Lidar Investigation of Geospace-Atmosphere Temperature, Composition, Chemistry, and Dynamics at McMurdo, Antarctica

The uppermost layers in the atmosphere act as a shield that protects life on Earth from incoming solar radiation and meteoroids. The dynamics of this region are known to affect critical modern technologies, including aviation, satellite communications and navigation systems. This project will use powerful lasers located in McMurdo Station, Antarctica, to study this key transition region between Earth and space. Lidars detect metal atoms deposited at high altitudes by cosmic dust and meteoroids that are vaporized as they enter the atmosphere. The project will conduct another four years of lidar observations, resulting in 18 years of iron density and temperature data, and 11 years of sodium, temperature, and vertical wind data. The team will characterize the behavior of high atmospheric layers, leading to a better understanding of interactions in the Earth-Sun system. This award will extend the project’s Antarctica-based observations to nearly two solar cycles, establishing a valuable long-term database. This project will provide exceptional opportunities for training junior researchers in the field in Antarctica. It will also enhance international collaboration in Antarctic research and include broad public exploration of the complex Sun-Earth system. This project will continue year-round operations of the Na Doppler and Fe Boltzmann lidars at Arrival Heights near McMurdo Station, Antarctica, from September 2026 through August 2030. These complementary lidar systems simultaneously measure atmospheric temperature in the ~30-200 km range, neutral Na and Fe densities in the ~70-200 km range, and vertical winds in the mesopause region, producing a highly valuable observational record of the coupled ionosphere-thermosphere-mesosphere (ITM) system. This project will cover a significant portion of the declining phase of Solar Cycle 25, resulting in the accumulation of ~18 and 11 years of Fe and Na lidar data, respectively. These data will enable compelling new science, building upon previous discoveries made through this program and combining data analysis with model simulations. The study of thermosphere-ionosphere metal layers and their response to geomagnetic forcing and solar variability will significantly advance our understanding of complex space-atmosphere interactions. The project will characterize gravity-wave-induced transport and forcing on the upper atmosphere, with applications to a wide range of research problems. The team will use a multistep vertical wave coupling framework to better assess the impact of lower atmosphere forcing on the ionosphere and thermosphere. The project will establish long-term records of temperatures and metal layers and quantify various-scale effects, crucial for calibrating satellite observations and validating general circulation models. These contributions will establish a baseline against which long-term trends in a changing Antarctica will be assessed decades from now. This project addresses important ITM science identified in the National Academies’ 2024 Decadal Survey for Solar and Space Physics. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.