中文摘要：

以1a的探空资料为参照,对南半球4个不同季节COSMIC掩星观测的折射指数、温度及气压廓线在0～30km高度区间的精度进行了分析。结果表明,虽然就整个高度区间平均而言,春季掩星廓线的精度最差,但不同高度区间掩星廓线的精度差别较大。无论折射指数、气压还是温度,掩星廓线在5～25km区间的精度都优于0～5km与25～30km区间。在0～5km的低对流层,由于水汽的影响,夏季的折射指数廓线精度最低;冬季则最高。在5km以上,夏季气压廓线的精度比其他季节高。不同季节各高度层掩星温度廓线的精度则无显著差异。

英文摘要：

With one year of radiosonde observations as reference,the precision of GPS radio occultation （RO） atmospheric parameter profiles,including refractivity profiles,temperature profiles and pressure profiles,in four different austral seasons are compared and analyzed at 0～30 km altitude.We found that in average,the precision of RO profiles is worse in the austral spring than in the other three seasons.But in different altitude regions,the precision of RO profiles varies greatly.Generally,RO profiles are more precise at 5～25 km than at 0～5 km and at 25～30 km.In the lower troposphere of 0～5 km,the precision of RO refractivity profiles is the worst in the austral Summer and best in the austral winter.This is that the water vapor content in the atmosphere is the highest in summer and is the lowest in the winter.Above 5 km,the precision of RO pressure profiles is the highest in the Austral summer.The precision of RO temperature profiles doesn＇t vary much in different seasons and in different altitude regions.