关于确认太阳射电精细结构的几个问题

本文主要讨论了太阳射电快速观测记录中可能存在的几种非太阳因素，分析或定量估计了它们的影响，这些因素主要来自天线跟踪效应、接收机增益起伏效应以及地球大气吸收、折射等，估计、分析这些效应对确认太阳射电爆发中的精细结构现象是有益的。     

2.63.8GHZ太阳微波爆发中的精细结构

微波Ⅲ型爆发和微波尖峰辐射是太阳微波爆发中两个主要的精细结构,由于微波段比长波段的情况更复杂,单从形态上很难区分。１９９４ 年Ｉｓｌｉｋｅ ＆ Ｂｅｎｚ 给出１３ＧＨｚ 频带上的各类爆发分类定义,本文参考了其中关于微波Ⅲ型爆发和微波尖峰辐射的分类,分析北京天文台２ ．６３ ．８ＧＨｚ 频带上观测到的微波尖峰辐射的精细结构,发现该定义有局限性,重新定义了本波段上的微波Ⅲ型爆发和微波尖峰辐射,并讨论了这种分类定义与设备时间分辨率的关系     

3厘米波段太阳射电爆发中精细结构的特征

本文扼要介绍南京大学天文系3厘米波段在1989－1992年间观测射电精细结构的结果，指出该波段存在三种类型的精细结构，并简要讨论它们可能的产生机制．     

论白光太阳磁象仪的原理

本文根据在考虑磁光效应的条件下由斯托克斯参数转移方程组的数值解求得的斯托克斯参数轮廓,探讨V轮廓的不对称性和剩余圆偏振产生的原因,并论证白光磁象仪的工作原理。本文指出,V轮廓的不对称量与磁场强度和速度场精度都有关,因此文[1]和[4]的两个极端性论断都与实际情况不符。     

关于太阳底部贯穿对流区的延伸程度

众所周知 ,贯穿对流对恒星演化有至关重要的影响 .然而至今对此问题尚无完善的理论处理方法 .尽管该问题已经取得了很大的进展[1-4 ] ,但在恒星演化计算中处理贯穿对流最广泛的仍是某种唯象的混合长理论[5,6] .日震学提供了一个探测太阳内部结构的强有力手段 ,它对恒星对流理论给出了一个严格的限制 .　　在过去几年中 ,利用日震方法探测太阳对流区之下贯穿对流区的结构引起了人们的特别关注 .所有的理论研究都是根据这样一种简单的唯象贯穿对流模型[5-9] :在稍许高于绝热温度梯度的对流区的下方 ,紧贴着的是一个稍许低于绝热温度梯度的贯穿…     

THE INFLUENCE OF SOLAR PHOTOGRAVITATION ON THE MOTION OF COMET TAIL

On the basis of photogravitational theory, the influence of solar photogravitation on the motion of comet tail is discussed in this paper. It is shown that for plasma tail and some of the dust tail, there are two coplaner libration points L6, L7, and three collinear points L21, L22,L3 at most. The regions in which the dust grain of comet tail can move are also obtained.     

EVOLUTION OF A DELTA GROUP IN THE PHOTOSPHERE AND CORONA

We present a study of the evolution of NOAA AR 7205 in the photosphere and corona, including an analysis of sunspot motions, and show the evolutionary aspects of flare activity using full-disc white-light observations from Debrecen, vector magnetograms from Mees Observatory, Hawaii, and Yohkoh soft X-ray observations. NOAA AR 7205 was born on the disc on 18 June, 1992. During the first 3 days it consisted of intermittent minor spots. A vigorous evolution started on 21 June when, through the emergence and merging (v 100–150 m s^-1) of several bipoles, a major bipolar sunspot group was formed. Transverse magnetic fields and currents indicated the presence of shear (clockwise twist) already on 21 June (with 0.015 Mm^-1). On 23 June, new flux emerged in the trailing part of the region with the new negative polarity spot situated very close to the big positive polarity trailing spot of the main bipole. The secondary bipole seemed to emerge with high non-potentality (currents). From that time the AR became the site of recurrent flare activity. We find that all 14 flares observed with the Yohkoh satellite occurred between the highly sheared new bipole and the double-headed principal bipole. Currents observed in the active region became stronger and more extended with time. We propose that the currents have been (i) induced by sunspot motions and (ii) increased by non-potential flux emergence leading to the occurrence of energetic flares (X1.8 and X3.9). This observation underlines the importance of flare analysis in the context of active region evolution.     

RELEVANCE OF CME TO THE STRUCTURE OF LARGE-SCALE SOLAR MAGNETIC FIELDS

The relevance of the occurrence rate and location of CME events to two main systems (giant and supergiant) of the large-scale solar magnetic field structure has been investigated. The clustering of CME events and solar flares toward the neutral line of the global field system (neutral line of the source surface field) corroborates the finding by Hundhausen that CME locations track the heliomagnetic equator. A good correlation has been revealed between the CME occurrence rate and variations of the index of the effective solar multipole, that characterizes the typical scale of the global solar magnetic field. The CME rate exhibits sharp jumps/decreases when the index of the effective solar multipole passes through n=4. The observations of X-ray 'blow-out' effects have been analyzed as probable manifestations of CMEs on the disk and have been compared with the large-scale magnetic field structure. As shown by the analysis, the X-ray arcades straddle the neutral line and occur, or at least tend to occur, where the neutral line exhibits a sharp bend. A conclusion is made that CME events are caused by interaction of two large-scale field systems, one of them (the global field system) determining the location of CMEs and another (the system of closed magnetic fields) their occurrence rate.     

黑子活动区流场精细结构

本文通过太阳活动区光球和色球速度场和磁场观测资料,讨论了黑子活动区附近流场的精细结构,论述了太阳大气中物质的流动呈纤维结构,以及速度场纤维与磁场,色球纤维和网络结构之间的关系。     

太阳射电尖峰爆的非线性调制过程

本文论述了在太阳射电尖峰爆中研究观测量之间统计关系的重要性。并在非线性参量稳定性模型的基础上，给出尖峰爆中尖峰出现重复率Ｒ与爆发流量密度ｓ及尖峰的调制幅度△ｓ与ｓ之间统计关系的理论预期。Ｒ－Ｓ统计关系的理论预期与观测结果符合得很好。     

关于太阳白光耀斑连续发射起源的讨论

白光耀斑研究近年来获得较大进展，对其连续发射起源机制目前流行三种解释．一是耀斑形成过程中所产生的色球凝聚[1-3]，二是非热粒子注入大气致氢原子非热激发和电离[4-6]，三是色球强加热所引起的对大气深层的辐射反加热[7]．这三类解释具有一个共性，即除了自身直接对连续谱     

质子耀斑的日面分布特征

在２２太阳活动周中，日面上有三个较强的质子活动复活体，它们爆发峰值流量≥１００ｐｆｕ和≥１０００ｐｆｕ的质子耀斑各占同类耀斑总数的７０．４％和８３．３％。活动复活体分别位于北纬２６°─３５°和南纬２０°─２９°纬度带上，由于它们周期性（１─２．６年）地再现，从而形成了日面质子耀斑的活动经度和纬度明显集中趋势。     

关于太阳耀斑脉动现象机制的译注

近年来,人们在日冕中发现了许多准周期脉动现象,对脉动机制的研究引起了广泛的关注。本文译注了三类典型的脉动理论机制,并初步讨论了它们之间的联系和区别。这些理论机制有助于研究和解释新的观测事件     

THE EFFECT OF SEEING ON SOLAR MAGNETIC FLUX MEASUREMENTS

We investigate the influence of seeing upon measurement of magnetic flux of photospheric fields. For this purpose we quantify seeing variation in one day's observation at Big Bear Solar Observatory in terms of the Fried function, a Modulation Transfer Function for the atmospheric seeing. The temporal variation of seeing quality is compared with that of magnetic flux measured in a quiet region with size 5 \times 4 near the solar disk center. A good correlation is found between the seeing change and apparent evolution of magnetic flux values, implying, as a possibility, that magnetic flux measurement might have been modulated by seeing. Based on a simple model of ensembles of Gaussian magnetic elements we argue that even the net flux as well as the total flux can change due to seeing variation if the magnetograph has a finite detection threshold and if the intrinsic fluxes in one and the other polarities are unbalanced.     

表面边界位置对太阳ρ模本征振荡频率的影响

本文研究了表面边界位置对太阳ρ模绝热本征振荡频率的影响。数值计算结果表明，对于ｖ４０００μＨｚ的中低阶ｐ模，表面边界置于温度极小点所引起的本征振荡频率的计算误差随着ｖ和ｌ的增大，表面边界点位置对太阳理论振荡频率的影响增大，色球结构对太阳ｐ模振荡频率的影响已变得不可忽略。     

用斯托克斯轮廓推导太阳矢量磁场和热力学参量的三维结构

一种根据斯托克斯轮廓分析推导太阳矢量磁场和热力学参量的空间三维结构的新方法在本文中提出．在不考虑散射和原子偏振的假设下，该方法由三个具有不同功能的操作分别作用于太阳大气中一层或二层斯托克斯轮廓组成．这三个操作构成一个运行单元．将此单元运用到从表面到光球底层所划分的大气层格点，然后对扫描区所有的点应用同样的程序便可获得太阳上观察区的矢量磁场和热力学参量的空间三维结构．文中给出了相应的流程图和三个操作的详细描述，并用简化了的程序对理论轮廓进行了拟合．结果表明此方法能较满意地导出矢量磁场尤其是磁场强度的三维空间结构，而热力学参量结构的推导还需进一步改进．     

STRUCTURE AND ROTATION OF THE SOLAR INTERIOR: INITIAL RESULTS FROM THE MDI MEDIUM-L PROGRAM

The medium-l program of the Michelson Doppler Imager instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to 300. The data for the program are partly processed on board because only about 3% of MDI observations can be transmitted continuously to the ground. The on-board data processing, the main component of which is Gaussian-weighted binning, has been optimized to reduce the negative influence of spatial aliasing of the high-degree oscillation modes. The data processing is completed in a data analysis pipeline at the SOI Stanford Support Center to determine the mean multiplet frequencies and splitting coefficients. The initial results show that the noise in the medium-l oscillation power spectrum is substantially lower than in ground-based measurements. This enables us to detect lower amplitude modes and, thus, to extend the range of measured mode frequencies. This is important for inferring the Sun's internal structure and rotation. The MDI observations also reveal the asymmetry of oscillation spectral lines. The line asymmetries agree with the theory of mode excitation by acoustic sources localized in the upper convective boundary layer. The sound-speed profile inferred from the mean frequencies gives evidence for a sharp variation at the edge of the energy-generating core. The results also confirm the previous finding by the GONG (Gough et al., 1996) that, in a thin layer just beneath the convection zone, helium appears to be less abundant than predicted by theory. Inverting the multiplet frequency splittings from MDI, we detect significant rotational shear in this thin layer. This layer is likely to be the place where the solar dynamo operates. In order to understand how the Sun works, it is extremely important to observe the evolution of this transition layer throughout the 11-year activity cycle.     

1966年3月24日耀斑的分析研究

本文用数据方法分析了紫金山天文台色球望远镜观测的１９９６年３月２４日３Ｂ级双带主资料，结果表明：由于新浮磁流改变背景磁场，光球剪切运动引起暗条圆柱轴向磁力线扭转而使暗条电流增加，致使暗条整体力学平衡破坏，驱动暗条向上运动。并对暗条上升运动与耀斑爆发的物理关系进行了分析讨论。     

ON THE PROBLEM OF THE RELATIONSHIP BETWEEN SOLAR FLARES AND CORONAL MASS EJECTIONS

Combination of SMM data with Mauna Loa and GOES measurements shows significant relationships between coronal mass ejections (CMEs) and solar flares, or, more precisely, long decay (duration) X-ray events (LDEs). This relationship is not understood in all its details. Although mass ejections are considered to be a more probable candidate for the role of a driver, there is a problem, namely, which of these two phenomena is cause and which is consequence. To understand this, one traditionally compares start times of CMEs and LDEs. We show that the study of the correlation between XUV line broadening and the origin of CME acceleration gives additional possibilities to solve this problem. In the EUV emission, such investigations might possibly be carried out in the framework of the SOHO program. In the soft X-rays, SMM and Yohkoh data are convenient, albeit not for the same event.     

太阳系P型逆行小天体运动的稳定区域问题

本文讨论了太阳系Ｐ型逆行小天体运动的稳定区域问题，首先，指出了Ｐ型逆行小天体顺行小天体的Ｈｉｌｌ稳定区域及数值稳定区域的差别，然后，讨论了大行星间Ｐ型逆行小天体存在的可能性问题。