A New Framework to Incorporate High‐Latitude Input for Mesoscale Electrodynamics

Abstract

Global circulation models (GCMs) for the ionosphere-thermosphere system traditionally use empirical models to specify upper boundary conditions to represent solar wind and magnetospheric drivers. However, the magnetosphere, ionosphere, and thermosphere systems are coupled on different spatial and temporal scales. During increased levels of geomagnetic activity, these empirical models can't resolve dynamic electric field variability (<500 km, <15 min) because of their statistical nature and/or low spatial and temporal resolutions. This results in an underestimation of energy input to the ionosphere, causing disagreements between model results and observations. This paper introduces a new framework to incorporate dynamic electric fields into GCMs: High-latitude Input for Mesoscale Electrodynamics (HIME). As a demonstration HIME uses the Poker Flat Incoherent Scatter Radar (PFISR) electric field estimates during an experiment on 2 March 2017. The electric potentials were calculated using the PFISR estimates and merged with a global empirical model of electric potential. A set of high-latitude electric potential drivers were used to drive the University of Michigan Global Ionosphere Thermosphere Model (GITM) to understand the effects of driving at different scales. Data versus model comparisons for ion temperature, electron temperature, and electron density are provided along the PFISR beams. The ion convection velocities and neutral winds at the PFISR location are compared with the PFISR and Scanning Doppler Imager data. The effects of different multiscale drivers are investigated. The results showed that energy deposited by HIME-driven simulations was locally larger by approximately an order of magnitude compared to the empirical model-driven results.

Energy Deposition by Mesoscale High‐Latitude Electric Fields Into the Thermosphere During the 26 October 2019 Geomagnetic Storm

“…Given different definitions of frictional heating in the literature (Brekke & Kamide, 1996; Thayer & Semeter, 2004; J. Zhu & Ridley, 2016), here we adopt the frictional heating definition from Ozturk et al. (2020) and J. Zhu and Ridley (2016) for GITM modeling. To identify the direct source of the Joule heating enhancement in GITM modeling, we compute the percentage of the frictional heating out of the Joule heating from both Weimer‐driven and HIME‐driven runs, shown in Figure 8c.…”

“…The existing open-source HIME version 1.0 focuses on incorporating the mesoscale electric field, while the capability of including the mesoscale auroral particle precipitation is under development and will be reported in a future publication. Ozturk et al (2020) presents the first application of HIME that uses PFISR-estimated 2D electric field as an upper boundary condition to drive GITM. The estimated electric field in the local region is merged with the global large-scale electric field from the Weimer model using a Gaussian filter for a smooth transition.…”

“…In particular, small‐scale and mesoscale electric field variabilities could contribute even more to the Joule heating than the large‐scale averaged electric field does (Deng et al., 2009; Matsuo & Richmond, 2008). Here we refer mesocale as a spatiotemporal scale between small‐scale and large‐scale, with a spatial scale between 100 and 500 km and a temporal scale between 2 and 15 min (Ozturk et al., 2020).…”

Addressing Gaps in Space Weather Operations and Understanding With Small Satellites

“…Mannucci et al (2020) emphasized the need for continuously available low latency observations directly relevant to space weather. There is growing observational evidence that without considering energy transport at multi-scales, energy input into the ionosphere may be underestimated (Chaston et al, 2005;Huang et al, 2017;Miles et al, 2018;Zhu et al, 2018;Ozturk et al, 2020).…”

Multi‐Scale Geomagnetic Forcing Derived From High‐Resolution Observations and Their Impacts on the Upper Atmosphere

“…In a recent study, Ozturk et al. (2020) incorporated the high‐resolution electric field derived from Poker Flat Incoherent Scatter Radar (PFISR) measurements into the Weimer (2005) potential pattern and used the merged potential pattern to drive the global ionosphere‐thermosphere model (GITM). Localized effects of the high‐resolution convection forcing on electron density, electron and ion temperature, and neutral winds around the PFISR location were investigated.…”