CEDAR: Simultaneous Fe and Na Doppler Lidar Measurements of Heat and Constituent Fluxes in the Mesopause Region and Neutral Metal Layers, Winds and Temperatures in the Thermosphere

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Two Doppler lidars, a newly developed iron (Fe) Doppler lidar and an existing sodium (Na) Doppler lidar will be operated simultaneously at Table Mountain near Boulder, CO, to acquire vertical profiles of neutral atmospheric horizontal and vertical winds, temperatures, and Fe and Na densities in the mesosphere and thermosphere to study coupling and transport processes between 80 and 150 km. The thermospheric metal layers themselves involve the coupling between ion and neutral metal layers, and the neutral winds and temperatures derived from these layers are two critical parameters needed for advancing our understanding of the space-atmosphere interaction region. The neutral wind and temperature data in the mesosphere and thermosphere will help validate global models that cover the lower and upper atmosphere (e.g., WACCM and WAM). The simultaneous measurements of Fe and Na layers and their fluxes will provide crucial information on the thermospheric metal layer formation, differential meteoric ablation, and cosmic dust velocity distribution. This work will lead to improvements in quantitative estimates of the cosmic dust input that has implications for a variety of geophysical processes throughout the polar atmosphere and Southern Ocean. Specifically, the dual lidar observations, along with correlative studies and model simulations, will be used to: (1) Characterize the recently discovered thermosphere Fe and Na layers above Table Mountain to determine how frequently they occur, how high they extend, how long they persist, and what mechanisms cause them to form; (2) Characterize neutral winds and temperatures in the 100-150 km region of the thermosphere by using the thermosphere Fe and Na layers as tracers. Explore coupling and transport processes via comparison with the Whole Atmosphere Model (WAM) simulations; and (3) Make simultaneous measurements of wave-induced vertical heat fluxes and the dynamical and chemical fluxes of Fe and Na in the mesopause region (80-105 km) to quantify the differential meteoric ablation of Fe and Na, constrain the various cosmic dust velocity distribution models, help validate the University of Leeds chemical ablation model (CABMOD) and significantly improve estimates of the global influx of cosmic dust. This project will provide research opportunities for a postdoc and a graduate student.