edu.ucar.opensky::articles:26716 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T19:00:46.684467 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7mc943x https://doi.org/10.5281/ZENODO.8178574 https Related JournalArticle #1 Multiscale Magnetosphere-Ionosphere Coupling During Storm- time: A Case Study of the Dawnside Current Wedge https://doi.org/10.5281/zenodo.8178574 https Related JournalArticle #2 Multiscale Magnetosphere-Ionosphere Coupling During Storm- time: A Case Study of the Dawnside Current Wedge https://doi.org/10.5065/D6RX99HX https Related Service #1 Cheyenne: SGI ICE XA Cluster Multiscale magnetosphere-ionosphere coupling during stormtime: A case study of the dawnside current wedge 2023-11-27T00:00:00Z publication https://n2t.org/ark:/85065/d7mc943x https://doi.org/10.1029/2023JA031594 Sorathia, K. A. author Michael, A. author Merkin, V. G. author Ohtani, S. author Keesee, A. M. author Sciola, A. author Lin, Dong author Garretson, J. author Ukhorskiy, A. Y. author Bao, S. author Roedig, C. B. author Pulkkinen, A. author UCAR/NCAR - Library publisher A characteristic feature of the main phase of geomagnetic storms is the dawn-dusk asymmetric depression of low- and mid-latitude ground magnetic fields, with largest depression in the dusk sector. Recent work has shown, using data taken from hundreds of storms, that this dawn-dusk asymmetry is strongly correlated with enhancements of the dawnside westward electrojet and this has been interpreted as a "dawnside current wedge" (DCW). Its ubiquity suggests it is an important aspect of stormtime magnetosphere-ionosphere (MI) coupling. In this work we simulate a moderate geomagnetic storm to investigate the mechanisms that give rise to the formation of the DCW. Using synthetic SuperMAG indices we show that the model reproduces the observed phenomenology of the DCW, namely the correlation between asymmetry in the low-latitude ground perturbation and the dawnside high-latitude ground perturbation. We further show that these periods are characterized by the penetration of mesoscale bursty bulk flows (BBFs) into the dawnside inner magnetosphere. In the context of this event we find that the development of the asymmetric ring current, which inflates the dusk-side magnetotail, leads to asymmetric reconnection and dawnward-biased flow bursts. This results in an eastward expansion and multiscale enhancement of the dawnside electrojet. The electrojet enhancement extends across the dawn quadrant with localized enhancements associated with the wedgelet current systems of the penetrating BBFs. Finally, we connect this work with recent studies that have shown rapid, localized ground variability on the dawnside which can lead to hazardous geomagnetically induced currents. 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 Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. None eng geoscientificInformation