Date of Award

Spring 2020

Project Type

Dissertation

Program or Major

Physics

Degree Name

Doctor of Philosophy

First Advisor

Marc Lessard

Second Advisor

Harlan Spence

Third Advisor

Lynn Kistler

Abstract

Ionospheric upwelling and outflow are large-scale processes which affect the dynamics of the greater magnetosphere-ionosphere-thermosphere system. Though these terms historically refer to the propensity of ions to increase in scale height and escape Earth's gravity due to a the collective effect of energization processes; that same behaviour is frequently observed to occur with neutral species within the cusp regions of the ionosphere. Although many different driving mechanisms have been identified which contribute to the energization and increase in scale height of the ionosphere, the relative energy budget of these individual drivers is debated. In this dissertation, data from the Rocket Experiment for Neutral Upwelling 2 (RENU2) will be presented as a case study of these energization processes. In particular, sub-kilometer scale features are examined to demonstrate that a significant portion of energy flux into the ionosphere is carried by fine-scale structures which have an integrated effect to cause the large-scale upwelling. An additional study is presented on the ability of pulsating aurora to drive upwelling. Pulsating aurora are spatially confined regions of periodic brightening driven by electron precipitation (on the order of 10s of keV) embedded in a diffuse aurora background (on the order of a few keV). Though these two studies are unrelated, both are linked by the idea of that large-scale responses of the ionosphere may be driven by fine-scale structures. Additionally, a section is presented on the development and first flight of an ejectable instrument to measure electron temperatures in a distributed array from a single sounding rocket. The ability to perform multi point measurements from a single rocket platform is paramount to understanding the fine scale coupling of the ionosphere to large scale phenomenon.

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