Time-dependent electron transport and optical emissions in the aurora

Thesis (Ph.D.) University of Alaska Fairbanks, 2000This thesis presents the first time-dependent transport model of auroral electrons. The evolution of the spherical electron intensity in phase space is studied for a variety of incident electron intensities. It is shown that the secondary electrons with energies 150 km can take over 300 ms to reach steady state in phase space. Since there are bright optical emissions in this region, such a time dependence in the auroral electrons is important. The emissions of N2(2PG) 3371 A and N+2 (1NG) 4278 A are studied for time-varying electron pulses to show for the first time that this ratio will change until the secondary electrons reach steady state in the ionosphere. The way in which the 3371A/4278A ratio changes with time-varying precipitation depends on the precipitating electron spectra. The changes in the emission ratio can be used to learn more about the auroral acceleration region and the role of the ionosphere in auroral emissions. Field-aligned bursts (FABs), often observed in electron spectra of instruments flying over flickering aurora, are modeled with the time-dependent transport model. How the ionosphere modifies these electrons is shown. The 3371 and 4278 A emissions of flickering FABs are modeled to study the optical effects of modulated electron intensities in time. A study of 4278 A emissions for electron source regions from 630 to 4,000 km are studied along with frequency variations from 5 to 100 Hz. This study shows that the percent variation of the maximum to the minimum column brightness is less for higher frequencies and more distant source regions. It is shown that with an accurate time-dependent transport calculation and 4278 A emission observations of flickering aurora it should be possible to deduce the source altitude of the modulated electrons creating the optical flickering

Nightside ionosphere of Mars: Modeling the effects of crustal magnetic fields and electron pitch angle distributions on electron impact ionization

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95654/1/jgre2678.pd

3UCubed: The IMAP Student Collaboration CubeSat Project

The 3UCubed project is a 3U CubeSat being jointly developed by the University of New Hampshire, Sonoma State University, and Howard University as a part of the NASA Interstellar Mapping and Acceleration Probe (IMAP)1 student collaboration. This project consists of a multidisciplinary team of undergraduate students from all three universities. The mission goal of the 3UCubed is to understand how Earth\u27s polar upper atmosphere (‘the thermosphere’ in Earth’s auroral regions) responds to particle precipitation and solar wind forcing and internal magnetospheric processes. 3UCubed includes two instruments with rocket heritage to achieve the science mission: an ultraviolet photomultiplier tube (UV-PMT) and electron retarding potential analyzer (ERPA). The spacecraft bus consists of the following subsystems–Attitude Determination and Control, Command and Data Handling, Power, Communication, Structural, and Thermal. Currently, the project is in the post-PDR stage, starting to build and test engineering models to develop a FlatSat prior to critical design review in 2023. The goal is to launch at least one 3U CubeSat a to collect science data close to the anticipated peak of Solar Cycle 25 around July 2025.2 Our mother mission–IMAP is also projected to launch in 2025, which will let us jointly analyze the science data of the main mission, providing the solar wind measurements and inputs to the magnetosphere with that of 3UCubed, providing the response of Earth’s cusp to these inputs

Engaging Citizen Scientists to Keep Transit Times Fresh and Ensure the Efficient Use of Transiting Exoplanet Characterization Missions

This white paper advocates for the creation of a community-wide program to maintain precise mid-transit times of exoplanets that would likely be targeted by future platforms. Given the sheer number of targets that will require careful monitoring between now and the launch of the next generation of exoplanet characterization missions, this network will initially be devised as a citizen science project -- focused on the numerous amateur astronomers, small universities and community colleges and high schools that have access to modest sized telescopes and off-the-shelf CCDs.Comment: White Paper submitted to Astro2020 Science Call, 5 pages, 3 figures, community comments and involvement are welcome

Engaging Citizen Scientists to Keep Transit Times Fresh and Ensure the Efficient Use of Transiting Exoplanet Characterization Missions

This white paper advocates for the creation of a community-wide program to maintain precise mid-transit times of exoplanets that would likely be targeted by future platforms. Given the sheer number of targets that will require careful monitoring between now and the launch of the next generation of exoplanet characterization missions, this network will initially be devised as a citizen science project -- focused on the numerous amateur astronomers, small universities and community colleges and high schools that have access to modest sized telescopes and off-the-shelf CCDs

Exploring Magnetism on Earth

Understanding the power of magnetism on Earth isnât always easy, and students and teachers alike will be glad to find out about this handy guide to the subject. Created by experts at NASA, this 15-page teacherâs guide was designed in partnership with other educators at Berkeley and several other participating institutions. The guide contains problems which examine Earthâs changing magnetic field in time and space, and how these changes can impact navigation on Earthâs surface. In terms of specific activities, the guide includes exercises on navigating the earth with a compass, the declining magnetic field, and the reversal of magnetic polarity. Each of these activities is explained in detail, and they all include relevant illustrations, graphs, questions, and an answer key

Magnetic Mystery Planets

The magnetic fields of the large terrestrial planets, Venus, Earth, and Mars, are all vastly different from each other. These differences can tell us a lot about the interior structure, interior history, and they can even give us clues to the atmospheric history of these planets. This paper highlights a classroom presentation and accompanying activity that focuses on the differences between the magnetic fields of Venus, Earth, and Mars, what these differences mean, and how we measure these differences. During the activity, students make magnetic field measurements and draw magnetic field lines of “mystery planets” using orbiting “spacecraft” (small compasses). Based on their observations, the students then determine whether they are orbiting Venus-like, Earth-like, or Mars-like planets. This activity is targeted to middle and high school audiences. However, we have also used a scaled-down version with elementary school audiences