1989年1月14日耀斑和纵向电流的关系

本文比较了Krall方法和势场方法判断横场方向的优劣,得出后者比前者有更高的准确率。并且对AR_(5312)活动区1989年1月14日的耀斑和纵向电流密度之间的关系进行了分析,结果为H_β初始亮点和光球纵向电流密度极大值之间有对应关系。     

球面上的块体系统非连续变形反分析法

根据球坐标系下弹性力学的几何方程，推导出球面上块体的位移方程。在球面块体边界均由大圆弧段构成的假设下，导出了块体间距离的计算公式，给出了排除块体间相互入侵和保持合理接触的运动学约束条件及其惩罚函数形式。按最小二乘原理，建立了球面坐标系下的法方程组及其系数矩阵的具体形式。最后，对入侵判定进行了讨论并提出了解决方法。     

EFFECT OF FUTURE SEA LEVEL RISE ON DISASTROUS FLOODS IN THE TAIHU LAKE LOWER REACH DEPRESSIONS AND COUNTERMEASURES

Use of numerical simulation of the tidal flow of the Changjiang River Estuary and the HuangpuRiver to forecast flood in the Taihu Lake lower reach drainage system for the case of future sea level riseof 0.4 m and 0.8 m,and floods preventing and reducing methods are discussed in this paper.     

Sediment movement in periodic alternating current

The present paper summarizes the results of previous studies, including the structure and principle of the rotary ring flume for researching the fine sediment movement, the mechanism of the flume, method of eliminating the influence of the centrifugal force and sediment movement experiments with periodic alternating current. Also included are the experiment-based relationship among sediment concentration, bed shear stress and silt carrying capacity, a proposed erosion-deposition function and bed erosion-deposition calculation together with the results of verification.     

南极地区地磁扰日变化S_D场特征

利用南极地磁资料研究了地磁扰日变化ＳＤ场特征。１）ＳＤ场变化不如Ｓｑ场变化规则,无明显的昼夜差异;太阳活动高年（１９９１年）比下降年（１９９４年）ＳＤ场变化更强烈。２）极隙区中山站ＳＤ场变幅比亚极光区长城站和北半球低纬区北京台的ＳＤ场变幅大１０倍以上。３）中山站Ｓ０Ｄ（Ｈ）变化呈“正弦波”形态,与长城站和北京台Ｓ０Ｄ（Ｈ）变化形态相反。４）中山站Ｓ０Ｄ等效电流矢量在早晨－下午（０２～１５ｈ）矢量方向为反时针西向,下午－夜间（１５～０２ｈ）矢量方向为顺时针东向,这是由极区东向、西向电射流和极区电流涡旋所引起;长城站与北京台Ｓ０Ｄ等效电流矢量很小,这是由极区东向和西向电射流的影响所致。     

在耀斑-日球电流片坐标系中——研究耀斑-激波相应地磁扰动的分布特征（Ⅱ）

本文采用一种新的坐标系--耀斑-日球电流片坐标系,对1966-1982年间由耀斑-激波所引起的277个耀斑-地磁扰动事件进行了分析.初步结果是:1.耀斑-地磁扰动事件在该坐标系中相对日球电流片的随机分布呈高斯分布,极大值在电流片附近;2.当地球和耀斑位于日球电流片同侧时,地磁扰动事件频次远高于异侧;3.地磁扰动强弱在该坐标系中的分布,亦呈现了同侧高于异侧,且极大值多在日球电流片附近;4.耀斑-激波能流密度ρ₂V₂³及其跃变量ρ₂V₂³-ρ₁V₁³在该坐标系中具有十分类似于相应磁扰水平的分布,其离散程度后者略大于前者. 根据本文的结果可以看出,对耀斑-地磁扰动研究来说,近太阳日球电流片的存在是一个重要的特征面,它对耀斑-地磁扰动的产生和强弱水平有重要影响,使太阳耀斑活动与地磁活动效应之间的对应关系变得复杂化了.     

对西北太平洋海域表层密度流的初步探索

在文［９］［１０］关于西北太平洋海面动力地形研究的基础上,本文对该海域表层密度流进行了初步探索。特别是用０．５°×０．５°方区多年船测资料,对西部边界流——黑潮进行了专门研究。结果表明,该海域表面密度流模式与主要由风驱动的大洋总的环流模式基本一致。据研究结果,对文［９］给出的海面动力地形和全球海面动力地形的某些特征作出了解释。另外,还就卫星测高在确定大洋环流的局限性和若干概念性问题提出了明确的看法。     

Study of the longitudinal expansion velocity of the substorm current wedge

In this work we examine simultaneous observations from the two geosynchronous satellites GOES-5 and GOES-6 located at 282°E and 265°E respectively, and from middle and low latitude ground observatories located within 250°E and 294°E geographic longitude, during isolated substorms of moderate activity. The spatial distribution of our observation points allows us to make a detailed study of the azimuthal expansion of the substorm current wedge. The data analysis shows evidence that the substorm initiation and development mechanism include the cross-tail current diversion/disruption, the substorm current wedge formation and the azimuthal expansion of the inner plasma sheet. The triggering mechanism is initially confined in a longitudinally narrow sector, estimated to be less than 15° and located very close to local midnight to the east or to the west. The current disruption region expands both eastward and westward in the magnetotail, so that the location of major field-aligned currents flowing into the ionosphere shifts successively eastward, and the location of the currents flowing out of the ionosphere shifts successively westward. Evidence was found that the perturbation travels toward the west with velocities greater than those expanding the wedge eastward. The drastic decrease of the velocity with the azimuthal distance from the location of the disturbance initiation, i.e., the onset sector, indicates that the energy release is a very localized phenomenon. Finally, the transient D perturbation observed by the geosynchronous satellites suggests that the field-aligned currents forming the wedge have a longitudunally limited extent.