International Heliophysical Year in China (Solar Physics)

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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

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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
  year, photosphere and choromosphere magnetic
  field
• 8-cm Full-disc Calcium Monochromator test
  working, 3933Å for Calcium monochromatic image

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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, 10MHz, 2- 10
  quiet Sun level

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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

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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

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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.

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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, started
  in 2004, 3 element test in 2005, 100 element
  construction in 2006, plan to observe in 2007.
• PI Dr. Yan Y.H.

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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

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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

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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

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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 ? is justified
  and applied for a closed-form non-constant-a
  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)

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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)

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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)

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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., EPS, 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).

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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)

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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 (ZhangHuang, 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)

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The processes responsible for heating the
different types of the corona

• In a low-ß plasma such as coronal holes, kinetic
  dissipation 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)

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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., AA,
  2000a,b)
• The turbulent viscosity exerts a non-negligible
  influence on the solar p-mode oscillations (Bi et
  al., AA, 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., AA, 2000)

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Solar Predictions (long-term)

• A series of predictions for solar cycle are
  proposed, such as cycle 23 also might be of
  shorter length, ending in late 2006 or early 2007
  (Li et al., AA, 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)

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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
  AA, 2003a,b)

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Thank you for your attention