183 citations · 1.7k across the 55 of their papers we have counts for
55 papers
Direct power spectral density estimation from structure functions without Fourier transforms
Mark A. Bishop, Sean Oughton, Tulasi N. Parashar +1
Second-order structure functions and power spectral densities are popular tools in the study of statistical properties across scales, particularly for the analysis of turbulent flo…
Sub-ion scale current sheets in kinetic Alfvén wave turbulence
Johan Sharma, Ch Akshath Kumar, Kirit D. Makwana +2
3D kinetic particle-in-cell (PIC) simulations are performed using the kinetic Alfvén wave (KAW) eigenvector relations from a two-fluid model as initial conditions, in order to stud…
Constraining solar wind transport model parameters using Bayesian analysis
Mark Bishop, Sean Ougthon, Tulasi Parashar +1
We apply nested-sampling (NS) Bayesian analysis [AshtonEA22] to a model for the transport of MHD-scale solar wind fluctuations. The dual objectives are to obtain improved constrain…
De-Biasing Structure Function Estimates From Sparse Time Series of the Solar Wind: A Data-Driven Approach
Daniel Wrench, Tulasi N. Parashar
Structure functions, which represent the moments of the increments of a stochastic process, are essential complementary statistics to power spectra for analysing the self-similar b…
Scale Separation Effects on Simulations of Plasma Turbulence
Jago Edyvean, Tulasi N. Parashar, Tom Simpson +7
Understanding plasma turbulence requires a synthesis of experiments, observations, theory, and simulations. In the case of kinetic plasmas such as the solar wind, the lack of colli…
Higher-order nonequilibrium term: Effective power density quantifying evolution towards or away from local thermodynamic equilibrium
M. Hasan Barbhuiya, Paul A. Cassak, Subash Adhikari +3
A common approach to assess the nature of energy conversion in a classical fluid or plasma is to compare power densities of the various possible energy conversion mechanisms. A for…
Scale and Time Dependence of Alfvénicity in the Solar Wind as Observed by {\it Parker Solar Probe}
Panisara Thepthong, Peera Pongkitiwanichakul, David Ruffolo +4
Alfvénicity is a well-known property, common in the solar wind, characterized by a high correlation between magnetic and velocity fluctuations. Data from the Parker Solar Probe (PS…
Statistics of Turbulence in the Solar Wind. I. What is the Reynolds Number of the Solar Wind?
Daniel Wrench, Tulasi N. Parashar, Sean Oughton +2
The Reynolds number, Re, is an important quantity for describing a turbulent flow. It tells us about the bandwidth over which energy can cascade from large scales to smaller ones,…
Scale Filtering Analysis of Kinetic Reconnection and its Associated Turbulence
Subash Adhikari, Yan Yang, William H. Matthaeus +3
Previously, using an incompressible von Kármán-Howarth formalism, the behavior of cross-scale energy transfer in magnetic reconnection and turbulence was found to be essentially id…
Power spectrum estimation methods on intracluster medium surface brightness fluctuations
Mark Bishop, Yvette Perrott, Tulasi Parashar +1
Accurate estimation of galaxy cluster masses is a central problem in cosmology. Turbulence is believed to introduce significant deviations from the hydrostatic mass estimates. Esti…
Probing the evolution of galaxy clusters using SZ effect and non-thermal emission: first results from A1413
Mohini Pachchigar, Yvette Perrott, Tulasi Parashar
Mass is the most fundamental property of galaxy clusters. However, measuring it is still a challenge. Calibrating mass from intracluster medium observables such as the Sunyaev-Zel'…
Effective Viscosity, Resistivity, and Reynolds Number in Weakly Collisional Plasma Turbulence
Yan Yang, William H. Matthaeus, Sean Oughton +6
We examine dissipation and energy conversion in weakly collisional plasma turbulence, employing in situ observations from the Magnetospheric Multiscale (MMS) mission and kinetic Pa…
Statistics of Pressure Fluctuations in Turbulent Kinetic Plasmas
Subash Adhikari, William H. Matthaeus, Tulasi N. Parashar +2
In this study we explore the statistics of pressure fluctuations in kinetic collisionless turbulence. A 2.5D kinetic particle-in-cell (PIC) simulation of decaying turbulence is use…
Effect of a guide field on the turbulence like properties of magnetic reconnection
Subash Adhikari, Michael A. Shay, Tulasi N. Parashar +4
The effect of an external guide field on the turbulence-like properties of magnetic reconnection is studied using five different 2.5D kinetic particle-in-cell (PIC) simulations. Th…
The essential role of multi-point measurements in investigations of turbulence, three-dimensional structure, and dynamics: the solar wind beyond single scale and the Taylor Hypothesis
W. H. Matthaeus, S. Adhikari, R. Bandyopadhyay +49
Space plasmas are three-dimensional dynamic entities. Except under very special circumstances, their structure in space and their behavior in time are not related in any simple way…
Isotropization and Evolution of Energy-Containing Eddies in Solar Wind Turbulence: Parker Solar Probe, Helios 1, ACE, WIND, and Voyager 1
Manuel Enrique Cuesta, Rohit Chhiber, Sohom Roy +6
We examine the radial evolution of correlation lengths perpendicular (\(λ_C^{\perp}\)) and parallel (\(λ_C^{\parallel}\)) to the magnetic-field direction, computed from solar wind…
Observations of Cross Scale Energy Transfer in the Inner Heliosphere by Parker Solar Probe
Tulasi N. Parashar, William H. Matthaeus
The solar wind, a continuous flow of plasma from the sun, not only shapes the near Earth space environment but also serves as a natural laboratory to study plasma turbulence in con…
Exploring the potential of neural networks to predict statistics of solar wind turbulence
Daniel Wrench, Tulasi N. Parashar, Ritesh K. Singh +2
Time series datasets often have missing or corrupted entries, which need to be ignored in subsequent data analysis. For example, in the context of space physics, calibration issues…
Pressure-Strain Interaction as the Energy Dissipation Estimate in Collisionless Plasma
Yan Yang, William H. Matthaeus, Sohom Roy +4
The dissipative mechanism in weakly collisional plasma is a topic that pervades decades of studies without a consensus solution. We compare several energy dissipation estimates bas…
Intermittency in the Expanding Solar Wind: Observations from Parker Solar Probe (0.16au), Helios 1 (0.3-1au), and Voyager 1 (1-10au)
Manuel Enrique Cuesta, Tulasi N. Parashar, Rohit Chhiber +1
We examine statistics of magnetic field vector components to explore how intermittency evolves from near sun plasma to radial distances as large as 10 au. Statistics entering the a…
Energy Dissipation in Turbulent Reconnection
R. Bandyopadhyay, A. Chasapis, W. H. Matthaeus +6
We study the nature of pressure-strain interaction at reconnection sites, detected by NASA's Magnetospheric Multiscale (MMS) Mission. We employ data from a series of published case…
Magnetic reconnection as an energy cascade process
S. Adhikari, T. N. Parashar, M. A. Shay +5
Reconnection and turbulence are two of the most commonly observed dynamical processes in plasmas, but their relationship is still not fully understood. Using 2.5D kinetic particle-…
Interplay of Turbulence and Proton-Microinstability Growth in Space Plasmas
Riddhi Bandyopadhyay, Ramiz A. Qudsi, William H. Matthaeus +13
Numerous prior studies have shown that as proton beta increases, a narrower range of proton temperature anisotropy values is observed. This effect has often been ascribed to the ac…
A Detailed Examination of Anisotropy and Timescales in Three-dimensional Incompressible Magnetohydrodynamic Turbulence
Rohit Chhiber, William H. Matthaeus, Sean Oughton +1
When magnetohydrodynamic turbulence evolves in the presence of a large-scale mean magnetic field, an anisotropy develops relative to that preferred direction. The well-known tenden…