2013年平流层爆发性增温期间高纬电离层半日潮汐波研究

基于Sondrestrom站(67°N, 51°W)非相干散射雷达观测数据, 研究了2013年平流层爆发性增温(SSW)事件发生后高纬地区电离层F层和E层半日潮汐波.同时, 对1月非SSW发生期间和不同太阳活动期间高纬电离层中的半日潮汐波进行了统计分析, 并和2013年SSW事件发生后的结果进行了比较.研究发现, SSW发生后F层经向风中的半日潮汐波有显著增强, 其振幅大于80 m·s^-1的时间持续了至少60 h, 最大值达到109 m·s^-1.在180~330 km范围内, 半日潮汐波振幅平均大了24 m·s^-1.在E层高度上, 经向风中的半日潮汐波也在SSW发生后迅速增强, 最大值达到109 m·s^-1, 在108~117 km范围内, 其振幅平均大了33 m·s^-1.在E层纬向风中, 半日潮汐波振幅在120 km处连续超过36 h的时间内大于70 m·s^-1, 最大值达到92 m·s^-1.不同太阳活动期间的半日潮汐波统计结果显示, 和低太阳活动期间相比, 高太阳活动期间半日潮汐波在F层和E层平均增强14 m·s^-1.这明显小于SSW期间24和33 m·s^-1的增幅, 表明高太阳活动不是2013年SSW期间高纬电离层半日潮汐波增强的主要原因.我们的研究表明2013年高纬电离层半日潮汐波的增强很可能是受到SSW事件的影响.

Study of the ionospheric semidiurnal tides at high latitude during the sudden stratospheric warming event in 2013

Based on the observations from the Sondrestrom (67°N, 51°W) incoherent scatter radar, we present a study of the semidiurnal tides (SDTs) in the F and E regions after onset of a sudden stratospheric warming (SSW) event in January 2013.A statistical analysis during non-SSW periods and under different solar activities is also presented.The statistical results are further compared with the results after the SSW event in 2013.After the occurrence of the 2013 SSW, the F region SDT amplitude in the meridional wind increases dramatically.The maximum amplitude of the SDT is 109 m·s-1 and the amplitude is greater than 80 m·s-1 for more than 60 hours.In an altitude range from 180 to 330 km, the SDT amplitude during the SSW increases 24 m·s-1 on average.In the E region, the SDT amplitude in the meridional wind increases rapidly with a maximum value of 109 m·s-1.The SDT amplitude during the SSW increases 33 m·s-1 on average between 108 and 117 km.At 120 km, the SDT amplitude in the zonal wind is greater than 70 m·s-1 for more than 36 hours continuously, and the maximum is 92 m·s-1.The statistical results of the SDT amplitude under different solar activities suggest that compared with the low solar activity period, the amplitude during the high solar activity period has an average increase of 14 m·s-1 in the F and E regions. This is significantly smaller than the increase of 24 and 33 m·s-1 during the 2013 SSW, indicating that high solar activity is not the main reason for the enhancement of the SDT amplitude after the onset of the 2013 SSW. Our analysis suggests that the enhancement of the ionospheric SDTs in the high latitudes is very likely affected by the 2013 SSW.