中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Long- and Short-term Variability of Galactic Cosmic-Ray Radial Intensity Gradients between 1 and 9.5 au: Observations by Cassini, BESS, BESS-Polar, PAMELA, and AMS-02

文献类型:期刊论文

作者Roussos, Elias4; Dialynas, Konstantinos3; Krupp, Norbert4; Kollmann, Peter2; Paranicas, Christopher2; Roelof, Edmond C.2; Yuan, Chongjing1; Mitchell, Donald G.2; Krimigis, Stamatios M.2,3
刊名ASTROPHYSICAL JOURNAL
出版日期2020-12-01
卷号904期号:2页码:15
ISSN号0004-637X
关键词Galactic cosmic rays Heliosphere Outer planets Solar cycle
DOI10.3847/1538-4357/abc346
英文摘要Spatial gradients of galactic cosmic-ray (GCR) fluxes are important for studying charged particle transport in the heliosphere. Little is known so far about how these gradients evolve with time. Here we present how the radial gradient (G(r)) evolves between 2006 January and 2017 September using Cassini measurements of >300 MeV protons, which we combine with proton spectra obtained by advanced observatories at Earth (BESS, BESS-Polar, PAMELA, and AMS-02). All gradient calculations were performed for a nearly constant heliocentric distance of Cassini from Earth's orbit and near the ecliptic, thus revealing only how G(r) changes with time. The variability patterns of G(r) are well established as they rely on a single data set for similar to 9.5 au and accurately cross-calibrated GCR spectra for Earth at 1 au. We show that over solar-cycle timescales, G(r) is regulated by both the polarity of the solar magnetic field and the solar-cycle phase. During the negative-polarity phase (A < 0, 2006-2014), gradients are stronger and more stable with an average of G(r) = 3.5 0.3%/au and with evidence of a minimum around the 2009 solar minimum. The gradient peaks at similar to 4%/au around the solar maximum and subsequently experiences a gradual drop to similar to 2%/au in the A > 0 phase (2014-2017). Regular G(r) enhancements over yearly or biennial timescales are also observed, in phase with quasi-biennial oscillations in GCR intensity. While all aforementioned results are based on Cassini measurements that are integral in energy, they are most representative for GCR protons in the low gigaelectronvolt range.
WOS关键词ENERGETIC PARTICLE OBSERVATIONS ; HELIOSPHERIC MODULATION ; CYCLE DEPENDENCE ; HELIUM SPECTRA ; SOLAR-WIND ; VOYAGER 2 ; MAGNETOSPHERE ; INSTRUMENT ; 1.3-YEAR ; JUPITER
资助项目German Space Agency (DLR)[50 OH 1101] ; German Space Agency (DLR)[50 OH 1502] ; Max Planck Society ; NASA[18-DRIVE18 2-0029] ; NASA[80NSSC20K0603]
WOS研究方向Astronomy & Astrophysics
语种英语
出版者IOP PUBLISHING LTD
WOS记录号WOS:000594983200001
资助机构German Space Agency (DLR) ; German Space Agency (DLR) ; Max Planck Society ; Max Planck Society ; NASA ; NASA ; German Space Agency (DLR) ; German Space Agency (DLR) ; Max Planck Society ; Max Planck Society ; NASA ; NASA ; German Space Agency (DLR) ; German Space Agency (DLR) ; Max Planck Society ; Max Planck Society ; NASA ; NASA ; German Space Agency (DLR) ; German Space Agency (DLR) ; Max Planck Society ; Max Planck Society ; NASA ; NASA
源URL[http://ir.iggcas.ac.cn/handle/132A11/98658]  
专题地质与地球物理研究所_中国科学院地球与行星物理重点实验室
通讯作者Roussos, Elias
作者单位1.Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China
2.Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA
3.Acad Athens, Off Space Res & Technol, Athens, Greece
4.Max Planck Inst Solar Syst Res, Justus Von Liebig Weg 3, D-37077 Gottingen, Germany
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GB/T 7714
Roussos, Elias,Dialynas, Konstantinos,Krupp, Norbert,et al. Long- and Short-term Variability of Galactic Cosmic-Ray Radial Intensity Gradients between 1 and 9.5 au: Observations by Cassini, BESS, BESS-Polar, PAMELA, and AMS-02[J]. ASTROPHYSICAL JOURNAL,2020,904(2):15.
APA Roussos, Elias.,Dialynas, Konstantinos.,Krupp, Norbert.,Kollmann, Peter.,Paranicas, Christopher.,...&Krimigis, Stamatios M..(2020).Long- and Short-term Variability of Galactic Cosmic-Ray Radial Intensity Gradients between 1 and 9.5 au: Observations by Cassini, BESS, BESS-Polar, PAMELA, and AMS-02.ASTROPHYSICAL JOURNAL,904(2),15.
MLA Roussos, Elias,et al."Long- and Short-term Variability of Galactic Cosmic-Ray Radial Intensity Gradients between 1 and 9.5 au: Observations by Cassini, BESS, BESS-Polar, PAMELA, and AMS-02".ASTROPHYSICAL JOURNAL 904.2(2020):15.

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来源:地质与地球物理研究所

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