全球电离层峰值参数的季节变化

Seasonal Variations of Global Ionospheric N_(m)F_(2)and h_(m)F_(2)

针对全球电离层峰值参数的季节变化问题,使用2006-2019年COSMIC掩星电离层月均值数据和小波分析方法分析了全球电离层N_(m)F_(2)和h_(m)F_(2)季节变化特征,结果表明:电离层N_(m)F_(2)和h_(m)F_(2)随地方时、季节、纬度存在显著差异,电离层峰值参数均与太阳活动水平表现出正相关性,月均值相关系数分别达到了0.9和0.8以上;正午电离层N_(m)F_(2)在太阳活动高年期间存在显著年、半年等季节变化特征,午夜基本以年变化为主,且南半球电离层N_(m)F_(2)季节变化特征更为明显;正午电离层h_(m)F_(2)所有年份均存在显著年变化特征,午夜期间季节性变化特征不太明显,且南半球电离层h_(m)F_(2)季节变化特征强于北半球;电离层峰值参数的季节变化规律在太阳活动高年期间更为显著;太阳活动指数和电离层峰值参数中似乎存在25~35个月的周期信号,但未通过显著性检验,综合分析研究认为电离层中的等离子体不会受到QBO现象影响.

The seasonal variations of global ionospheric N_(m)F_(2) and h_(m)F_(2) have been analyzed by using the monthly COSMIC ionospheric data from 2006 to 2019 and wavelet analysis method.The results show that the ionospheric N_(m)F_(2) and h_(m)F_(2) are significantly different with local time,season and latitude.The ionospheric peak parameters have positive correlation with the solar activity,and their correlation coefficients are above 0.9 and 0.8,respectively.The ionospheric N_(m)F_(2) at noon exists significantly annual and semiannual variations,especially under the high solar activity conditions.However,the annual variation of ionospheric N_(m)F_(2) has been mainly observed at nighttime.Meanwhile,the annual variation of ionospheric h_(m)F_(2) at noon is significant in all years,but almost absent during midnight.Additionally,and the seasonal variations of ionospheric N_(m)F_(2) and h_(m)F_(2) in the southern hemisphere are more obvious than that in the northern hemisphere.Additionally,the seasonal variations of ionospheric peak parameters are more significant during high solar activity years.Moreover,there seem to be periodic signals of 25~35 months in the solar activity index and ionospheric peak parameters,but their power spectrum are not greater than 95%significance level,and we thought that the ionosphere would be not affected by the QBO signal.