XIANG Zheng,
LIN XianHao,
CHEN Wei et al
.2021.Global morphology of NWC and NAA very-low-frequency transmitter signals in the inner magnetosphere: A survey using Van Allen Probes EMFISIS measurements Chinese Journal of Geophysics(in Chinese),64(11): 3860-3869,doi: 10.6038/cjg2021P0131
基于范阿伦双星EMFISIS观测数据的NWC和NAA人工甚低频台站信号的内磁层全球统计分布
项正, 林显浩, 陈薇, 王勇, 陆鹏, 龚文颖, 马文琛, 花漫, 刘阳希子
武汉大学电子信息学院空间物理系, 武汉 430072
Global morphology of NWC and NAA very-low-frequency transmitter signals in the inner magnetosphere: A survey using Van Allen Probes EMFISIS measurements
XIANG Zheng, LIN XianHao, CHEN Wei, WANG Yong, LU Peng, GONG WenYing, MA WenChen, HUA Man, LIU YangXiZi
Department of Space Physics, School of Electronic Information, Wuhan University, Wuhan 430072, China
Abstract：Signals from ground-based artificial VLF transmitters can penetrate through the ionosphere and leak into the Earth's magnetosphere, leading to inner radiation belt electrons precipitation into the atmosphere. It is of great scientific significance to study the global spatial distribution characteristics of VLF transmitter signals for analyzing the loss of radiation belt electrons. In this study, using 6 years high-quality wave measurements from Van Allen Probes during 2013-2018, we investigate the global distribution characteristics of NWC (19.8 kHz) and NAA (24.0 kHz) transmitter signals in detail, and systematically analyze the dependences of the transmitter signals distribution on the geographic latitude and longitude, L-shell, MLT, and geomagnetic activity level. The results suggest that the VLF transmitter signals in the inner magnetosphere mainly propagate along the magnetic field line across the station position. The averaged wave power intensities peak on the nightside of the Earth, and become more intensive in the winter months. The electron density is lower in the nightside and winter due to reduced sunlight, thus more wave powers leak into the magnetosphere. Meanwhile, the geomagnetic activities have slight influences on the global distributions of VLF transmitter signals. Based on these statistical observations, we obtain the global distribution characteristics of NWC and NAA transmitter signals intensities, which provide key information for further analysis of the wave-particles interactions between the VLF signals and radiation belt electrons.
Abel B, Thorne R M. 1998. Electron scattering loss in Earth's inner magnetosphere:2. Sensitivity to model parameters. Journal of Geophysical Research:Space Physics, 103(A2):2397-2407, doi:10.1029/97JA02920. Agapitov O V, Artemyev A V, Mourenas D, et al. 2014. Inner belt and slot region electron lifetimes and energization rates based on AKEBONO statistics of whistler waves. Journal of Geophysical Research:Space Physics, 119(4):2876-2893, doi:10.1002/2014JA019886. Albert J M, Starks M J, Selesnick R S, et al. 2020. VLF transmitters and lightning-generated whistlers:2. Diffusion of radiation belt electrons. Journal of Geophysical Research:Space Physics, 125(3):e2019JA027030, doi:10.1029/2019JA027030. Baker D N, Kanekal S G, Horne R B, et al. 2007. Low-altitude measurements of 2-6 MeV electron trapping lifetimes at 1.5 ≤ L ≤ 2.5. Geophysical Research Letters, 34(20):L20110, doi:10.1029/2007GL031007. Cao X, Ni B B, Summers D, et al. 2020. Hot plasma effects on the pitch-angle scattering rates of radiation belt electrons due to plasmaspheric hiss. The Astrophysical Journal, 896(2):118, doi:10.3847/1538-4357/ab9107. Chen Y P, Yang G B, Ni B B, et al. 2016. Development of ground-based ELF/VLF receiver system in Wuhan and its first results. Advances in Space Research, 57(9):1871-1880, doi:10.1016/j.asr.2016.01.023. Chen Y P, Ni B B, Gu X D, et al. 2017. First observations of low latitude whistlers using WHU ELF/VLF receiver system. Science China-Technological Sciences, 60(1):166-174, doi:10.1007/s11431-016-6103-5. Claudepierre S G, Ma Q, Bortnik J, et al. 2020. Empirically estimated electron lifetimes in the Earth's radiation belts:Comparison with theory. Geophysical Research Letters, 47(3):e2019GL086056, doi:10.1029/2019GL086056. Clilverd M A, Horne R B. 1996. Ground-based evidence of latitude-dependent cyclotron absorption of whistler mode signals originating from VLF transmitters. Journal of Geophysical Research:Space Physics, 101(A2):2355-2367, doi:10.1029/95JA03153. Clilverd M A, Rodger C J, Nunn D. 2004. Radiation belt electron precipitation fluxes associated with lightning. Journal of Geophysical Research:Space Physics, 109(A12):A12208, doi:10.1029/2004JA010644. Cunningham G S, Botek E, Pierrard V, et al. 2020. Observation of high-energy electrons precipitated by NWC transmitter from PROBA-V low-Earth orbit satellite. Geophysical Research Letters, 47(16):e2020GL089077, doi:10.1029/2020GL089077. Fu S, Yi J, Ni B B, et al. 2020. Combined scattering of radiation belt electrons by low-frequency hiss:Cyclotron, Landau, and bounce resonances. Geophysical Research Letters, 47(5):e2020GL086963, doi:10.1029/2020GL086963. Gamble R J, Rodger C J, Clilverd M A, et al. 2008. Radiation belt electron precipitation by man-made VLF transmissions. Journal of Geophysical Research:Space Physics, 113(A10):A10211, doi:10.1029/2008JA013369. Graf K L, Inan U S, Piddyachiy D, et al. 2009. DEMETER observations of transmitter-induced precipitation of inner radiation belt electrons. Journal of Geophysical Research:Space Physics, 114(A7):A07205, doi:10.1029/2008JA013949. Green A, Li W, Ma Q, et al. 2020. Properties of lightning generated whistlers based on Van Allen Probes observations and their global effects on radiation belt electron loss. Geophysical Research Letters, 47(17):e2020GL089584, doi:10.1029/2020GL089584. Gu X D, Yin Q, Ni B B, et al. 2017a. A statistical analysis of the global distribution of inner magnetospheric lower-band chorus waves based on Van Allen Probes EMFISIS observations. Chinese Journal of Geophysics (in Chinese), 60(4):1249-1258, doi:10.6038/cjg20170401. Gu X D, Yin Q, Zhou R X, et al. 2017b. A statistical analysis of the global distribution of inner magnetospheric upper-band chorus waves based on Van Allen Probes EMFISIS observations. Chinese Journal of Geophysics (in Chinese), 60(4):1259-1267, doi:10.6038/cjg20170402. Gu X D, Xia S J, Fu S, et al. 2020. Dynamic responses of radiation belt electron fluxes to magnetic storms and their correlations with magnetospheric plasma wave activities. The Astrophysical Journal, 891(2):127, doi:10.3847/1538-4357/ab71fc. Hua M, Li W, Ni B B, et al. 2020. Very-Low-Frequency transmitters bifurcate energetic electron belt in near-earth space. Nature Communications, 11:4847, doi:10.1038/s41467-020-18545-y. Hua M, Ni B B, Li W, et al. 2021. Statistical distribution of bifurcation of Earth's inner energetic electron belt at tens of keV. Geophysical Research Letters, 48(3):e2020GL091242, doi:10.1029/2020GL091242. Imhof W L, Reagan J B, Voss H D, et al. 1983. Direct observation of radiation belt electrons precipitated by the controlled injection of VLF signals from a ground-based transmitter. Geophysical Research Letters, 10(4):361-364, doi:10.1029/GL010i004p00361. Inan U S, Chang H C, Helliwell R A, et al. 1985. Precipitation of radiation belt electrons by man-made waves:A comparison between theory and measurement. Journal of Geophysical Research:Space Physics, 90(A1):359-369, doi:10.1029/JA090iA01p00359. Koons H C, Edgar B C, Vampola A L. 1981. Precipitation of inner zone electrons by whistler mode waves from the VLF transmitters UMS and NWC. Journal of Geophysical Research:Space Physics, 86(A2):640-648, doi:10.1029/JA086iA02p00640. Kulkarni P, Inan U S, Bell T F, et al. 2008. Precipitation signatures of ground-based VLF transmitters. Journal of Geophysical Research:Space Physics, 113(A7):A07214, doi:10.1029/2007JA012569. Li W, Ma Q, Thorne R M, et al. 2015. Statistical properties of plasmaspheric hiss derived from Van Allen Probes data and their effects on radiation belt electron dynamics. Journal of Geophysical Research:Space Physics, 120(5):3393-3405, doi:10.1002/2015JA021048. Ma Q, Mourenas D, Li W, et al. 2017. VLF waves from ground-based transmitters observed by the Van Allen Probes:Statistical model and effects on plasmaspheric electrons. Geophysical Research Letters, 44(13):6483-6491, doi:10.1002/2017GL073885. Ma Q L, Li W, Thorne R M, et al. 2016. Electron scattering by magnetosonic waves in the inner magnetosphere. Journal of Geophysical Research:Space Physics, 121(1):274-285, doi:10.1002/2015JA021992. Ma X, Xiang Z, Ni B B, et al. 2020. On the loss mechanisms of radiation belt electron dropouts during the 12 September 2014 geomagnetic storm. Earth and Planetary Physics, 4(6):598-610, doi:10.26464/epp2020060. Meredith N P, Horne R B, Clilverd M A, et al. 2019. An investigation of VLF transmitter wave power in the inner radiation belt and slot region. Journal of Geophysical Research:Space Physics, 124(7):5246-5259, doi:10.1029/2019JA026715. Ni B B, Bortnik J, Thorne R M, et al. 2013. Resonant scattering and resultant pitch angle evolution of relativistic electrons by plasmaspheric hiss. Journal of Geophysical Research:Space Physics, 118(12):7740-7751, doi:10.1002/2013JA019260. Ni B B, Li W, Thorne R M, et al. 2014. Resonant scattering of energetic electrons by unusual low-frequency hiss. Geophysical Research Letters, 41(6):1854-1861, doi:10.1002/2014GL059389. Ni B B, Hua M, Zhou R X, et al. 2017. Competition between outer zone electron scattering by plasmaspheric hiss and magnetosonic waves. Geophysical Research Letters, 44(8):3465-3474, doi:10.1002/2017GL072989. Ni B B, Huang H, Zhang W X, et al. 2019. Parametric sensitivity of the formation of reversed electron energy spectrum caused by plasmaspheric hiss. Geophysical Research Letters, 46(8):4134-4143, doi:10.1029/2019GL082032. Ross J P J, Meredith N P, Glauert S A, et al. 2019. Effects of VLF transmitter waves on the inner belt and slot region. Journal of Geophysical Research:Space Physics, 124(7):5260-5277, doi:10.1029/2019JA026716. Sauvaud J A, Maggiolo R, Jacquey C, et al. 2008. Radiation belt electron precipitation due to VLF transmitters:Satellite observations. Geophysical Research Letters, 35(9):L09101, doi:10.1029/2008GL033194. Selesnick R S, Albert J M, Starks M J. 2013. Influence of a ground-based VLF radio transmitter on the inner electron radiation belt. Journal of Geophysical Research:Space Physics, 118(2):628-635, doi:10.1002/jgra.50095. Vampola A L, Kuck G A. 1978. Induced precipitation of inner zone electrons, 1. Observations. Journal of Geophysical Research:Space Physics, 83(A6):2543-2551, doi:10.1029/JA083iA06p02543. Xia Z Y, Chen L J, Zhima Z, et al. 2020. Spectral broadening of NWC transmitter signals in the ionosphere. Geophysical Research Letters, 47(13):e2020GL088103, doi:10.1029/2020GL088103. Xiang Z, Tu W C, Li X L, et al. 2017. Understanding the mechanisms of radiation belt dropouts observed by Van Allen Probes. Journal of Geophysical Research:Space Physics, 122(10):9858-9879, doi:10.1002/2017JA024487. Xiang Z, Tan J Q, Ni B B, et al. 2017. A statistical analysis of the global distribution of plasmaspheric hiss based on Van Allen Probes wave observations. Acta Physica Sinica (in Chinese), 66(3):039401, doi:10.7498/aps.66.039401. Xiang Z, Tu W C, Ni B B, et al. 2018. A statistical survey of radiation belt dropouts observed by Van Allen Probes. Geophysical Research Letters, 45(16):8035-8043, doi:10.1029/2018GL078907. Xiang Z, Li X L, Temerin M A, et al. 2020a. On energetic electron dynamics during geomagnetic quiet times in Earth's inner radiation belt due to atmospheric collisional loss and CRAND as a source. Journal of Geophysical Research:Space Physics, 125(2):e2019JA027678, doi:10.1029/2019JA027678. Xiang Z, Li X L, Ni B B, et al. 2020b. Dynamics of energetic electrons in the slot region during geomagnetically quiet times:Losses due to wave-particle interactions versus a source from cosmic ray albedo neutron decay (CRAND). Journal of Geophysical Research:Space Physics, 125(9):e2020JA028042, doi:10.1029/2020JA028042. Yi J, Gu X D, Li Z P, et al. 2019. Modeling and analysis of NWC signal propagation amplitude based on LWPC and IRI models. Chinese Journal of Geophysics (in Chinese), 62(9):3223-3234, doi:10.6038/cjg2019N0190. Yi J, Gu X D, Cheng W, et al. 2020. A detailed investigation of low latitude tweek atmospherics observed by the WHU ELF/VLF receiver:2. Occurrence features and associated ionospheric parameters. Earth and Planetary Physics, 4(3):238-245, doi:10.26464/epp2020023. Zhou R X, Gu X D, Yang K X, et al. 2020. A detailed investigation of low latitude tweek atmospherics observed by the WHU ELF/VLF receiver:1. Automatic detection and analysis method. Earth and Planetary Physics, 4(2):120-130, doi:10.26464/epp2020018. 附中文参考文献 顾旭东, 殷倩, 倪彬彬等. 2017a. 基于Van Allen Probes EMFISIS波动仪器观测的内磁层下频带哨声合声波全球分布的统计分析. 地球物理学报, 60(4):1249-1258, doi:10.6038/cjg20170401. 顾旭东, 殷倩, 周若贤等. 2017b. 基于Van Allen Probes EMFISIS波动仪器观测的内磁层上频带哨声合声波全球分布的统计分析. 地球物理学报, 60(4):1259-1267, doi:10.6038/cjg20170402. 项正, 谈家强, 倪彬彬等. 2017. 基于范阿伦卫星观测数据的等离子体层嘶声全球分布的统计分析. 物理学报, 66(3):039401, doi:10.7498/aps.66.039401. 易娟, 顾旭东, 李志鹏等. 2019. 基于LWPC和IRI模型的NWC台站信号传播幅度建模分析. 地球物理学报, 62(9):3223-3234, doi:10.6038/cjg2019N0190.
| 
