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<p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US" style="font-family: "Times New Roman", serif;">Dear Colleagues,<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US" style="font-family: "Times New Roman", serif;"> </span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); text-align: justify;"><span lang="EN-US" style="font-family: "Times New Roman", serif;">The AOGS 23rd Annual Meeting (AOGS2026) will take place from 2 to 7 </span><span style="font-family: "Times New Roman", serif;">August</span><span style="font-family: "Times New Roman", serif;"> 2026, in Fukuoka, Japan. We would like to bring your attention to session ST11: Upper Atmosphere Variations Caused by Natural Events in the Solar-Terrestrial Environment, which will emphasize all aspects of upper atmosphere disturbances caused by natural events, including seismic activity, tsunamis, volcanic eruptions, hurricanes, solar eclipses, and geomagnetic storms in the solar-terrestrial environment.</span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US"> </span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><b><span lang="EN-US" style="font-family: "Times New Roman", serif;">Session Scope</span></b><span lang="EN-US" style="font-family: "Times New Roman", serif;"><o:p></o:p></span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); text-align: justify;"><span lang="EN-US" style="font-family: "Times New Roman", serif;">Earth’s upper atmosphere, including the ionized component, the ionosphere, is sensitive to upward-propagated disturbances from the lower altitudes. These disturbances can be in the form of atmospheric acoustic and gravity waves (AGWs), large-scale planetary waves, or tides. Lithospheric activities and lower atmospheric disturbances, such as seismic activity, tsunamis, volcanic eruptions, hurricanes, tornadoes, and meteorological disturbances, can generate them. Another source of the disturbances comes from solar-terrestrial events, such as magnetic storms. Magnetic storms could also drive global atmospheric and thermospheric disturbances through the input of energy from electromagnetic and energetic precipitations. These disturbances interact with the upper atmosphere through various complex processes, thereby providing opportunities for a better understanding of vertical coupling and teleconnection throughout the entire atmosphere. The objective of this session is to stimulate discussions on upper atmospheric disturbances in both neutral and ionized components resulting from disturbances caused by these natural events in the solar-terrestrial environment. The new observation techniques, as well as the space weather forecasting/nowcasting of the data assimilation models, have also been solicited.<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US" style="font-family: "Times New Roman", serif;"> </span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US" style="font-family: "Times New Roman", serif;">You can find more information, as well as the abstract submission at: </span>https://www.asiaoceania.org/AOGS2026/Home</p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US" style="font-family: "Times New Roman", serif;"> </span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US" style="font-family: "Times New Roman", serif;">Please note that the deadline for abstract submission is 23 January 2026. We would appreciate your attendance at the meeting and your contribution to the community.</span><span lang="EN-US"><o:p></o:p></span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US"> </span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US" style="font-family: "Times New Roman", serif;">Sincerely,<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"><span lang="EN-US" style="font-family: "Times New Roman", serif;"><br></span></p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Chi-Yen Lin</p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Charles Lin</p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Elvira Astafyeva</p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Huixin Liu</p><p class="MsoNormal" style="margin: 0cm; font-size: medium; font-family: 新細明體, serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);">Kentaro Kitamura</p></body></html>