SuperDARN雷达的对流测量评估

An evaluation of SuperDARN convection measurements

通过与DMSP卫星测量的二维离子漂移矢量的比较,对SuperDARN雷达对流测量进行了评估。二维对流矢量的比较表明,两种观测手段的测量总体上相符,其中对流方向的相关性和一致性均优于对流大小;当对流较强时,SuperDARN测量值有偏低的趋势。进一步分析表明,SuperDARN的视线速度测量与DMSP离子漂移测量的一致性较高,暗示由视线速度推断对流矢量的模型存在局限性,不能有效地反映出对流图像的小尺度结构。

The present study gives an evaluation of the SuperDARN convection measurements based on the comparison of the 2-D plasma convection vectors obtained by the SuperDARN HF radars and the DMSP satellites. It is shown that the convection measurements derived from the two observation systems are consistent on the whole. The correlation and consistency of the convection azimuth are both better than those of the convection magnitude. A tendency for the SuperDARN velocities to be smaller is shown for strong convection. Further analysis indicates that the agreement between the SuperDARN line-of-sight velocity and the DMSP ion drift measurements is better than that of the 2-D convection comparison. This implies that the SuperDARN fit procedure, which reprocesses the line-of-sight velocities into the convection vectors, can not effectively reflect the small-scale convection structures.