基于GPS TEC的2022年1月15日汤加火山喷发激起的电离层行扰分析

Analysis of ionospheric disturbance induced by Tonga volcanic eruption on January 15,2022 based on GPS TEC

2022年1月15日南太平洋汤加海底火山发生剧烈喷发,是近30年来最大规模的火山爆发,产生的强烈大气波动为开展火山喷发电离层扰动研究提供了难得的机会。本文利用GPS数据探测火山附近、新西兰、澳大利亚和中国地区的电离层扰动,从波形、频率、传播速度和时空分布等角度分析汤加火山喷发电离层行扰(TIDs)的特征,并利用电离层测高站、海平面监测站和大气压监测站的观测数据进一步验证TIDs的传播特征。研究结果发现,汤加火山喷发在其附近区域、新西兰、澳大利亚和中国地区引起了3类TIDs。在火山附近东、西、南、北方向上均探测到第一类TIDs, TIDs的传播速度为617~972 m/s,该类TIDs极有可能由火山喷发产生的声波引起。汤加火山喷发仅在火山附近东、西方向引起第二类TIDs,其传播速度分别为472 m/s和418 m/s,可能由声波传播过程中衍生的声重力波或者混合波引起,形成机理有待进一步研究。汤加火山喷发在新西兰、澳大利亚和中国地区引发了第三类TIDs,其传播速度为328~352 m/s,该类TIDs与Lamb波密切相关。

On January 15,2022,the Tonga undersea volcano in the South Pacific Ocean erupted violently,which was the largest volcanic eruption in the past 30 years and produced strong atmospheric fluctuations,providing a rare opportunity for the study of volcanic ionospheric disturbances.Ionospheric disturbances caused by volcanic eruptions are calculated using GPS data near volcanoes,New Zealand,Australia and China,and the characteristics of traveling ionospheric disturbances(TIDs)were analyzed in terms of waveform,frequency,propagation speed and space-time distribution.The ionosonde,sea level monitoring and atmospheric pressure monitoring data are used to further analyze the propagation characteristics of TIDs.The results indicate that the eruption of the Tonga volcano has caused three types of TID in its vicinity:New Zealand,Australia and China.The first type of TIDs were detected in the vicinity of the volcano in the east,west,south and north directions,with a propagation speed of approximately 617~972 m/s.This type of TIDs is highly likely caused by sound waves generated by volcanic eruptions.The Tonga volcanic eruption only causes the second type of TIDs in the east and west directions near the volcano,and its propagation speed is about 472 m/s and 418 m/s,which may be caused by acoustic gravity waves or mixed waves derived from sound waves.The formation mechanism of the second type of TIDs needs further study.The Tonga volcanic eruption triggered the third type of TIDs in New Zealand,Australia and China,with a propagation velocity of about 328~352 m/s.This type of TIDs is closely related to Lamb waves.