第23太阳活动周的黑子数峰值特征预报

Using the characteristic values of sunspot number variations during the descent and ascent of solar cycles,a neural network is designed to make long-term predications of the ascending period and the maximum smoothed monthly mean sunspot number for the Solar Cycle　23. Moreover,the factor of geomagnetic disturbance is also added as an input. The trained and tested results from Solar Cycle 12 to 22 have been obtained. Finally,the predictions of the ascending period and the maximum smoothed monthly mean sunspot number are given for Solar Cycle 23.     

射电日像仪天线及工作频率的设想

The article analysizes the current situation and opportunity of the development of radioheliograph in China. It provides an idea to construct the radioheliograph by three stepsfrom small sized,to middle sized,then tobig sized. Each step is to construct a complete radioheliograph. The article also analysizes some important technical performance,such as diameter of element antenna,overall pointing error and observing frequency.     

太阳活动短期预报效果及预报评价的探讨

In the paper,the effects of short-term prediction techniques of solar activity of the World Warning Agency (W) and Beijing Astronomical Observatory in 1970s(B7) and 1990s(B9) were analyzed statistically by the standard of the effects of the persistance prediction technique(CH) in the same periods of time. A Q-index evaluating effects of prediction has been put forward;the index indicates the synthesis of positive effects of correct forecasts and negative effects of false forecasts. Against the persistence prediction (CH),the effects of WWA prediction (W),BAO prediction using 1970s' technique (B7) and 1990s' technique (B9) during the same periods of time as (CH) have been evaluated by the Q-index. Based on the above,we have advanced a concrete scientific way to improve the short-term prediction technique. Especially,we have raised that in order to improve prediction technique,the results of persistence prediction should become the basic component of short-term prediction of solar activity;namely,present prediction of forecasting the levels of solar activity should be transformed to forecast the coming change of solar activity levels with the aim of using the effects of persistence prediction fully.     

1982年6月12日耀斑的巴耳末线半宽特征

Usually,because of the Starkbroadening for the spectrum lines,the half widths of hydrogen higher Balmer emission lines of the solar flare increase with the principal quantum number N. Their variation curve,as observed before,has a minimum value near N=8 or 9. However,a curve for the solar flare which occurred at the limb of solar disk on June 12,1982shows an all-time decline with increasing N. How to explain this phenomena remains to be discussed.     

对太阳活动区的自动监测、资料处理 及研究的一些新方法

In this paper we introduce the results of our investigations for some new methods of the automatic observation forecast、data processing and research,IncludingAutomatic forecast and capture of solar flare events;A method in drawing light curves of solar flares with high accuracy;A method for the automatic observation of solar active regions etc.     

CME与米波射电爆发相关性研究

A correlation between the coronal mass ejection(CME) and the meter wavelength radio bursts is analyzed in this paper. It is found that type Ⅱ and type Ⅳ bursts have very good correlation with CME. Noise storms occur several tens minutes before the onset of the moving type Ⅳ bursts. A sudden stop of noise storms can be used as a sign to foresee the possibility of a following CME. The three kinds of the moving type Ⅳ also introduced in this present papersolated source type,the expanding-arc moving Ⅳ type and the advancing front type.     

第23周太阳活动峰年北京天文台太阳射电观测

An introduction to the instrumonts to be used for solar radio observations in Beijing in Solar Cycle 23 is made in this paper. They are 10cm solar radio telescope which has been used for a long time,and 1.0～2.0GHz,2.6～3.8GHz and 5.2～7.6GHz spectrometers. The former two spectrometers has passed a test,showing high guality,and the 5.2～7.6GHz one will be in operation from 1999. It is believed that highl gualified data should be obtained in the next solar cycle.     

人造双行星与地球组成的太阳和行星际观测网

A Solar and interplanetary observational system composed of two artificial planets and the earth is suggested for the solar-terrestrial study and prediction.The two planets should move along the earth's orbit around the sun. The angle distance between the two planets and between them with the earth is 120°. This system can be used to improve greatly the short-term,midiu-mterm solar activity predictions and monitor an earth-toward coronal mass ejection,giving an accurate warning of a solar-terrestrial disturbance. Observational data obtained by this system would be very useful in a model work of solar wind and an evolution study of structures in solar atmosphere such as solar active regions and magnetic fields with various scales.     

太阳活动22周低年质子事件的预报分析

In this paper,5 proton events and corresponding active regions in the descending phase of Solar Cycle 22(1993～1995) are analysed. The result shows that (1)The proton flares in 1993～1995 occurred mainly in the longitudy zone of 140～270 degree. (2)4 of 5 events (80%) studied have their small magnetic fluxes to disappear in their magnetic flux regions with a major polarity,one day before the event. (3)It is 60% of the event studied to show characteristic of the merging of 2 or greater than 2 magnetic fluxes with similar polarity in their active regions,one day before of the proton event. The results are possibly useful for the short-term prediction of proton events.     

空间天气学

Birth and new characteristics of 《Space Weather》 and its base—three kind of the global structure are briefly presented in this paper,respectively.     

Prediction of sunspot number amplitude and solar cycle length for cycles 24 and 25

The prediction of solar activity strength for solar cycles 24 and 25 is made on the basis of extrapolation of sunspot number spectral components. Monthly sunspot number data during the 1850–2007 interval (solar cycles 9–23) are decomposed into several levels and searched for periodicities by iterative regression in each level. For solar cycle 24, the peak is predicted in November 2013 with a sunspot number of 113.3. The cycle is expected to be weak, with a length of 133 mo (months) or 11.1 yr. The sunspot number maximum in cycle 25 is predicted to occur in April 2023 with a sunspot number 132.1 and a solar cycle length of 118 mo or 9.8 yr. Thus, solar cycle 24 is predicted to have an intensity 23% lower than cycle 23, and cycle 25 will be 5% lower than cycle 23.     

Prediction of cycle 24 based on information about solar activity during the last 10 000 years

The average and maximal numbers of sunspot groups in the approaching solar cycle (cycle 24) have been predicted using paleoastrophysical information about solar activity during the last more than 10000 years. The linear and nonlinear prediction methods have been applied. It has been indicated that, from the standpoint of solar paleoastrophysics, the next cycle will most probably be average: the number of sunspot groups at a maximum will reach 68–101. The probability that cycle 24 will be powerful (more than 160 sunspot groups), which was predicted by some researchers, is low (not higher than 2%).     

第二十二太阳黑子周特征值预报

太阳活动对地球的影响是人们关心的重要研究课题。太阳黑子相对数作为描述太阳活动的一个参量,虽然不如射电流量密度等参量具有明确的物理意义,但是由于它有较长的观测历史以及在统计上可较好地反映太阳活动的变化,因此在较长期的太阳活动预报等工作中仍是个常用的参量,为有关部门所使用。 将上一个太阳周即第21周的种种预报极值与实际极值165.3比较,可知:一般说     

太阳黑子相对数最强周期的小波分析

利用小波变换,分析了1749年以来每个太阳活动周太阳黑子相对数的最强周期以及第1～22太阳活动周的最强周期. 分析结果表明,在第5和第6个太阳活动周,太阳黑子相对数最强的周期分别为64.67年和69.31年;在第13～15太阳活动周,太阳黑子相对数的最强周期分别为98.02年,105.06年和105.06年. 在第1～22太阳活动周中,太阳黑子相对数最强的周期是128个月,约10.67年,其他太阳活动周的最强周期介于9.29～11.43年之间. 本文最后给出了128个月周期的幅度随时间的变化.     

A straightforward estimation of the maximum sunspot number for cycle 23

Using the annual number of geomagnetically quiet days (aa < 20 γ) for the year after the solar minimum, this precursor method predicts that the maximum sunspot number for cycle 23 will be 140 + 32, indicating that cycle 23 will be similar to cycles 21 and 22.     

Long-term variations in sunspot characteristics

Relative variations in the number of sunspots and sunspot groups in activity cycles have been analyzed based on data from the Kislovodsk Mountain Astronomical Station and international indices. The following regularities have been established: (1) The relative fraction of small sunspots decreases linearly and that of large sunspots increase with increasing activity cycle amplitude. (2) The variation in the average number of sunspots in one group has a trend, and this number decreased from ～12 in cycle 19 to ～7.5 in cycle 24. (3) The ratio of the sunspot index (Ri) to the sunspot group number index (G _gr) varies with a period of about 100 years. (4) An analysis of the sunspot group number index (G _gr) from 1610 indicates that the Gnevyshev-Ohl rule reverses at the minimums of secular activity cycles. (5) Ratio of the total area to area of Ssp/Sum nuclei has long-term variation with a period approximately 8 cycles. Minimum ratio falls on 16–17 cycles of activity. (6) It has been indicated that the magnetic field intensity and sunspot area in the current cycle are related to the amplitude of the next activity cycle.     

月平滑太阳黑子相对数的预报

建国以来,不少天文工作者在太阳活动长期预报、中期和短期预报方面作了大量工作,但是,太阳活动的一至几年的中长期预报却很少有人涉足。本文试图用门限自回归模型和二次曲线方法,探讨时间长度为一年的月平滑黑子相对数的预报。并给出两种方法的综合预报结果。     

A statistical study of the relationship between the solar cycle length and tree-ring index values

We have determined the correlation coefficient between tree-ring index values and the sunspot cycle length for 69 tree-ring data sets from around the world of greater than 594 years duration. A matrix of correlation coefficients is formed with varying delay and smoothing parameters. Similar matrices, formed from the same data, but randomly scrambled, provide a control against which we can draw conclusions about the influence of the solar cycle length on climate with a reasonable degree of confidence. We find that the data confirm an association between the sunspot cycle length and climate with a negative maximum correlation coefficient for 80% of the data sets considered. This implies that wider tree-rings (i.e. more optimum growth conditions) are associated with shorter sunspot cycles. Secondly, we find that the climatic effect of the solar cycle length is smoothed by several decades and the degree of smoothing is dependent on the elevation and the geographical location of the trees employed. Thirdly, we find evidence for a cyclic variation of ∼200 years period in either solar cycle length or tree ring index. © 1999 Elsevier Science Ltd. All rights reserved.     

The Ratio Between the Number of Sunspot and the Number of Sunspot Groups

Data from three solar observatories (Learmonth, Holloman, and San Vito) are used to study the variations in the average number of sunspots per sunspot group. It is found that the different types of sunspot groups and the number of sunspots in these groups have different solar cycle and cycle to cycle variations. The varying ratio between the average number of sunspots and the number of sunspot groups is shown to be a real feature and not a result of changing observational instruments, observers’ experience, calculation schemes, etc., and is a result of variations in the solar magnetic fields. Therefore, the attempts to minimize the discrepancies between the sunspot number and sunspot group series are not justified, and lead to the loss of important information about the variability of the solar dynamo.