Chuanfei Dong

Boston University | BU · Department of Astronomy

A comprehensive study of the solar wind interaction with the Martian upper atmosphere is presented. Three global models: the 3-D Mars multifluid Block Adaptive Tree Solar-wind Roe Upwind Scheme MHD code (MF-MHD), the 3-D Mars Global Ionosphere Thermosphere Model (M-GITM), and the Mars exosphere Monte Carlo model Adaptive Mesh Particle Simulator (M-...

We address the important question of whether the newly discovered exoplanet, Proxima Centauri b (PCb), is capable of retaining an atmosphere over long periods of time. This is done by adapting a sophisticated multi-species MHD model originally developed for Venus and Mars, and computing the ion escape losses from PCb. The results suggest that the i...

Significance The search for exoplanets has rapidly emerged as one of the most important endeavors in astronomy. This field received a major impetus with the recent discovery of seven temperate Earth-sized exoplanets orbiting the nearby ultracool dwarf star TRAPPIST-1. One of the most crucial requirements for conventional (surface-based) planetary h...

The plasmoid instability in evolving current sheets has been widely studied due to its effects on the disruption of current sheets, the formation of plasmoids, and the resultant fast magnetic reconnection. In this Letter, we study the role of the plasmoid instability in two-dimensional magnetohydrodynamic (MHD) turbulence by means of high-resolutio...

Magnetohydrodynamic turbulence regulates the transfer of energy from large to small scales in many astrophysical systems, including the solar atmosphere. We perform three-dimensional magnetohydrodynamic simulations with unprecedentedly large magnetic Reynolds number to reveal how rapid reconnection of magnetic field lines changes the classical para...

When the solar wind interacts with the ionosphere of an unmagnetized planet, it induces currents that form an induced magnetosphere. These currents and their associated magnetic fields play a pivotal role in controlling the movement of charged particles, which is essential for understanding the escape of planetary ions. Unlike the well-documented m...

Mars lacks a global intrinsic dipole field but possesses localized crustal fields, making it unique in the solar system. Recent observations revealed that electrons can be injected into the crustal fields, and exhibit drift-dispersed bursts due to the magnetic drift motion, which are characterized by increases or decreases in energy over time in th...

Plain Language Summary Like supersonically fast fighter jets creating sonic shocks in the air, planet Earth typically moves in the magnetized solar wind at super‐Alfvénic speeds and generates a bow shock. Here we report unprecedented observations of Earth's magnetosphere interacting with a sub‐Alfvénic solar wind brought by an erupted magnetic flux...

In the absence of a substantial ionosphere, solar wind protons dominate the plasma content within Mercury’s magnetosphere. However, Mercury is surrounded by a tenuous neutral exosphere composed primarily of sodium atoms, which can be continuously ionized. The production of sodium ions is concentrated on the dayside, and these ions can subsequently...

When the solar wind speed falls below the local Alfvén speed, the magnetotail transforms into an Alfvén wing configuration. A Grid Agnostic Magnetohydrodynamics for Extended Research Applications (GAMERA) simulation of Earth's magnetosphere using solar wind parameters from the 24 April 2023 sub‐Alfvénic interval is examined to reveal modifications...

Plain Language Summary Ion escape into space, driven by solar wind interactions with Mars, plays a pivotal role in the evolution of the Martian atmosphere. An important escape channel of planetary oxygen ions is the current sheet in the nightside magnetotail. Yet, our existing understanding of plasma characteristics within this magnetic structure r...

Previous studies suggested that Mercury’s terrestrial-like magnetosphere could possess Earth-like field-aligned currents (FACs) despite having no ionosphere. However, due to the limited coverage of spacecraft observations, our knowledge about Mercury’s FACs is scarce. Here, to survey the establishment and global pattern of Mercury’s FACs, we used A...

Large-scale characterization of exoplanetary atmospheres is on the horizon, thereby making it possible in the future to extract their statistical properties. In this context, by using a well-validated model in the solar system, we carry out 3D magnetohydrodynamic simulations to compute nonthermal atmospheric ion escape rates of unmagnetized rocky e...

Large-scale characterization of exoplanetary atmospheres is on the horizon, thereby making it possible in the future to extract their statistical properties. In this context, by using a well validated model in the solar system, we carry out three-dimensional magnetohydrodynamic simulations to compute nonthermal atmospheric ion escape rates of unmag...

In experiments performed with the OMEGA EP laser system, proton deflectometry captured magnetic field dynamics consistent with collisionless shock formation driven by strongly magnetized relativistic electrons. During laser-foil interactions, shocks can form as relativistic electrons and strong surface magnetic fields generated by a short-pulse las...

In December 2022, an extremely low‐density solar wind stream encountered first the Earth and then Mars, shortly after the radial alignment of the two planets (i.e., Mars opposition). As the low‐density stream passed Mars, the properties of the Mars‐solar wind interaction changed dramatically in response to the low solar wind Alfvénic Mach number an...

Recently it has been identified that our Moon had an extensive magnetosphere for several hundred million years soon after it was formed when the Moon was within 20 Earth Radii (RE) from the Earth. Some aspects of the interaction between the early Earth-Moon magnetospheres are investigated by mapping the interconnected field lines between the Earth...

Mars lacks a global magnetic field, and instead possesses small-scale crustal magnetic fields, making its magnetic environment fundamentally different from intrinsic magnetospheres like those of Earth or Saturn. Here we report the discovery of magnetospheric ion drift patterns, typical of intrinsic magnetospheres, at Mars using measurements from Ma...

The Martian MPB (Magnetic Pileup Boundary) is a key boundary in the Mars/Solar Wind interaction as it is here that part of the momentum and energy from the solar wind plasma are transferred to the planetary plasma. Since this interaction is for the most part collisionless, the transfer is mediated by electric and magnetic fields. The acceleration p...

A major obstacle in cultivating a robust Heliophysics (and broader scientific) community is the lack of diversity throughout science, technology, engineering, and mathematics (STEM) fields. For many years, this has been understood as a “leaky pipeline” analogy, in which predominately minority students initially interested in STEM gradually fall (or...

Heliophysics is the field that ``studies the nature of the Sun, and how it influences the very nature of space - and, in turn, the atmospheres of planetary bodies and the technology that exists there.'' However, NASA's Heliophysics Division tends to limit study of planetary magnetospheres and atmospheres to only those of Earth. This leaves explorat...

The development of machine learning techniques enables us to discover partial differential equations from sparse data, which has important implications for modeling complex physical systems. In this paper, based on the output from 1D Vlasov-Ampere simulations, we adopt Fourier Neural Operator (FNO) to learn partial differential equations from kinet...

Kinetic approaches are generally accurate in dealing with microscale plasma physics problems but are computationally expensive for large-scale or multiscale systems. One of the long-standing problems in plasma physics is the integration of kinetic physics into fluid models, which is often achieved through sophisticated analytical closure terms. In...

Space weather observations and modeling at Mars have begun but it must be significantly increased to support the future of Human Exploration on the Red Planet. A comprehensive space weather understanding of a planet without a global magnetosphere and a thin atmosphere is very different from our situation at Earth so there is substantial fundamental...

Mars lacks a planetary-scale intrinsic magnetosphere, and instead possesses small-scale crustal magnetic fields, creating a distinct class of plasma environments from intrinsic magnetospheres such as that of Earth or Saturn. Here we report the discovery of intrinsic magnetospheric ion behavior at Mars based on the measurements provided by Mars Atmo...

Magnetic reconnection is prevalent in magnetized plasmas in space and laboratories. Despite significant investigations on reconnection in electron–ion plasmas, studies of reconnection in magnetized plasmas with negatively charged dust grains are quite sparse. Here, we report the first fully kinetic simulations of collisionless reconnection in a thr...

Citizen science connects scientists with the public to enable discovery, engaging broad audiences across the world. There are many attributes that make citizen science an asset to the field of heliophysics, including agile collaboration. Agility is the extent to which a person, group of people, technology, or project can work efficiently, pivot, an...

Study Analysis Group 21 (SAG21) of NASA’s Exoplanet Exploration Program Analysis Group (ExoPAG) was organized to study the effect of stellar contamination on space-based transmission spectroscopy, a method for studying exoplanetary atmospheres by measuring the wavelength-dependent radius of a planet as it transits its star. Transmission spectroscop...

A large number of heliophysicists from across career levels, institution types, and job titles came together to support a poster at Heliophysics 2050 and the position papers for the 2024 Heliophysics decadal survey titled “Cultivating a Culture of Inclusivity in Heliophysics,” “The Importance of Policies: It’s not just a pipeline problem,” and “Men...

Traditionally, heliophysics is characterized as the study of the near-Earth space environment, where plasmas and neutral gases originating from the Earth, the Sun, and other solar system bodies interact in ways that are detectable only through in-situ or close-range (usually within ∼10 AU) remote sensing. As a result, heliophysics has data from the...

Deriving governing equations of complex physical systems based on first principles can be quite challenging when there are certain unknown terms and hidden physical mechanisms in the systems. In this work, we apply a deep learning architecture to learn fluid partial differential equations (PDEs) of a plasma system based on the data acquired from a...

Collisionless magnetic reconnection typically requires kinetic treatment that is, in general, computationally expensive compared to fluid-based models. In this study, we use the magnetohydrodynamics with an adaptively embedded particle-in-cell (MHD-AEPIC) model to study the interaction of two magnetic flux ropes. This innovative model embeds one or...

Traditionally, heliophysics is characterized as the study of the near-Earth space environment, where plasmas and neutral gases originating from the Earth and the Sun, and to a lesser extent other solar system bodies, interact in ways that are detectable only through in-situ or close-range (usually within ~10 AU) remote sensing. As a result, helioph...

Collisionless magnetic reconnection typically requires kinetic treatments that are, in general, computationally expensive compared to fluid-based models. In this study, we use the magnetohydrodynamics with adaptively embedded particle-in-cell (MHD-AEPIC) model to study the interaction of two magnetic flux ropes. This innovative model embeds one or...

Space weather refers to conditions around a star, like our Sun, and its interplanetary space that may affect space- and ground-based assets as well as human life. Space weather can manifest as many different phenomena, often simultaneously, and can create complex and sometimes dangerous conditions. The study of space weather is inherently trans-dis...

In this study we present the observation of Mercury’s inner southern magnetosphere and surrounding regions, never previously explored, as detected by the two ion sensors of the instrument package: ‘Search for Exospheric Refilling and Emitted Natural Abundances’ (SERENA), named ‘Planetary Ion CAMera’ (PICAM) and ‘Miniaturized Ion Precipitation Analy...

Space weather observations and modeling at Mars have begun but they must be significantly increased to support the future of Human Exploration on the Red Planet. A comprehensive space weather understanding of a planet without a global magnetosphere and a thin atmosphere is very different from our situation at Earth so there is substantial fundament...

Plain Language Summary Without the protection of an intrinsic magnetic field, solar wind can interact directly with the Martian atmosphere and drive ion escape, which plays a vital role in the evolution of the planetary atmosphere. It was shown that, on average, all Martian ions accelerated by the solar wind flow downstream and escape to interplane...

Kinetic approaches are generally accurate in dealing with microscale plasma physics problems but are computationally expensive for large-scale or multiscale systems. One of the long-standing problems in plasma physics is the integration of kinetic physics into fluid models, which is often achieved through sophisticated analytical closure terms. In...

Space weather observations and modeling at Mars have begun but they must be significantly increased to support the future of Human Exploration on the Red Planet. A comprehensive space weather understanding of a planet without a global magnetosphere and a thin atmosphere is very different from our situation at Earth so there is substantial fundament...

The search for life beyond the Earth is the overarching goal of the NASA Astrobiology Program, and it underpins the science of missions that explore the environments of Solar System planets and exoplanets. However, the detection of extraterrestrial life, in our Solar System and beyond, is sufficiently challenging that it is likely that multiple mea...

Magnetohydrodynamic turbulence regulates the transfer of energy from large to small scales in many astrophysical systems, including the solar atmosphere. We perform three-dimensional magnetohydrodynamic simulations with unprecedentedly large magnetic Reynolds number to reveal how rapid reconnection of magnetic field lines changes the classical para...

Executive Summary: The low number of funded Venus R&A projects does not appear to be due to under-selection. Selection rates for Venus proposals in NASA R&A programs are on par with or better than overall program selection rates, indicating that Venus topics are currently under-proposed.

Deriving governing equations of complex physical systems based on first principles can be quite challenging when there are certain unknown terms and hidden physical mechanisms in the systems. In this work, we apply a deep learning architecture to learn fluid partial differential equations (PDEs) of a plasma system based on the data acquired from a...

Heliophysics theory and modeling build understanding from fundamental principles to motivate, interpret, and predict observations. Together with observational analysis, they constitute a comprehensive scientific program in heliophysics. As observations and data analysis become increasingly detailed, it is critical that theory and modeling develop m...

Magnetic reconnection is prevalent in magnetized plasmas in space and laboratories. Despite significant investigations on reconnection in electron-ion plasmas, studies of reconnection in magnetized plasmas with negatively charged dust grains are quite sparse. Here we report the first fully kinetic simulations of collisionless reconnection in a thre...

Mercury has a terrestrial‐like magnetosphere which is usually taken as a scaled‐down‐version of Earth's magnetosphere with a similar current system. We examine Mercury's magnetospheric current system based on a survey of Mercury's magnetic field measured by the Mercury Surface, Space Environment, Geochemistry, and Ranging spacecraft as well as comp...

Ganymede, like Earth, has an aurora, but it is hardly observable to the human eye as the dominating wavelengths are in the ultraviolet range. Ganymede is the largest moon of Jupiter, and it has a magnetosphere of its own inside Jupiter's magnetosphere. Ultraviolet emissions have been observed in two bands around the moon, resembling the ovals of Ea...

Mercury has a terrestrial-like magnetosphere which is usually taken as a scaled-down-version of Earth’s magnetosphere with a similar current system. We examine Mercury’s magnetospheric current system based on a survey of Mercury’s magnetic field measured by the Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) spacecraft as...

The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be comp...