<html><body><p class="-wm-MsoNormal" style="margin:0cm;font-size:medium;font-family:Calibri,sans-serif"><span style="font-family:Arial,sans-serif"></span></p><span style="font-size:16px"><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:Arial,sans-serif">Dear colleagues, </span><span style="font-family:Arial,sans-serif"><br><br>We would like to draw your attention to a new session of the EGU General Assembly 2023.</span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:Arial,sans-serif"> </span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:Arial,sans-serif">AS1.32 </span><span style="font-family:Arial,sans-serif"><br>Structural changes in the middle and upper atmosphere <br>Convener: Juan Antonio Añel <br>Co-conveners: M. G. Mlynczak, Viktoria Sofieva, Petr Šácha, Laura de la Torre <br>Link: </span><span style="font-family:'Times New Roman',serif"><a href="https://meetingorganizer.copernicus.org/EGU23/sessionmodification/46821" title="https://meetingorganizer.copernicus.org/EGU23/sessionmodification/46821"><span style="font-family:Arial,sans-serif">https://meetingorganizer.copernicus.org/…821</span></a></span><span style="font-family:Arial,sans-serif"> </span><span style="font-family:'Times New Roman',serif"></span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:'Open Sans',sans-serif"> </span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:'Open Sans',sans-serif">Evidence of the impacts of climate change on the middle and upper atmosphere is increasing, making clear the critical need for observational data to monitor and understand trends. For example, a contraction of the stratosphere has been quantified, but we still face significant limitations on the data available to assess it. Past efforts to study trends have focused mainly on the atmospheric levels separately (mesosphere, thermosphere, ionosphere), where cooling and contraction have also been observed. Monitoring these trends and their impacts on satellites and space debris needs a continued effort, providing better data and improved insight into the consequences that increased carbon dioxide has on the middle and upper atmosphere.</span><span style="font-family:'Times New Roman',serif"></span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:'Times New Roman',serif"> </span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:'Open Sans',sans-serif">We encourage abstract submissions concerning long-term as well as short-term changes to the structure of the atmosphere, its parts or localized circulation phenomena and underlying mechanisms. We especially welcome presentations about existing data, data gaps and measurements to monitor trends in the middle and upper atmosphere and the impacts, for example, changes of the drag on space objects. Also, studies evaluating and documenting underlying causes and modelling or projecting changes of these mechanisms are particularly welcomed.</span><span style="font-family:'Times New Roman',serif"></span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:Arial,sans-serif"><br>Two important deadlines: Abstract submission deadline is</span><span style="font-family:'Open Sans',sans-serif"> 10 January 2023, 13:00 CET.</span><span style="font-family:'Open Sans',sans-serif"></span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:'Times New Roman',serif">Applications for financial support are possible by submitting your abstract by 1 December 2022, 13:00 CET.</span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span style="font-family:Arial,sans-serif">https://egu23.eu/programme/how_to_submit.html<br><br><br>Sincerely, <br>Petr Šácha.</span><span style="font-family:'Times New Roman',serif"></span></p><p class="-wm-MsoNormal" style="margin:0cm;font-family:Calibri,sans-serif"><span lang="EN-US"> </span></p></span><p class="-wm-MsoNormal" style="margin:0cm;font-size:medium;font-family:Calibri,sans-serif"><span lang="EN-US"></span></p></body></html>