This project was a collaboration between the United States Antarctic Program (USAP) and Antarctica New Zealand (AntNZ). Under the support of National Science Foundation (NSF) OPP-1246405 and OPP-1246431 awards, the lidar team from University of Colorado Boulder operates the first Fe Boltzmann lidar in an AntNZ laboratory at Arrival Heights Observatory near McMurdo, Antarctica. This lidar has been measuring temperatures from 30 to ~200 km, Fe densities, and polar mesospheric clouds (PMCs) for ~10 years. In January 2018 the lidar team installed and began operating a Na Doppler lidar alongside the Fe lidar, which provides simultaneous measurements of temperature, vertical wind, and Na density in the mesosphere and lower thermosphere (MLT) to complement the Fe lidar data. These two lidars are so advanced that together they can make measurements from ~10 km up to ~200 km with high-precision laser spectroscopy in space and atmosphere, enabling a broad range of important science studies. The lidar team has conducted extensive science investigations using the lidar data and numerical modeling, made groundbreaking science discoveries, trained PhD, master, and undergraduate students along with postdoctoral researchers, promoted female scientists, produced press releases, made public outreach, and fostered international collaborations in Antarctica.

Intellectual Merit: At least 12 science topics have been investigated using the McMurdo lidar data. Nearly 40 journal papers have emerged from the observations on the topics of 1) polar mesospheric clouds, 2) thermosphere-ionosphere metal layers, 3) mesospheric metal layers, 4) gravity waves, 5) tidal waves, 6) planetary waves, 7) plasma-neutral coupling (coupling from topside down), 8) cosmic dust influx, 9) vertical transport, 10) thermal structures, 11) vertical coupling and general circulation (from bottom up), and 12) quasi-biennial oscillation. These studies break new ground for science discoveries and breakthroughs. 

The lidar research has led to numerous eye-opening discoveries and some are transformative to advancing the space-atmosphere sciences. For example, in contrast to a traditional view that meteoric Fe layers are confined to 75-110 km, the McMurdo Fe lidar has observed the neutral Fe layers up to ~200 km in the ionospheric E-F regions (Chu et al., 2011). This discovery opens a new window to observing the neutral thermosphere and studying the plasma-neutral interactions with ground-based instruments (Chu and Yu, 2017). Another example is the discovery of persistent gravity waves in the MLT (Chen et al., 2016). This new class of large-scale waves are dominant and perpetual in the McMurdo MLT temperature, but could not be simulated by many general circulation models. Inspired by lidar discoveries and combining data with theories and modeling, Vadas et al. (2018) proposed a "primary-secondary" wave coupling mechanism to reconcile the differences between the MLT and stratospheric gravity waves (Zhao et al., 2017; Chu et al., 2018). McMurdo lidar data provides the first observational evidence for this secondary wave generation theory (Vadas et al., 2018). The 12 topics and ~40 journal publications are only a small fraction of the important science that can be addressed by the datasets of temperature, Fe and Na, vertical wind, and PMCs. The McMurdo lidar project contributes significantly to advancing our understandings of the coupling from the atmosphere to geospace and space-atmosphere interactions.

Broader Impacts: The McMurdo lidar project has provided exceptional training opportunities to many students and postdocs, producing numerous top PhDs and the next-generation of young scientists. Six PhDs (Yu, Smith, Fong, Chen, Zhao, and Li) were produced from the McMurdo lidar projects, along with five master degrees, four postdocs (Huang, Lu, Wang, and Lin), and 12 winter-over lidar scientists. Many lidar students have won NSF CEDAR (Coupling, Energetics, and Coupling of Atmospheric Regions) poster competition prizes: Four 1st-place prizes (Yamashita, Chen, Yu, and Fong), three 2nd-place prizes, and one undergraduate honorable mention (Geraghty). The projects have helped promote three female scientists (Chu, Vadas, and Lu) with the Principal Investigator, Dr. Chu, winning the CEDAR Prize Lecture Award in 2019.

Lidar projects are highly interdisciplinary and cutting-edge, involving a wide range of engineering and scientific skills. Students working in Antarctica gain extensive knowledge in laser physics, electrical, computer and mechanical engineering, photonics, signal processing, and atmospheric sciences, as well as real world experience in building lidar instruments and making them work under challenging conditions. Such trainings produce scientists/engineers who are exceptionally versatile and adaptable. They typically have a wide variety of employment opportunities upon graduation. Many students and postdocs trained on the McMurdo lidar project have found their dream jobs, such as tenure-track faculty positions (Yu, Lu, and Lin), NASA civil servant (Smith), research positions (Huang, Yamashita, & Wang), and industry lead engineers (Roberts, Fong, & Chen). Numerous press releases were made on the McMurdo discoveries, increasing the public awareness. Such sophisticated lidars have become a centerpiece of the Arrival Heights Geospace-Atmosphere Observatory in Antarctica, inspiring multi-dimensional science exploration and discoveries in the complex, nonlinear, and dynamic Sun-Earth system.

Last Modified: 10/23/2021
Modified by: Xinzhao Chu