C. Shen's research while affiliated with Harbin Institute of Technology and other places

Publications (123)

Article
Full-text available
We review the range of applications and use of the curlometer, initially developed to analyze Cluster multi‐spacecraft magnetic field data; but more recently adapted to other arrays of spacecraft flying in formation, such as MMS small‐scale, 4‐spacecraft configurations; THEMIS close constellations of 3–5 spacecraft, and Swarm 2–3 spacecraft configu...
Article
Full-text available
The geomagnetic field originates from interior dynamo currents and can be approximated well by a simple dipolar field in the vicinity of Earth's surface. Given that the dipolar field is induced by a current loop, it is possible to invert the loop parameters by tracing the sampled magnetic field geometry. Drawing on the analysis of field geometric s...
Article
Full-text available
Plain Language Summary The oscillation of a magnetotail current sheet, known as the magnetotail flapping motion, plays an important role in dissipating the magnetic field energy stored in a magnetotail. This flapping motion is a common dynamic behavior of a magnetotail, which has been observed widely for Earth and other planets of our solar system....
Article
Full-text available
The flapping motion of Mercury's magnetotail current sheet is investigated based on the observations of MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER). The typical flapping period in Mercury's magnetotail is much shorter (~13 s), comparing with ~10–20 min at Earth's magnetotail. The magnetic field oscillation amplitude in...
Article
Full-text available
Flapping motion of the current sheets of planetary magnetotails is a common dynamic phenomenon. Previous studies of the Earth's magnetotail suggest that its flapping motion has two forms, that is, kink-like flapping that can propagate as waves toward both flanks and steady flapping that moves up and down but does not propagate. Although some models...
Article
Full-text available
A kink-like flapping event of Earth magnetotail current sheet, which consists of two frequency bands successively, is studied by the multipoint observations of Cluster. The multipoint analysis of Cluster observations demonstrates that the higher frequency band (period is about 10 min) has faster propagation velocity (about 30 km/s), shorter wavelen...
Article
Full-text available
In this study, we use the magnetic field data measured by MESSENGER from 2011 to 2015 to investigate the average magnetic field morphology of Mercury's magnetotail in the down tail 0–3 RM (RM = 2440 km, Mercury's radius). It is found that Mercury has a terrestrial-like magnetotail, the magnetic field structure beyond 1.5 RM down tail is stretched s...
Article
An earlier statistical survey suggested that the flow-aligned component of upstream interplanetary magnetic field (IMF) may play an important role in controlling the lobe-asymmetries of the Venusian magnetotail. The tail current sheet would be displaced and the magnetic field configuration would show asymmetries with respect to the current sheet. T...
Article
For the first time, the current density distribution in the inner equatorial magnetosphere ranging from 4 to 12 RE (RE is the Earth radius, 6371km) has been obtained by using Time History of Events and Macroscale Interactions during Substorms (THEMIS) (P3, P4, and P5) three point magnetic measurements. This study mainly focuses on the storm events...
Article
Theory predicts that the first adiabatic invariant of a charged particle may be violated in a region of highly curved field lines, leading to significant pitch angle scattering for particles whose gyroradius are comparable to the radius of the magnetic field line curvature. This scattering generates more isotropic particle distribution functions, w...
Article
Based on high-resolution measurements from NASA's Magnetospheric Multiscale mission, we present the dynamics of electrons associated with current systems observed near the diffusion region of magnetic reconnection at Earth's magnetopause. Using pitch angle distributions (PAD) and magnetic curvature analysis we demonstrate the occurrence of electron...
Article
During the first several months of the three-spacecraft Swarm mission all three spacecraft came repeatedly into close alignment, providing an ideal opportunity for validating the proposed dual spacecraft method for estimating current density from the Swarm magnetic field data. Two of the Swarm spacecraft regularly fly side-by-side in closely simila...
Article
Self-consistent kinetic (particle-in-cell) model of magnetotail thin current sheet (TCS) is used to understand the formation of self-consistent sheared magnetic structures. It is shown that shear configurations appear in TCS as a result of self-consistent evolution of some initial magnetic perturbation at current sheet center. Two general shapes of...
Article
Many previous studies have demonstrated that the interplanetary magnetic field (IMF) can control the magnetospheric dynamics. Immediate magnetospheric responses to the external IMF has been assumed for a long time. The specific processes by which IMF penetrates into magnetosphere, however, is actually unclear. Solving this issue will help to accura...
Article
Full-text available
We show for the first time, with direct, multispacecraft calculations of electric current density, and other methods, matched signatures of field-aligned currents (FACs) sampled simultaneously near the ionosphere at low (~500 km altitude) orbit and in the magnetosphere at medium (~2.5 RE altitude) orbits using a particular Swarm and Cluster conjunc...
Article
Based on the continuous magnetic measurements of the multiple ground observatories, the structure of the geomagnetic field disturbance and its temporal variations have been investigated, and the evolution of the storm ring current is deduced accordingly. Assuming the geomagnetic disturbance around Earth's surface is approximately linearly varying i...
Article
Knowing the magnetic field distribution in the magnetotail current sheet (CS) is essential for exploring magnetotail dynamics. In this study, using a joint dataset of Cluster/TC-1, the radial profile of the magnetic field in the magnetotail CS with radial distances covering 8<r<20 RE under different geomagnetic activity states (i.e., AE≤100 nT for...
Conference Paper
The imminent launch of the 3 Swarm spacecraft into low, polar Earth orbits; the planned coordination of Swarm with the 4 Cluster spacecraft through joint operations, and the further possible coordination with the recently launched 2 spacecraft RBSP mission, provides an unprecedented, distributed space dataset of 'clustered' multi-point measurements...
Article
Unambiguous knowledge of magnetic field structure and the electric current distribution is critical for understanding the origin, evolution and related dynamic properties of magnetic flux ropes (MFRs). In this paper, a survey of 13 MFRs in the Earth's magnetotail are conducted by Cluster multi-point analysis, so that their force-free feature, i.e.,...
Article
Full-text available
THEMIS observed several magnetopause crossings periodically at the duskside of magnetopause under southward IMF, with significant sunward returning flows inside the magnetopause. The vortex features of the flows and the periodic enhancements in the calculated vorticity normal to the spacecraft plane could be found in the observation. The distortion...
Article
Full-text available
Magnetic disturbances caused by the Earth's ring current, particularly during storm time activity, have a dominant effect on the geomagnetic field. Strong currents and large kinetic and magnetic energies can change considerably local field geometry, and depress the ground geomagnetic field. The multi-spacecraft magnetic measurements of Cluster allo...
Article
Full-text available
With consideration of magnetic field line curvature (FLC) pitch angle scattering and charge exchange reactions, the O+ (>300 keV) in the inner magnetosphere loss rates are investigated by using an eigenfunction analysis. The FLC scattering provides a mechanism for the ring current O+ to enter the loss cone and influence the loss rates caused by cha...
Article
Full-text available
The fine magnetic field structure of two successive plasmoids previously reported is investigated by magnetic rotation analysis using four Cluster satellite data. Between these two plasmoids, opposite trends of curvature radius (Rc) variations of the magnetic field lines from the boundary to the inner part are found. The different variations of Rc...
Article
On 14 June 2007, four Time History of Events and Macroscale Interactions during Substorms spacecraft observed a flux transfer event (FTE) on the dayside magnetopause, which has been previously proved to be generated by multiple, sequential X-line reconnection (MSXR) in a 2-D context. This paper reports a further study of the MSXR event to show the...
Article
Full-text available
1] We develop a new simple method for inferring the orientation of a magnetic flux rope, which is assumed to be a time-independent cylindrically symmetric structure via the direct single-point analysis of magnetic field structure. The model tests demonstrate that, for the cylindrical flux rope regardless of whether it is force-free or not, the meth...
Article
Full-text available
We report a multiple spacecraft observation of the 2012 May 17 GLE event. Using the coronagraph observations by SOHO/LASCO, STEREO-A/COR1, and STEREO-B/COR1, we identify two eruptions resulting in two coronal mass ejections (CMEs) that occurred in the same active region and close in time (~2 minutes) in the 2012 May 17 GLE event. Both CMEs were fas...
Article
Full-text available
1] We present a generalized multipoint analysis of physical quantities, such as magnetic field and plasma flow, based on spatial gradient properties, where the multipoint data may be taken by irregular (distorted) configurations of any number of spacecraft. The methodology is modified from a previous, fully 3-D gradient analysis technique, designed...
Article
Full-text available
1] In this exploration, it is revealed for the first time that the full magnetic field gradient and current density distribution can be derived from two spacecraft magnetic field measurements under the assumptions that the magnetic field is approximately stationary and force-free, conditions which are particularly relevant to low altitude regions o...
Article
Full-text available
1] We report a clear transition through a reconnection layer at the low-latitude magnetopause which shows a complete traversal across all reconnected field lines during northwestward interplanetary magnetic field (IMF) conditions. The associated plasma populations confirm details of the electron and ion mixing and the time history and acceleration...
Data
Full-text available
We report a clear transition through a reconnection layer at the low-latitude magnetopause which shows a complete traversal across all reconnected field lines during northwestward interplanetary magnetic field (IMF) conditions. The associated plasma populations confirm details of the electron and ion mixing and the time history and acceleration thr...
Article
Full-text available
The Kelvin-Helmholtz Instability (KHI) can drive waves at the magnetopause. These waves can grow to form rolled-up vortices and facilitate transfer of plasma into the magnetosphere. To investigate the persistence and frequency of such waves at the magnetopause we have carried out a survey of all Double Star 1 magnetopause crossings, using a combina...
Article
Full-text available
1] The strong magnetic field B y component (in GSM coordinates) has been increasingly noticed to play an important role in the dynamics of tail current sheet (CS). The distribution profile of strong B y components in the tail CS (i.e., those with guide field), however, is not well known. In the present work, by using the simultaneous multipoint obs...
Data
Full-text available
1] A self-consistent theory of relatively thin anisotropic current sheets (TCS) in collisionless plasma is developed, taking into account the presence of a guiding field B y (all notations are used in the GSM coordinate system). TCS configurations with a finite value of guiding field B y are often observed in Earth's magnetotail and are typical for...
Article
The combined magnetic effect of the Earth's ring current (RC), the system of connecting field aligned currents (FACs) and the ionospheric polar currents, forms the dominant external influence on the measured Geomagnetic field. These induced magnetic signals have significant effect at low Earth orbit (LEO), and will be surveyed by the three Swarm sp...
Article
The Kelvin Helmholtz Instability can drive waves at the magnetopause. These waves can grow to form rolled up vortices and facilitate transfer of plasma into the magnetosphere. Using a method previously presented by Hasegawa et al., 2006, we present a survey of all Double Star 1 magnetopause crossings that display characteristics of rolled up vortic...
Article
Full-text available
During April to July 2007 a combination of 10 spacecraft provided simultaneous monitoring of the dayside magnetopause across a wide range of local times. The ar-ray of four Cluster spacecraft, separated at large distances (10 000 km), were traversing the dawn-side magnetopause at high and low latitudes; the five THEMIS spacecraft were of-ten in a 4...
Article
This paper investigates the structure of the magnetic field near the magnetopause (MP) by analyzing the multiple-point magnetic measurements from the Cluster mission. In this paper, the spatial distribution of the curvature radius of the MP surface at the noon-midnight meridian and for situations with moderate dynamical pressure of solar wind is im...
Article
Full-text available
Revealed the dawn-dusk asymmetry of tail current sheetStatistically revealed 3-D geometric magnetic structure of tail current sheetVerified the relationship between neutral sheet and minimum curvature radius
Article
Full-text available
How the solar wind affects the location of the magnetopause has been widely studied and excellent models of the magnetopause based on in situ observations in the solar wind and at the magnetopause have been established, while the careful insight into the responses of the magnetopause to the variations in the solar wind can still provide us some new...
Article
Full-text available
The extent of where magnetic reconnection (MR), the dominant process responsible for energy and plasma transport into the magnetosphere, operates across Earth's dayside magnetopause has previously been only indirectly shown by observations. We report the first direct evidence of X-line structure resulting from the operation of MR at each of two wid...
Article
The properties of plasmas (in space) are fundamentally governed by both ‘cross-scale’ coupling and comparative temporal behaviour operating over the micro-, meso-, and (MHD-) fluid regimes: for example, under conditions of turbulence, during magnetic reconnection and in shocks and other plasma boundaries. These themes map to a number of related and...
Article
Full-text available
During April to July 2007 a combination of 10 spacecraft provided simultaneous monitoring of the dayside magnetopause across a wide range of local times. The array of four Cluster spacecraft, separated at large distances (10 000 km), were traversing the dawn-side magnetopause at high and low latitudes; the five THEMIS spacecraft were often in a 4 +...
Article
Full-text available
While the Cluster spacecraft were located near the high-latitude magnetopause, between 1010 and 1040 UT on 16 January 2004, three typical flux transfer event (FTE) signatures were observed. During this interval, simultaneous and conjugated all-sky camera measurements, recorded at Yellow River Station, Svalbard, are available at 630.0 and 557.7 nm t...
Article
The Chinese National Space Agency (CNSA) Double Star (DSP) spacecraft, TC-1 and TC-2 were launched in December 2003 and July 2004 into near equatorial and polar orbits respectively. During more than 3 years of operations they have maintained a close phasing with the ESA four-spacecraft mission to produce the first, well coordinated multi-scale meas...
Article
Full-text available
The magnetic field in many regions of magnetosphere has a complex topological structure. As a parameter to measure the topological complexity, the concept of magnetic helicity is a useful tool in magnetospheric physics. Here we present a case study of magnetic helicity in the flux rope (FR) in the near-Earth plasma sheet (PS) based on the in-situ o...
Article
Full-text available
The relationship between the average structure of the inner magnetospheric large-scale electric field and geomagnetic activity levels has been investigated by Double Star TC-1 data for radial distances ρ between 4.5 R E and 12.5 R E and MLT between 18:00 h and 06:00 h from July to October in 2004 and 2005. The sunward component of the electric fiel...
Article
The current sheet in Earth’s magnetotail often flaps, and the flapping waves could be induced propagating towards the dawn and dusk flanks, which could make the current sheet dynamic. To explore the dynamic characteristics of current sheet associated with the flapping motion holistically and provide reasonable physical interpretations, detailed dir...
Article
Full-text available
This paper was published as Journal of Geophysical Research, 2010, 115, A07228. Copyright 2010 by the American Geophysical Union. It is also available from http://www.agu.org/pubs/crossref/2010/2009JA014446.shtml. Doi: 10.1029/2009JA014446 We statistically investigated features of the field-aligned current (FAC) distribution in plasma sheet boundar...
Article
We use a special conjuntion of several satellites (ACE, Wind, Cluster, THEMIS, Geotail and DoubleStar) and ground based magnetometers and cameras, on 14 June 2007, to follow ro-tational magnetic structures from the solar wind, via amplification through the bow shock, motion of the magnetopause and signatures on the ground. The structures crossing t...
Article
1. The Definition of Front: The Front is the interface induced by the interaction between the earthward flow and tailward flow which are both carried with magnetic flux. 2. Types of the Front (1) Tailward Front: velocity of the tailward flow and the magnetic flux carried by the tailward flow is larger than the velocity of the earthward flow and the...
Article
The strong By component (in GSM coordinates), as the guide field, has been noticed increasingly to play an important roles in the dynamics of tail current sheet (CS), but the distribution profile of strong By component in tail CS is unknown until now. In this research, by using the simultaneous multi-point observations of Cluster, the distribution...
Article
On the 11th July 2006, during a period of northward IMF, the Geotail, Double Star 1 and Cluster spacecraft all crossed the magnetopause region within 2 hours (UT) of one another while separated by many hours in local time. During this time large-scale oscillations were observed in both ground based and spacecraft data. We utilize these numerous mea...
Article
The nature of the interaction of the solar wind and associated magnetic field benefits from simultaneous coverage over a range of different magnetopause sites. We consider Cluster, Double Star and THEMIS conjunctions which allow exploration of the conjugate response of the dayside magnetopause and dawn/dusk flanks. In particular, during the April t...
Article
Full-text available
When the solar wind Mach number is low, typically such as in magnetic clouds, the physics of the bow shock leads to a downstream ion-to-electron temperature ratio that can be notably lower than usual. We utilize this property to trace solar wind plasma entry into the magnetosphere by use of Cluster measurements in the vicinity of the dusk magnetopa...