Dayside Magnetic Depression Following Interplanetary Shock Arrivals During the February 1958 and July 1959 Superstorms
Abstract The present study investigates mid‐ and low‐latitude ground magnetic disturbances observed following the arrival of three interplanetary (IP) shocks during the super‐geomagnetic storms of February 1958 and July 1959. One may expect that after IP shocks, the H (northward) magnetic component...
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| Format: | Article |
| Language: | English |
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Wiley
2024-10-01
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| Series: | Space Weather |
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| Online Access: | https://doi.org/10.1029/2024SW004017 |
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| author | Shinichi Ohtani Yoko Odagi Ayako Matsuoka Toshihiko Iyemori |
| author_facet | Shinichi Ohtani Yoko Odagi Ayako Matsuoka Toshihiko Iyemori |
| author_sort | Shinichi Ohtani |
| collection | DOAJ |
| description | Abstract The present study investigates mid‐ and low‐latitude ground magnetic disturbances observed following the arrival of three interplanetary (IP) shocks during the super‐geomagnetic storms of February 1958 and July 1959. One may expect that after IP shocks, the H (northward) magnetic component increases globally but especially on the dayside. However, in each event, the H component was depressed sharply for 1–2 hr in the dawn‐to‐noon sector, whereas it increased in other local time (LT) sectors. Observed magnetic deflections suggest that there existed field‐aligned currents (FACs) flowing into and out of the auroral zone around the western and eastern edges of the LT sector of the dayside H depression. These features strongly suggests that the observed H depression was a remote effect of a R1‐sense FAC system. It was previously reported that similar ground magnetic disturbances were observed after the SSC of the 2003 Halloween storm, which reveals striking similarities to the well‐known H depression observed at Colaba during the 1859 Carrington storm. It is therefore suggested that the external driving behind IP shocks, especially those associated with major storms, is most optimum for the sharp reduction of the dayside H component through the formation and intensification of the dayside FAC system. Associated magnetic disturbances are considered to be larger in magnitude with increasing magnetic latitude, and oriented azimuthally as well as meridionally. Such magnetic disturbances in dayside midlatitudes may not be discussed very often as a target of space weather, but their potential impacts on ground infrastructures probably require closer attention. |
| format | Article |
| id | doaj-art-e2900e38fb1144689517ad2946a1bf82 |
| institution | Kabale University |
| issn | 1542-7390 |
| language | English |
| publishDate | 2024-10-01 |
| publisher | Wiley |
| record_format | Article |
| series | Space Weather |
| spelling | doaj-art-e2900e38fb1144689517ad2946a1bf822025-01-14T16:31:08ZengWileySpace Weather1542-73902024-10-012210n/an/a10.1029/2024SW004017Dayside Magnetic Depression Following Interplanetary Shock Arrivals During the February 1958 and July 1959 SuperstormsShinichi Ohtani0Yoko Odagi1Ayako Matsuoka2Toshihiko Iyemori3Johns Hopkins University Applied Physics Laboratory Laurel MD USAData Analysis Center for Geomagnetism and Space Magnetism Graduate School of Science Kyoto University Kyoto JapanData Analysis Center for Geomagnetism and Space Magnetism Graduate School of Science Kyoto University Kyoto JapanData Analysis Center for Geomagnetism and Space Magnetism Graduate School of Science Kyoto University Kyoto JapanAbstract The present study investigates mid‐ and low‐latitude ground magnetic disturbances observed following the arrival of three interplanetary (IP) shocks during the super‐geomagnetic storms of February 1958 and July 1959. One may expect that after IP shocks, the H (northward) magnetic component increases globally but especially on the dayside. However, in each event, the H component was depressed sharply for 1–2 hr in the dawn‐to‐noon sector, whereas it increased in other local time (LT) sectors. Observed magnetic deflections suggest that there existed field‐aligned currents (FACs) flowing into and out of the auroral zone around the western and eastern edges of the LT sector of the dayside H depression. These features strongly suggests that the observed H depression was a remote effect of a R1‐sense FAC system. It was previously reported that similar ground magnetic disturbances were observed after the SSC of the 2003 Halloween storm, which reveals striking similarities to the well‐known H depression observed at Colaba during the 1859 Carrington storm. It is therefore suggested that the external driving behind IP shocks, especially those associated with major storms, is most optimum for the sharp reduction of the dayside H component through the formation and intensification of the dayside FAC system. Associated magnetic disturbances are considered to be larger in magnitude with increasing magnetic latitude, and oriented azimuthally as well as meridionally. Such magnetic disturbances in dayside midlatitudes may not be discussed very often as a target of space weather, but their potential impacts on ground infrastructures probably require closer attention.https://doi.org/10.1029/2024SW004017superstormsdayside geomagnetic depressionstorm sudden commencementdayside current wedgesolar wind compressionsolar wind‐magnetosphere‐ionosphere coupling |
| spellingShingle | Shinichi Ohtani Yoko Odagi Ayako Matsuoka Toshihiko Iyemori Dayside Magnetic Depression Following Interplanetary Shock Arrivals During the February 1958 and July 1959 Superstorms Space Weather superstorms dayside geomagnetic depression storm sudden commencement dayside current wedge solar wind compression solar wind‐magnetosphere‐ionosphere coupling |
| title | Dayside Magnetic Depression Following Interplanetary Shock Arrivals During the February 1958 and July 1959 Superstorms |
| title_full | Dayside Magnetic Depression Following Interplanetary Shock Arrivals During the February 1958 and July 1959 Superstorms |
| title_fullStr | Dayside Magnetic Depression Following Interplanetary Shock Arrivals During the February 1958 and July 1959 Superstorms |
| title_full_unstemmed | Dayside Magnetic Depression Following Interplanetary Shock Arrivals During the February 1958 and July 1959 Superstorms |
| title_short | Dayside Magnetic Depression Following Interplanetary Shock Arrivals During the February 1958 and July 1959 Superstorms |
| title_sort | dayside magnetic depression following interplanetary shock arrivals during the february 1958 and july 1959 superstorms |
| topic | superstorms dayside geomagnetic depression storm sudden commencement dayside current wedge solar wind compression solar wind‐magnetosphere‐ionosphere coupling |
| url | https://doi.org/10.1029/2024SW004017 |
| work_keys_str_mv | AT shinichiohtani daysidemagneticdepressionfollowinginterplanetaryshockarrivalsduringthefebruary1958andjuly1959superstorms AT yokoodagi daysidemagneticdepressionfollowinginterplanetaryshockarrivalsduringthefebruary1958andjuly1959superstorms AT ayakomatsuoka daysidemagneticdepressionfollowinginterplanetaryshockarrivalsduringthefebruary1958andjuly1959superstorms AT toshihikoiyemori daysidemagneticdepressionfollowinginterplanetaryshockarrivalsduringthefebruary1958andjuly1959superstorms |