Search Publications
Propagation of the Interplanetary Shock Induced Pulse: New Observations by the Global Navigation Satellite System
Zong, Qiugang; Zhang, Hui; Chen, Xingran +3 more
We revisited a typical interplanetary (IP) shock event on 7 November 2004, with high time resolution (1 s) total electron content (TEC) observations. The IP shock impinged on the dayside magnetopause at ∼18:27 UT, and launched a pulse into the magnetosphere. Using the multi-spacecraft timing method, the pulse was estimated to propagate at an angul…
Data-Based Modeling of the Magnetosheath Magnetic Field
Semenov, V. S.; Erkaev, N. V.; Tsyganenko, N. A.
A quantitative model of the magnetosheath (MS) magnetic structure is developed, using a multi-year set of Geotail, Themis, Cluster, and MMS magnetometer and plasma instrument data. The MS database is created using an identification algorithm, based on observed magnetic field magnitudes and proton densities, normalized by their concurrent interplan…
Statistical Mapping of Magnetic Topology at Venus
Persson, Moa; Xu, Shaosui; Frahm, Rudy A. +3 more
Despite Venus having insignificant intrinsic magnetic fields, the magnetic connectivity between the solar wind and the Venus ionosphere, or magnetic topology, is not as simple as expected and is also important for characterizing the Venus space environment. This study provides a technique combining superthermal electron energy and pitch angle dist…
Solar Wind Protons Forming Partial Ring Distributions at Comet 67P
Gunell, H.; Nilsson, H.; Richter, I. +5 more
We present partial ring distributions of solar wind protons observed by the Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko. The formation of ring distributions is usually associated with high activity comets, where the spatial scales are larger than multiple ion gyroradii. Our observations are made at a low-activity comet at a heliocentric …
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…