单台地磁夜均值资料研究半年周期变化的电磁响应

用地磁夜均值资料研究半年周期变化的电磁响应 (地磁内外场比值 Q1) ,如夜均值半年周期变化的源场分布符合 P01分布模式 ,则可用单台资料进行计算 ,有利于进行地区性深地磁测深的研究 .本文选择了质量较好的 5个台约 2 6年的连续资料 ,又搜集了可用的全球分布的台站资料进行分析计算 .结果表明 ,从夜均值估算的半年周期变化的 Q1更为可靠 .原因可能是源场模式不同 .一般的日均值资料不符合 P01模式 ,而夜均值资料则比较符合 P01模式 .本文对此作了源场分布的研究 .

ELECTROMAGNETIC RESPONSE FUNCTION FOR THE SEMI-ANNUAL VARIATIONS ESTIMATED BY THE SINGLE- STATION METHOD USING THE NIGHT-TIME VALUES OF THE GEOMAGNETIC FIELDS

The geomagnetic night time values were used to estimate the electromagnetic response function Q 1 for half year period. If the spatial structure of the source field can be described by the approximation, one can estimate the Q 1 value using the single station Z/H method. This technique enables us to carry out regional deep geomagnetic sounding by the method. The data used for analyses are geomagnetic night time values for about, typically, 26 years from 5 good quality stations and for several years from 34 stations distributed over the globe. The results indicate that the night time values yield more reliable response estimates for half year period compared to the usual estimates obtained from daily means. It implies that the approximation for the night time fields holds good for the half year period, but the daily means are not suitable for estimating the response function of the semi annual variations by using the single station method. Source field analyses for daily means data and night time means data have also been ca rried out in this paper.