The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cos...The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cosmic ray albedo neutron decay(CRAND),radial diffusion, and local acceleration have been considered principal sources of electrons, whereas protons are predominantly from CRAND and solar protons. In this article, lightning-induced neutrons from Earth's upper atmosphere are suggested as a possible source of protons and electrons in the inner radiation belt. These terrestrial neutrons can contribute to the inner belt population by undergoing nuclear decay. Several approaches are proposed and discussed to evaluate the potential contribution of lightning-induced neutrons to the inner belt, including magnitude estimation, Monte Carlo simulations, and in situ observations. This article discusses some avenues of further study to determine the contribution of lightning-induced neutrons to the inner radiation belt.展开更多
The Van Allen radiation belts are an extraordinary science discovery in the Earth magnetosphere and consist of two electron belts.The inner Van Allen belt contains electrons of 10s to 100s keV;the outer belt consists ...The Van Allen radiation belts are an extraordinary science discovery in the Earth magnetosphere and consist of two electron belts.The inner Van Allen belt contains electrons of 10s to 100s keV;the outer belt consists mainly of 0.1-10 MeV electrons.Their dynamics have been analyzed for decades.The newly-launched Van Allen Probes provide unprecedented opportunities to investigate the inner belt more thoroughly.Data from this advanced mission have allowed scientists to demonstrate that the inner belt was formed not only through inward transport of outer belt electrons but Cosmic Ray Albedo Neutron Decay(CRAND)has also played an important role.In addition,the inner belt electrons show energy-dependent variations and present“zebra stripe”structures in the energy spectrum.At the same time,scientists have further confirmed that the electrons in the inner radiation belt get lost through coulomb collision and wave-particle interaction.Despite these advances,important questions remain unanswered and require further investigation.The launch of Macao Science Satellite-1 mission,with its low inclination angle and low altitude orbit,will provide advanced radiation belt data for better understanding of the structure and dynamics of the inner electron radiation belt.展开更多
The Macao Science Satellite-1(MSS-1),designed by the Macao University of Science and Technology and the National Space Science Center(NSSC)of China,is equipped to detect the fine structure of the magnetic field over t...The Macao Science Satellite-1(MSS-1),designed by the Macao University of Science and Technology and the National Space Science Center(NSSC)of China,is equipped to detect the fine structure of the magnetic field over the South Atlantic Anomaly(SAA)region,monitoring geomagnetic field variations,and obtaining the energetic electron spectrum distributions in the Earth’s inner radiation belt.In this study,we simulate the distributions of trapped,quasi-trapped,and untrapped electrons along the orbit of MSS-1 based on a drift-source model.The simulation results show that the particle detector with 90°looking direction can observe trapped electrons in the SAA region,untrapped electrons in the regions conjugated with the SAA region at the north hemisphere,and quasitrapped electrons in all other regions.In contrast,the detectors with<60°looking directions can measure only untrapped electrons.Generally,quasi-trapped electron fluxes accumulate along the drift trajectory and are due primarily to CRAND,until reaching the SAA region where quasi-trapped electrons are all lost into the atmosphere.展开更多
基金supported by the National Natural Science Foundation of China (No. 42225405 and No. 42350710200)。
文摘The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cosmic ray albedo neutron decay(CRAND),radial diffusion, and local acceleration have been considered principal sources of electrons, whereas protons are predominantly from CRAND and solar protons. In this article, lightning-induced neutrons from Earth's upper atmosphere are suggested as a possible source of protons and electrons in the inner radiation belt. These terrestrial neutrons can contribute to the inner belt population by undergoing nuclear decay. Several approaches are proposed and discussed to evaluate the potential contribution of lightning-induced neutrons to the inner belt, including magnitude estimation, Monte Carlo simulations, and in situ observations. This article discusses some avenues of further study to determine the contribution of lightning-induced neutrons to the inner radiation belt.
基金supported by NSFC research grant 41974191China National Space Administration project D020303the National Key R&D Program of China 2020YFE0202100。
文摘The Van Allen radiation belts are an extraordinary science discovery in the Earth magnetosphere and consist of two electron belts.The inner Van Allen belt contains electrons of 10s to 100s keV;the outer belt consists mainly of 0.1-10 MeV electrons.Their dynamics have been analyzed for decades.The newly-launched Van Allen Probes provide unprecedented opportunities to investigate the inner belt more thoroughly.Data from this advanced mission have allowed scientists to demonstrate that the inner belt was formed not only through inward transport of outer belt electrons but Cosmic Ray Albedo Neutron Decay(CRAND)has also played an important role.In addition,the inner belt electrons show energy-dependent variations and present“zebra stripe”structures in the energy spectrum.At the same time,scientists have further confirmed that the electrons in the inner radiation belt get lost through coulomb collision and wave-particle interaction.Despite these advances,important questions remain unanswered and require further investigation.The launch of Macao Science Satellite-1 mission,with its low inclination angle and low altitude orbit,will provide advanced radiation belt data for better understanding of the structure and dynamics of the inner electron radiation belt.
基金supported by the National Natural Science Foundation of China(Grant Nos.42188101,42174190,42025404,41904143,41974186,and 41904144)the Fundamental Research Funds for the Central Universities(2042021kf0016)+2 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)the pre-research projects on Civil Aerospace Technologies funded by the China National Space Administration(Grant Nos.D020303,D020308,D020104)the China Postdoctoral Science Foundation Project(Grant No.2019M662700,2020M672405)。
文摘The Macao Science Satellite-1(MSS-1),designed by the Macao University of Science and Technology and the National Space Science Center(NSSC)of China,is equipped to detect the fine structure of the magnetic field over the South Atlantic Anomaly(SAA)region,monitoring geomagnetic field variations,and obtaining the energetic electron spectrum distributions in the Earth’s inner radiation belt.In this study,we simulate the distributions of trapped,quasi-trapped,and untrapped electrons along the orbit of MSS-1 based on a drift-source model.The simulation results show that the particle detector with 90°looking direction can observe trapped electrons in the SAA region,untrapped electrons in the regions conjugated with the SAA region at the north hemisphere,and quasitrapped electrons in all other regions.In contrast,the detectors with<60°looking directions can measure only untrapped electrons.Generally,quasi-trapped electron fluxes accumulate along the drift trajectory and are due primarily to CRAND,until reaching the SAA region where quasi-trapped electrons are all lost into the atmosphere.
