Large-amplitude Bidirectional Anisotropy of Cosmic-Ray Intensity Observed with Worldwide Networks of Ground-based Neutron Monitors and Muon Detectors in 2021 November
We analyze the cosmic-ray variations during a significant Forbush decrease observed with worldwide networks of ground-based neutron monitors and muon detectors during 2021 November 3–5. Utilizing the difference between primary cosmic-ray rigidities monitored by neutron monitors and muon detectors, w...
Gespeichert in:
| Veröffentlicht in: | The Astrophysical journal 2022-10, Vol.938 (1), p.30 |
|---|---|
| Hauptverfasser: | , , , , , , , , , , , , , , , , , , , , , , , , , , |
| Format: | Artikel |
| Sprache: | eng |
| Schlagworte: | |
| Online-Zugang: | Volltext |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| container_end_page | |
|---|---|
| container_issue | 1 |
| container_start_page | 30 |
| container_title | The Astrophysical journal |
| container_volume | 938 |
| creator | Munakata, K. Kozai, M. Kato, C. Hayashi, Y. Kataoka, R. Kadokura, A. Tokumaru, M. Mendonça, R. R. S. Echer, E. Lago, A. Dal Rockenbach, M. Schuch, N. J. Bageston, J. V. Braga, C. R. Jassar, H. K. Al Sharma, M. M. Duldig, M. L. Humble, J. E. Sabbah, I. Evenson, P. Mangeard, P.-S. Kuwabara, T. Ruffolo, D. Sáiz, A. Mitthumsiri, W. Nuntiyakul, W. Kóta, J. |
| description | We analyze the cosmic-ray variations during a significant Forbush decrease observed with worldwide networks of ground-based neutron monitors and muon detectors during 2021 November 3–5. Utilizing the difference between primary cosmic-ray rigidities monitored by neutron monitors and muon detectors, we deduce the rigidity spectra of the cosmic-ray density (or omnidirectional intensity) and the first- and second-order anisotropies separately for each hour of data. A clear two-step decrease is seen in the cosmic-ray density with the first ∼2% decrease after the interplanetary shock arrival followed by the second ∼5% decrease inside the magnetic flux rope (MFR) at 15 GV. Most strikingly, a large bidirectional streaming along the magnetic field is observed in the MFR with a peak amplitude of ∼5% at 15 GV, which is comparable to the total density decrease inside the MFR. The bidirectional streaming could be explained by adiabatic deceleration and/or focusing in the expanding MFR, which have stronger effects for pitch angles near 90°, or by selective entry of GCRs along a leg of the MFR. The peak anisotropy and density depression in the flux rope both decrease with increasing rigidity. The spectra vary dynamically, indicating that the temporal variations of density and anisotropy appear different in neutron monitor and muon detector data. |
| doi_str_mv | 10.3847/1538-4357/ac91c5 |
| format | Article |
| fullrecord | <record><control><sourceid>proquest_cross</sourceid><recordid>TN_cdi_proquest_journals_2724312928</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>2724312928</sourcerecordid><originalsourceid>FETCH-LOGICAL-c350t-64be459561adc2d0e41b2c743471c98d5e2d9bf5d2392cad3087e821ea74c5533</originalsourceid><addsrcrecordid>eNp1kUtLAzEUhYMoWB97lwG3js2zM7PU-oTagii6GzLJrUbbZEwylv4hf6czVHTl6nIP53wXzkXoiJJTXoh8SCUvMsFlPlS6pFpuocGvtI0GhBCRjXj-vIv2YnzrV1aWA_Q1UeEFMrVsFja1BvC5NTaATtY7tcBnzkafgm_W2M_x2Mel1dm9WuNbl8BFm9Z4VkcIn2DwyqZX_OTDwqxsB5pCWvnwHvvgdfCtM1mtYuebQtsRHb7zziYfIlbO4Lu2Uy4gdZd7yTrMCKN46j9hWUM4QDtztYhw-DP30ePV5cP4JpvMrm_HZ5NMc0lSNhI1CFnKEVVGM0NA0JrpXHCRU10WRgIzZT2XhvGSaWU4KXIoGAWVCy0l5_voeMNtgv9oIabqzbehayJWLGeCU1ayonORjUsHH2OAedUEu1RhXVFS9d-o-uqrvvpq840ucrKJWN_8Mf-1fwOVz43a</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>2724312928</pqid></control><display><type>article</type><title>Large-amplitude Bidirectional Anisotropy of Cosmic-Ray Intensity Observed with Worldwide Networks of Ground-based Neutron Monitors and Muon Detectors in 2021 November</title><source>IOP Publishing Free Content</source><source>DOAJ Directory of Open Access Journals</source><source>Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals</source><source>Alma/SFX Local Collection</source><creator>Munakata, K. ; Kozai, M. ; Kato, C. ; Hayashi, Y. ; Kataoka, R. ; Kadokura, A. ; Tokumaru, M. ; Mendonça, R. R. S. ; Echer, E. ; Lago, A. Dal ; Rockenbach, M. ; Schuch, N. J. ; Bageston, J. V. ; Braga, C. R. ; Jassar, H. K. Al ; Sharma, M. M. ; Duldig, M. L. ; Humble, J. E. ; Sabbah, I. ; Evenson, P. ; Mangeard, P.-S. ; Kuwabara, T. ; Ruffolo, D. ; Sáiz, A. ; Mitthumsiri, W. ; Nuntiyakul, W. ; Kóta, J.</creator><creatorcontrib>Munakata, K. ; Kozai, M. ; Kato, C. ; Hayashi, Y. ; Kataoka, R. ; Kadokura, A. ; Tokumaru, M. ; Mendonça, R. R. S. ; Echer, E. ; Lago, A. Dal ; Rockenbach, M. ; Schuch, N. J. ; Bageston, J. V. ; Braga, C. R. ; Jassar, H. K. Al ; Sharma, M. M. ; Duldig, M. L. ; Humble, J. E. ; Sabbah, I. ; Evenson, P. ; Mangeard, P.-S. ; Kuwabara, T. ; Ruffolo, D. ; Sáiz, A. ; Mitthumsiri, W. ; Nuntiyakul, W. ; Kóta, J.</creatorcontrib><description>We analyze the cosmic-ray variations during a significant Forbush decrease observed with worldwide networks of ground-based neutron monitors and muon detectors during 2021 November 3–5. Utilizing the difference between primary cosmic-ray rigidities monitored by neutron monitors and muon detectors, we deduce the rigidity spectra of the cosmic-ray density (or omnidirectional intensity) and the first- and second-order anisotropies separately for each hour of data. A clear two-step decrease is seen in the cosmic-ray density with the first ∼2% decrease after the interplanetary shock arrival followed by the second ∼5% decrease inside the magnetic flux rope (MFR) at 15 GV. Most strikingly, a large bidirectional streaming along the magnetic field is observed in the MFR with a peak amplitude of ∼5% at 15 GV, which is comparable to the total density decrease inside the MFR. The bidirectional streaming could be explained by adiabatic deceleration and/or focusing in the expanding MFR, which have stronger effects for pitch angles near 90°, or by selective entry of GCRs along a leg of the MFR. The peak anisotropy and density depression in the flux rope both decrease with increasing rigidity. The spectra vary dynamically, indicating that the temporal variations of density and anisotropy appear different in neutron monitor and muon detector data.</description><identifier>ISSN: 0004-637X</identifier><identifier>EISSN: 1538-4357</identifier><identifier>DOI: 10.3847/1538-4357/ac91c5</identifier><language>eng</language><publisher>Philadelphia: The American Astronomical Society</publisher><subject>Amplitudes ; Anisotropy ; Astrophysics ; Cosmic ray intensities ; Deceleration ; Density ; Detectors ; Forbush decreases ; Galactic cosmic rays ; Magnetic fields ; Magnetic flux ; Monitors ; Muons ; Pitch (inclination) ; Primary cosmic rays ; Rigidity ; Sensors ; Spectra</subject><ispartof>The Astrophysical journal, 2022-10, Vol.938 (1), p.30</ispartof><rights>2022. The Author(s). Published by the American Astronomical Society.</rights><rights>2022. The Author(s). Published by the American Astronomical Society. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c350t-64be459561adc2d0e41b2c743471c98d5e2d9bf5d2392cad3087e821ea74c5533</citedby><cites>FETCH-LOGICAL-c350t-64be459561adc2d0e41b2c743471c98d5e2d9bf5d2392cad3087e821ea74c5533</cites><orcidid>0000-0002-6105-9562 ; 0000-0002-0417-6877 ; 0000-0001-6584-9054 ; 0000-0002-4913-8225 ; 0000-0003-1485-9564 ; 0000-0001-7929-810X ; 0000-0003-3414-9666 ; 0000-0002-3948-3666 ; 0000-0002-2982-1887 ; 0000-0001-7771-4341 ; 0000-0002-4361-6492 ; 0000-0002-9737-9429 ; 0000-0002-3776-072X ; 0000-0002-0890-0607 ; 0000-0001-7463-8267 ; 0000-0003-2931-8488 ; 0000-0001-9400-1765 ; 0000-0002-2090-351X ; 0000-0003-4865-6968 ; 0000-0002-7720-6491 ; 0000-0002-4486-237X ; 0000-0002-7037-322X ; 0000-0002-2131-4100 ; 0000-0002-3715-0358 ; 0000-0002-8351-6779 ; 0000-0002-4698-1671 ; 0000-0002-1664-5845</orcidid></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktopdf>$$Uhttps://iopscience.iop.org/article/10.3847/1538-4357/ac91c5/pdf$$EPDF$$P50$$Giop$$Hfree_for_read</linktopdf><link.rule.ids>314,776,780,860,27901,27902,38867,53842</link.rule.ids></links><search><creatorcontrib>Munakata, K.</creatorcontrib><creatorcontrib>Kozai, M.</creatorcontrib><creatorcontrib>Kato, C.</creatorcontrib><creatorcontrib>Hayashi, Y.</creatorcontrib><creatorcontrib>Kataoka, R.</creatorcontrib><creatorcontrib>Kadokura, A.</creatorcontrib><creatorcontrib>Tokumaru, M.</creatorcontrib><creatorcontrib>Mendonça, R. R. S.</creatorcontrib><creatorcontrib>Echer, E.</creatorcontrib><creatorcontrib>Lago, A. Dal</creatorcontrib><creatorcontrib>Rockenbach, M.</creatorcontrib><creatorcontrib>Schuch, N. J.</creatorcontrib><creatorcontrib>Bageston, J. V.</creatorcontrib><creatorcontrib>Braga, C. R.</creatorcontrib><creatorcontrib>Jassar, H. K. Al</creatorcontrib><creatorcontrib>Sharma, M. M.</creatorcontrib><creatorcontrib>Duldig, M. L.</creatorcontrib><creatorcontrib>Humble, J. E.</creatorcontrib><creatorcontrib>Sabbah, I.</creatorcontrib><creatorcontrib>Evenson, P.</creatorcontrib><creatorcontrib>Mangeard, P.-S.</creatorcontrib><creatorcontrib>Kuwabara, T.</creatorcontrib><creatorcontrib>Ruffolo, D.</creatorcontrib><creatorcontrib>Sáiz, A.</creatorcontrib><creatorcontrib>Mitthumsiri, W.</creatorcontrib><creatorcontrib>Nuntiyakul, W.</creatorcontrib><creatorcontrib>Kóta, J.</creatorcontrib><title>Large-amplitude Bidirectional Anisotropy of Cosmic-Ray Intensity Observed with Worldwide Networks of Ground-based Neutron Monitors and Muon Detectors in 2021 November</title><title>The Astrophysical journal</title><addtitle>APJ</addtitle><addtitle>Astrophys. J</addtitle><description>We analyze the cosmic-ray variations during a significant Forbush decrease observed with worldwide networks of ground-based neutron monitors and muon detectors during 2021 November 3–5. Utilizing the difference between primary cosmic-ray rigidities monitored by neutron monitors and muon detectors, we deduce the rigidity spectra of the cosmic-ray density (or omnidirectional intensity) and the first- and second-order anisotropies separately for each hour of data. A clear two-step decrease is seen in the cosmic-ray density with the first ∼2% decrease after the interplanetary shock arrival followed by the second ∼5% decrease inside the magnetic flux rope (MFR) at 15 GV. Most strikingly, a large bidirectional streaming along the magnetic field is observed in the MFR with a peak amplitude of ∼5% at 15 GV, which is comparable to the total density decrease inside the MFR. The bidirectional streaming could be explained by adiabatic deceleration and/or focusing in the expanding MFR, which have stronger effects for pitch angles near 90°, or by selective entry of GCRs along a leg of the MFR. The peak anisotropy and density depression in the flux rope both decrease with increasing rigidity. The spectra vary dynamically, indicating that the temporal variations of density and anisotropy appear different in neutron monitor and muon detector data.</description><subject>Amplitudes</subject><subject>Anisotropy</subject><subject>Astrophysics</subject><subject>Cosmic ray intensities</subject><subject>Deceleration</subject><subject>Density</subject><subject>Detectors</subject><subject>Forbush decreases</subject><subject>Galactic cosmic rays</subject><subject>Magnetic fields</subject><subject>Magnetic flux</subject><subject>Monitors</subject><subject>Muons</subject><subject>Pitch (inclination)</subject><subject>Primary cosmic rays</subject><subject>Rigidity</subject><subject>Sensors</subject><subject>Spectra</subject><issn>0004-637X</issn><issn>1538-4357</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2022</creationdate><recordtype>article</recordtype><sourceid>O3W</sourceid><recordid>eNp1kUtLAzEUhYMoWB97lwG3js2zM7PU-oTagii6GzLJrUbbZEwylv4hf6czVHTl6nIP53wXzkXoiJJTXoh8SCUvMsFlPlS6pFpuocGvtI0GhBCRjXj-vIv2YnzrV1aWA_Q1UeEFMrVsFja1BvC5NTaATtY7tcBnzkafgm_W2M_x2Mel1dm9WuNbl8BFm9Z4VkcIn2DwyqZX_OTDwqxsB5pCWvnwHvvgdfCtM1mtYuebQtsRHb7zziYfIlbO4Lu2Uy4gdZd7yTrMCKN46j9hWUM4QDtztYhw-DP30ePV5cP4JpvMrm_HZ5NMc0lSNhI1CFnKEVVGM0NA0JrpXHCRU10WRgIzZT2XhvGSaWU4KXIoGAWVCy0l5_voeMNtgv9oIabqzbehayJWLGeCU1ayonORjUsHH2OAedUEu1RhXVFS9d-o-uqrvvpq840ucrKJWN_8Mf-1fwOVz43a</recordid><startdate>20221001</startdate><enddate>20221001</enddate><creator>Munakata, K.</creator><creator>Kozai, M.</creator><creator>Kato, C.</creator><creator>Hayashi, Y.</creator><creator>Kataoka, R.</creator><creator>Kadokura, A.</creator><creator>Tokumaru, M.</creator><creator>Mendonça, R. R. S.</creator><creator>Echer, E.</creator><creator>Lago, A. Dal</creator><creator>Rockenbach, M.</creator><creator>Schuch, N. J.</creator><creator>Bageston, J. V.</creator><creator>Braga, C. R.</creator><creator>Jassar, H. K. Al</creator><creator>Sharma, M. M.</creator><creator>Duldig, M. L.</creator><creator>Humble, J. E.</creator><creator>Sabbah, I.</creator><creator>Evenson, P.</creator><creator>Mangeard, P.-S.</creator><creator>Kuwabara, T.</creator><creator>Ruffolo, D.</creator><creator>Sáiz, A.</creator><creator>Mitthumsiri, W.</creator><creator>Nuntiyakul, W.</creator><creator>Kóta, J.</creator><general>The American Astronomical Society</general><general>IOP Publishing</general><scope>O3W</scope><scope>TSCCA</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7TG</scope><scope>8FD</scope><scope>H8D</scope><scope>KL.</scope><scope>L7M</scope><orcidid>https://orcid.org/0000-0002-6105-9562</orcidid><orcidid>https://orcid.org/0000-0002-0417-6877</orcidid><orcidid>https://orcid.org/0000-0001-6584-9054</orcidid><orcidid>https://orcid.org/0000-0002-4913-8225</orcidid><orcidid>https://orcid.org/0000-0003-1485-9564</orcidid><orcidid>https://orcid.org/0000-0001-7929-810X</orcidid><orcidid>https://orcid.org/0000-0003-3414-9666</orcidid><orcidid>https://orcid.org/0000-0002-3948-3666</orcidid><orcidid>https://orcid.org/0000-0002-2982-1887</orcidid><orcidid>https://orcid.org/0000-0001-7771-4341</orcidid><orcidid>https://orcid.org/0000-0002-4361-6492</orcidid><orcidid>https://orcid.org/0000-0002-9737-9429</orcidid><orcidid>https://orcid.org/0000-0002-3776-072X</orcidid><orcidid>https://orcid.org/0000-0002-0890-0607</orcidid><orcidid>https://orcid.org/0000-0001-7463-8267</orcidid><orcidid>https://orcid.org/0000-0003-2931-8488</orcidid><orcidid>https://orcid.org/0000-0001-9400-1765</orcidid><orcidid>https://orcid.org/0000-0002-2090-351X</orcidid><orcidid>https://orcid.org/0000-0003-4865-6968</orcidid><orcidid>https://orcid.org/0000-0002-7720-6491</orcidid><orcidid>https://orcid.org/0000-0002-4486-237X</orcidid><orcidid>https://orcid.org/0000-0002-7037-322X</orcidid><orcidid>https://orcid.org/0000-0002-2131-4100</orcidid><orcidid>https://orcid.org/0000-0002-3715-0358</orcidid><orcidid>https://orcid.org/0000-0002-8351-6779</orcidid><orcidid>https://orcid.org/0000-0002-4698-1671</orcidid><orcidid>https://orcid.org/0000-0002-1664-5845</orcidid></search><sort><creationdate>20221001</creationdate><title>Large-amplitude Bidirectional Anisotropy of Cosmic-Ray Intensity Observed with Worldwide Networks of Ground-based Neutron Monitors and Muon Detectors in 2021 November</title><author>Munakata, K. ; Kozai, M. ; Kato, C. ; Hayashi, Y. ; Kataoka, R. ; Kadokura, A. ; Tokumaru, M. ; Mendonça, R. R. S. ; Echer, E. ; Lago, A. Dal ; Rockenbach, M. ; Schuch, N. J. ; Bageston, J. V. ; Braga, C. R. ; Jassar, H. K. Al ; Sharma, M. M. ; Duldig, M. L. ; Humble, J. E. ; Sabbah, I. ; Evenson, P. ; Mangeard, P.-S. ; Kuwabara, T. ; Ruffolo, D. ; Sáiz, A. ; Mitthumsiri, W. ; Nuntiyakul, W. ; Kóta, J.</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c350t-64be459561adc2d0e41b2c743471c98d5e2d9bf5d2392cad3087e821ea74c5533</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2022</creationdate><topic>Amplitudes</topic><topic>Anisotropy</topic><topic>Astrophysics</topic><topic>Cosmic ray intensities</topic><topic>Deceleration</topic><topic>Density</topic><topic>Detectors</topic><topic>Forbush decreases</topic><topic>Galactic cosmic rays</topic><topic>Magnetic fields</topic><topic>Magnetic flux</topic><topic>Monitors</topic><topic>Muons</topic><topic>Pitch (inclination)</topic><topic>Primary cosmic rays</topic><topic>Rigidity</topic><topic>Sensors</topic><topic>Spectra</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Munakata, K.</creatorcontrib><creatorcontrib>Kozai, M.</creatorcontrib><creatorcontrib>Kato, C.</creatorcontrib><creatorcontrib>Hayashi, Y.</creatorcontrib><creatorcontrib>Kataoka, R.</creatorcontrib><creatorcontrib>Kadokura, A.</creatorcontrib><creatorcontrib>Tokumaru, M.</creatorcontrib><creatorcontrib>Mendonça, R. R. S.</creatorcontrib><creatorcontrib>Echer, E.</creatorcontrib><creatorcontrib>Lago, A. Dal</creatorcontrib><creatorcontrib>Rockenbach, M.</creatorcontrib><creatorcontrib>Schuch, N. J.</creatorcontrib><creatorcontrib>Bageston, J. V.</creatorcontrib><creatorcontrib>Braga, C. R.</creatorcontrib><creatorcontrib>Jassar, H. K. Al</creatorcontrib><creatorcontrib>Sharma, M. M.</creatorcontrib><creatorcontrib>Duldig, M. L.</creatorcontrib><creatorcontrib>Humble, J. E.</creatorcontrib><creatorcontrib>Sabbah, I.</creatorcontrib><creatorcontrib>Evenson, P.</creatorcontrib><creatorcontrib>Mangeard, P.-S.</creatorcontrib><creatorcontrib>Kuwabara, T.</creatorcontrib><creatorcontrib>Ruffolo, D.</creatorcontrib><creatorcontrib>Sáiz, A.</creatorcontrib><creatorcontrib>Mitthumsiri, W.</creatorcontrib><creatorcontrib>Nuntiyakul, W.</creatorcontrib><creatorcontrib>Kóta, J.</creatorcontrib><collection>IOP Publishing Free Content</collection><collection>IOPscience (Open Access)</collection><collection>CrossRef</collection><collection>Meteorological & Geoastrophysical Abstracts</collection><collection>Technology Research Database</collection><collection>Aerospace Database</collection><collection>Meteorological & Geoastrophysical Abstracts - Academic</collection><collection>Advanced Technologies Database with Aerospace</collection><jtitle>The Astrophysical journal</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Munakata, K.</au><au>Kozai, M.</au><au>Kato, C.</au><au>Hayashi, Y.</au><au>Kataoka, R.</au><au>Kadokura, A.</au><au>Tokumaru, M.</au><au>Mendonça, R. R. S.</au><au>Echer, E.</au><au>Lago, A. Dal</au><au>Rockenbach, M.</au><au>Schuch, N. J.</au><au>Bageston, J. V.</au><au>Braga, C. R.</au><au>Jassar, H. K. Al</au><au>Sharma, M. M.</au><au>Duldig, M. L.</au><au>Humble, J. E.</au><au>Sabbah, I.</au><au>Evenson, P.</au><au>Mangeard, P.-S.</au><au>Kuwabara, T.</au><au>Ruffolo, D.</au><au>Sáiz, A.</au><au>Mitthumsiri, W.</au><au>Nuntiyakul, W.</au><au>Kóta, J.</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Large-amplitude Bidirectional Anisotropy of Cosmic-Ray Intensity Observed with Worldwide Networks of Ground-based Neutron Monitors and Muon Detectors in 2021 November</atitle><jtitle>The Astrophysical journal</jtitle><stitle>APJ</stitle><addtitle>Astrophys. J</addtitle><date>2022-10-01</date><risdate>2022</risdate><volume>938</volume><issue>1</issue><spage>30</spage><pages>30-</pages><issn>0004-637X</issn><eissn>1538-4357</eissn><abstract>We analyze the cosmic-ray variations during a significant Forbush decrease observed with worldwide networks of ground-based neutron monitors and muon detectors during 2021 November 3–5. Utilizing the difference between primary cosmic-ray rigidities monitored by neutron monitors and muon detectors, we deduce the rigidity spectra of the cosmic-ray density (or omnidirectional intensity) and the first- and second-order anisotropies separately for each hour of data. A clear two-step decrease is seen in the cosmic-ray density with the first ∼2% decrease after the interplanetary shock arrival followed by the second ∼5% decrease inside the magnetic flux rope (MFR) at 15 GV. Most strikingly, a large bidirectional streaming along the magnetic field is observed in the MFR with a peak amplitude of ∼5% at 15 GV, which is comparable to the total density decrease inside the MFR. The bidirectional streaming could be explained by adiabatic deceleration and/or focusing in the expanding MFR, which have stronger effects for pitch angles near 90°, or by selective entry of GCRs along a leg of the MFR. The peak anisotropy and density depression in the flux rope both decrease with increasing rigidity. The spectra vary dynamically, indicating that the temporal variations of density and anisotropy appear different in neutron monitor and muon detector data.</abstract><cop>Philadelphia</cop><pub>The American Astronomical Society</pub><doi>10.3847/1538-4357/ac91c5</doi><tpages>11</tpages><orcidid>https://orcid.org/0000-0002-6105-9562</orcidid><orcidid>https://orcid.org/0000-0002-0417-6877</orcidid><orcidid>https://orcid.org/0000-0001-6584-9054</orcidid><orcidid>https://orcid.org/0000-0002-4913-8225</orcidid><orcidid>https://orcid.org/0000-0003-1485-9564</orcidid><orcidid>https://orcid.org/0000-0001-7929-810X</orcidid><orcidid>https://orcid.org/0000-0003-3414-9666</orcidid><orcidid>https://orcid.org/0000-0002-3948-3666</orcidid><orcidid>https://orcid.org/0000-0002-2982-1887</orcidid><orcidid>https://orcid.org/0000-0001-7771-4341</orcidid><orcidid>https://orcid.org/0000-0002-4361-6492</orcidid><orcidid>https://orcid.org/0000-0002-9737-9429</orcidid><orcidid>https://orcid.org/0000-0002-3776-072X</orcidid><orcidid>https://orcid.org/0000-0002-0890-0607</orcidid><orcidid>https://orcid.org/0000-0001-7463-8267</orcidid><orcidid>https://orcid.org/0000-0003-2931-8488</orcidid><orcidid>https://orcid.org/0000-0001-9400-1765</orcidid><orcidid>https://orcid.org/0000-0002-2090-351X</orcidid><orcidid>https://orcid.org/0000-0003-4865-6968</orcidid><orcidid>https://orcid.org/0000-0002-7720-6491</orcidid><orcidid>https://orcid.org/0000-0002-4486-237X</orcidid><orcidid>https://orcid.org/0000-0002-7037-322X</orcidid><orcidid>https://orcid.org/0000-0002-2131-4100</orcidid><orcidid>https://orcid.org/0000-0002-3715-0358</orcidid><orcidid>https://orcid.org/0000-0002-8351-6779</orcidid><orcidid>https://orcid.org/0000-0002-4698-1671</orcidid><orcidid>https://orcid.org/0000-0002-1664-5845</orcidid><oa>free_for_read</oa></addata></record> |
| fulltext | fulltext |
| identifier | ISSN: 0004-637X |
| ispartof | The Astrophysical journal, 2022-10, Vol.938 (1), p.30 |
| issn | 0004-637X 1538-4357 |
| language | eng |
| recordid | cdi_proquest_journals_2724312928 |
| source | IOP Publishing Free Content; DOAJ Directory of Open Access Journals; Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals; Alma/SFX Local Collection |
| subjects | Amplitudes Anisotropy Astrophysics Cosmic ray intensities Deceleration Density Detectors Forbush decreases Galactic cosmic rays Magnetic fields Magnetic flux Monitors Muons Pitch (inclination) Primary cosmic rays Rigidity Sensors Spectra |
| title | Large-amplitude Bidirectional Anisotropy of Cosmic-Ray Intensity Observed with Worldwide Networks of Ground-based Neutron Monitors and Muon Detectors in 2021 November |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-02-14T10%3A24%3A56IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_cross&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Large-amplitude%20Bidirectional%20Anisotropy%20of%20Cosmic-Ray%20Intensity%20Observed%20with%20Worldwide%20Networks%20of%20Ground-based%20Neutron%20Monitors%20and%20Muon%20Detectors%20in%202021%20November&rft.jtitle=The%20Astrophysical%20journal&rft.au=Munakata,%20K.&rft.date=2022-10-01&rft.volume=938&rft.issue=1&rft.spage=30&rft.pages=30-&rft.issn=0004-637X&rft.eissn=1538-4357&rft_id=info:doi/10.3847/1538-4357/ac91c5&rft_dat=%3Cproquest_cross%3E2724312928%3C/proquest_cross%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=2724312928&rft_id=info:pmid/&rfr_iscdi=true |