Abstract Magnetic disturbances caused by the Earth's ring current, particularly during storm time activity, have a dominant effect on geomagnetic field. Strong currents and large kinetic magnetic energies can change considerably local field geometry depress ground The multispacecraft measurements of Cluster allow extensive in situ coverage current. We select 48 crossing events to investigate variation current density distribution configuration find direct evidence for existence an inner,...

Abstract Theory predicts that the first adiabatic invariant of a charged particle may be violated in region highly curved field lines, leading to significant pitch angle scattering for particles whose gyroradius are comparable radius magnetic line curvature. This generates more isotropic distribution functions, with important impacts on presence or absence plasma instabilities. Using curvature analysis based multipoint Cluster spacecraft observations, we present investigation vicinity an ion...

Abstract For the first time, current density distribution in inner equatorial magnetosphere ranging from 4 to 12 R E ( is Earth radius, 6371 km) has been obtained by using Time History of Events and Macroscale Interactions during Substorms (THEMIS) (P3, P4, P5) three point magnetic measurements. This study mainly focuses on storm events when constellation THEMIS spacecraft relatively small separation distance. Two cases with different activities are displayed illustrate effectiveness method....

Abstract Understanding the motion of charged particles in electromagnetic field inner magnetosphere is essential for space science and weather. Charge accumulation can occur due to dipole magnetic convective electric fields this region. However, until recent Magnetospheric Multiscale (MMS) mission, there were few means detect charge distribution situ. We report unambiguous situ observation spatial excess density by MMS mission. find that a positive (negative) accumulates dusk (dawn) side...

We explore the geometry of flapping motion geomagnetotail current sheet with magnetic measurements Cluster (constellation) using a newly developed technique. The principal curvatures and directions surfaces are successfully deduced by normal field analysis (NFA). Results show that minimum curvature approximately along Sun-Earth line, while ones maximum mostly in dawn-dusk plane. It is confirmed tail wave arising Y-Z plane, but not bent line.

Geometrical invariants of magnetic field gradient tensors are used to classify the topological structures a field. This study presents statistical analysis on geometrical based high-quality data measured by magnetospheric multiscale mission in turbulent magnetosheath. The method for classification velocity topologies cannot be applied with strong intensity directly because transformed zero selecting co-moving reference frame which is zero. During field, flux ropes and tubes most possible...

Abstract Shock ripples and shock–discontinuity interactions (SDIs) have long been proposed to explain the frequent occurrence of high‐speed jets (HSJs) in magnetosheath; however, there is no direct observational evidence for either them occurring near a shock. Herein, we report large‐scale, long‐duration undulated quasi‐perpendicular shock surface that capable generating HSJs. Based on curvatures estimated undulation nearby hot flow anomaly (HFA), suggest ripple mechanism SDI combine...

Abstract Flux transfer events are momentary occurrences of self‐adjusting, rope‐like magnetized plasma structures near Earth's magnetopause, typically associated with a southward interplanetary magnetic field direction. This study aims to investigate the structural characteristics during three phases (initial, intermediate and final) flux entanglement explore gradient properties. Using Nonlinear Magnetic Field Gradient Algorithm (NMG), we computed curvature, helix angle, torsion. Our...

Abstract Predicting SYM‐H index is significant in space weather because it quantifies the degree of perturbation geomagnetic field during storm. This study presents a composite model to predict based on solar wind parameters by combining empirical magnetospheric dynamical equation with neural networks. The formula for predicted originates from well‐known relationship between interplanetary conditions and Dst index. In particular, coefficients are determined using networks that excel at...

With consideration of magnetic field line curvature (FLC) pitch angle scattering and charge exchange reactions, the O+ (>300 keV) in inner magnetosphere loss rates are investigated by using an eigenfunction analysis. The FLC provides a mechanism for ring current to enter cone influence caused reactions. Assuming that change is small each event, diffusion equation including term constructed solved; eigenvalues identified. resultant approximately equal linear superposition rate without...

Aircraft simulation platform is the most important supporting technology in aircraft development process. This can be used for validating design of subsystem and also it provides necessary data design. Wind has great impact on flight parameter. In order to accurately simulate wind model calculate parameters, a modeling method parameter under field environment established. Firstly, various sub-systems which affecting parameters are analyzed, some mathematical models Secondly, atmospheric...

Abstract This study presents statistical features of magnetic field curvature in the magnetosheath region. Two sets high-quality and plasma data measured by Magnetospheric Multiscale mission are analyzed multiple-point analysis method. The results include following: (a) probability distribution function (PDF) exhibits two different power laws consistent with previous studies; PDF small curvatures depends on condition large shows better agreement. (b) validate derived relation between current...

The transformation of the electromagnetic fields in different frames reference (wether inertial or non-inertial frames) is problem frequently met during measurements space and relative analysis. For example, to draw values spacecraft comoving frame from measured rotational with a reasonable accuracy. Another example calculation charge density based on four-point electrostatic field observations MMS; present analysis not very satisfactory there still no rigid evaluation method applied....

The magnetopause plays a pivotal role in the coupling among solar wind, magnetosheath, and magnetosphere. By analyzing crossing events using MMS, we reveal local non-neutrality of electric charges boundary layer associated field. There are two types structures. In one group, which typically occurs on dusk side, field directs towards Earth. other, generally day away from spatial extent this spans approximately 600 km, is at scale ion gyrational motion. These findings provide valuable insights...

The drag reduction efficacy of a large-scale flow control over rough surface is studied via direct numerical simulations turbulent channels (at friction Reynolds numbers Reτ=180) by combining together wall riblets and streamwise counter-rotating swirls. In particular, the height triangular h+≈10 (+indicating units), while number (NRib in range 1–56) along periodic spanwise direction varied to find optimum. swirls are generated opposed wall-jet forcing (SOJF) Navier–Stokes equation, whose...

In this research, the validity of Bernoulli's theorem for solar wind crossing Earth's bow shock has been investigated based on space explorations. Using plasma and interplanetary magnetic field data from OMNI database, along with magnetosheath measured by magnetospheric multiscale satellite in 2016 2018, 95 events were selected to study Bernoulli invariant upstream downstream (from unshocked region shocked region). Statistical investigations show that differences characteristic energy...

This paper focuses on the warpage of high-density FC- PBGA device during packaging process. The finite element analysis software ANSYS Workbench is used to simulate FC-PBGA in process bump reflow, underfill, and heat-sink adhesion. At same time, influence various package parameters analyzed. simulation results show that has largest amount shows shape "cry face" after reflow. underfill heatsink adhesion have certain effect improving warpage, while chip size thickness great warpage. With...