(71b) Observations of Atmospheric Conditions during the 2020 Solar Eclipse over South America

Despite the challenges of conducting field work in an international setting during the global COVID-19 pandemic, a field project entitled “Atmospheric Gravity Wave Radiosonde Field Campaign for Eclipse 2020” was successfully conducted in Chile during the total solar eclipse (TSE) on December 14, 2020. The project collected radiosonde and surface measurements before, during, and after the TSE at Toltén and Villarrica, Chile, along the path of totality, to study the atmospheric impacts of the TSE with a focus on atmospheric gravity waves (momentum and energy transfer) generated by the TSE in the stratosphere.

High resolution radiosonde soundings were collected from both sites, with 48 hours of hourly high-altitude balloon launches centered around totality. Soundings profiled temperature, pressure, relative humidity, windspeed, and wind direction every 1 second (equivalent to ~5 m vertically) from the surface into the stratosphere. Additional surface measurements were collected using a Lufft weather station every 30 seconds over the duration of the campaign.

Unfortunately, the meteorological conditions surrounding the actual eclipse were not ideal. An atmospheric river (AR) was co-located with the TSE path before and during TSE on December 14, 2020, based on analysis of the integrated water vapor and integrated vapor transport. The AR brought downpours and thick cloud cover to both field sites. However, the data collected allowed for detailed analysis of the combinatorial impacts of the AR and TSE on solar irradiance, surface temperature, evolution of the planetary boundary layer, lapse rate, and generation of atmospheric gravity waves. These impacts will be discussed in detail.

Additionally, a nearly identical field campaign will be conducted in Lakeview, OR during the annular solar eclipse event on October 14, 2023. Radiosondes will be launched 24 hours prior to totality and 6 hours after totality in this campaign. Very preliminary results of the impacts of the eclipse on solar irradiance, surface temperature, evolution of the planetary boundary layer, lapse rate, and generation of atmospheric gravity waves will also be presented.