Observations of Inertial Gravity Waves during the 2020 Solar Eclipse over South America

Atmospheric gravity waves (AGWs), known to redistribute energy and momentum between atmospheric layers, affect both small scale weather events and planetary circulation and variability. AGWs are not explicitly included in numerical weather prediction, however their affects are parameterized. Observations of AGWs at all scales are important to refining these parameterizations, contributing to better descriptions of their effects in weather models and forecasts. Solar eclipses were confirmed to be a source of AGWs in the lower stratosphere in 2019. Seeking to replicate these results, data was collected during the total solar eclipse on December 14, 2020 and analyzed. During a 50 h campaign centered around totality, balloon-borne measurements were recorded on 1 h intervals from two sites along the path of totality (Toltén & Villarrica) in Chile. Linear wave theory predicts that low frequency inertial waves have a helical structure when plotted on a hodograph. Thus, temperature and wind velocity data were analyzed for gravity waves using the hodograph detection technique. Multiple polynomial fits were investigated to remove background fluctuations before the monochromatic wave components in each profile were extracted using a band-pass Butterworth filter. The resulting perturbation profiles were inspected for regions containing elliptical features and measured by fitting an ellipse to the observed data. The polarization and dispersion relations were used to extract wave parameters from the identified elliptical regions. The resultant wave parameters are used to determine the source of each identified wave. The waves detected with hodograph techniques from the 2020 solar eclipse data will be discussed.