Watching the thermosphere respond to disturbances: tracking large-scale thermospheric gravity waves with GOLD
Atmospheric gravity waves are ubiquitous throughout all levels of Earth’s atmosphere. At thermospheric altitudes, these may result from upward propagation of waves originating in the lower atmosphere or be generated by strong forcing in the auroral region. These are sometimes referred to as traveling atmospheric disturbances (TADs). It is believed that they are often closely related to ionospheric perturbations known as traveling ionospheric disturbances (TIDs). While observations of TIDs are relatively commonplace, observations of the neutral gravity waves at these altitudes are comparatively rare, especially in the middle thermosphere from ~120 – 200 km altitude. Far UV observations offer one way of observing the middle thermosphere, where abundant photoelectrons produce Far UV dayglow. During several campaigns, GOLD has been able to identify gravity waves in this region. Owing to its extended field of view, GOLD is also able to track the motion of these waves over large distances. This allows properties of these waves such as their periods to be deduced. With the inclusion of ICON wind observations, their intrinsic properties can also be found. This presentation shows the results from a multi-year survey of all the gravity waves observed by GOLD during these campaigns, along with a comparison to ground-based GNSS observations of concurrent TIDs.
Scott England is an Associate Professor in the Aerospace and Ocean Engineering Department at Virginia Tech. He did his PhD at the University of Leicester, UK, studying coupling of energy and momentum between different regions of the atmosphere via atmospheric waves. He spent 12 years at the Space Sciences Laboratory at the University of California, Berkeley, where his studies focused on the interaction between atmospheric waves and charged particles in the near-Earth space environment. He has been working at Virginia Tech since 2016 and currently focuses on using remote sensing instruments to study the upper atmosphere and near-earth space environment. He is the Project Scientist for the NASA’s ICON spacecraft, a Co-Investigator on NASA’s GOLD mission.