Search Publications
Cataloging Stream Interaction Regions at MAVEN: A Cross-comparative Study with STEREO-A
Allen, Robert C.; Lee, Christina O.; Halekas, Jasper S. +5 more
Stream interaction regions (SIRs) are long-lasting solar wind structures that result from stable fast solar wind interacting with preceding slow solar wind. These structures have been examined in depth throughout the heliosphere, particularly at 1 au; however, due to sparse observations, SIRs have not been characterized thoroughly at 1.5 au. Thank…
Ion Charge States from a Global Time-dependent Wave-turbulence-driven Model of the Solar Wind: Comparison with in Situ Measurements
Riley, Pete; Rivera, Yeimy J.; Lionello, Roberto
Solar wind charge-state measurements contain a wealth of knowledge related to the properties of the solar corona from where they originated. However, their interpretation has remained challenging because it convolves coronal temperature, density, and velocity along the particles' trajectory through the corona before they "freeze in" and are convec…
Fluctuations Driven by Multicomponent Pickup Ion Distributions in the Outer Heliosheath
Roytershteyn, Vadim; Mousavi, Ameneh; Fraternale, Federico +1 more
The stability of a realistic multicomponent pickup ion (PUI) velocity distribution derived from a global model of neutral atoms in the heliosphere, which treats hydrogen and helium atoms self-consistently and includes equations for electrons and helium ions, is investigated using linear instability analysis and hybrid simulations. Linear instabili…
Juno Observations of Langmuir Waves in Association with Interplanetary Shocks from ~1.3 to ~5.4 au
Cattell, C.; Elliott, S.; Hanson, E. L. M. +1 more
Langmuir waves are often observed upstream of planetary bow shocks and interplanetary (IP) shocks. Waveform capture (WFC) measurements, obtained during Juno's cruise phase, reveal the occurrence of Langmuir waves, as well as other wave modes, in association with IP shocks and IP coronal mass ejections (ICMEs) at distances from ∼1.3 to ∼5.4 au. Thi…
Immersed in Solar Physics
Hirayama, Tadashi
Since I have lived a rather ordinary life, my focus will center on what I have studied, with only exceptional personal matters being discussed. Nevertheless, rather new ideas are presented in Section 6.2 on the flare theory and in Section 9 on the mechanism of the 22-year solar cycle. These ideas have been included in light of my 90 years of age, …
Solar orbiter: a short review of the mission and early science results
Müller, Daniel; Harra, Louise
On 9 February 2020 at 11:03 pm EST, an Atlas V 411 rocket launched the ESA/ NASA Solar Orbiter mission. This mission was the culmination of decades of work across many countries to achieve the goal of getting close to the Sun and measuring how the Sun creates and maintains the heliosphere. The mission's goal is to understand how the inner heliosph…
Constraining Solar Wind Transport Model Parameters Using Bayesian Analysis
Parashar, Tulasi N.; Oughton, Sean; Bishop, Mark A. +1 more
We apply nested-sampling Bayesian analysis to a model for the transport of magnetohydrodynamic-scale solar wind fluctuations. The dual objectives are to obtain improved constraints on parameters present in the turbulence transport model (TTM) and to support quantitative comparisons of the quality of distinct versions of the transport model. The TT…
Spectral Structures of Jovian Broadband Kilometric Radiation Revealed by Cassini and Juno
Kurth, W. S.; Píša, D.; Fischer, G. +2 more
Cassini flew past Jupiter in 2000/2001, and Juno has been orbiting the gas giant since mid-2016. Here we focus on the spectral properties of Jovian broadband kilometric radiation (bKOM), and we classified them according to their slope in the time–frequency spectrum and distinguish four categories with negative, positive, mixed, or no slope in freq…
Stability and instability of Langmuir waves via active subspace decompositions
Mattingly, G.; Longaker, B.; Palmer, N. +2 more
We study the stability and instability of Langmuir waves propagating in a hot, unmagnetized plasma modeled by the Vlasov–Poisson system and encompassing a variety of velocity distributions, including perturbations of Lorentzian, Kappa, and incomplete Maxwellian steady states. The influence of both high-frequency spatial perturbations and physical …
A Case Study of Interstellar Material Delivery: α Centauri
Wiegert, Paul A.; Gregg, Cole R.
Interstellar material has been discovered in our solar system, yet its origins and details of its transport are unknown. Here, we present α Centauri as a case study of the delivery of interstellar material to our solar system. α Centauri is a mature triple star system that likely harbors planets, and is moving toward us with the point of the close…