An algorithm for extracting zonal mean and migrating tidal fields in the middle atmosphere from satellite measurements: Applications to TIMED/SABER–measured temperature and tidal modeling

Abstract

[1] For a data series with grid points that do not uniformly cover a whole wave cycle in both space and time, traditional least squares fitting methods will lead to biased estimates of the zonal mean and wave components as a result of aliasing between these elements. We introduce a set of formal regularity conditions to select available grid points that reduce aliasing while obtaining the zonal mean and tidal components from unevenly sampled or incomplete measurements. The algorithm is used to self-consistently investigate the effect of the zonal mean field on the seasonal variation of diurnal tide in the upper middle atmosphere using temperature measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite. We first unbiasly derive both the zonal mean and migrating tidal components from the measurements, then simulate the seasonal variation of the migrating diurnal tide using a spectral tidal model with the measured zonal mean as input, and finally compare the seasonal variation of the measured tide with the modeled one. The model and measurement comparisons show self-consistently and more conclusively the dominant effect of the zonal mean wind on the seasonal variation of the migrating diurnal tide in the upper middle atmosphere.Citation: Zhu, X., J.-H. Yee, E. R. Talaat, M. Mlynczak, L. Gordley, C. Mertens, and J. M. Russell III (2005), An algorithm for extracting zonal mean and migrating tidal fields in the middle atmosphere from satellite measurements: Applications to TIMED/ SABER -measured temperature and tidal modeling,

High-altitude data assimilation system experiments for the northern summer mesosphere season of 2007

“…Data analysis studies to date have employed complex asynoptic mapping or least-squares fitting algorithms that require assumptions about stationarity, aliasing and seasonal dependences (e.g., Wu et al, 1995;Burrage et al, 1995;Forbes et al, 1997;Zhu et al, 2005). While these assumptions can be tested and the procedures improved with the help of MLT fields from general circulation models (GCMs) (Oberheide et al, 2003;McLandress and Zhang, 2007) and addition of data from other instruments (Drob et al, 2000;Azeem et al, 2000), final mean mesospheric temperature estimates from these algorithms can still have large uncertainties (Drob et al, 2000;Oberheide et al, 2003;Zhu et al, 2005). NWP systems combine aspects of all the aforementioned algorithms by optimally assimilating MLT data from a variety of sources with the aid of a full-physics GCM to constrain the system dynamically and optimally fill gaps.…”

A Spectral Parameterization of Drag, Eddy Diffusion, and Wave Heating for a Three-Dimensional Flow Induced by Breaking Gravity Waves

“…For example, the physics module for calculating radiative heating and photolysis rates provides the parameterized force to drive the dynamics and photochemistry. This partially affects the dynamics with bounded or controllable uncertainty because the time-independent problem of radiative transfer is well defined and solvable for a given input of atmospheric parameters, such as temperature and species, solar irradiance spectrum, and kinetics database (e.g., Zhu 2004;Mlynczak and Zhou 1998;Zhu et al 2007). From the perspective of satellite measurements and the global modeling of atmospheric structure, it is often the large-scale dynamics and transport that can be observed directly with instruments and simulated explicitly with models.…”

“…For example, tidal winds were directly observed from the Upper Atmosphere Research Satellite High Resolution Doppler Imager (UARS/HRDI) and were used to estimate the momentum deposition based on the derived velocity correlation terms that characterize the effect of tides on the zonal mean flow (Lieberman and Hays 1994). The temperature measured from the Sounding of the Atmosphere using Broadband Emission Radiometer (SABER) onboard the Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) satellite has been used to derive planetary-scale waves for both temperature and winds and the associated wave force terms such as the Eliassen-Palm flux divergence of tides in the middle atmosphere (Zhu et al 2005(Zhu et al , 2008. These large-scale fields derived from satellite observations can be directly assimilated into numerical models in a diagnostic analysis to gain additional physical insights into middle atmosphere dynamics (e.g., Akmaev 1997;Zhu et al 2005).…”

MIPAS observations of longitudinal oscillations in the mesosphere and the lower thermosphere: climatology of odd-parity daily frequency modes

“…Starting with 84 km, the perturbation is stronger during the equinoxes than during solstices. This is due to the influence of the seasonal variation of the symmetry of the heating source (Forbes et al, 2001) and the zonal winds in the middle atmosphere (McLandress, 2002;Zhu et al, 2005), probably below 70 km (Achatz et al, 2008). Amplitudes are smaller than 1 K for latitudes larger than 70 • at this altitude.…”