太阳活动11年周期与南极海冰的可能联系

本文利用1979—2018年NCEP-DOE再分析资料、Hadley中心提供的全球海冰密集度格点资料以及反映太阳活动11年周期变化的太阳黑子数资料,研究了太阳活动与南极海冰变化的可能联系和其中涉及的物理过程。结果表明,太阳活动偏强年,南极半岛-威德尔海海冰密集度增加,罗斯海外围海冰密集度减少,反之亦然。通过定义一个反映上述变化的南极海冰偶极子指数,我们发现其与南极涛动(Antarctic Oscillation,AAO)的变化具有显著的负相关关系,与AAO密切相联系的绕极急流的非对称性结构在这一过程中起到了关键作用。当AAO强度较强时,西风急流在南极半岛-威德尔海一带向南偏转,在罗斯海附近向北偏转,引起暖空气易于进入南极半岛-威德尔海,而更多的冷空气进入罗斯海外围,从而造成海冰分布的偶极子结构。而当AAO为负位相时,情况与上述相反。对流层AAO模态对太阳活动的响应,可能在太阳活动与南极海冰两者的联系中起到了桥梁作用。进一步的研究揭示出太阳活动影响AAO的信号很可能源于平流层温度的响应,再通过对流层的平均经圈环流的调整,大气质量得以重新分布,在太阳活动偏强年,对流层低层易于出现负的AAO型响应。     

PRELIMINARY STUDY ON THE FLOODING AND DROUGHT CLAMITY DURING PAST 1500 YEARS IN THE HAI′AN REGION，JIANGSU PROVINCE

Collection and arrangement of the historical records of climatic changes and environment evolution,espectial-lyin the aspect of calamities,are made on the history documents of past 1500 years about Haiˊan region,Jiangsu Province.There existed two obvious flooding-drought frequently-occurring periods:one was from 1550 AD to 1850 AD and another was 100 AD to 1200AD.The period of 1550 AD to1850 AD is interrupted by two relatively arid and cold climatic periods:one was from 1630 AD to 1700 AD and another was 1750 AD to 1820 AD.The main characteristic of the calamity periods is that they occurred by turns,and sometimes,both drought and flooding occurred in the same year.The instability of the climatic changes in the Little Ice Age may be the main reason of the frequently-occurring flooding and drought in Haiˊan region.Research results also show that the frequently-occurring periods of flooding and drought is in close relationship with the solar activity,and therefore,occurrence of the flooding and drought may be in relation with the intensity of the solar activity.This hypothesis may need further study in the future.     

强电离层突然骚动与太阳耀斑活动的关系

本文统计分析了1986年至1993年11月的强电离层突然骚动(>3-级的SID)与太阳耀斑活动之间的相关关系。结果表明:(1)88％的强电离层突然骚动是与太阳耀斑爆发相关的。(2)82％的强电离层突然骚动是与高能X-射线耀斑(C、M、X级)有关系的。(3)强电离层突然骚动在太阳耀斑瀑发后发生的概率高于在耀斑瀑发前发生的概率,它们的发生率分别为49％和39％。(4)两者同时发生的概率为12％。     

用实测波浪数据确定JONSWAP谱参数

本文给出应用实测波浪数据确定JONSWAP谱参数的方法，若Hs,Tz,Tc分别为实的有效波高，平均上跨零线周期，平均峰－峰周期并令y=Tz/Tc，本文导出求解谱参数γ值的方程f（γ，y）＝0。根据这个方程的解并应用最小二乘法，γ作为y的函数的表达式可写为（对于2.54≤γ≤15.34及1.6≤y≤1.79）。     

Multi-wavelength Diagnostics of Bombardment by Non-thermal Particles in Solar Flares

Chromospheric lines, including Ha, Lyα, Lyβand CaⅡK, CaⅡ8542, are systemically and quantitatively investigated with respect to the non-thermal excitation and ionization due to particle beam bombardment for a series of solar semi-empirical atmospheric models. As a result we propose to use the contrast in the integrated intensity of hydrogen lines to estimate the total energy flux of the bombarding beam during the solar flare impulsive phase. Partial frequency redistribution is considered in the Lyαline calculation and a smaller intensity enhancement in the Ha line-centers is found than in the previous results of Fang et al.     

Influence of the Choice of Core-Envelope Transition Point on the Binary Merger of Two Main-sequence Components

We have studied the influence of different choices of core-envelope transition point on the final merger of contact binaries with two main-sequence components. A binary of 1.00 + 0.90M⊙ with an initial orbital period of 0.35d is examined. The mass fraction of the primary mixed with the matter of the secondary, qmix, determined by the chosen core-envelope transition point, ranges from 0.04 to 1.00 in our analysis. If as qmix< 0.8, none of the     

Size-Flux Relation in Solar Active Regions

We present a study of the relationship between integral area and corresponding total magnetic flux for solar active regions. It is shown that some of these relationships are satisfied to simple power laws. Fractal examination showed that some of these power laws can not be justified inside the simple models of stationary magnetic flux tube aggregation. All magnetic fluxes and corresponding areas were calculated using the data measured with the Solar Magnetic Field Telescope of the Huairou Solar Observing Station in Beijing.     

微波Ⅲ型爆发与日冕物质抛射的统计分析

对国家天文台2.6～3.8GHz频谱仪在第23太阳活动周上升段(1996～1998)记录到的Ⅲ型爆发,与日冕物质抛射(CME)作了统计分析。发现微波Ⅲ型爆发可能是CME的先兆现象,并讨论了它们的辐射机制。     

应用ATA的对数周期馈源方案于FAST的可能性探讨

介绍应用于美国凤凰计划的Allen望远镜阵(ATA)的对数周期馈源(LPA)概况，初步给出此种馈源的基本参数及性能，仿真估算了其驻波比和方向图，并结合正在进行中的我国500m孔径球面射电望远镜(FAST)计划，探讨了应用这种宽带馈源的可能性及其限制。