Contents

ⅱ　　　　　　　　　　　　　　　　　Contents

Contents

Enome, S. and Hirayama, T…………………………………………………………………..ⅰ

Contents　………………………………………………………………………………………………ⅱ

Program　………………………………………………………………………………………………ⅸ

Yohkoh Reviews:

Thermal Plasmas in the Solar Corona: the Yohkoh Soft X-Ray Observations

Hudson, H. S. ..................................................................................................................1

High-energy Solar Flare Observations by Yohkoh: A Review

Kosugi,T………………………………………………………………………………………….11

The Nobeyama Radioheliograph Introductions:

The Nobeyama Radioheliograph - Hardware System -

Nishio, M., Nakajima, H., Enome, S., Shibasaki, K., Takano, T., Hanaoka,

Y., Torii, C., Shiomi, Y., Sekiguchi, H., Bushimata, T., Kawashima, S.,

Shinohara, N., Koshiishi, H., Kosugi, T., Sawa, M., Kai, K., Irimajiri, Y.,

Nohmi, H., Honda, K., Shinohara, H., Ito, T., Miyawaki, M., Imoto, A.,

Takabayashi, T., Nishikawa, K., Futagawa, N., Tanaka, S., Morikawa, H.,

Kitahara, Y., Harakawa, K., and Mishima, K……………………………………………. 19

Processing of the Nobeyama Radioheliograph Data

Hanaoka, Y., Shibasaki, K., Nishio, M., Enome, S., Nakajima, H., Takano,

T., Torii, C., Sekiguchi, H., Bushimata, T., Kawashima, S., Shinohara, N.,

Irimajiri, Y., Koshiishi, H., Kosugi, T., Shiomi, Y., Sawa, M., and Kai.K....................35

The Nobeyama Radioheliograph Data use

Shibasaki, K., Enome, S., Nakajima, H., Nishio, M., Takano,T., Hanaoka,

Y., Torii, C., Sekiguchi, H., Kawashima, S., Bushimata, T., Shinohara, N.,

Koshiishi, H., and Shiomi, Y…………………………………………………………………45

I. Coronal Dynamics and Quiet Corona

Observations of the structure and dynamics of coronal loops.

Strong, K. T……………………………………………………………………………………..53

The X-ray intensity distribution of the solar corona and its variability.

Hara, H. …………………………………………………………………………………………57

Active-region transient brightenings and the heating of active region corona

Shimizu, T……………………………………………………………………………………….61

Microflaring at the feet of large active region loops.

Porter, J., Moore, R.T., Roumeliotis, G., Shimizu, T., Tsuneta, S., Sturrock,

P. A., and Acton, L. W. ………………………………………………………………………　65

Observzational signatures of nanoflare heating

Poletto, G. and Kopp, R……………………………………………………………………… 71

Contents　　　　　　　　　　　　　　　　　　　 ⅲ

Coronal X-ray jet

Shibata, K., Yokoyama, T., and Shimojo, M……………………………….……………….75

Observation of 17GHz radio emission from X-ray bright points.

kundu, M. R., Shibasaki, K., Enome, S., and Nitta, N………………………………….. .79

Ejection of heated mass into a helix-like structure from active region NOAA 7172 on

May 21-27, 1992.

Uchida Y., Fludra, A., Khan, J., and McAllister, A……………………………………… 83

Observations of enhanced coronal heating in sheared magnetic fields.

Moore,R. T., Porter, J., Roumeliotis, G., Tsuneta, S., Shimizu, T. Sturrock,

P.A., and Acton, L. W………………………………………………………………………… 89

Dynamic coronal heating by magnetic flux interaction.

Priest,E.R………………………………………………………………………………………..93

Characteristics of microflares seen in helium-like sulphur spectra: GOES A-class flares

during the minimum activity phase.

Watanabe, Te………………………………………………………………………………….. .99

Low-speed solar winds observed at distances of　20-60 Rs and coronal structure　of

their source regions.

Kojima, M., Misawa, H., Kozuka, Y., Yamauchi, Y., Watanabe, H., and

Manoharan, P. K………………………………………………………………………………105

Real time prediction and observation of interplanetary events.

Manoharan, P. K., Ananthakrishnan, S., Detman, T. R., Dryer, M., Lein-

bach, H., Kojima, M., Watanabe, Ta., and Khan, J………………………………………109

Spectroscopic observations of coronal emission lines and their relation to soft X-ray

Ichimoto, K., Kumagai, K., Sakurai, T., Hara, H., Takeda, A., and Yohkoh

SXT Team……………………………………………………………………………………….113

Ⅱ.Flares

Energy transport mechanisms and the event of 16th December 1991.

Culhane, J. L., Phillips, A. T., Kosugi, T., Inda-Koide, M., and Pike, C. D. ………...117

Positron annihilation line from the 15 November 1991 Flare.

Kawabata, K., Yoshimori, M., Suga, K., Morimoto, K., Hiraoka, T., Sato, J.,

and Ohki, K……………………………………………………………………………………123

Hard and soft X-ray observations of a super-hot thermal flare of 6 February, 1992.

Kosugi, T., Sakao, T., and Masuda, S., Hara, H., Shimizu, T, and Hudson,

H.S………………………………………………………………………………………………127

Yohkoh Bragg Crystal Spectrometer (BCS) observations of the 6-Feb-1992 Limb

Sterling, A.C……………………………………………………………………………………131

A very small two-ribbon flare of GOES X-ray class B6.7.

Suematsu Y. ……………………………………………………………………………………135

ⅳ　　　　　　　　　　　　　　　　　　Contents　　　　　　　　　　　　　　　　　　　

Temperature analysis of the post-flare loops of June 25-26, 1992.
Anwar, B., Hiei, E., Hudson, H. S., Acton, L. W., Lemen, J. R., and Metcalf,

T.R………………………………………………………………………………………..…… 137

Alignment of radio, soft X-ray and hard X-ray images of sources in impulsive

and gradual phases of the flare of 1992 August 17-18.

Enome, S., Nakajima, H., Shibasaki, K., Nishio, M., Takano, T., Hanaoka,

Y., Torii, C., Shiomi, Y., Sekiguchi, H., Bushimata, T., Kawashima, S.,

Shinohara, N., Irimajiri, Y., Koshiishi, H., Choi, Y. -S.,Sakai, J., Takahashi,

M., Takakura, T., Sakao, T.,and Kosugi, T. ................................................................141

A comparison of hard X-ray, soft X-ray and microwave sources in solar flares.

Yaji, K., Kosugi, T., Sakao, T., Masuda, S., Inda-Koide, M. and Hanaoka, Y. ……..143

Flares on September 6, 1992.

Kitai R., Kurokawa, H., Funakoshi, Y., Nakai, Y., Shibata, K., Yaji, K.,

Nitta, N .,and Yohkoh Team and NAOJ Flare Telescope Team ......………….......... 147

Evolution and radio activity of a flare productive active region NOAA 7321.

Nishio, M., Takakura, T., Ikeda, H., Nakajima, H., Enome, S., Shibasaki, K.,

Takano, T., Hanaoka, Y., Choi, Y.-S., and Koshiishi, H ........................................... 151

Evolution of flare source inferred from hard X-ray and radio observation: Solar burst

on 27 October 1992.

Takakura, T., and HXT Group: Nishio, M., and the Radioheliograph Group……. 157

Yohkoh HXT/SXT observations of a two-loop interaction solar flare on 9 December

Inda-Koide, M. ................................. ……………………………………………………161

OVRO and NRO observations of the solar flare on 1993 June 3.

Gary, D., Enome, S., and Bruner, M. ........................................................................ 165

Hard X-ray imaging observations of footpoint sources in impulsive solar flares.

Sakao, T., Kosugi, T., Masuda, S., Yaji, K., Inda-Koide, M., and

Makishima, K ............................................................................................................ 169

The electron density in the localized bright regions at the tops of flare loops.

Doschek, G. A.. ...........................................................................................................173

Morphology of the 10 million degree plasma in solar flares and the failure of the

chromospheric evaporation model.

Seely, J. F., Feldman, U., Doschek,G. A., Strong, K. T., Acton, L. W.,

Uchida, Y., and Tsuneta, S. ....................................................................................... 177

Long duration events observed with the Nobeyama Radioheliograph.

Hanaoka,Y. ................................................................................................................. 181

Morphological development of gradual nonthermal microwave flares.

Nakajima, H., Enome, S., Shibasaki, K., Nishio, M., Takano, T., Hanaoka,

Y., Torii, C., Shiomi, Y., Sekiguchi, H., Bushimata, T., Kawashima, S.,

Shinohara, N., and Koshiishi, H. .............................................................................. 185

BCS spectra from flares on 6th September 1992.

Kato, T., and Fujiwara, T., BCS Group ..................... …………………………………..191

Hα and X-ray signatures of chromospheric heating observed in solar flares.

Wülser, J.-P., Canfield, R. C., Sakao, T., Masuda, S., Kosugi, T., and

Tsuneta, S. .................................................................................................................. 195

Contents　　　　　　　　　　　　　　　　　　ⅴ

Energy transport during a solar flare: VLA observations of the M1.9 flare of 20 Aug.

Bastian, T. S., Nitta, N., Kiplinger, A. L., and Dulk, G. A. …...............................199

Multiwavelength observations of a solar flare.

White, S. M., Silva, A. S., Pater, I. de, Lin, R. P., Gary, D. E., Hudson, H.

S., Doyle, J. G., Hagyard, M. J., and Kundu, M. R……………………….............. …203

Structural changes of radio sources during early phase of small bursts.

Shibasaki, K., Enome, S., Nakajima, H., Nishio, M., Takano, T., Hanaoka,

Y., Torii, C., Sekiguchi, H., Kawashima, S., Bushimata, T., Shinohara, N.,

Koshiishi, H., and Shiomi, Y. ....................................................................................... 205

Vertical structure of hard X-ray sources in solar flares.

Masuda, S..................................................................................................................209

Thermal and nonthermal energizations in solar flares: Soft X-ray spectroscopic and

hard X-ray observations.

Cheng, C.-C., Rilee, M., and Uchida, Y......................................................................... 213

Evidence for both electron acceleration and direct heating in solar flares.

Dennis, B. R., Holman, G. D., Hudson, H. S., Kosugi, T., Strong, K. T., and

Zarro, D. ........................................................................................................................ 217

Studying solar flares with Yohkoh and the Compton Gamma-Ray Observatory.

Zarro, D.M., Mariska, J. T., and Dennis, B. R……….................................................. 221

DC electric fields in solar flares: Theory meets observation.

Benka, S.........................................................................................................................225

Stochastic acceleration in the diffusion region and the structure of slow shocks in

Hirayama, T.. ................................................................................................................231

The current profile and energy release in solar flares.

Melrose, D. B.................................................................................................................235

Impulsive acceleration and bulk heating of flare plasma by plasma turbulence.

Petrosian, V. ............................................................................................. 239

Experimental investigation of three dimensional magnetic reconnection by use of two

colliding spheromaks.

Ono, Y., Akao, T., Morita, A., Katsurai, M., and Yamada, M. ............................. 243

Computer simulations on the fast reconnection mechanism.

Ugai, M. ....................................................................................................................... 247

Particle dynamics in two colliding plasmas.

Takeuchi, S. ..................................................................................................................251

Coalescence of two current loops with a kink instability simulated by a 3-D EM

Nishikawa, K., Sakai, J.-I., Zhao, J., Neubert, T., and Buneman, O........................ 255

Evolution of coronal mm-wave sources.

Krüger, A., Hildebrandt, J., Urpo, S., and Pohjolainen, S......................................... 259

Energetic electrons and magnetic field structures in the corona.

Pick, M., Raoult, A., Trottet, G., Vilmer, N., Strong, K., and Magalhaes, A……… 263

ⅵ　　　　　　　　　　　　　　　　　　Contents

Solar neutron events of June 4th and 6th, 1991.

Muraki, Y., Sakakibara, S., Shibata, S., Murakami, K., Takahashi, K., Pyle,

K. R., Sakai, T., and Mitsui, K. .................................................................................. 267

Properties of energetic particles studied from Gamma-ray observations.

Yoshimori, M., Suga, K., Morimoto, K., Hiraoka, T., Sato, J., Kawabata, K.,

and Ohki, K. ............................................................................................................... 271

On the origin of long lasting gamma ray emission from solar flares.

Ramaty, R.and Mandzhavidze, N.............................................................................. 275

Ionization states of solar-flare particles.

Sakurai, K................................................................................................................... 279

Ⅲ.Active Regions

A morphological study of magnetic shear development in a flare-productive region

Kurokawa, H.,Kitai, R., Kawai, G., Shibata, K., Yaji, K., Ichimoto, K.,

Nitta, N., and Zhang, H............................................................................................. 283

HRTS observations of explosive events in a flaring active region.

Dere, K. P. and Martin, S. F....................................................................................... 289

Combined HRTS-8 sounding rocket observations and Yohkoh soft X-ray observations

of NOAA active region 7260 at the solar limb.

Korendyke, C. M., Dere, K. P., Brueckner, G. E., Waljeski, K., and Lemen,

J.R. ...............................................................................................................................293

Evolution of active regions leading to flares.

Schmieder, B., Demoulin, P., Henoux, J.-C., Driel-Gesztelyi, L. v., Mandrini,

C., and Rovira, M. ........................................................................................................297

The photospheric-to-coronal iron abundance from X-ray lines observed by Yohkoh

and other satellites.

Phillips, K. J. H., Pike,C. D., Lang, J., Watanabe, Te., and Zarro, D. M. …………...301

Implications of coronal abundance variations.

Saba, J. L. R. and Strong, K. T. ................................................................................. 305

Ⅳ.Instrumentation

First CCD observations of a flare in H-epsilon and Ca-II(H).

Rolli, E......................................................................................................................... 309

The High Energy Solar Physics Mission (HESP)

Dennis B.R. ................................................................................................................ 313

Ⅴ. Posters

Coronal structures observed in X-rays (NIXT) and H-α surges.

Schmieder, B., Mouradian, Z., Golub, L., and Antiochos, S.. ………………….......... 317

Propagation of radio waves in the sun's corona: Angular broadening in the limit of

small-angle scattering.

Bastian, T. S. ................................................................................................................321

Contents　　　　　　　　　　　　　　　　　　ⅶ

The new solar submillimeter-wave telescope project (SST).

Kaufmann, P., Parada, N. J., Magun, A., Rovira, M., Ghielmetti, H., and

Levato, H....................................................................................................................... 323

Determining point spread function of space observations using bid algorithm.

Karovska, M. and Hudson, H. S. ...................................................................... 327

The fine scale structure of the solar limb in a coronal hole.

Karovska, M. and Arndt, M. B..................................................................................331

Thermal conduction in the transition region and its effects on the energy balance of

open coronal regions.

Hammer, R. .................................................................................................................. 335

Microflares and their related events.

Schmieder, B., Fontenla, J., Tandberg-Hanssen, E., and Simnett, G. M. .................. 339

Metric Type III bursts from flaring X-ray bright points.

Kundu, M. R., Strong, K. T., Pick, M., Harvey, K. T., Kane, S. R., White,

S. M., and Hudson, H. S............................................................................................... 343

Study of active region magnetic field structures using VLA radio, Yohkoh X-ray and

Mees optical observations.

Gopalswamy, N., Schmahl, E. J., Kundu, M. R., Lemen, J. R., Strong, K.

T., Canfield, R. C., and Beaujardiere, J. de la............................................................ 347

Evolution of an active region and flare productivity.

Kundu, M. R., Shibasaki, K., Enome, S., Nitta, N., Bruner, M., Sakao, T.,

and Kosugi, T. .............................................................................................353

VLA stereoscopy of solar active regions.

Aschwanden, M. J. and Bastian, T. S……………………………………………………...357

Rotation rates of soft X-ray coronal structures.

Kozuka, Y., Watanabe, Ta., Kojima, M., Ohyama, M., and Saito, T. ....................... 359

A potential field model for open field lines in the active region corona.

Sakurai, T. ................................................................................................................... 363

Numerical simulation of reconnection between emerging flux and coronal field.

Yokoyama, T. and Shibata, K......................................................................................... 367

The high energy gamma-ray flare of June 15, 1991: Some evidence of prolonged

particle acceleration at the post-eruptive phase.

Akimov, V. V., Belov, A. V., Chertok, I. M., Kurt, V. G., Leikov, N. G.,

Magun, A., and Melnikov, V. F..................................................................................... 371

A Search for "Black-Light Flares"

Driel-Gesztelyi, L. v., Hudson, H.S., Anwar, B., and Hiei, E..................................... 375

A relation of variabilities between the solar dust ring and the solar magnetic field.

Isobe, S.and Kumar, A. S. ........................................................................................... 379

Thermal and density structure of the inner corona observed at the 1991 total solar

Takeda, A., Kurokawa, H., Kitai, R., and Ishiura, K. .............................................. 381

Flares in active region NOAA 7260-Role of emerging flux.

Nitta, N., Driel-Gesztelyi, L. v., Leka, K. D., Mickey, D. L., Metcalf, T. R.,

Wülser, J.-P., Ichimoto, K., Sakurai, T., and Shibata, K........................................... 385

ⅷ　　　　　　　　　　　　　　　　Contents

Multi spacecraft observations and thick-target electron beam models for the 15-NOV-

McTiernan, J. M., Kane, S. R., Hurley, K., Laros, J. G., Fenimore, E. E.,

Klebsadel, R. W., Sommer, M., and Yoshimori, M. .................................................... 389

Long duration events in magnetic arcades and large loops.

Fludra, A., Jakimiec, J., Tomczak, M., Culhane, J. L, and Acton, L.W.................... 393

Analysis of three Yohkoh white-light flares.

Hudson, H. S., Driel-Gesztelyi, L. v., and Kosugi, T. ................................................. 397

Solar wind velocity near the sun: Results from interplanetary scintillation observa-

tions in 1989-1992.

Tokumaru, M., Mori, H., Tanaka, T., Kondo, T., and Yamauchi, Y. ...........................401

Evidence of additional production of high energy neutrons during the solar flare on

Struminsky, A., Matsuoka, M., and Takahashi, K. .......................................... 405

Red asymmetries of optical lines at the impulsive phase of solar flares.

Shoji, M. and Kurokawa, H. ....................................................................................... 409

Preliminary reduction of data obtained with a full disk magnetograph.

Liu, Y., Song, G., Wang, Jingshan, and Wang, Jingxiu ..................................... 413

Soft X-ray feature in active regions associated with meter wavelength solar radio

Watari, S., Isobe, T., and Yohkoh SXT Team ....................................................417

Correlation between solar microwave bursts and hard X-ray flares.

Fu, Q., Liu, Y., and Li, C. ............................................................................................. 421

List of participants ................................................................................................................425

Author index.......................................................................................................................... 435