Nonmigrating Tidal Variability from SABER on Multiple Planetary Wave Timescales in the Mesosphere and Lower Thermosphere
Abstract
The prominent eastward-propagating nonmigrating diurnal tide with zonal wave number 3 (DE3) originates from tropical deep convection and introduces a large longitudinal and local time variability in temperature, wind and density. The DE3 is thus a key ingredient in the meteorological driving of geospace; a key science question of the notional DYNAMIC and GDC decadal survey missions, and for GOLD and ICON. DE3 short-term tidal variability in particular is not well understood and part of the motivation for constellation missions. Single satellites such as TIMED nevertheless provide a pathway to identify multi-timescale tidal variability from days to years in order to refine measurements requirements for forthcoming missions. This work utilizes 16 years of SABER DE3 tidal deconvolution diagnostics that provides a unique opportunity to investigate interannual changes in short-term tidal variability on various planetary wave time scales with emphasis on the 10-day wave. The approach is based on information-theoretic techniques using Bayesian statistics, time dependent probability density functions and Kullback-Leibler divergence followed by multiple linear regression analysis. This paper exemplifies the statistically significant response to the interannual changes in short-term DE3 variability on planetary wave timescales associated with the quasi-biennial oscillation (QBO), El Niño-Southern Oscillation (ENSO), solar cycle and other natural drivers. The physical significance of results in relation to SABER planetary wave diagnostics and needed measurements to fully close on the science question will be discussed.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSA43B3206K
- Keywords:
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- 0358 Thermosphere: energy deposition;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 2427 Ionosphere/atmosphere interactions;
- IONOSPHERE;
- 2431 Ionosphere/magnetosphere interactions;
- IONOSPHERE;
- 2437 Ionospheric dynamics;
- IONOSPHERE