A5076869074- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Ionosphere and magnetosphere dynamics
- Oceanographic and Atmospheric Processes
- Geophysics and Gravity Measurements
- Meteorological Phenomena and Simulations
- Reservoir Engineering and Simulation Methods
- Magnetic confinement fusion research
- Electromagnetic Launch and Propulsion Technology
- Climate variability and models
- Plasma Diagnostics and Applications
- Topological Materials and Phenomena
- Solar Radiation and Photovoltaics
- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
University of Hawaiʻi at Mānoa
2024
University of Hawaii System
2024
Indian Institute of Science Education and Research Kolkata
2018-2023
Ravenshaw University
2013
Abstract The activity of stars such as the Sun varies over timescales ranging from very short to long—stellar and planetary evolutionary timescales. Experience our solar system indicates that short-term, transient events stellar flares coronal mass ejections create hazardous space environmental conditions impact Earth-orbiting satellites atmospheres. Extreme superflares may play a role in atmospheric loss unsuitable for life. Slower, long-term evolutions Sun-like millennia billions years...
Magnetic clouds (MCs) are flux-rope magnetic structures forming a subset of solar coronal mass ejections which have significant space weather impacts. The geoeffectiveness MCs depends on their properties evolve during interplanetary passage. Based an analysis observations spanning two cycles we establish that interacting with the ambient wind field (i.e., heliospheric open flux) lose substantial amount initial flux via reconnection, in some cases, reduce geoeffectiveness. We find linear...
Abstract On 2017 August 21, a total solar eclipse swept across the contiguous United States, providing excellent opportunities for diagnostics of Sun’s corona. The coronal structure is notoriously difficult to observe except during eclipses; thus, theoretical models must be relied upon inferring underlying magnetic outer atmosphere. These are necessary understanding role fields in heating corona million degrees and generation severe space weather. Here we present methodology predicting field...
ABSTRACT Magnetic fields generated in the Sun’s interior by dynamo mechanism drive solar activity over a range of time-scales. Direct sunspot observations exist for few centuries; reconstructed variations based on cosmogenic isotopes open flux and cosmic ray thousands years. While such reconstructions indicate presence extreme fluctuations past, causal links between millennia scale activity, consequent coronal field, wind, remain elusive; lack field compounds this issue. By utilizing...
On 2019 July 2 a total solar eclipse -- visible across some parts of the Southern Pacific Ocean, Chile and Argentina will enable observations Sun's large-scale coronal structure. The structure corona their emission characteristics are determined by underlying magnetic fields which also govern heating eruptive events. However, field measurements remain an outstanding challenge. Computational models serve important purpose in this context. Earlier work has demonstrated that is governed slow...
The compact plasma system(CPS) at Ravenshaw University, India consists of a curved vacuum chamber which is nothing but part toroid. To produce gas injected washer stacked gun designed and tested. pulse forming network (PFN) to energize the gun. It Guillemin E type capacitors having equal capacitance 5.5 μF inductors inductances 1.5 μH. width PFN ∼ 7.6 μs for seven stage network, as tested with known resistive circuit.
Knowledge of the global magnetic field distribution and its evolution on Sun's surface is crucial for modeling coronal field, understanding solar wind dynamics, computing heliospheric open flux predicting cycle strength. As far side Sun cannot be observed directly high-latitude observations always suffer from projection effects, we often rely transport simulations (SFT) to model long-term distribution. Meridional circulation, large-scale north-south component flow profile, one key components...
Abstract Knowledge of the global magnetic field distribution and its evolution on Sun’s surface is crucial for modeling coronal field, understanding solar wind dynamics, computing heliospheric open flux distribution, predicting cycle strength. As far side Sun cannot be observed directly high-latitude observations always suffer from projection effects, we often rely transport (SFT) simulations to model long-term distribution. Meridional circulation, large-scale north–south component flow...
Magnetic fields generated in the Sun's interior by solar dynamo mechanism drive activity over a range of time-scales. While space-based observations corona exist only for few decades, direct sunspot centuries, open flux and cosmic ray variations can be reconstructed through studies cosmogenic isotopes thousands years. such reconstructions indicate presence extreme fluctuations past, causal links between millennia scale activity, consequent coronal field, modulation remain elusive. By...
Motivated by the observation of Skyrmion-like magnetic textures in 2D itinerant ferromagnets Fe$_n$GeTe$_2$ ($n \geq3$), we develop a microscopic model combining magnetism and spin-orbit coupling on triangular lattice. The ground state absence field consists filamentary domain walls revealing striking similarity with our force microscopy experiments Fe$_3$GeTe$_2$. In presence field, these filaments were found to break into large size bubbles experiments. We identify uniaxial anisotropy as...
On 21 August 2017 a total solar eclipse swept across the contiguous United States providing excellent opportunities for diagnostics of Sun's corona. The coronal structure is notoriously difficult to observe except during eclipses; thus theoretical models must be relied upon inferring underlying magnetic outer atmosphere. These are necessary understanding role fields in heating corona million degrees and generation severe space weather. Here we present methodology predicting field based on...
Abstract Regular reconstruction of global solar corona constrained by observational data is required to monitor the space weather variations. We develop a model for simulating coronal magnetic field using magnetofrictional approach. Here we perform simulations study evolution associated with bipolar active region in response photospheric flows.
Earth and Space Science Open Archive PosterOpen AccessYou are viewing the latest version by default [v1]Understanding Global Coronal Magnetic Fields using Data-constrained Magnetohydrodynamic ModelAuthorsSoumyaranjanDashiDDibyenduNandyBhargavVaidyaSee all authors Soumyaranjan DashiDCorresponding Author• Submitting AuthorCenter of Excellence in Sciences India, IISER KolkataiDhttps://orcid.org/0000-0003-0103-6569view email addressThe was not providedcopy addressDibyendu NandyIndian Institute...
Earth and Space Science Open Archive PosterOpen AccessYou are viewing the latest version by default [v1]Dynamics of Sun's Polar Field: Possible Insights from Out Ecliptic ObservationsAuthorsSoumyaranjanDashiDDibyenduNandyShaonwitaPalSee all authors Soumyaranjan DashiDCorresponding Author• Submitting AuthorIndian Institute Education Research KolkataiDhttps://orcid.org/0000-0003-0103-6569view email addressThe was not providedcopy addressDibyendu NandyIndian Kolkataview addressShaonwita...