The investigators will develop a Kalman filtering technique for global wind mapping. Kalman filtering uses statistics and sequential estimation to produce daily gridded synoptic mappings from asynchronous satellite measurements. Global daily synoptic mappings enable objective determination of spatial wave propagation and day-to-day variability of planetary scale features. Synoptic fields lend themselves easily to conventional longitude-time Fourier analysis and are convenient for assimilation into numerical models. Because of their ease of interpretation, mapped synoptic fields have been widely used by the scientific community investigating tropospheric and stratospheric dynamics. However, the Kalman filtering approach traditionally requires the prescription of planetary-scale geophysical statistics, which are largely unknown for mesospheric and lower thermospheric winds. The main objective of this study is to determine these unknown statistics from an existing lower thermospheric wind data set. The results will be used to 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.
