The investigators will upgrade an existing Fabry Perot Interferometer (FPI) at the Arequipa Optical Observatory in Peru. The upgrade will produce a capability for mesopause measurements of winds and temperatures with high accuracy and frequent sampling rates. The modifications will also improve the measurements of thermospheric winds, temperatures, and airglow intensities interleaved with the mesosphere measurements. These observations will contribute to the study of major features of mesopause dynamics such as the diurnal tidal winds and temperatures, and planetary wave variations in a region of the Southern Hemisphere where the current samping distribution by ground-based stations is sparse. These nighttime measurements, combined with Jicamarca Radar measurements of daytime winds, will help ameliorate the sampling and aliasing errors that satellite measurements suffer due to the slow precession of the spacecraft in local time. The upgrade will also make possible the study of mesopause small-scale gradients in wind, temperature, and hydroxyl airglow intensities that may arise from orographic wave effects. Also included in the effort is an upgrade in an imaging camera at Arequipa, involving the procurement and installation of a broadband filter to make possible the imaging observations of nocturnal variations of hydroxyl intensities. The Arequipa observations will support CEDAR/TIMED science goals. CEDAR, which stands for Coupling, Energetics, and Dynamics of Atmospheric Regions, is a global change program that combines theoretical modeling with ground-based measurements to study the upper atmosphere and ionosphere. TIMED, for Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics, is a NASA satellite program to study similar regions of the atmosphere. The joint CEDAR/TIMED program aims to coordinate ground-based and space-based observations to achieve better understanding of physical processes in the lower thermosphere and ionosphere.
