CEDAR: Studies of Tidal Variability and Planetary Wave Evolution Using Sequential Estimation Applied to Satellite and Radar Winds

Northwest Research Associates, Incorporated, Seattle WA

Investigators

Abstract

The wind-measuring instrument on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite, TIDI, samples about 15 longitudes per day at 4 distinct local times between 50 S and 50 N. This observing pattern allows the definition of planetary-scale waves and diurnal tides on a near-daily basis. The leading objectives of this project are to assimilate TIDI and radar winds in order to facilitate studies of short-term tidal and planetary wave evolution. Ground-based and satellite data will be assimilated using the method of sequential estimation, a technique chosen because of its potential to optimize wave definitions that retain short-term variations of dynamical significance. Tidal and planetary wave coefficients for wavenumbers 0-5 will be disseminated to the TIMED/CEDAR community. It is expected that wide access to the data in an easily understood form will help to foster collaborative studies with the modelling community. The results of the proposed work are expected to maximize the potential of ground and space-based data to sort out the global-scale versus the local-scale causes of tidal and planetary scale variations that originate below and within the mesosphere and lower thermosphere (MLT). These goals are consistent with CEDAR Phase 3 objectives addressing coupling of the lower levels to the MLT.