edu.ucar.opensky::articles:43838 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T17:46:56.024913 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.net/ark:/85065/d7794930 Seasonal and interannual variation of the interhemispheric coupling during the austral winter in WACCM6 2025-06-28T00:00:00Z publication https://n2t.net/ark:/85065/d7794930 https://doi.org/10.1029/2024JD043265 Koshin, D. author Pedatella, Nicholas M. author Smith, Anne K. author UCAR/NCAR - Library publisher We investigate interhemispheric coupling (IHC) during the austral winter by examining global characteristics of the dynamical fields initiated by stratospheric warming in the Southern Hemisphere using output of the Whole Atmosphere Community Climate Model version 6 covering 195 simulation years. About 100 events were extracted and analyzed, focusing on the seasonal and interannual variation of the IHC response in the Northern Hemisphere. The seasonal variation can be explained by differences in the background atmosphere. The upward shift and weakening of the gravity wave forcing during the IHC in September are opposite to the characteristics of July and August. However, the mean zonal wind and the momentum deposition of gravity waves in the northern middle atmosphere in September are also opposite to those in July and August. Together, these result in the same sign of the anomaly. Additionally, an interannual variation in the altitude of the warming in the northern polar region is also observed, with warmings split at 100&#160;km. A warming that appears above 100&#160;km is explained by an additional mechanism of gravity wave modulation, which drives the winter&#8208;to&#8208;summer circulation in the lower thermosphere, while a warming below 100&#160;km corresponds to the weakening of the summer&#8208;to&#8208;winter circulation in the upper mesosphere. Correspondingly, no warming is observed near 100&#160;km, where the circulation and its modulation are absent. This interannual variation of the IHC is influenced by the intraseasonal oscillation, which represents a similar meridional temperature structure in the global middle atmosphere. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication <span style="font-family:Arial;font-size:10pt;font-style:normal;font-weight:normal;" data-sheets-root="1">Copyright 2025 American Geophysical Union (AGU).</span> None eng geoscientificInformation