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Thermospheric Wave Activity in Neutral Winds and Temperature Above Antarctica

Mark
Conde
Geophysical Institute, University of Alaska Fairbanks
Abstract text

We present signatures of wave-like perturbations in Earth's neutral thermosphere above Antarctica, derived from long time series measurements of wind and temperature that were obtained using ground-based Doppler spectroscopy of the 630 nm optical emission from atomic oxygen. This widely-used technique typically requires dark-sky observing conditions, and so cannot provide continuous time-series results spanning more than a single night. However, the observatories at McMurdo and South Pole stations in Antarctica are at sufficiently high latitude that they experience several months of continuous darkness during winter. Further, clear-sky conditions can persist for many days at South Pole. As a result, we have recently obtained a remarkable 28-day stretch of virtually uninterrupted thermospheric wind and temperature measurements from South Pole during April of 2026. Filtering these data to remove periods longer than 6 hours shows that wave-like oscillations were ubiquitous at 240 km altitude during this observing run, with bursts of enhanced perturbations occurring during times of elevated magnetic activity. (Unfiltered) perturbation spectra generally follow a -5/3 log-log slope, with clear peaks also appearing at diurnal and semi-diurnal periods, plus several higher harmonics. These data will support multiple future studies, including investigating the relative roles of multi-step vertical coupling versus in-situ geomagnetic forcing in exciting these wave oscillations.

Authors
Mark Conde, University of Alaska Fairbanks
Kylee Branning, University of Alaska Fairbanks
Sharon Vadas, NorthWest Research Associates
Allan Weatherwax, Massachusetts Institute of Technology
Andrew Gerrard, New Jersey Institute of Technology
Non-Student
Poster category
POLA - Polar Aeronomy
Poster number
3