international heliophysical year in china (solar physics)

CAWSES meeting, Sept. 2004 Beijing, China

International Heliophysical Year in China (Solar Physics)

Huang Guangli1, Zhang Mei2 & Yan Yihua2 1. Purple Mountain Observatory, Nanjing, China

2. National Astronomical Observatories, Beijing, China


Optical Telescopes in Huairou Station (http://sun.bao.ac.cn/smct/intro_smct2_e.html)

• 60-cm Solar 9 Channel Telescope – test working• 35-cm Solar Magnetic Field Telescope – full year,

FeI 5324.19Å for photosphere and H 4861.34 Å for chromosphere

• 10-cm Full-Disc Vector Magnetograph – test working• 14-cm Full-disc & Local H-alpha Telescope – full ye

ar, photosphere and choromosphere magnetic field• 8-cm Full-disc Calcium Monochromator – test worki

ng, 3933Å for Calcium monochromatic image


Radio Telescopes in Huairou Station (http://srg.bao.ac.cn/radiospectr.html)• 1-2 GHz Spectrometer, 4MHz/5ms, 2-10 quiet

Sun level, with polarization of 10%• 2.6-3.8 GHz Spectrometer, 10MHz/8ms, 2- 10

quiet Sun level, with polarization of 10%• 5.2-7.6 GHz Spectrometer, 20 MHz/5ms, 2- 10

quiet Sun level, with polarization of 10%• 2840 MHz for Solar-Geophysical Data, 10MH

z, 2- 10 quiet Sun level


Solar Telescopes in Yunnan Astronomical Observatory (http://

www.ynao.ac.cn)

• 50-cm Solar Stokes Spectrum Telescope, with accuracy of about 10-4, field of view 3’ (200 days)

• 18-cm Solar H-alpha Telescope, 0.5 Å band, joint international observations (300 days)

• 50-cm Sunspot Telescope (300 days)• 26-cm H-alpha Solar Fine Structure Telescope

(150 days)• 0.7-1.5 GHz Radio Spectrometer


Solar Telescopes in Purple Mountain Observatory (http://www.pmo.ac.cn)

• 26-cm H-alpha Solar Fine Structure Telescope, 0.25, 1”, 20-30 fps

• Multi-channel Infrared Solar Spectrograph, HeI 10830 Å, CaII 8542 Å, and H-alpha

• 4.5-7.5 GHz Radio Spectrometer, 20 MHz, 5ms

• Sunspot Telescope for Solar-Geophysical Data


YunNan Solar Telescope Solar Telescopes in near future (1)

• 1-m, IR (0.3-2.5 μm), 0.3 arcsec, 10-4 Stokes• Location: Fuxian Lake Station• Progress: mechanical part, electric control system,

and some optical elements finished or started in cooperation with Russia

• Spectrograph and Magnetic Analyzer in process• Will be mounted in 2005, and observed in 2006• PI: Dr. Liu Z.


Solar Radio Spectral HeliographSolar Telescopes in near future (2)

• 1-15 GHz, 30 MHz (1-5 GHz) and 100MHz (5-15 GHz), 1.3”-20”, 100 ms, 20db, 100 of 3-m, 3km

• Location: Miyun Station of NAOs• Progress: 3 million USD of total budget, start

ed in 2004, 3 element test in 2005, 100 element construction in 2006, plan to observe in 2007.

• PI: Dr. Yan Y.H.


Solar Group in Nanjing University, Dept of Astronomy

• There is a strong solar group in Nanjing University, Dept of Astronomy, with Prof. Fang C. (Academician), Prof. Ding M.D., Prof. Chen P. F., Prof. Tang Y. H., several post doctor, and graduated students

• 21-m Solar Tower: H-alpha and CaII 8542 Å, spectral resolution of 0.05-0.06 Å


Solar Groups in Chinese Academy of Science

• Huairou Station (optical): Zhang H.Q. (Leader), Deng Y.Y., Bao S.D., Zhang M., technicians and students

• Huairou Station (radio): Yan Y.H. (Leader), Wang M., Wang S.J., Liu Y.Y., technicians and students

• The Group of Solar Magnetism and Activity: Wang J.X. (Leader), Zhang J., Ma Z.G., Xiao C.J., Wang R.G., and students

• The Group of Solar Predictions: Wang H.N. (Leader), Tian L.R., and students


Solar Groups in Chinese Academy of Science (cont)

• The Group of Solar Activities and Circles: Li K.J. (Leader), Qu Z.Q., and students.

• The Group of Star Oscillations and Interior Structures: Bi S.L. (Leader), and students

• The Group of Solar High-Energy Researches: Gan W.Q. (Leader), Chang J., Li H., Li Y.P., Yu X.F., and students.

• The Group Solar Activities: Huang G.L. (Leader), Wu D.J., Ji H.S., Xu F.Y., and students


The magnetic evolution of the Sun and the helioshere

• The emerging delta AR associates with the current helicity from the sub-atmosphere and redistribution in the upper atmosphere. The ratio of magnetic shear and current helicity provides information on the non-potentiality of solar flare-producing regions (Zhang, et al., MNRAS, 2001; 2002; ApJL, 2001)

• The solution of a local parameter λ is justified and applied for a closed-form non-constant-α force-free field with finite energy content in free space around the Sun (Yan et al., ApJL, 2001; Space Sci. Rew., 2003; Li et al., MNRAS, 2004)


The magnetic evolution of the Sun and the helioshere (cont)

• The 3D structure and evolution of vector magnetic fields and line-of-sight velocities is obtained by Stokes profiles (Qu et al., Solar Phys., 2001; IAU Symp 219, 2003)

• The mapping of circular polarization in a filament may provide a supplementary diagnosis of the filament magnetic field, in addition to the mapping of linear polarization via the Hanle effect (Wang et al., Solar Phys., 2003)

• The 2-D coronal magnetic field is calculated from spectral index, brightness temperature, turnover frequency and frequency in a microwave burst source (Huang, New Astronomy, 2001; 2002)


The initiation of transient events (flares and CMEs - observations)

• The initial disturbance in the filament and the initial brightening around the filament took place at the cancellation sites. The repeated flare-CME activities are triggered by the continuous emergence of moving magnetic features (Zhang et al., ApJ, 2001a,b; 2002; Song et al., Solar Phys., 2003)

• High-cadence and high-resolution time sequences of far H-alpha off-band images provide a unique tool to study the evolution of the fine structure of flare kernels (Ji et al., ApJ, 2003, 2004)

• The radio signature of magnetic reconnection is obtained, such as the bi-directional type III drift pairs and type II-like, and the twisted magnetic ropes (Huang et al., New Astronomy, 2003; Solar Physics, 2003; JGR, 2004)


The initiation of transient events (flares and CMEs - theories)

• When the reconnection-favored emerging flux appears either within or on the outer edge of the filament channel, the flux rope would lose its equilibrium. A piston-driven shock is formed along the envelope of the expanding CME. The legs of the shock may produce Moreton waves. A slower moving wavelike structure, with an enhanced plasma region ahead, corresponds to observed EIT waves (Chen et al., EP&S, 2001; AdSpR, 2002; ApJ, 2002).

• Solar observations show that magnetic reconnection can occur in the weakly ionized lower atmosphere. 2 and 3-D solutions of steady state magnetic reconnection derived in incompressible, partially ionized plasmas (Ji et al., Solar Physics, 2001; ApJ, 2001a,b).


The acceleration and propagation of solar energetic particles

• The hydrogen line profiles are good tools for diagnosing the total flux of the particle beam. The emissions in the wings of H-alpha could exhibit fast fluctuations, related to small-scale injection of high-energy electrons (Fang et al., IAU Symp219, 2003; Ding et al., ApJ, 2001; 2002; Liu et al., ApJL, 2001).

• 54 BATSE/CGRO hard X-ray events are fitted by power-law electrons with a lower energy cutoff from 45 to 97 keV, changed from smaller before the peak flux, to larger at the peak, and then back to smaller after the peak (Gan et al., ApJ, 2001; Solar Phys, 2002; CJAA, 2002)


The acceleration and propagation of solar energetic particles (cont)

• Three very hard photon spectra of Yohkoh/HXT events may result from superposition of a strong Compton backscattering component. The joint effects of Compton backscattering and low-energy cutoff are calculated. The low cutoff energy are estimated in two solar microwave and hard X-ray bursts (Zhang&Huang, ApJL, 2003; Solar Phys, 2004; Huang et al., New Astron, 2004).

• A dissipative nonlinear inertial Alfvén wave is proposed as the formation of the strong electric spikes in the auroral ionosphere and magnetosphere as well as the field_aligned electron acceleration. The effective acceleration region for auroral electrons with energies of the order of keV (Wu et al., Physical Review E, 2003; JGR, 2004)


The processes responsible for heating the different types of

the corona • In a low-β plasma such as coronal holes, kinetic dissi

pation of Alfvén waves due to the wave-particle resonant interaction can directly lead to electron heating. In the main body of the dense plume, which is embedded in a nearly uniformly magnetized coronal hole, the dissipation of the wave energy can provide an additional local electron heating that is enough to balance the extra radiative loss of the dense bright plume. (Wu et al., ApJ 2003)


The energy transport mechanisms from the solar interior

• Under solar interior conditions, the equation of state of the thermodynamic functions of partly ionized and weakly coupled plasmas includes a detailed account of electron degeneracy, Coulomb coupling and pressure ionization (Bi et al., A&A, 2000a,b)

• The turbulent viscosity exerts a non-negligible influence on the solar p-mode oscillations (Bi et al., A&A, 2000). For the radial modes we find that the Reynolds stress produces signification modifications in structure and p-mode spectrum (Bi et al., ApSS, 2003). The mode frequency is sensitive to the effect of magnetic fields, it can be used as a diagnostic tool for the presence of turbulent magnetic fields in the convection zone (Bi et al., A&A, 2000)


Solar Predictions (long-term)• A series of predictions for solar cycle are proposed, such as c

ycle 23 also might be of shorter length, ending in late 2006 or early 2007 (Li et al., A&A, 2002); the conventional start of cycle 24 occurs in 2007.2 (Li, JGR, 2002); the activity of the solar active prominences occurs earlier at higher latitudes leads by 4 years that at low latitudes (Li et al., Solar Physics, 2002); the polar faculae cycle is in complete anti-phase with the sunspot cycle, and highly correlated with the sunspot cycle with a time shift of 51months into the following sunspot cycle, the solar activity of a cycle usually has the same beginning and end times, but different maximum amplitudes at different maximum times in hemispheres (Li et al., PASJ, 2002a,b; ApJ, 2001; New Astronomy 2003; Solar Physics, 2003)


Solar Predictions (short-term)

• Some important physical parameters, such as vertical currents, current helicity, magnetic separatrix, position of singular points are related to pre-status of solar events. Some important criteria are used to be indicator for solar activity forecast (Wang et al., 34th COSPAR Scientific Assembly, 2002)

• Area, magnetic class, net magnetic flux, Carrington longitude and tilt angle of AR may serve to predict the AR producing hazarded space weather (Tian et al., Solar Phys, 2002; 2003; A&A, 2003a,b)


Thank you for your attention

international heliophysical year in china (solar physics)

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