A5089048775- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Magnetic confinement fusion research
- Geophysics and Gravity Measurements
- Earthquake Detection and Analysis
- Space exploration and regulation
- Spacecraft Design and Technology
- Astro and Planetary Science
- Plasma Diagnostics and Applications
- Magnetic Field Sensors Techniques
- Distributed and Parallel Computing Systems
- GNSS positioning and interference
- Meteorological Phenomena and Simulations
- Insurance, Mortality, Demography, Risk Management
- Planetary Science and Exploration
- Scientific Computing and Data Management
- Magnetic properties of thin films
- Magnetic Properties and Applications
- Atmospheric Ozone and Climate
- Spaceflight effects on biology
- Characterization and Applications of Magnetic Nanoparticles
- Spacecraft and Cryogenic Technologies
- 3D Modeling in Geospatial Applications
- Service-Oriented Architecture and Web Services
Goddard Space Flight Center
2015-2024
Heliophysics
2008-2024
Community Coordinated Modeling Center
2004-2024
Communications Consortium Media Center
2019-2023
Politecnico di Milano
2023
Saint-Petersburg State University of Technology and Design
2020-2021
Kazan State Power Engineering University
2021
Space Research Institute
1985-2018
Departamento de Ciência e Tecnologia
2017
Universidade de São Paulo
2017
The Geospace Environmental Modeling (GEM) Reconnection Challenge project is presented and the important results, which are in a series of companion papers, summarized. Magnetic reconnection studied simple Harris sheet configuration with specified set initial conditions, including finite amplitude, magnetic island perturbation to trigger dynamics. evolution system explored broad variety codes, ranging from fully electromagnetic particle cell (PIC) codes conventional resistive...
The structure of the dissipation region in collisionless magnetic reconnection is investigated by means kinetic particle-in-cell simulations and analytical theory. Analyses reconnecting current sheets without guide field, which keep all parameters fixed with exception electron mass, exhibit very similar large scale evolutions time scales. A detailed comparison two runs different masses reveals parameters, such as ion flow velocities field structures. electron-scale phenomena proper, however,...
A new measure to identify a small-scale dissipation region in collisionless magnetic reconnection is proposed. The energy transfer from the electromagnetic field plasmas electron's rest frame formulated as Lorentz-invariant scalar quantity. tested by two-dimensional particle-in-cell simulations typical configurations: symmetric and asymmetric reconnection, with without guide field. innermost surrounding site accurately located all cases. We further discuss implications for nonideal MHD dissipation.
Particle‐in‐cell simulations are used to investigate collisionless magnetic reconnection in thin current sheets, based on the configuration chosen for Geospace Environment Modeling (GEM) challenge [ Birn et al. , this issue]. The emphasis is overall evolution, as well details of particle dynamics diffusion region. Here electron distributions show clear signatures nongyrotropy, whereas ion simpler structure. investigations extended sheets different widths. we derive a scaling law evolution...
In this paper we continue the community‐wide rigorous modern space weather model validation efforts carried out within GEM, CEDAR and SHINE programs. particular effort, in coordination among Community Coordinated Modeling Center (CCMC), NOAA Space Weather Prediction (SWPC), modelers, science community, focus on studying models' capability to reproduce observed ground magnetic field fluctuations, which are closely related geomagnetically induced current phenomenon. One of primary motivations...
Reconnection between the magnetosphere and magnetosheath at dayside magnetopause is studied for southward IMF using high‐resolution 3‐D MHD simulations. The BATSRUS code run CCMC with a resistive spot added on to ensure that fast reconnection occurs control physics. A large range of Mach numbers (1.9–15) are run. rate nose measured compared local plasma parameters upstream‐solar wind parameters. It found controlled by four parameters: B s (the magnetic field strength in magnetosheath), m...
The Kelvin-Helmholtz waves have been observed along the Earth's low-latitude magnetopause and suggested to play a certain role in entry of solar wind plasma into magnetosphere.In situ observations KH (KHW) and, particular, nonlinear stage instability, i.e., rolled-up vortices (KHVs), reported occur preferentially for northward interplanetary magnetic field (IMF).Using Cluster data, we present first observation nonlinearly developed KHW during southward IMF.The analysis reveals that there is...
Extreme space weather events are known to cause adverse impacts on critical modern day technological infrastructure such as high‐voltage electric power transmission grids. On 23 July 2012, NASA's Solar Terrestrial Relations Observatory‐Ahead (STEREO‐A) spacecraft observed in situ an extremely fast coronal mass ejection (CME) that traveled 0.96 astronomical units (∼1 AU) about 19 h. Here we use the Space Weather Modeling Framework (SWMF) perform a simulation of this rare CME. We consider...
Objective quantification of model performance based on metrics helps us evaluate the current state space physics modeling capability, address differences among various approaches, and track improvements over time. The Coupling, Energetics, Dynamics Atmospheric Regions (CEDAR) Electrodynamics Thermosphere Ionosphere (ETI) Challenge was initiated in 2009 to assess accuracy ionosphere/thermosphere models reproducing ionosphere thermosphere parameters. A total nine events five physical...
Abstract There is a growing concern over possible severe societal consequences related to adverse space weather impacts on man‐made technological infrastructure. In the last two decades, significant progress has been made toward first‐principles modeling of events, and three‐dimensional (3‐D) global magnetohydrodynamics (MHD) models have at forefront this transition, thereby playing critical role in advancing our understanding weather. However, extreme events still major challenge even for...
This paper reports the metrics‐based results of D st index part 2008–2009 GEM Metrics Challenge. The Challenge asked modelers to submit for four geomagnetic storm events and five different types observations that can be modeled by statistical, climatological or physics‐based models magnetosphere‐ionosphere system. We present 30 model settings were run at Community Coordinated Modeling Center institutions various these events. To measure performance each against observations, we use...
Acquiring quantitative metrics‐based knowledge about the performance of various space physics modeling approaches is central for weather community. Quantification helps users products to better understand capabilities models and choose approach that best suits their specific needs. Further, analyses are important addressing differences between measuring guiding progress in field. In this paper, results ground magnetic field perturbation part Geospace Environment Modeling 2008–2009 Challenge...
In an effort to quantitatively assess the current capabilities of Ionosphere/Thermosphere (IT) models, IT model validation study using metrics was performed. This is a main part CEDAR Electrodynamics Thermosphere Ionosphere (ETI) Challenge, which initiated at workshop in 2009 better comprehend strengths and weaknesses models predicting system, trace improvements ionospheric/thermospheric specification forecast. For challenge, two strong geomagnetic storms, four moderate three quiet time...
We report the first in situ observation of high‐latitude magnetopause (near northern duskward cusp) Kelvin‐Helmholtz waves (KHW) by Cluster on January 12, 2003, under strongly dawnward interplanetary magnetic field (IMF) conditions. The fluctuations unstable to instability (KHI) are found propagate mostly tailward, i.e., along direction almost 90° both magnetosheath and geomagnetic fields, which lowers threshold KHI. configuration across boundary layer near cusp region during IMF is similar...
Collisionless magnetized plasmas have the tendency to isotropize their velocity distribution function around local magnetic field direction, i.e., be gyrotropic, unless some spatial and/or temporal fluctuations develop at particle gyroscales. Electron gyroscale inhomogeneities are well known during reconnection process. Nongyrotropic electron functions been observed play a key role in dissipative process breaking line connectivity. In this paper, we present new method quantify deviation of...
Both electron inertia and nongyrotropic effects were analysed using 2 1/2‐dimensional hybrid simulations of collisionless magnetic reconnection. The traditional approach which treats ions as particles electrons an isotropic massless fluid was modified. In the new model mass dependence introduced both in expression for electric field evolution equation full pressure tensor. This comprehensive includes ion kinetics, incorporates Hall effects, describes leading terms dynamics responsible...
Modeling is an important tool in understanding physical processes the space weather. Model performance studies evaluate quality of model operation by comparing its output to a measurable parameter interest. In this paper we studied combination halo coronal mass ejection (CME) analytical cone and ENLIL three‐dimensional MHD heliosphere model. We examined CME arrival time magnitude impact at 1 AU for different geoeffective events, including October 2003 Halloween Storm 14 December 2006 storm...
Asymmetric reconnection is being investigated by means of particle-in-cell simulations. The research has two foci: the direction line in configurations with nonvanishing magnetic fields; and question why can be faster if a guide field added to an otherwise unchanged asymmetric configuration. We find that prefers direction, which maximizes available energy, show this coincides bisection angle between asymptotic fields. Regarding difference rates planar models, we demonstrate provide essential...
Abstract Particle‐in‐cell simulations in a 2.5‐D geometry and analytical theory are employed to study the electron diffusion region asymmetric reconnection with guide magnetic field. The analysis presented here demonstrates that similar case without field, in‐plane flow stagnation null of field well separated. In addition, it is shown electric at local X point again dominated by inertial effects, whereas remains nongyrotropic pressure effects point. A comparison between Larmor radii gradient...
This paper presents the detailed comparative analysis of full particle and hybrid simulations collisionless magnetic reconnection. The comprehensive simulation code employed in this study incorporates essential electron kinetics terms evolution pressure tensor addition to ion bulk flow inertia effects. As was demonstrated our previous publications, nongyrotropic effects play dominant role supporting reconnection electric field immediate vicinity neutral X point. parameters are chosen match...