Data-driven Modeling of the Day-to-Day Variability of the Equatorial Electrojet Using Ground- and Space-based Magnetometer Data Journal Article uri icon

Overview

abstract

  • The equatorial electrojet (EEJ) is an important manifestation of; ionospheric electrodynamics. Day-to-day changes of the EEJ result from; E-region dynamo processes that are primarily driven by highly variable; atmospheric waves propagating up from the lower and middle atmosphere.; Progress has been made in our understanding that upward propagating; tides are one of the major contributors to the day-to-day variability in; the EEJ, however current models are limited in their ability to capture; the vertical propagation of tides from the lower and middle atmosphere; to the upper atmosphere due to difficulties to adequately represent many; processes that influence it. In this study, we thus propose a new; data-driven approach to modeling day-to-day variability by taking; advantage of widely available ground-based magnetic field measurements.; The new approach based on an ensemble transform adjustment method is; applied to the Thermosphere-Ionosphere-Electrodynamics General; Circulation Model (TIE-GCM) lower boundary conditions (LBCs) at about 97; km altitude in order to make the model’s tidal characteristics to be; more consistent with observed magnetic perturbations associated with the; EEJ. In this method, TIE-GCM ensemble simulations are driven by; high-latitude ionospheric convection and auroral particle precipitation; patterns specified by the AMGeO and by atmospheric waves and tides based; on MERRA meteorological reanalysis. As part of forward modeling, the 3D; Dynamo electrodynamic module is used to calculate magnetic perturbations; on the ground and at low Earth orbit altitudes. A detailed analysis of; the 21-day period from March 1 to 22, 2009 has shown that the modeled; EEJ with the LBCs adjusted using ground-based magnetic perturbation data; improves the agreement of the model to independent magnetic field; observations from CHAMP. The use of routinely available ground-based; magnetometer data to constrain the TIE-GCM LBCs could provide an; opportunity to investigate how day-to-day tidal variability drives; equatorial electrodynamics variability.

publication date

  • November 7, 2021

has restriction

  • hybrid

Date in CU Experts

  • November 9, 2021 3:08 AM

Full Author List

  • Lien C-P; Matsuo T; Maute A; Stolle C

author count

  • 4

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