Japan Geoscience Union Meeting 2019

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[E] Oral

P (Space and Planetary Sciences ) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM09] Vertical coupling in the atmosphere and Ionosphere

Wed. May 29, 2019 1:45 PM - 3:15 PM A03 (TOKYO BAY MAKUHARI HALL)

convener:Huixin Liu(Earth and Planetary Science Division, Kyushu University SERC, Kyushu University), Loren Chang(Institute of Space Science, National Central University), Yuichi Otsuka(Institute for Space-Earth Environmental Research, Nagoya University), Chairperson:Patrick Espy(Norwegian University of Science and Technology), Astrid Maute(National Center for Atmospheric Research, US)

2:35 PM - 2:55 PM

[PEM09-04] Observations of MLT dynamics using meteor radars and meteor radar networks

★Invited Papers

*Gunter Stober1, Vivien Matthias2, Sven Wilhelm1, Dimitry Pokhotelov1, Alexander Kozlovsky3, Evgenia Belova4, Johan Kero4, Chris Hall5, Masaki Tsutsumi6 (1.Leibniz Institute of Atmospheric Physics, 2.Potsdam Institute for Climate Impact Research, Earth System Analysis - Research Domain 1, Potsdam, Germany, 3.Sodankylä Geophysical Observatory, Sodankylä, FIN-99600, Finland, 4.Swedish Institute of Space Physics, Box 812, 98128 Kiruna, Sweden, 5.Tromsø Geophysical Observatory UiT-the Arctic University of Norway, Tromsø, Norway, 6.National Institute of Polar Research, Tokyo, Japan)

Keywords:meteor radar, horizontally resolved winds, planetary waves, atmospheric tides and gravity waves, vertical coupling

The winter 2015/16 was characterized by an unusually strong polar vortex with values up to 2 standard deviations guiding the mid-latitude planetary waves into the subtropical mesosphere. This exceptionally strong wave activity in the subtropical mesosphere led to a regionally reversed meridional temperature gradient resulting in a zonal wind reversal between 70 and 80 km at polar latitudes due to the thermal wind relation. This regional wind reversal changes the propagation conditions for waves propagating upward from the mesosphere into the thermosphere/ionosphere. The variability of the thermosphere/ionosphere is influenced by forcing from below and thus by gravity waves and atmospheric tides propagating upward from the mesosphere into the thermosphere.
To investigate the change in propagation characteristics of gravity waves and tides in the upper mesosphere/ lower thermosphere (MLT) during this unusual zonal wind reversal in winter 2015/16 we use data from a meteor radar network in Scandinavia. With this network we are able to apply tomographic wind field analysis obtaining horizontally resolved wind fields and horizontal wavelength spectra. Further, we are able to assess the spatial and temporal day-to-day variability of tides.