Bibliography

Auroral Energy Flux and Joule Heating Derived From Global Maps of Field-Aligned Currents

We calculate auroral energy flux and Joule heating in the high-latitude ionosphere for 27 geomagnetically active days using two-dimensional maps of field-aligned currents determined by the Active Magnetosphere and Planetary Response Experiment. The energy input to the ionosphere due to Joule heating increases more rapidly with geomagnetic activity than that due to precipitating particles. The energy flux varies more smoothly with time than Joule heating, which is impulsive in nature on time scales from minutes to tens of minutes. These impulsive events correlate well with recoveries in the Sym-H index, with the maximum correlation when compared to Sym-H recoveries 70 min later. Because of prior studies that have associated transient recoveries of Sym-H with substorm expansions, the delay found here suggests that dissipation of energy in the ionosphere occurs during the substorm growth phase prior to the release of magnetic energy caused by diversion of tail currents.

Robinson, R.; Zanetti, L.;

Published by: Geophysical Research Letters      Published on:

YEAR: 2021     DOI: 10.1029/2020GL091527

Geomagnetic storms; Auroral energy flux; auroral energy input; auroral substorms; Joule heating; ring current

Determination of Auroral Electrodynamic Parameters From AMPERE Field-Aligned Current Measurements

We calculate high latitude electrodynamic parameters using global maps of field-aligned currents from the Active Magnetosphere and Planetary Response Experiment (AMPERE). The model is based on previous studies that relate field-aligned currents to auroral Pedersen and Hall conductances measured by incoherent scatter radar. The field-aligned currents and conductances are used to solve for the electric potential at high latitudes from which electric fields are computed. The electric fields are then used with the conductances to calculate horizontal ionospheric currents. We validate the results by simulating the SuperMAG magnetic indices for 30 geomagnetically active days. The correlation coefficients between derived and actual magnetic indices were 0.68, 0.76, and 0.84 for the SMU, SML, and SME indices, respectively. We show examples of times when the simulations differ markedly from the measured indices and attribute them to either small-scale, substorm-related current structures or the effects of neutral winds. Overall, the performance of the model demonstrates that with few exceptions, auroral electrodynamic parameters can be accurately deduced from the global field-aligned current distribution provided by AMPERE.

Robinson, R.; Zanetti, Larry; Anderson, Brian; Vines, Sarah; Gjerloev, Jesper;

Published by: Space Weather      Published on:

YEAR: 2021     DOI: 10.1029/2020SW002677

space weather; auroral currents; auroral electrodynamics; conductivities; electric fields; field-aligned currents

Statistical relations between auroral electrical conductances and field-aligned currents at high latitudes

Robinson, RM; Kaeppler, Stephen; Zanetti, Larry; Anderson, Brian; Vines, Sarah; Korth, Haje; Fitzmaurice, Anna;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2020     DOI:

Statistical Relations Between Field-Aligned Currents and Precipitating Electron Energy Flux

Measurements of field-aligned currents from the Active Magnetosphere and Planetary Electrodynamics Response Experiment are combined with measurements of far ultraviolet emissions from the Global Ultraviolet Imager on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite to examine the correlation between parallel currents and auroral electron energy flux. The energy flux is derived from the far ultraviolet emissions in the N₂ Lyman-Birge-Hopfield bands. We find that energy flux correlates with field-aligned currents in both upward and downward current regions. The correlations vary with magnetic local time with the strongest dependences near magnetic midnight. The data are binned and averaged to construct a model of precipitating particle energy flux as a function of field-aligned current and magnetic local time. With Active Magnetosphere and Planetary Electrodynamics Response Experiment data as input, the model yields accurate estimates of the hemispheric power input from precipitating particles.

Robinson, R.; Zhang, Y.; Anderson, B.; Zanetti, L.; Korth, H.; Fitzmaurice, A.;

Published by: Geophysical Research Letters      Published on: 08/2018

YEAR: 2018     DOI: 10.1029/2018GL078718

The evolving space weather system—Van Allen Probes contribution

Zanetti, LJ; Mauk, BH; Fox, NJ; Barnes, RJ; Weiss, M; Sotirelis, TS; Raouafi, N-E; Kessel, RL; Becker, HN;

Published by: Space Weather      Published on:

YEAR: 2014     DOI:

Assessment of ionospheric measurement techniques in support of space weather requirements

Erlandson, RE; Paxton, LJ; Kelly, MA; Rogers, AQ; Zanetti, LJ;

Published by:       Published on:

YEAR: 2009     DOI:

Atmospheric, oceanic, and space environment research at APL

Zanetti, Lawrence;

Published by: Johns Hopkins APL technical digest      Published on:

YEAR: 2003     DOI: