Print Email Facebook Twitter Intraannual variability of tides in the thermosphere from model simulations and in situ satellite observations Title Intraannual variability of tides in the thermosphere from model simulations and in situ satellite observations Author Häusler, K. Hagan, M.E. Forbes, J.M. Zhang, X. Doornbos, E. Bruinsma, S. Lu, G. Faculty Aerospace Engineering Department Space Engineering Date 2015-01-24 Abstract In this paper, we provide insights into limitations imposed by current satellite-based strategies to delineate tidal variability in the thermosphere, as well as the ability of a state-of-the-art model to replicate thermospheric tidal determinations. Toward this end, we conducted a year-long thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM) simulation for 2009, which is characterized by low solar and geomagnetic activity. In order to account for tropospheric waves and tides propagating upward into the ?30–400 km model domain, we used 3-hourly MERRA (Modern-Era Retrospective Analysis for Research and Application) reanalysis data. We focus on exospheric tidal temperatures, which are also compared with 72 day mean determinations from combined Challenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellite observations to assess the model's capability to capture the observed tidal signatures and to quantify the uncertainties associated with the satellite exospheric temperature determination technique. We found strong day-to-day tidal variability in TIME-GCM that is smoothed out when averaged over as few as ten days. TIME-GCM notably overestimates the 72 day mean eastward propagating tides observed by CHAMP/GRACE, while capturing many of the salient features of other tidal components. However, the CHAMP/GRACE tidal determination technique only provides a gross climatological representation, underestimates the majority of the tidal components in the climatological spectrum, and moreover fails to characterize the extreme variability that drives the dynamics and electrodynamics of the ionosphere-thermosphere system. A multisatellite mission that samples at least six local times simultaneously is needed to provide this quantification. To reference this document use: http://resolver.tudelft.nl/uuid:07fc2767-47df-41ac-8fe6-d4a4ca1ae83e DOI https://doi.org/10.1002/2014JA020579 Publisher American Geophysical Union Embargo date 2015-07-24 ISSN 2169-9402 Source Journal of Geophysical Research: Space Physics, 120 (1), 2015 Part of collection Institutional Repository Document type journal article Rights © 2014 American Geophysical Union Files PDF Doornbos_2015.pdf 4.07 MB Close viewer /islandora/object/uuid:07fc2767-47df-41ac-8fe6-d4a4ca1ae83e/datastream/OBJ/view