太阳射电快速频漂和偏振逆转波的传播解释

本文研究了寻常波和非常波在线性传播条件下，对快速毫秒级spike的时延、频漂和偏振逆转的影响．计算表明，在（20－40）×Baumbach－Alien的电子密度分布下，由于传播产生的时延，偏振逆转等约为30－300ms，这与观测结果在量级上是一致的．这说明在快速活动中传播效应是一个重要的因素．

An Interpretation of Rapid Frequency Drift and Polarization Sense Reversals by Radio Wave Propagation in the Solar Corona

In this paper, we consider the influence of radio wave propagation in the corona on the time delays (or frequency drift) and reversals of polarization sense of millisecond spikes. The calculation sliow: (1) The time delays at 2645 MHz and 2545 MHz are about 30-300 ms due to the differences of O and X mode group velocity for (20-40) Baumbach- Allen electron density distribution. This is consistent with the observational records of 1991 May 16. (2) The time differences of RH and LH peaks (reversals of polarization sense) at 2545 MHz are about 30-116 ms. This is also consistent with observational results of 1991 May 16. If the radio source is between the O-mode and X-mode reflect level, only O-mode wave could escape and X-mode could not escape from the corona. The formula of frequency drift shows that the drift rate should be small at the center of solar disk and large at the limb. However the available statistics are still inadequate to sustain this conclusion.