Impacts of stratospheric sudden warming events in the mesosphere and lower thermosphere

Kumiko WATANABE; Takashi TANAKA; Yasunobu MIYOSHI

Presentation information

Oral

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

[P-EM36_28PM2] Physics and Chemistry in the Atmosphere and Ionosphere

Mon. Apr 28, 2014 4:15 PM - 6:00 PM 312 (3F)

Convener:*Yuichi Otsuka(Solar-Terrestrial Environment Laboratory, Nagoya University), Takuya Tsugawa(National Institute of Information and Communications Technology), Seiji Kawamura(National Institute of Information and Communications Technology), Chair:Mitsuru Matsumura(Center for Space Science and Radio Engineering, University of Electro-Communications), Tatsuhiro Yokoyama(National Institute of Information and Communications Technology)

5:15 PM - 5:30 PM

[PEM36-P02_PG] Impacts of stratospheric sudden warming events in the mesosphere and lower thermosphere

3-min talk in an oral session

*Kumiko WATANABE¹, Takashi TANAKA¹, Yasunobu MIYOSHI² (1.Department of Earth and Planetary Sciences, Graduate School of Sciences, Kyushu University, 2.Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University)

Keywords:stratospheric sudden warming, mesosphere, lower thermosphere

Impacts of stratospheric sudden warming (SSW) events on the middle and upper atmosphere have been widely recognized. However, due to an insufficient number of global observations, SSW's effects on the general circulation in the mesosphere and lower thermosphere (MLT) are not well known. In this study, we investigate the short term variation of the temperature, zonal wind and meridional wind in the MLT region during SSW events using a general circulation model that contains the region from the troposphere to the thermosphere. We conducted GCM simulation with meteorological reanalysis data during the period from November 1, 2008 to March 31, 2010. Our results show that the temperature drop occurs in the Southern hemisphere, during SSW events. This means that SSW influences the general circulation in the summer hemisphere. Furthermore, it is found that the temperature in winter polar region in the lower thermosphere increases during SSW events. This is related to upward propagation of the planetary wave excited in the mesosphere.