N. M. Viall
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View article: Polarimeter to Unify the Corona and Heliosphere (PUNCH)
Polarimeter to Unify the Corona and Heliosphere (PUNCH) Open
The Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission is a NASA Small Explorer to determine the cross-scale processes that unify the solar corona and heliosphere. PUNCH has two science objectives: (1) understand how coronal s…
View article: Connecting Solar Orbiter and L1 Measurements of Mesoscale Solar Wind Structures to Their Coronal Source Using the ADAPT-WSA Model
Connecting Solar Orbiter and L1 Measurements of Mesoscale Solar Wind Structures to Their Coronal Source Using the ADAPT-WSA Model Open
Much of the dynamics of the ambient solar wind (SW) manifests at mesoscales—scales larger than kinetic but smaller than global structures. Mesoscale structures often form at the Sun, survive to 1 au, and are geoeffective. Identifying their…
View article: Deriving the Coronal Separatrix‐Web With the WSA Model
Deriving the Coronal Separatrix‐Web With the WSA Model Open
We demonstrate a new capability of the Wang‐Sheeley‐Arge (WSA) model to routinely derive the coronal separatrix web (S‐web) as a standard data product. We describe our methodology for deriving the squashing factor () and we use Carrington …
View article: Metis Observations of Alfvénic Outflows Driven by Interchange Reconnection in a Pseudostreamer
Metis Observations of Alfvénic Outflows Driven by Interchange Reconnection in a Pseudostreamer Open
This study presents observations of a large pseudostreamer solar eruption and, in particular, the post-eruption relaxation phase, as captured by Metis, on board the Solar Orbiter, on 2022 October 12, during its perihelion passage. Utilizin…
View article: Magnetohydrodynamic Turbulence Simulations as a Testing Ground for PUNCH
Magnetohydrodynamic Turbulence Simulations as a Testing Ground for PUNCH Open
The Polarimeter to UNify the Corona and Heliosphere (PUNCH) will image macroscopic features of the inner heliosphere and also admit sufficiently high spatial resolution to probe scales of turbulence within the upper end of the inertial ran…
View article: Connecting the Low to High Corona: Propagating Disturbances as Tracers of the Near-Sun Solar Wind
Connecting the Low to High Corona: Propagating Disturbances as Tracers of the Near-Sun Solar Wind Open
We revisit a quiet 14 day period of solar minimum during 2008 January and track substreamer propagating disturbances (PDs) from low heights in STEREO/EUVI to the extended corona through STEREO/COR1 and into STEREO/COR2 along nonradial path…
View article: Outer Zone Relativistic Electron Response to Mesoscale Periodic Density Structures in the Solar Wind: Van Allen Probes Measurements
Outer Zone Relativistic Electron Response to Mesoscale Periodic Density Structures in the Solar Wind: Van Allen Probes Measurements Open
We investigate the relativistic and the ultra‐relativistic outer radiation belt electron response to the Periodic Density Structures (PDS) in the solar wind. We have studied four intervals between 0000 UT and 1500 UT during 17 January 2013…
View article: Azimuthal Size Scales of Solar Wind Periodic Density Structures
Azimuthal Size Scales of Solar Wind Periodic Density Structures Open
Periodic density structures (PDSs) are quasiperiodic variations of solar wind density ranging from a few minutes to a few hours. PDSs advect with the solar wind and have radial length scales ( L x ) of tens to several thousand megameters, …
View article: Solar Wind Periodic Density Structures: Size Scales and Geo-effectiveness
Solar Wind Periodic Density Structures: Size Scales and Geo-effectiveness Open
Mesoscale transient structures affecting the solar wind-magnetosphere coupling can be either generated in the near-Earth environment or already present in the pristine solar wind. Among the solar wind mesoscale structures, in recent years,…
View article: Periodic Mesoscale Density Structures Comprise a Significant Fraction of the Solar Wind and Are Formed at the Sun
Periodic Mesoscale Density Structures Comprise a Significant Fraction of the Solar Wind and Are Formed at the Sun Open
Mesoscale density structures in the solar wind are often periodic, with f ∼ 0.1–5 mHz. They are trains of advected density structures with radial length scales of ∼100–10,000 Mm. While studies have shown that these periodic density structu…
View article: Mesoscale dynamics — the key to unlocking the universal physics of multiscale feedback
Mesoscale dynamics — the key to unlocking the universal physics of multiscale feedback Open
Whitepaper #201 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research; infrastructure/workforce/other programmatic. Additional topics: fundamental space plasma theory; state of the professi…
View article: Critical Solar Wind Measurements Required For the Next Generation Space Weather Prediction Mission: Science Motivation for the Seven Sisters Mission
Critical Solar Wind Measurements Required For the Next Generation Space Weather Prediction Mission: Science Motivation for the Seven Sisters Mission Open
Whitepaper #298 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: laboratory space plasma physics; space-based missions/projects; user-need-driven basic space weathe…
View article: An Inclusive Heliophysics Community
An Inclusive Heliophysics Community Open
Whitepaper #150 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: infrastructure/workforce/other programmatic. Additional topics: other programmatic; state of the profession.
View article: CME Origins and Propagation: Importance of the Polar Perspective
CME Origins and Propagation: Importance of the Polar Perspective Open
Whitepaper #089 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: space weather applications; basic research. Additional topics: space weather research/operations/research loop; solar physics; space-b…
View article: The Open Flux Problem: The Need for High Latitude Observations
The Open Flux Problem: The Need for High Latitude Observations Open
The Sun's open magnetic field is a fundamental aspect of coronal and heliospheric physics.The primary source location of the open magnetic field is believed to be coronal holes, usually detected by the absence of EUV and/or X-ray emission.…
View article: Firefly: The Case for a Holistic Understanding of the Global Structure and Dynamics of the Sun and the Heliosphere
Firefly: The Case for a Holistic Understanding of the Global Structure and Dynamics of the Sun and the Heliosphere Open
status: Published
View article: Deciphering the Birth Region, Formation, and Evolution of Ambient and Transient Solar Wind Using Heavy Ion Observations
Deciphering the Birth Region, Formation, and Evolution of Ambient and Transient Solar Wind Using Heavy Ion Observations Open
This white paper outlines the key scientific topics to address in the upcoming decade using observations of heavy ion composition.• The Sun's chemical composition: identifying specific mechanisms driving elemental variation in the corona •…
View article: The Multiview Observatory for Solar Terrestrial Science (MOST)
The Multiview Observatory for Solar Terrestrial Science (MOST) Open
Whitepaper #138 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research; infrastructure/workforce/other programmatic. Additional topics: solar physics; state of the profession; space-based mi…
View article: Solaris: A Focused Solar Polar Discovery-class Mission to achieve the Highest Priority Heliophysics Science Now
Solaris: A Focused Solar Polar Discovery-class Mission to achieve the Highest Priority Heliophysics Science Now Open
Whitepaper #164 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: space weather applications; basic research. Additional topics: space weather research/operations/research loop; solar physics; space-b…
View article: On Solving the Outstanding Questions in Solar Wind Physics
On Solving the Outstanding Questions in Solar Wind Physics Open
The Sun and the heliosphere is a system-of-systems, where the physics of cross-regional and cross-scale coupling determines the state of the system.We describe the outstanding questions of solar wind physics as well as potential solutions,…
View article: The Heliophysics Digital Resource Library: An Open, Flexible, Easily Used Infrastructure for Data, Software, Registration, Documentation, and Services
The Heliophysics Digital Resource Library: An Open, Flexible, Easily Used Infrastructure for Data, Software, Registration, Documentation, and Services Open
Whitepaper #342 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: infrastructure/workforce/other programmatic. Additional topics: research tools and infrastructure.
View article: Observing Coronal Microscales and their Connection with Mesoscales
Observing Coronal Microscales and their Connection with Mesoscales Open
Whitepaper #330 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: ground-based missions/projects; solar physics; space-based missions/projects; system science.
View article: Solar Coronal Polarization Diagnostics with H I Ly-α
Solar Coronal Polarization Diagnostics with H I Ly-α Open
Whitepaper #047 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: solar physics; space-based missions/projects; user-need-driven basic space weather research.
View article: Heating of the Magnetically Closed Corona and Physical Models of Solar and Stellar Spectral Irradiances
Heating of the Magnetically Closed Corona and Physical Models of Solar and Stellar Spectral Irradiances Open
Whitepaper #209 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: space weather applications; basic research. Additional topics: space weather research/applications/operations pipeline; solar physics;…
View article: The Importance of Policies: It’s not just a pipeline problem
The Importance of Policies: It’s not just a pipeline problem Open
Continue towards a truly open science approach in Heliophysics2. Find new solutions to provide more stability to soft money scientists 3. Work towards more accessibility and equity across different sections of our community 4. Government i…
View article: A Strategy to Close Key Questions about the Middle Solar Corona During this Decade
A Strategy to Close Key Questions about the Middle Solar Corona During this Decade Open
The middle corona, the region roughly spanning heliocentric altitudes from 1.5-6 R ⊙ , encompasses almost all of the influential physical transitions and processes that govern the behavior of coronal outflow into the heliosphere.Eruptions …
View article: The Critical Coronal Transition Region: A Physics-framed Strategy to Uncover the Genesis of the Solar Wind and Solar Eruptions
The Critical Coronal Transition Region: A Physics-framed Strategy to Uncover the Genesis of the Solar Wind and Solar Eruptions Open
Our current theoretical and observational understanding suggests that critical properties of the solar wind and Coronal Mass Ejections (CMEs) are imparted within 10 Rs, particularly below 4 Rs.This seemingly narrow spatial region encompass…
View article: Sun-2-Stars (S2S): Unified Understanding of Our Space Environs from the Sun’s Poles through the 3D Solar Wind and Out Toward the Stars
Sun-2-Stars (S2S): Unified Understanding of Our Space Environs from the Sun’s Poles through the 3D Solar Wind and Out Toward the Stars Open
Whitepaper #359 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: space weather applications; basic research. Additional topics: other space weather; solar physics; space-based missions/projects; user…
View article: The Critical Coronal Transition Region: A Physics-framed Strategy to Uncover the Genesis of the Solar Wind and Solar Eruptions
The Critical Coronal Transition Region: A Physics-framed Strategy to Uncover the Genesis of the Solar Wind and Solar Eruptions Open
Our current theoretical and observational understanding suggests that critical properties of the solar wind and Coronal Mass Ejections (CMEs) are imparted within 10 Rs, particularly below 4 Rs. This seemingly narrow spatial region encompas…