太阳活动区的模糊分类与活动性预测

运用模糊聚类分析的方法，研究太阳活动区特性。根据Hα、软X射线耀斑与黑子群各项特征因子的数据，进行标准化处理，分别运用模糊理论中的夹角余弦法，算术平均最小法进行标定，构造模糊相似矩阵与等价矩阵，根据模糊动态聚类分析方法，确定不同λ阈值，按照活动性强弱，对24个活动区进行分类。理论计算结果表明，不同等级类型的活动区强度预测与活动区实际活动性相一致，作为太阳活动水平预报，模糊聚类分析也是一种有效的方法。     

第21周的太阳活动

本文介绍第21周太阳活动的概况。简要报导1976年极小期以来的太阳活动观测结果。对1977年9月、1978年2月和4—5月的三个大活动区及其黑子群的形态特征和耀斑活动分别予以描述。利用大约二年的活动周升段的黑子观测数据,对21周的活动峰期和峰值进行预测评论。     

太阳活动预报中的模糊识别综合指数

在太阳活动预报中,预报因子的选取和处理对预报效果影响甚大。本文在云台原有的平均综合指数基础上,运用模糊识别方法,给出了一种模糊识别综合指数,它能更好地表征太阳日面活动区的活动特征。这种方法简单、方便,较充分地利用了预报因子中所含有的有用信息,从而使识别预报率有所提高。     

预报第23周平滑月平均太阳黑子数的一种方法

利用已知的22个完整太阳活动周平滑月平均黑子数的记录，对正在进行的太阳周发展趋势给出了预测方法，并应用于第23周，同时与其他预报方法的结果进行了比较。     

1988年2月20日事件的初步分析(英文)

通常太阳活动水平紧密相关于日面活动区的结构及其演化特征。活动区愈复杂,活动水平愈强,太阳耀斑事件的频率愈高。当然也有一些例外,一是太阳耀斑事件与黑子活动区有时并不那么密切,甚至无关,如无黑子耀斑等;二是太阳光学事件与射电微波事件之间,也没有完全的一一对应关系,有时甚至相反,如有射电事件而没有光学事件等。88年2月20日事件正是属于后一种情况,也就是显著的微波事件对立于一般水平的光学事件。利用光学资料与射电资料,发现2695与2700MHz上的每日缓变流量与4951活动区的黑子数N和改正面积A呈好的相关。特别是与改正面积同步变化(见图3),由此可见,在二波段上的缓交流量变化可归之于仅仅是4951活动区演化的贡献,而日面上其它活动区则相对稳定,从而对此事件的4951活动区进行了初步分析,提出:对日面西边缘新生发展迅速的活动区,具有极性反转、分布紧密又呈异常排列的黑子群,它们的缓变分量迅猛增长,流量谱呈A1型等特征,可作为某些耀斑事件的预测因子。     

强质子耀斑活动区的形态和旋转特征

本文研究结果表明：同一黑子群在日面期间的顺或反时针方向的旋转运动会先后并存．质子耀斑前1～2无，黑子群的旋转角速度达到极大．耀斑后，磁绳的松弛，黑子群可能会反向旋转，强的剪切过程和质子耀斑可能会再度出现．强质子耀斑活动区的共同特征是：（1）形态为单个团状结构δ型黑子，即众多异极性本影核紧锁在同一黑子半影中；（2）黑子面积＞1000×10－6半球面积，日面跨度＞10°；（3）黑子群都有快速的旋转运动．这类活动区，如果在日面西部活动性明显地增强，那么这个活动区在未来转到日面边缘及其背后、或再次从日面东边缘转出时，定能再次爆发耀斑和伴随较强质子事件。     

太阳整体行为研究

黑子相对数与黑子群在日面纬度上分布的蝴蝶图表征着太阳长期活动演化的特征，本文主要对这二者尤其是后者进行了研究。太阳活动在日面上分布表现为不对称，这是近30年太阳物理研究的主要内容之一。本文对这一领域进行了详细调研，发现太阳活动的南北半球分布不对称性的确存在，是否存在东西半球分布不对称目前还没有定论，但在日面经度上的分布肯定是不均匀的。本文还利用太阳22周活动极大时期X射线（Imp≥M1.0）耀斑事件进行了统计分析，给出了不对称演化特征，发现不对称性并不是事件活动剧烈程度的函数。统计分析表现21周太阳活动既不是已往方面中所述的南半球占优，也不是北半球占优。本文总结了以往对太阳长期活动特征研究的结论，也分析了黑子面积描述的活动周期特征，发现可用一个二参数函数来描述太阳活动周，这个结论对太阳长期活动预防是有用的。本文还详细解剖了蝴蝶图，揭示了其所含的物理信息，同时将不对称研究引入到这种解剖工作中，或是定量再现已有的一些定律，一些效应，或是揭示一些新的长期活动特征。本文最后对太阳长期活动预报方法和预报结构进行了总结，21－23周的预报事例说明前兆因子方法比其它方法要好。本文用Moscow中子监测值对23周作了预报，其峰值为151．1（月平均黑子相对数），对23周事例的总结分析表明其峰值为162．3。     

廿一周升段产生质子耀斑的背景条件及其在质子事件予报中的作用

本文分析了廿一太阳活动周上升段产生质子耀斑的背景条件,评价了它们对质子事件预报的贡献,得出以下几点结论: 1.廿一周升段95.5％的质子活动区分布在30°-90°和120°-210°两个卡林顿经度带上。前一经度带主要产生强烈质子事件,后一经度带主要产生弱质子事件。 2.各活动经度带存在着时间大约为一年的活动期和间歇期,两个经度带互相交替。全球的质子事件存在着73±0.7天的周期。 3.用相关性预报水平总指标对各种产生质子耀斑的背景条件评价的结果是,对质子事件预报贡献较大的背景特征依次为:黑子群出现长命旋涡(α_0=0471);面积≥1000单位的黑子群(α_0=0.365);磁型为结δ构(α_0=0.300);反常极性黑子群(α_0=0.275);F型黑子群(α_0=0.239)……     

太阳双极黑子的无力磁场理论和耀斑能量

本文根据已得到的无作用力磁场的通解,求出了双极黑子磁场的表达式,并求出双极黑子的扭转场磁能M,势场磁能M_p,可释放的自由磁能△M,磁通量Φ,总电流Ι,无力因子α和磁场衰减因子k等重要参量。这些量可表为场强B、半影纤维的扭转角δ和两黑子中心距离l的函数,后3个量可测出。△M的公式可供太阳预报工作参考使用。将上述公式应用于1978年7月太阳活动区,算出各参量,其中△M的量级为10~(32)尔格,足够供该活动区耀斑等活动现象的能量。     

太阳活动区强磁场图的照相观测

黑子群的强磁场结构及其演化特点对于太阳活动预报和活动区物理研究都是一项基本的观测资料。从1975年底起,我们参考了资料(1)的经验,着手对本台现有太阳光谱仪(2)进行部份的改装,设计了一个简单的附加电路,将原Hδ波段的落片架置横,换上橙色的滤光片OG5,用Fel6173谱线进行黑子群强磁场的扫描照相试验。目前已参加了我国黑子极大磁场资料的常规发布项目。一年的观测日数约285天。     

Automatic Detection of Sunspots and Extractionof Their Feature Parameters

Sunspots are solar features located in active regions of the Sun, whose number is an indicator of the Sun's magnetic activity. With a substantial increase in the quantity of solar image data, the automated detection and verification of various solar features have become increasingly important for the accurate and timely forecasts of solar activity and space weather. In order to use the high time-cadence SDO/HMI data to extract the main sunspot features for forecasting solar activities, we have established an automatic detection method of sunspots based on mathematical morphology, and calculated the sunspot group area and sunspot number. By comparing our results with those obtained from the Solar Region Summary compiled by NOAA/SWPC, it is found that the sunspot group areas and sunspot numbers computed with our algorithm are in good agreement with the active region values released by SWPC, and the corresponding correlation coefficients for the sunspot group area and sunspot number are 0.77 and 0.79, respectively. By using the method of this paper, the high time-cadence feature parameters can be obtained from the HMI data to provide the timely and accurate inputs for the solar activity forecast.     

The fuzzy forecast of the activity of solar active regions

In this paper, the theory and method of fuzzy mathematics are applied to forecast the activity of solar active regions. According to the correlation between flares and several solar activity indices of active regions, the membership functions are constructed to comprehensively evaluate and predict the activity of solar active regions. By means of data reduction and analysis, some comparatively accurate results of prediction have been obtained. The accuracy of predicting the activity grades of active regions is higher than 97%. This implies that the method of fuzzy forecast is a good one for solar activity prediction. This revised version was published online in July 2006 with corrections to the Cover Date.     

Sunspot groups at high latitude

Data of sunspot groups at high latitude (35°), from the year 1874 to the present (2000 January), are collected to show their evolutional behaviour and to investigate features of the yearly number of sunspot groups at high latitude. Subsequently, an evolutional pattern of sunspot group number at high latitude is given in this paper. Results obtained show that the number of sunspot groups of a solar cycle at high latitude rises to a maximum value about 1 yr earlier than the time of the maximum of sunspot relative numbers of the solar cycle, and then falls to zero more rapidly. The results also show that, at the moment, solar activity described by the sunspot relative numbers has not yet reached its minimum. In general, sunspot groups at high latitude have not appeared on the solar disc during the last 3 yr of a Wolf solar cycle. The asymmetry of the high latitude sunspot group number of a Wolf solar cycle can reflect the asymmetry of solar activity in the Wolf solar cycle, and it is suggested that one could further use the high latitude sunspot group number during the rising time of a Wolf solar cycle, maximum year included, to judge the asymmetry of solar activity over the whole solar cycle.     

Comparison of sunspot area data bases

Sunspot area measurements play an important role in the studies of sunspot groups and variations in solar irradiance. However, the measured areas may be burdened with systematic and random errors, which may affect the results in these fields. Mainly the total solar irradiance models can be improved by using more precise area data. In order to choose the most appropriate area data for a given study or create a homogeneous composite area data base, there is a need to compare the sunspot areas provided by different observatories. In this study we statistically investigated all the available corrected sunspot area data bases for the years 1986 and 1987. We find that the photographic data bases are in good agreement with each other but there are important systematic differences between the photographic and sunspot drawings data bases. We give the characteristic parameters for the systematic and random errors as well as the possible reasons for them.     

Long-Term Sunspot Number Prediction based on EMD Analysis and AR Model

The Empirical Mode Decomposition (EMD) and Auto-Regressive model (AR) are applied to a long-term prediction of sunspot numbers. With the sample data of sunspot numbers from 1848 to 1992, the method is evaluated by examining the measured data of the solar cycle 23 with the prediction: different time scale components are obtained by the EMD method and multi-step predicted values are combined to reconstruct the sunspot number time series. The result is remarkably good in comparison to the predictions made by the solar dynamo and precursor approaches for cycle 23. Sunspot numbers of the coming solar cycle 24 are obtained with the data from 1848 to 2007, the maximum amplitude of the next solar cycle is predicted to be about 112 in 2011-2012.     

Common Characteristics of the Active Regions of Strong Proton Flares

Common characteristics of nine active regions with strong proton flares in the 22nd solar activity cycle have been presented. Results show that the typical morphology of these active regions is a -type sunspot with a single multiple structure, in which there are many umbras with different magnetic polarities, packed tightly by a single penumbra. In these active regions, the rotating directions of the sunspot groups are nearly independent of their position on the solar disk. When the angle of rotation approaches the positive or the negative maximum, proton flares may occur in these active regions. After proton flares, sunspot groups rotate in the inverse direction because of the slack in the flux rope.     

On the rotation rates of sunspot groups

The analysis of Greenwich sunspot data for cycle No. 18 shows: (1) higher rotation rates for the southern sunspot belt than for the northern belt, (2) lower rotation rates and a tendency to a more rigid rotation for greater sunspot groups, (3) lower rotation rates and a tendency to a more rigid rotation for older sunspot groups, (4) no dependence of rotation rates on the life-time of sunspot groups, (5) a tendency to a more rigid rotation at the activity minimum. Results Nos. 2, 3, and 5 could be interpreted in terms of the evolution and interplay of the active regions, as the regions age. If we assume that the sunspot group life-time is a function of their depth in the solar atmosphere, result No. 4 shows that rotation rates do not depend on the depth.     

22周上升相日面各经度带的活动规律

本文回顾了１９８３年以来一些对太阳活动的谱分析结果。大致可分为两种规律：在太阳活动１１年周期的上升相一般呈现８０天左右的周期。下降相呈现１５０天左右的周期。这些规律均是由太阳全日面总体活动指数得到的谱分析结果。文中将第２２周上升段（１９８７．１．１—１９８８．７．３１）的太阳黑子群和Ｘ射线耀斑按经度带作了极大熵谱估计。结果表明，各经度带的活动规律不同，同一经度带内，太阳黑子群和Ｘ射线耀斑的出现规律也不尽相同。这种将事件按经度带分布得到的活动规律对事件本身的中期预报将会有实际应用价值。