This work has investigated the seasonal and universal time ( UT) variation of the occurrence frequency and magnetic latitude (Mlat) of Sub-Auroral Polarization Streams (SAPS) in both hemispheres using DMSP particle observations. It is found that (1) SAPS tend to occur mostly in equinox seasons, showing strong magnetic activity dependence; (2) The second most frequent occurrence of SAPS is in winter, which may be related to substorm processes; ( 3 ) Ionospheric conductivity has an important influence on SAPS occurrence, with more frequent occurrence at lower conductivity; (4) SAPS tend to shift equatorward with low ionospheric conductivity.%利用DMSP卫星粒子数据,对南北半球20 000多个亚极光区极化流(SAPS)事件进行统计学分析,重点研究SAPS的发生率及其发生位置隧季节和世界时的分布,研究表明:(1)SAPS的发生率有明显的季节和世界时依赖性,主要发生在春秋季节,显示出较强的地磁活动依赖性;(2)SAPS在冬至也较多发生,可能与亚暴过程有关;(3)电离层电导率对SAPS的发生有重要影响,SAPS主要发生在较弱的电离层电导率期间;(4)SAPS发生磁纬与磁地方时较好线性相关,当电离层电导率较弱时,SAPS倾向于向低纬度移动.
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