电离层电子总量水平梯度和相关系数

电离层电子总量水平梯度和相关系数是进行越境越障空间物理研究时的基本参量。本文分析了当同步信标卫星ATS-6停泊于东非地区上空时,在西欧观测到的太阳宁静年条件下电离层电子含量水平分布和空间相关性。指出纬向梯度、经向梯度、全梯度矢量的昼夜变化与季节特性。文中提出并论述中纬度TEC水平梯度矢量的指日效应:在北半球,冬季时梯度矢量指向的昼间进程是东南-南-西南,方位角变化小,幅值与幅值变化亦小;夏季时梯度矢量指向的昼间进程是东-南-西,方位角变化大,幅值与幅值变化亦大。梯度矢量箭头具有判然的指日性,即追随太阳方位角而变。梯度矢量幅值,在非低纬区条件下,随太阳仰角的增大而增大。文中还述及电子总量空间相关系数的表现规律并探讨了产生中纬度电离层这种时空行为的可能的动力学原因。

HORIZONTAL GRADIENTS AND CORRELATION COEFFICIENTS IN TOTAL ELECTRON CONTENT OF THE IONOSPHERE

Horizontal gradients and correlation coefficients in the ionospheric TEC are among the basic parameters in space-physical research of exceeding the limits and surmounting the obstacles. In the present paper, the. horizontal distribution and space correlation of TEC observed in Western Europe under quiet solar condition during phase II of synchronous beacon satellite ATS-6 when it was repositioned at 35 °E over Eastern Africa are analysed. The latitudinal and longitudinal gradients, their diurnal variations and seasonal characteristics are dealt with. It is proposed and discussed that the sun-pointing effect of daytime horizontal gradient vectors in the ionospheric TEC is such that: On the Northern Hemisphere, in winter, daytime course of gradient direction is the southeast-south-southwest; and in summer, the east-south-west. In winter, daytime extent of azimuthal variation, the gradient magnitude and its fluctuation are smaller; and in summer, greater. In other words, the direction of daytime gradient vectors has apparently the co-rotational nature with the sun or the sun-pointing character following the azimuth of the sun, and the corresponing gradient magnitude and its variation, beyond equatorial belt and low latitudes, increase along with the. rise of solar elevation. The manifestation pattern of TEC space correlation coefficient at mid-latitudes and the possible involved dynamic causes are also inquired.