A5100355780- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Ionosphere and magnetosphere dynamics
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Solar Radiation and Photovoltaics
- Geophysics and Gravity Measurements
- Gamma-ray bursts and supernovae
- Meteorological Phenomena and Simulations
- Calibration and Measurement Techniques
- Magnetic confinement fusion research
- Circadian rhythm and melatonin
- Photovoltaic System Optimization Techniques
- Radio Astronomy Observations and Technology
- Earthquake Detection and Analysis
- Oceanographic and Atmospheric Processes
- Astrophysical Phenomena and Observations
- Magnetic and Electromagnetic Effects
- Retinal Development and Disorders
- Photoreceptor and optogenetics research
- Dust and Plasma Wave Phenomena
- Complexity and Algorithms in Graphs
- Energy Load and Power Forecasting
- Big Data Technologies and Applications
- Composite Structure Analysis and Optimization
Stanford University
2015-2024
Chinese Academy of Sciences
1995-2023
Shandong University
2020-2023
National Astronomical Observatories
1993-2023
Changchun Institute of Optics, Fine Mechanics and Physics
2022
Tianjin University
2015
Tsinghua University
2011
Institute of Semiconductors
2009
Culham Science Centre
2008
Culham Centre for Fusion Energy
2008
The Helioseismic and Magnetic Imager (HMI) instrument investigation as a part of the NASA Solar Dynamics Observatory (SDO) is designed to study convection-zone dynamics solar dynamo, origin evolution sunspots, active regions, complexes activity, sources drivers magnetic activity disturbances, links between internal processes corona heliosphere, precursors disturbances for space-weather forecasts. A brief overview instrument, objectives, standard data products presented.
The Helioseismic and Magnetic Imager (HMI) investigation (Solar Phys. doi: 10.1007/s11207-011-9834-2 , 2011) will study the solar interior using helioseismic techniques as well magnetic field near surface. HMI instrument is part of Solar Dynamics Observatory (SDO) that was launched on 11 February 2010. designed to measure Doppler shift, intensity, vector at photosphere 6173 Å Fe i absorption line. consists a front-window filter, telescope, set waveplates for polarimetry, an...
A new data product from the Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) called Space-weather HMI Active Region Patches (SHARPs) is now available. SDO/HMI first space-based instrument to map full-disk photospheric vector magnetic field with high cadence continuity. The SHARP series provide maps in patches that encompass automatically tracked concentrations for their entire lifetime; quantities include its uncertainty, along Doppler velocity, continuum...
The Helioseismic and Magnetic Imager (HMI) began near-continuous full-disk solar measurements on 1 May 2010 from the Solar Dynamics Observatory (SDO). An automated processing pipeline keeps pace with observations to produce observable quantities, including photospheric vector magnetic field, sequences of filtergrams. primary 720s observables were released in mid 2010, Stokes polarization parameters measured at six wavelengths as well intensity, Doppler velocity, line-of-sight field. More...
We report the evolution of magnetic field and its energy in NOAA active region 11158 over 5 days based on a vector magnetogram series from Helioseismic Magnetic Imager (HMI) board Solar Dynamic Observatory (SDO). Fast flux emergence strong shearing motion led to quadrupolar sunspot complex that produced several major eruptions, including first X-class flare Cycle 24. Extrapolated non-linear force-free coronal fields show substantial electric current free increase during early near low-lying...
Solar active region (AR) 12192 of 2014 October hosts the largest sunspot group in 24 years. It is most prolific flaring site Cycle so far, but surprisingly produced no coronal mass ejection (CME) from core during its disk passage. Here, we study magnetic conditions that prevented eruption and consequences ensued. We find AR to be "big mild"; exhibits weaker non-potentiality, stronger overlying field, smaller flare-related field changes compared two other major flare-CME-productive ARs (11429...
The heliospheric magnetic field is of pivotal importance in solar and space physics. rooted the Sun's photosphere, where it has been observed for many years. Global maps based on full disk magnetograms are commonly used as boundary conditions coronal wind models. Two primary observational constraints models (1) open regions model should approximately correspond to holes emission, (2) magnitude flux match that inferred from situ spacecraft measurements. In this study, we calculate both MHD...
NASA's Solar Dynamics Observatory (SDO) was launched 11 February 2010 with 3 instruments on board, including the Helioseismic and Magnetic Imager (HMI). Since beginning normal operations 1 May 2010, HMI has observed Sun's entire visible disk almost continuously. collects sequences of polarized filtergrams taken at a fixed cadence two 4096 x cameras from which are computed arcsecond-resolution maps photospheric observables: line-of-sight (LoS) velocity magnetic field, continuum intensity,...
It is well known that the long-term evolution of photospheric magnetic field plays an important role in building up free energy to power solar eruptions. Observations, despite being controversial, have also revealed a rapid and permanent variation response coronal restructuring during eruption. The Helioseismic Magnetic Imager instrument (HMI) on board newly launched Solar Dynamics Observatory (SDO) produces seeing-free full-disk vector magnetograms at consistently high resolution cadence,...
The fan-spine magnetic topology is believed to be responsible for many curious features in solar explosive events. A spine field line links distinct flux domains, but direct observation of such a feature has been rare. Here we report unique event observed by the Solar Dynamic Observatory where set hot coronal loops (over 10 MK) connected quasi-circular chromospheric ribbon at one end and remote brightening other. Magnetic extrapolation suggests that these are partly tracers evolving line....
Abstract Magnetic free energy powers solar flares and coronal mass ejections, the buildup of magnetic helicity might play a role in development unstable structures that subsequently erupt. To better understand roles large eruptions, we have characterized evolution associated with 21 X-class from 2010 to 2017. Our sample includes both confined eruptive events, 6 15 each category, respectively. Using Helioseismic Imager vector field observations several hours before after event, employ (a)...
This paper investigates the solar origin of impulsive energetic particle (SEP) events, often referred to as 3He-rich flares, by attempting locate source regions 117 events observed at ~2-3 MeV amu-1. Given large uncertainties when ions these energies were injected, we use type III radio bursts that occur within a 5 hr time window preceding ion onset, and search in EUV X-ray full-disk images for brightenings around times bursts. In this way find sources 69 events. High cadence reveal jet...
As each solar cycle progresses, remnant magnetic flux from active regions (ARs) migrates poleward to cancel the old-cycle polar field. We describe this polarity reversal process during Cycle 24 using four years (2010.33–2014.33) of line-of-sight field measurements Helioseismic and Magnetic Imager. The total associated with ARs reached maximum in north 2011, more than two earlier south; is significantly weaker 23. relatively slow, north–south asymmetric, episodic. estimate that global axial...
A deep learning network, Long-Short Term Memory (LSTM) is used in this work to predict whether the maximum flare class an active region (AR) will produce next 24 hours $\Gamma$. We considered $\Gamma$ are $\ge M$, C$ and any class. The essence of using LSTM, which a recurrent neural its capability capture temporal information data samples. input features time sequences 20 magnetic parameters from SHARPs - Space-weather HMI Active Region Patches. analyzed regions June 2010 Dec 2018,...
Abstract Most solar radio telescopes operate below ∼18 GHz and cannot realize a complete frequency coverage of the microwave spectrum, especially in optically thin regime during bursts, which can provide unique information about magnetic field burst area corona. Therefore, development high-frequency observation equipment is demanded by community. In this paper, we present spectrum system operating at 35–40 GHz. system, signal acquired an 80 cm Cassegrain circularly polarized antenna, then...
The Lobster Eye Imager for Astronomy (LEIA), a pathfinder of the Wide-field X-ray Telescope Einstein Probe (EP) mission, was successfully launched onboard SATech-01 satellite Chinese Academy Sciences on 27 July 2022. In this paper, we introduce design and on-ground test results LEIA instrument. Using state-of-the-art Micro-Pore Optics (MPO), wide field-of-view (FoV) 346 square degrees (18.6 * 18.6 degrees) imager is realized. An optical assembly composed 36 MPO chips used to focus incident...
Abstract It has been suggested that the ratio of photospheric direct to return current, ∣DC/RC∣, may be a better proxy for assessing ability solar active regions produce coronal mass ejection (CME) than others such as amount shear along polarity inversion line (PIL). To test this conjecture, we measure both quantities prior eruptive and confined flares varying magnitude. We find eruptive-flare source have ∣DC/RC∣ > 1.63 PIL above 45° (average values 3.2 68°, respectively), tending larger...