linkages between the atmosphere on the Earth and sun Phần 10

Interplanetary Consequences of a Large CME 491 10 1 19 20 21 22 Hours 107 30 25 106 20 15 10 105 5 SCET 20:00 21:00 RAU 6.68 6.68 0 22:00 23:00 6.68 6.68 Fig. 2 Radio spectra from the WAVES and Cassini missions. Cassini was located at 8.7AU 104 1000 Shock at 1 AU proton flux > 1Mev proton flux > 30Mev proton flux > 100Mev 100 10 1 0.1 4d12h 5d00h 12h 6d00h 12h 7d00h 12h Day and Time(UT) Fig. 3 Particle profiles in different energy bands 492 M. Lahkar et al. Fig. 4 Ooty IPS images showing the current sheet location (top left), CME deflection by the coronal hole (top right), CME compression of the solar wind (bottom left), and CME propagation (bottom right). The Sun is located at the center of each image. The twoimages at top right represent solar-wind speed; the others represent density 8 B 4 0 Theta –50 –200 Phi 0 5 Bx 0 5 By 0 –5 5 Bz 0 –5 0 DST –30 16 8 Density 6 x 105 Temperature 3 x 10 6 4 5 Theta 0 –5 Phi 0 –5 0 Br –2 4 Bt –4 0 Bn –5 Density 1 1.6 x 106 Temperature 8 x 10 560 Speed 480 6.5 7 7.5 8 Date Nov2003 900 Speed 600 12 14 16 Date 18 Nov2003 Fig. 5 1-AU and Ulysses hourly averages of solar wind parameters As Ulysses was favorably located in the CME propagationdirection, it could record the nose part of the CME and its shock, as indicated by a speed value of over 900km s1 at 5AU. At Earth, the shock speed was below 600km s1, suggest-ing that the eastern tail swept the Earth. From these measurements we infer a speed profile V R0:4 to Earth. However, the deceleration V R0:2 out to 5AU near Ulysses implies gradual decline in speed along the CME propagation direc-tion, which is in good agreement with the IPS measurements. Interplanetary Consequences of a Large CME 493 3 Conclusion Our study shows the characteristics of a fast-moving CME and its interactions with transient and solar-wind structures at different distances from the Sun with good consistency between diverse diagnostics. The enhancement in radio emission and production of high-energy particles suggest that the magnetic field associated with the CME was strong. The gradual decline in CME speed suggests that the inter-nal magnetic energy of the CME supported its propagation, including expansion in overcoming the aerodynamical drag imposed by the ambient solar wind (e.g., Manoharan 2006). Acknowledgment We thank the Cassini, GOES, SOHO, TRACE, Ulysses, Wind, and OMNI-database teams for making their data available on the web. We also thank B. Jackson and the UCSD team for the IPS tomography analysis package. M. Lahkar thanks the National Centre for Radio Astrophysics (TIFR) for financial support. This work is partially supported by the CAWSES–India program sponsored by the Indian Space Research Organisation (ISRO). References Bougeret, J.-L., Kaiser, M. L., Kellogg, P. J., et al. 1995, Space Sci. Rev., 71, 231 Brueckner, G. E., Howard, R. A., Koomen, M. J., et al. 1995, Solar Phys., 162, 357 Gargate, L., Bingham, R., Fonseca, R. A., Silva, L. O. 2006, AGU Fall Meeting Abstracts, B1518 Gopalswamy, N., Yashiro, S., Kaiser, M. L., Howard, R. A., Bougeret, J.-L. 2001, ApJ, 548, L91 Kliore, A. J., Anderson, J. D., Armstrong, J. W., et al. 2004, Space Sci. Rev., 115, 1 Manoharan, P. K. 2006, Solar Phys., 235, 345 Manoharan, P. K., Kundu, M. R. 2003, ApJ, 592, 597 Manoharan, P. K., Tokumaru, M., Pick, M., et al. 2001, ApJ, 559, 1180 Solar System Resonances on Light-Travel Time Scales Set Up before Proto-Sun’s Nuclear Ignition M.H. Gokhale Abstract A scenario is presented showing how solar-system resonances on time scales of light travel could have got set up before the onset of nuclear reactions in the proto-Sun. Such resonances may expedite the onset of nuclear ignition in the proto-Sun and the redistribution and loss of the proto-Sun’s angular momentum. 1 Introduction To ensure compatibility between models of solar variability phenomena and the standardmodel(SSM)oftheSun’smeanstructureandevolution,onemustconstruct a hydrodynamic solar model (HDSM) whose mean structure equals the SSM and whose hydrodynamic state keeps producing acoustic waves and toroidal magnetic fields whose dissipation produces solar-like variability phenomena. The differential rotation that is needed to produce toroidal magnetic fields may be maintained by deposition of angularmomentum by g-mode waves at loci of absorption.The main-tenance of these waves (and of acoustic waves) needs maintenance of a spectrum of normal-mode oscillations of the HDSM’s mass elements (i.e., oscillations with frequencies of the normal modes of the SSM). I suggest that the power-input needed to maintain this spectrum may originate from gravitational energy–momentum exchanges of the HDSM’s mass elements with the planets through resonances on time scales of planet-to-Sun speed-of-light travel time (e.g., about 43min between the Sun and Jupiter). This suggestion is based on the facts that the frequencies of many solar acoustic modes lie in the 1=TP range for the inner planets, where TP is the light-travel time per planet, and that the frequencies of many solar g-modes lie in the 360–410Hz range perpetually traversed up and down by 1=TJ as Jupiter moves in its elliptic orbit. This sugges-tion leads to the question how such resonances get set up initially. In this paper, I propose a mechanism setting up such resonances in the proto-solar system which M.H. Gokhale () 205 Sairang Aptts, New D. P. Road, Kothrud, Pune 311038, India S.S. Hasan and R.J. Rutten (eds.), Magnetic Coupling between the Interior 494 and Atmosphere of the Sun, Astrophysics and Space Science Proceedings, DOI 10.1007/978-3-642-02859-5 65, Springer-Verlag Berlin Heidelberg 2010 Solar System Resonances 495 may also expedite the onset of nuclear ignition near the proto-Sun’s center as well as redistribution and loss of the proto-Sun’s angular momentum. 2 Fourier Frequencies in Momentum Transfer Resonances on time scales of solar-system light travel are possible under the working hypothesis that the energy–momentum exchanges between the solar mass elements and the planets can be represented by waves with periodicities equal to the respective light-travel times and with amplitudes consistent with PPN expressions for the accelerations used in the standard ephemeris. The standard theory of the origin of the solar system (cf. Shu et al. 1993; Boss 1998) says that the latter was formed by the break-up of a circum-solar parent disk into the proto-Sun and proto-planetary rings. Consider the turbulent gravitational dynamics of the parent-disk’s earlier evolution that led to this break-up. Let Pk, withk D 1;2;:::,representthediskmasselementsthatcontributedtomasselement P of ring P, and let mi represent a mass element of the proto-Sun. Throughout the evolution, small changes in the energyand momentumof Pk at each instant of time t and the associated changes in the energy and momentum of mi must both be spread over an interval of length T D r.Pk;mi;t/=c around t, with c the velocity of light. Let f.P ! mi;t/ represent the rate at which mi receives gravitational momentum from any Pk during the interval .t T=2;t CT=2/. Along with each r.Pk;mi;t/, the interval-length T.Pk;mi;t/ and the light travel time pro-file (LTTP) of the rate f during this interval evolve both on longer time scales. Turbulence in the parent disk couples such LTTPs mutually during their evolution, so that the LTTP of every f during a given light-travel interval will contain ups and downs covering a wide range of frequencies, including 1=T.Pk;mi;t/ and depending on the locations of P1;P2;::: relative to mi. While different mass elements merge to form mass element P in ring P and while all mi converge to form the proto-Sun, the wide range of the Fourier frequencies of the LTTP of each f shrinks towards p D c=RP , where RP is the average radius of the result-ing ring P. Ultimately, the Fourier frequencies of the LTTP of each particular rate f.P ! mi;t/ of momentumsupply will lie in a band of small width, say P , around each respective P D c=RP . This width will depend on the initial locations of the mass elements but will be much less than P as the thickness of the resulting ring is much less than RP . Each term in the Fourier expansion of the resulting LTTP of each f over each light-travel interval T will be as if provided by a momentum wave of period T propagating from P to mi. Thus, the energy–momentum exchanges between the Sun’s mass elements and the planetaryrings underthe resonances on time scales of light-travel. ... - tailieumienphi.vn