HAO Colloquium - Katelynn Greer, CU LASP

Investigating the Thermosphere-Ionosphere System through Earth's FUV Emissions

The Earth’s upper atmosphere emits in the Far-UV (120 to 200nm); image at these wavelengths are indicative of the changes in, and evolution of, the lower thermosphere and ionosphere. The GOLD instrument is an imaging spectrograph that measures the Earth’s emissions from 132 to 162 nm on the limb and disk. These measurements are used to image thermospheric temperature and composition near 160 km on the dayside disk at half-hour time scales, as well as nighttime ionospheric plasma densities.  Significant challenges in understanding and predicting the thermosphere and ionosphere continue to exist; current models still fall short of properly describing night time phenomena, the variability of day time airglow and the thermal structure of the lower thermosphere.   New observations from the GOLD mission have allowed the unambiguous determination of the equatorial ionospheric anomaly (EIA) in space and time, challenging long-held assumptions about the phenomena, including the decay of the EIA and the formation of depletions (bubbles).  The uncharacterized day-to-day variability of the dayglow has been a hot topic of discussion given the strong forcing of waves from the lower atmosphere during this solar minimum. Here we will discuss new discoveries enabled by Far-UV observations of thermospheric gravity waves, solar terminator waves, and the equatorial ionospheric anomaly.

Date and time: 
Wednesday, August 21, 2019 - 2:00pm to 3:00pm