Search Publications
Statistical Survey of Magnetic Forces Associated With Earthward Bursty Bulk Flows Measured by MMS 2017-2021
Hamrin, M.; Karlsson, T.; Shi, Q. Q. +8 more
We investigate the magnetic forces (the magnetic pressure gradient force, the curvature force, and their sum the j × B-force) associated with earthward bursty bulk flows (BBFs) using Magnetospheric Multiscale (MMS) data from five tail seasons (2017-2021). For the first time, the magnetic forces are inferred downtail of XGSM = −20 RE and…
Numerical Prediction of Changes in Atmospheric Chemical Compositions During a Solar Energetic Particle Event on Mars
Leblanc, François; Vandaele, Ann Carine; Aoki, Shohei +11 more
Precipitation of solar energetic particles (SEPs) into planetary atmospheres causes changes in atmospheric chemical composition through ionization, dissociation, and excitation of atmospheric molecules. In contrast to the terrestrial atmosphere, where depletion of ozone in the polar mesosphere has been studied by observations and models for decade…
Long-Term Density Trend in the Mesosphere and Lower Thermosphere From Occultations of the Crab Nebula With X-Ray Astronomy Satellites
Katsuda, Satoru; Enoto, Teruaki; Sato, Kosuke +9 more
We present long-term density trends of the Earth's upper atmosphere at altitudes between 71 and 116 km, based on atmospheric occultations of the Crab Nebula observed with X-ray astronomy satellites, ASCA, RXTE, Suzaku, NuSTAR, and Hitomi. The combination of the five satellites provides a time period of 28 years from 1994 to 2022. To suppress seaso…
Effects of the Ionospheric Conductance on the Dynamics of the Magnetotail
El-Alaoui, Mostafa; Walker, Raymond J.; McPherron, Robert L.
We have carried out a series of numerical experiments designed to evaluate the sensitivity of global magnetohydrodynamic simulations to changes in ionospheric conductance. We multiplied the precipitating energy fluxes due to both strong pitch angle scattering and parallel currents by constant factors in the Robinson et al. (1987,
Mesoscale Structure and Properties of the Terrestrial Magnetotail Plasma Sheet From the Magnetospheric Multiscale Mission
Vo, T.; Ergun, R. E.; Usanova, M. E. +1 more
Using Magnetospheric Multiscale mission (MMS) orbits in the Earth's magnetotail from 2017 to 2020, plasma conditions and the 3D spatial structure of inner-magnetotail plasma environments (with a focus on the plasma sheet (PS)) are studied with different approaches. Threshold conditions for distinguishing the PS, PS boundary layers, and lobes are d…
Magnetosphere-Ionosphere Drivers of Transient-Large-Amplitude Geomagnetic Disturbances: Statistical Analysis and Event Study
Nishimura, Yukitoshi; Moldwin, Mark B.; Weygand, James M. +2 more
We present a comprehensive statistical analysis of high-frequency transient-large-amplitude (TLA) magnetic perturbation events that occurred at 12 high-latitude ground magnetometer stations throughout Solar Cycle 24 from 2009 to 2019. TLA signatures are defined as one or more second-timescale dB/dt interval with magnitude ≥6 nT/s within an hour ev…
Dissecting Earth's Magnetosphere: 3D Energy Transport in a Simulation of a Real Storm Event
Toth, G.; Pulkkinen, T. I.; Brenner, A. +1 more
We present new analysis methods of 3D MHD output data from the Space Weather Modeling Framework during a simulated storm event. Earth's magnetosphere is identified in the simulation domain and divided based on magnetic topology and the bounding magnetopause definition. Volume energy contents and surface energy fluxes are analyzed for each subregio…
Comparative Solar Minima Using the McIntosh Archive
Gibson, Sarah E.; Webb, David F.; Hewins, Ian M. +3 more
The McIntosh Archive consists of four solar cycles (SC20-23) of synoptic maps of solar features (magnetic polarities, coronal holes, filaments, sunspots, plage) that were produced by Patrick McIntosh and his cartographers. In this paper we present the full Archive for the first time and find a hemispheric pattern of coronal hole polarity reflectin…
Multipoint Observations of Dispersive Scale Alfvénic Field-Line Resonances Associated With Substorm Auroral Beads
Frey, Harald U.; Wing, Simon; Chaston, Christopher C. +2 more
We present a case study of the field-aligned current (FAC) systems that transpire within the high-altitude auroral acceleration region of an "auroral bead" initiated double oval substorm observed on 23 February 2001 by the Cluster fleet. Conjunctive Cluster measurements and auroral images from IMAGE reveal that auroral bead current system formatio…
Characteristics of Magnetic Reconnection With a Finite X-Line Length
Lu, Quanming; Wang, Rongsheng; Lu, San +2 more
The characteristics of magnetic reconnection with a finite x-line length are studied using three-dimensional (3D) particle-in-cell (PIC) simulations. We simulate two cases: anti-parallel reconnection and guide field reconnection. In both cases, reconnection is triggered by an initial perturbation that is localized in the current direction, and the…