3 L, suggesting that the resonance conditions are satisfied in a very localized region of the magnetosphere. The electron precipitation was observed at the expected relativistic (> ~MeV) energies; however, the minimum energy of efficient electron precipitation was newly found to extend down to at least ~200-300 keV. The quantitative analysis using multi-point measurements combined with theoretical calculations in this dissertation provides a more comprehensive understanding of EMIC-driven precipitation, which is a critical electron loss process in the magnetosphere. Moreover, the results are helpful to improve currently existing models of radiation belt, ring current and atmosphere dynamics, as well as theories of wave-particle interactions.

ISBN: 9798641803814Subjects--Topical Terms:

517668
Astronomy.
Subjects--Index Terms:

Energetic electrons

Energetic Electron Precipitation Into the Earth's Upper Atmosphere Driven by Electromagnetic Ion Cyclotron Waves.
LDR:03752nmm a2200385 4500 001 2266975
005 20200623063218.5
008 220629s2020 ||||||||||||||||| ||eng d
020 $a 9798641803814
035 $a (MiAaPQ)AAI27833277
035 $a AAI27833277
040 $a MiAaPQ $c MiAaPQ
100 1 $a Capannolo, Luisa. $3 3544211
245 1 0 $a Energetic Electron Precipitation Into the Earth's Upper Atmosphere Driven by Electromagnetic Ion Cyclotron Waves.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2020
300 $a 209 p.
500 $a Source: Dissertations Abstracts International, Volume: 81-10, Section: B.
500 $a Advisor: Li, Wen.
502 $a Thesis (Ph.D.)--Boston University, 2020.
506 $a This item must not be sold to any third party vendors.
520 $a Energetic electrons undergo significant flux variations in the Earth's outer radiation belt, where magnetospheric waves play an important role in changing the energetic electron dynamics. In particular, electromagnetic ion cyclotron (EMIC) waves are suggested to drive efficient pitch angle scattering of relativistic electrons, which results in relativistic electron precipitation into the upper atmosphere. Such precipitation provides an important source of energy input into the upper atmosphere, where precipitating electrons can affect atmospheric chemistry and ionization. However, the quantitative role of EMIC waves in energetic electron precipitation in various regions of the magnetosphere is not fully understood. This dissertation aims to answer outstanding open questions on the characteristics and quantification of EMIC-driven precipitation, such as the spatial extent and the energy range of electron precipitation. The relationship between EMIC waves and electron precipitation is evaluated by analyzing magnetic conjunction events when EMIC waves are detected in the magnetosphere by near-equatorial satellites (Van Allen Probes, GOES) and precipitating electrons are measured by Low-Earth-Orbiting satellites (POES, FIREBIRD). Quasi-linear theory is used to quantify the role of various observed magnetospheric waves (e.g., EMIC waves, plasmaspheric hiss, magnetosonic waves) in the electron precipitation. Several in-depth case analyses show that EMIC waves are the main driver of the observed relativistic electron precipitation, while other waves play a minor role. The precipitation events were clearly identified within L shell of ~7.5, favorably near the dusk and night sectors. The analysis shows that each precipitation event was localized on average spatial scales of ~0.3 L, suggesting that the resonance conditions are satisfied in a very localized region of the magnetosphere. The electron precipitation was observed at the expected relativistic (> ~MeV) energies; however, the minimum energy of efficient electron precipitation was newly found to extend down to at least ~200-300 keV. The quantitative analysis using multi-point measurements combined with theoretical calculations in this dissertation provides a more comprehensive understanding of EMIC-driven precipitation, which is a critical electron loss process in the magnetosphere. Moreover, the results are helpful to improve currently existing models of radiation belt, ring current and atmosphere dynamics, as well as theories of wave-particle interactions.
590 $a School code: 0017.
650 4 $a Astronomy. $3 517668
650 4 $a Astrophysics. $3 535904
650 4 $a Physics. $3 516296
653 $a Energetic electrons
653 $a Magnetosphere
653 $a Precipitation
653 $a Radiation belts
653 $a Space weather
653 $a Waves
690 $a 0606
690 $a 0596
690 $a 0605
710 2 $a Boston University. $b Astronomy GRS. $3 3281771
773 0 $t Dissertations Abstracts International $g 81-10B.
790 $a 0017
791 $a Ph.D.
792 $a 2020
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=27833277