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1.
以２２周太阳活动低年（１９９３－１９９５）质子事件及其对应活动区的综合分析结果为判据,预报２３周太阳活动上升阶段的质子事件。从１９９７年１１月开始到１９９８年１２月,用该方法预报的质子事件共６个,报准３个,不确定一个,虚报１个,漏报１个（太阳背面产生的事件）。本对用该方法预报的结果进行了分析讨论,并与世界警报中心的预报结果进行了比对,结果表明,该方法对于质子事件的短期预报是有效的。 相似文献
2.
太阳质子事件耀斑的短期预报 总被引：1，自引：0，他引：1
王家龙 《中国天文和天体物理学报》1999,(4)
回顾产生太阳质子事件耀斑的短期预报,讨论短期预报在近期应做的研究．给出以下结论：（１）在６０年代和７０年代,质子事件耀斑的预报有相当大的进展;（２）新预报方法的探索和质子流在日冕与行星际的传播问题,是当前改进短期预报的关键;（３）对实际应用的短期预报工作的改进,可能需要从空间天气预报的角度,研究太阳活动区的分类． 相似文献
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4.
太阳质子事件耀斑的短期预报 总被引：1，自引：1，他引：0
回顾产生太阳质子事件耀斑的短期预报,讨论短期预报在近期应做的研究。给出以下结论：（１）在６０年代和７０年代,质子事件耀斑的预报有相当大的进展;（２）新预报方法的探索和质子流在日冕与行星际的传播问题,是当前改进短期预报的关键;（３）对实际应用的短期预报工作的改进,可能需要从空间天气预报的角度,研究太阳活动区的分类。 相似文献
5.
文中评价了２３ 周以来北京天文台的短期太阳活动预报工作,Ｘ 射线耀斑的报准率为８９ ．６ ％ ,太阳质子事件的报准率为６２ ．５ ％ 。另外,还叙述了第２３ 周峰年北京天文台太阳活动预报工作的选题（ 包括研究课题和实施课题 相似文献
6.
张勤 《紫金山天文台台刊》1999,18(2):147-150
本文给出了太阳２３ 周开始时间的确定、从开始到现在近两年间太阳活动的状况以及２３周上升期间的一些特点。分析表明,１９９６ 年１０ 月是２３ 周的第一个月,它的月平滑值是８ ．８ ;２３ 周的太阳活动虽然可能是高活动周,例如,国际推荐值为２０００ 年３ 月的１６０ ,但它可能不会超过前两周。根据上升期太阳活动的一些特征,还给出了在２３ 周峰年联测和空间灾害性扰动事件预报和预报方法研究中应注意的几个问题 相似文献
7.
就太阳质子事件预报研究的重要意义,产生太阳质子事件的太阳活动区的一般特征,质子耀斑的辐射特征,质子事件几个重要参数预报方法简述了目前的研究进展。还给出了当前为满足用户需要改进预报应着重研究的方面。 相似文献
8.
本文对第２２太阳周（１９８７年１月至１９９２年１２月）中发生过Ｍ级以上的Ｘ射线耀斑（Ｈα耀斑级别≥Ｍ级，并伴有Ｘ射线的耀斑）对应的３９５个活动区资料进行了耀斑指数的统计，得到的结果：１．２２太阳周Ｍ级以上Ｘ射线耀斑级别综合指数表，２．２２太阳周Ｍ级以上Ｘ射线耀斑总指数表，３．第２２太阳周Ｍ级以上Ｘ射线耀斑总指数随时间的变化曲线，４．第２２太阳周Ｍ级以上Ｘ射线濯斑总指数直方图，该图表明第２２太阳周活动的极大年分别是１９８９和１９９１年，为第２３周太阳活动预报提供了可用参数。 相似文献
9.
本文试图探讨紫台太阳活动预报的成效和漏报的原因。结果表明:在三天预报中没有一个质子事件是落在预报零级骚扰安全期间内。对半月预报分析表明,在预报危险期的时间间隔内出现质子事件的可能性比平时高出三倍。本文也分析了漏报的原因,为改进今后预报工作提供参考。 相似文献
10.
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)…… 相似文献
11.
王家龙 《中国天文和天体物理学报》1992,(4)
本文首先分析指出第22太阳周前半周的太阳活动所具有的特点:(1)有最高的起始极小值;(2)上升速度快;(3)升段时间最短;(4)峰期长,可能有双峰;(5)个别时段活动水平极高.然后对第22周后半周的活动情况做了预计:在后半周将可能观测到大约2800个活动区,28000个耀斑,210个X级X射线爆发和大约80次太阳质子事件.最后,应用本文给出的太阳周参量关系式.预报第23周太阳黑子数月均平滑值的峰值为119,位于2001.6年. 相似文献
12.
Based on the new catalogue of solar proton events (SPEs) for the period of 1997?–?2009 (Solar Cycle 23) we revisit the long-studied problem of the event-size distributions in the context of those constructed for other solar-flare parameters. Recent results on the problem of size distributions of solar flares and proton events are briefly reviewed. Even a cursory acquaintance with this research field reveals a rather mixed and controversial picture. We concentrate on three main issues: i) SPE size distribution for \({>}\,10~\mbox{MeV}\) protons in Solar Cycle 23; ii) size distribution of \({>}\,1~\mbox{GV}\) proton events in 1942?–?2014; iii) variations of annual numbers for \({>}\,10~\mbox{MeV}\) proton events on long time scales (1955?–?2015). Different results are critically compared; most of the studies in this field are shown to suffer from vastly different input datasets as well as from insufficient knowledge of underlying physical processes in the SPEs under consideration. New studies in this field should be made on more distinct physical and methodological bases. It is important to note the evident similarity in size distributions of solar flares and superflares in Sun-like stars. 相似文献
13.
Mykola I. Pishkalo 《Solar physics》2014,289(5):1815-1829
Correlations between monthly smoothed sunspot numbers at the solar-cycle maximum [R max] and duration of the ascending phase of the cycle [T rise], on the one hand, and sunspot-number parameters (values, differences and sums) near the cycle minimum, on the other hand, are studied. It is found that sunspot numbers two?–?three years around minimum correlate with R max or T rise better than those exactly at the minimum. The strongest correlation (Pearson’s r=0.93 with P<0.001 and Spearman’s rank correlation coefficient r S=0.95 with P=9×10?12) proved to be between R max and the sum of the increase of activity over 30 months after the cycle minimum and the drop of activity over 30 or 36 months before the minimum. Several predictions of maximal amplitude and duration of the ascending phase for Solar Cycle 24 are given using sunspot-number parameters as precursors. All of the predictions indicate that Solar Cycle 24 is expected to reach a maximal smoothed monthly sunspot number (SSN) of 70?–?100. The prediction based on the best correlation yields the maximal amplitude of 90±12. The maximum of Solar Cycle 24 is expected to be in December 2013?–?January 2014. The rising and declining phases of Solar Cycle 24 are estimated to be about 5.0 and 6.3 years, respectively. The minimum epoch between Solar Cycles 24 and 25 is predicted to be at 2020.3 with minimal SSN of 5.1?–?5.4. We predict also that Solar Cycle 25 will be slightly stronger than Solar Cycle 24; its maximal SSN will be of 105?–?110. 相似文献
14.
To investigate the relations between coronal mass ejection (CME) speed and magnetic field properties measured in the photospheric surface of CME source regions, we selected 22 disk CMEs in the rising and early maximum phases of the current Solar Cycle 24. For the CME speed, we used two-dimensional (2D) projected speed observed by the Large Angle and Spectroscopic Coronagraph onboard the Solar and Heliospheric Observatory (SOHO/LASCO), as well as a 3D speed calculated from the triangulation method using multi-point observations. Two magnetic parameters of CME source regions were considered: the average of magnetic helicity injection rate and the total unsigned magnetic flux. We then classified the selected CMEs into two groups, showing: i) a monotonically increasing pattern with one sign of helicity (group A: 16 CMEs) and ii) a pattern of significant helicity injection followed by its sign reversal (group B: 6 CMEs). We found that: 1) 3D speed generally shows better correlations with the magnetic parameters than the 2D speed for 22 CME events in Solar Cycle 24; 2) 2D speed and the magnetic parameters of 22 CME events in this solar cycle have lower values than those of 47 CME events in Solar Cycle 23; 3) all events of group B in Solar Cycle 24 occur only after the beginning of the maximum phase, a trend well consistent with that shown in Solar Cycle 23; 4) the 2D speed and the helicity parameter of group B events continue to increase in the declining phase of Solar Cycle 23, while those of group A events abruptly decrease in the same period. Our results indicate that the two CME groups have a different tendency in the solar cycle variations of CME speed and the helicity parameters. Active regions that show a complex helicity evolution pattern tend to appear in the maximum and declining phases, while active regions with a relatively simple helicity evolution pattern appear throughout the whole solar cycle. 相似文献
15.
The Prediction of Maximum Amplitudes of Solar Cycles and the Maximum Amplitude of Solar Cycle 24 总被引：1，自引：0，他引：1
Jia-Long Wang Jian-Cun Gong Si-Qing Liu Gui-Ming Le Jing-Lan Sun National Astronomical Observatories Chinese Academy of Sciences Beijing Center for Space Science Applied Research Chinese Academy of Sciences Beijing 《中国天文和天体物理学报》2002,2(6)
We present a brief review of predictions of solar cycle maximum amplitude with a lead time of 2 years or more. It is pointed out that a precise prediction of the maximum amplitude with such a lead-time is still an open question despite progress made since the 1960s. A method of prediction using statistical characteristics of solar cycles is developed: the solar cycles are divided into two groups, a high rising velocity (HRV) group and a low rising velocity (LRV) group, depending on the rising velocity in the ascending phase for a given duration of the ascending phase. The amplitude of Solar Cycle 24 can be predicted after the start of the cycle using the formula derived in this paper. Now, about 5 years before the start of the cycle, we can make a preliminary prediction of 83.2-119.4 for its maximum amplitude. 相似文献
16.
W. Dean Pesnell 《Solar physics》2014,289(6):2317-2331
We describe using Ap and F10.7 as a geomagnetic-precursor pair to predict the amplitude of Solar Cycle 24. The precursor is created by using F10.7 to remove the direct solar-activity component of Ap. Four peaks are seen in the precursor function during the decline of Solar Cycle 23. A recurrence index that is generated by a local correlation of Ap is then used to determine which peak is the correct precursor. The earliest peak is the most prominent but coincides with high levels of non-recurrent solar activity associated with the intense solar activity of October and November 2003. The second and third peaks coincide with some recurrent activity on the Sun and show that a weak cycle precursor closely following a period of strong solar activity may be difficult to resolve. A fourth peak, which appears in early 2008 and has recurrent activity similar to precursors of earlier solar cycles, appears to be the “true” precursor peak for Solar Cycle 24 and predicts the smallest amplitude for Solar Cycle 24. To determine the timing of peak activity it is noted that the average time between the precursor peak and the following maximum is ≈?6.4 years. Hence, Solar Cycle 24 would peak during 2014. Several effects contribute to the smaller prediction when compared with other geomagnetic-precursor predictions. During Solar Cycle 23 the correlation between sunspot number and F10.7 shows that F10.7 is higher than the equivalent sunspot number over most of the cycle, implying that the sunspot number underestimates the solar-activity component described by F10.7. During 2003 the correlation between aa and Ap shows that aa is 10 % higher than the value predicted from Ap, leading to an overestimate of the aa precursor for that year. However, the most important difference is the lack of recurrent activity in the first three peaks and the presence of significant recurrent activity in the fourth. While the prediction is for an amplitude of Solar Cycle 24 of 65±20 in smoothed sunspot number, a below-average amplitude for Solar Cycle 24, with maximum at 2014.5±0.5, we conclude that Solar Cycle 24 will be no stronger than average and could be much weaker than average. 相似文献
17.
Cui-Lian Zhu Jia-Long WangNational Astronomical Observatories Chinese Academy of Sciences Beijing 《中国天文和天体物理学报》2003,3(6):563-568
We present a verification of the short-term predictions of solar Xray bursts for the maximum phase (2000-2001) of Solar Cycle 23, issued by two prediction centers. The results are that the rate of correct predictions is about equal for RWC-China and WWA; the rate of too high predictions is greater for RWC-China than for WWA, while the rate of too low predictions is smaller for RWC-China than for WWA. 相似文献
18.
C. R. A. Augusto C. E. Navia M. N. de Oliveira A. A. Nepomuceno J. P. Raulin E. Tueros R. R. S. de Mendonça A. C. Fauth H. Vieira de Souza V. Kopenkin T. Sinzi 《Solar physics》2018,293(5):84
We report on the 22?–?23 June 2015 geomagnetic storm that occurred at the summer solstice. There have been fewer intense geomagnetic storms during the current solar cycle, Solar Cycle 24, than in the previous cycle. This situation changed after mid-June 2015, when one of the largest solar active regions (AR 12371) of Solar Cycle 24 that was located close to the central meridian, produced several coronal mass ejections (CMEs) associated with M-class flares. The impact of these CMEs on the Earth’s magnetosphere resulted in a moderate to severe G4-class geomagnetic storm on 22?–?23 June 2015 and a G2 (moderate) geomagnetic storm on 24 June. The G4 solstice storm was the second largest (so far) geomagnetic storm of Cycle 24. We highlight the ground-level observations made with the New-Tupi, Muonca, and the CARPET El Leoncito cosmic-ray detectors that are located within the South Atlantic Anomaly (SAA) region. These observations are studied in correlation with data obtained by space-borne detectors (ACE, GOES, SDO, and SOHO) and other ground-based experiments. The CME designations are taken from the Computer Aided CME Tracking (CACTus) automated catalog. As expected, Forbush decreases (FD) associated with the passing CMEs were recorded by these detectors. We note a peculiar feature linked to a severe geomagnetic storm event. The 21 June 2015 CME 0091 (CACTus CME catalog number) was likely associated with the 22 June summer solstice FD event. The angular width of CME 0091 was very narrow and measured \({\sim}\, 56^{\circ }\) degrees seen from Earth. In most cases, only CME halos and partial halos lead to severe geomagnetic storms. We perform a cross-check analysis of the FD events detected during the rise phase of Solar Cycle 24, the geomagnetic parameters, and the CACTus CME catalog. Our study suggests that narrow angular-width CMEs that erupt in a westward direction from the Sun–Earth line can lead to moderate and severe geomagnetic storms. We also report on the strong solar proton radiation storm that began on 21 June. We did not find a signal from this SEP at ground level. The details of these observations are presented. 相似文献
19.
S. W. Feng Y. Chen B. Li H. Q. Song X. L. Kong L. D. Xia X. S. Feng 《Solar physics》2011,272(1):119-136
In this paper we conduct a data survey searching for well-defined streamer wave events observed by the Large Angle and Spectrometric
Coronagraph (LASCO) on-board the Solar and Heliospheric Observatory (SOHO) throughout Solar Cycle 23. As a result, eight candidate events are found and presented here. We compare different
events and find that in most of them the driving CMEs’ ejecta are characterized by a high speed and a wide angular span, and
the CME–streamer interactions occur generally along the flank of the streamer structure at an altitude no higher than the
bottom of the field of view of LASCO C2. In addition, all front-side CMEs have accompanying flares. These common observational
features shed light on the excitation conditions of streamer wave events. 相似文献
20.
R. Miteva K.-L. Klein I. Kienreich M. Temmer A. Veronig O. E. Malandraki 《Solar physics》2014,289(7):2601-2631
We explore the link between solar energetic particles (SEPs) observed at 1 AU and large-scale disturbances propagating in the solar corona, named after the Extreme ultraviolet Imaging Telescope (EIT) as EIT waves, which trace the lateral expansion of a coronal mass ejection (CME). A comprehensive search for SOHO/EIT waves was carried out for 179 SEP events during Solar Cycle 23 (1997?–?2006). 87 % of the SEP events were found to be accompanied by EIT waves. In order to test if the EIT waves play a role in the SEP acceleration, we compared their extrapolated arrival time at the footpoint of the Parker spiral with the particle onset in the 26 eastern SEP events that had no direct magnetic connection to the Earth. We find that the onset of proton events was generally consistent with this scenario. However, in a number of cases the first near-relativistic electrons were detected too early. Furthermore, the electrons had in general only weakly anisotropic pitch-angle distributions. This poses a problem for the idea that the SEPs were accelerated by the EIT wave or in any other spatially confined region in the low corona. The presence of weak electron anisotropies in SEP events from the eastern hemisphere suggests that transport processes in interplanetary space, including cross-field diffusion, play a role in giving the SEPs access to a broad range of helio-longitudes. 相似文献