Conference meetings and presentations

  • Search

  • Reset

Inter-Hemispheric Asymmetry in the Ionosphere-Thermosphere System During the 8-9 October 2012 Geomagnetic Storm: Multi-Instrumental Observations and GITM Simulations

Presented on: December 17, 2021

Presented at: AGU Fall Meeting 2021

Presented by: Yu Hong, Yue Deng, Qingyu Zhu, Astrid Maute, Cheng Sheng, Daniel Welling, Ramon Lopez


During geomagnetic storms, the inter-hemispheric asymmetry in the Earth’s ionosphere-thermosphere (I-T) system can be very pronounced, and general circulation models (GCMs) have been widely used to study the inter-hemispheric asymmetry in the I-T system. One plausible mechanism causing the inter-hemispheric asymmetry in the I-T system is the asymmetric high-latitude electrodynamical forcings (i.e., electric field and auroral particle precipitation). However, such mechanism may not be well taken into account in most GCM studies since the high-latitude electrodynamical forcings in the GCMs are typically specified by empirical models in those studies. This is because empirical model only provides an average pattern under certain geophysical conditions and may not well capture the pattern at a certain time. In this study, to investigate the sensitivity of using more realistic high-latitude forcing to the inter-hemispheric asymmetry in the I-T system, the high-latitude electrodynamic forcings in the Global Ionosphere and Thermosphere Model (GITM) has been specified in two different ways, and the differences in the global I-T response have been investigated through a series of data-model and model-model comparisons. First, the time-dependent field-aligned currents (FACs) from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) data set are used to specify the high-latitude electric field with pre-defined auroral precipitation pattern. Second, the high-latitude electric field in GITM is specified by the Weimer 2005 empirical model. The 8-9 October 2012 storm will be focused on in this study. This work will help quantify the significance of inter-hemispheric asymmetries in the high-latitude electrodynamical forcings to the global I-T system, which will further contribute to a better understanding of the magnetosphere-ionosphere-thermosphere coupling processes.

Leave a Reply


Join the conversation