Chemistry and Physics Faculty Proceedings, Presentations, Speeches, Lectures

Measuring F-region ion-neutral coupling in response to increases in auroral precipitation

Event Name/Location

2017 Coupling, Energetics, and Dynamics of Atmospheric Regions conference in Keystone, Colorado

Date Range

18-23 June 2017

Presentation Date

2017

Document Type

Poster

Description

Neutral winds are a key factor in the dynamics of the ionosphere-thermosphere system. Previous observations have shown neutral and ion flows to bestrongly coupled during periods of auroral activity, but this coupling is suppressed when aurora is not present. This is primarily due to enhanced particle precipitation during auroral activity. Current simulations have difficulty reproducing momentum coupling on large scales due to the sensitivity of modeled winds to particle precipitation inputs. It is therefore critical to both accurately measure auroral precipitation as well as the resulting increase in the ion-neutral coupling. Recent advancements in high-resolution fitting of SuperDARN data have enabled us to generate a steady map of ion drifts over Alaska, coinciding with several optics sites. Available optical instruments include digital all-sky imagers and meridian spectrographs, which provide measurements of auroral intensity at three wavelengths. Also present are several Scanning Doppler Imagers, which can measure thermospheric winds and temperatures over a wide area. In this study, we have combined these three data sets in order to investigate the impact of increases in particle precipitation on ion-neutral coupling. We have found a significant correlation between enhancements auroral emission resulting from precipitation and increases in the ion-neutral coupling in the pre-magnetic midnight sector. In addition, we have quantified the time scale over which the coupling occurs, comparing our observations to previous theoretical estimates.

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