{"id":15488,"date":"2017-07-06T20:00:19","date_gmt":"2017-07-06T18:00:19","guid":{"rendered":"http:\/\/www.laterredufutur.com\/accueil\/?p=15488"},"modified":"2017-07-03T08:29:14","modified_gmt":"2017-07-03T06:29:14","slug":"le-bouclier-qui-nous-protege-du-vent-solaire","status":"publish","type":"post","link":"https:\/\/www.laterredufutur.com\/accueil\/le-bouclier-qui-nous-protege-du-vent-solaire\/","title":{"rendered":"Le bouclier qui nous prot\u00e8ge du vent solaire"},"content":{"rendered":"<div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"1\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n<p>Bouclier qui nous prot\u00e8ge du vent solaire, le champ magn\u00e9tique terrestre est utilis\u00e9 comme rep\u00e8re d\u2019orientation par les avions, les vaisseaux spatiaux et m\u00eame pour guider les forages profonds. Il est donc essentiel de mieux comprendre la physique du champ magn\u00e9tique de notre plan\u00e8te, produit essentiellement sous l\u2019effet des mouvements du fer liquide dans le noyau externe, 3000 km sous nos pieds.<\/p>\n<p>Mais les observations nous renseignent uniquement sur les ph\u00e9nom\u00e8nes se produisant \u00e0 la surface du noyau, et les exp\u00e9riences en laboratoire sont difficiles \u00e0 mettre en \u0153uvre. Reste la mod\u00e9lisation num\u00e9rique. Des chercheurs du CNRS et de l\u2019 Institut de physique du globe de Paris viennent de r\u00e9aliser les simulations num\u00e9riques les plus d\u00e9taill\u00e9es \u00e0 ce jour de ces mouvements et du champ magn\u00e9tique r\u00e9sultant, et de leurs variations sur quelques centaines d\u2019ann\u00e9es.<\/p><div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"2\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n\n<p>Ces mod\u00e9lisations en haute d\u00e9finition reproduisent un grand nombre de ph\u00e9nom\u00e8nes observ\u00e9s (par exemple des tornades polaires, \u00e0 la surface du noyau \u2013 voir illustration), tout en les associant \u00e0 la dynamique profonde du noyau. Elles ont \u00e9t\u00e9 rendues possibles gr\u00e2ce \u00e0 un important travail d&rsquo;optimisation du code informatique, et \u00e0 la r\u00e9partition du calcul sur 16 000 processeurs des supercalculateurs du GENCI. Prochaine \u00e9tape : \u00e9tendre ce genre de simulations \u00e0 l\u2019\u00e9chelle des temps g\u00e9ologiques, afin de mieux comprendre l\u2019inversion des p\u00f4les magn\u00e9tiques, dont la derni\u00e8re remonte \u00e0 780 000 ans.<\/p>\n<p><iframe loading=\"lazy\" title=\"Tequat_l299_st2ns_big67\" src=\"https:\/\/player.vimeo.com\/video\/223309160?dnt=1&amp;app_id=122963\" width=\"500\" height=\"500\" frameborder=\"0\" allow=\"autoplay; fullscreen; picture-in-picture; clipboard-write\"><\/iframe><\/p>\n<p>source : <a href=\"https:\/\/news.cnrs.fr\/articles\/now-in-hd-the-earths-turbulent-core\" target=\"_blank\" rel=\"noopener\">https:\/\/news.cnrs.fr\/<\/a><\/p>\n<p class=\"bawpvc-ajax-counter\" data-id=\"15488\">(657)<\/p>\n<!--CusAds0-->\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Bouclier qui nous prot\u00e8ge du vent solaire, le champ magn\u00e9tique terrestre est utilis\u00e9 comme rep\u00e8re d\u2019orientation par les avions, les&#8230;<\/p>\n","protected":false},"author":1,"featured_media":15489,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"ngg_post_thumbnail":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"Le bouclier qui nous prot\u00e8ge du vent solaire @laterredufutur","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[31],"tags":[2206,3612,137,75,127,684],"class_list":["post-15488","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-divers","tag-bouclier","tag-modelisation","tag-solaire","tag-terre","tag-vent-solaire","tag-video","wpcat-31-id"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/07\/bouclier-terre.jpg?fit=1200%2C574&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p631RN-41O","jetpack-related-posts":[{"id":18163,"url":"https:\/\/www.laterredufutur.com\/accueil\/le-champ-magnetique-protecteur-de-la-terre-a-failli-seffondrer-il-y-a-565-millions-dannees\/","url_meta":{"origin":15488,"position":0},"title":"Le champ magn\u00e9tique \u00ab protecteur \u00bb de la Terre a failli s\u2019effondrer il y a 565 millions d\u2019ann\u00e9es","author":"Admin","date":"30 janvier 2019","format":false,"excerpt":"Il y a 565 millions d'ann\u00e9es, le champ magn\u00e9tique de notre plan\u00e8te a failli s'\u00e9crouler. En \u00e9tudiant le noyau interne de la Terre, des scientifiques ont fait cette d\u00e9couverte sur notre bouclier protecteur. Le champ magn\u00e9tique de la Terre, qui nous sert de bouclier protecteur, a risqu\u00e9 de s\u2019effondrer il\u2026","rel":"","context":"Dans &quot;Arch\u00e9ologie&quot;","block_context":{"text":"Arch\u00e9ologie","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/archeologie\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/champ-magnetique_terre-magnetosphere.jpg?fit=1200%2C724&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/champ-magnetique_terre-magnetosphere.jpg?fit=1200%2C724&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/champ-magnetique_terre-magnetosphere.jpg?fit=1200%2C724&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/champ-magnetique_terre-magnetosphere.jpg?fit=1200%2C724&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/champ-magnetique_terre-magnetosphere.jpg?fit=1200%2C724&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":11676,"url":"https:\/\/www.laterredufutur.com\/accueil\/la-lune-jouerait-un-role-majeur-dans-le-maintien-du-champ-magnetique-terrestre\/","url_meta":{"origin":15488,"position":1},"title":"La Lune jouerait un r\u00f4le majeur dans le maintien du champ magn\u00e9tique terrestre","author":"Admin","date":"22 avril 2016","format":false,"excerpt":"Le champ magn\u00e9tique terrestre nous prot\u00e8ge chaque jour des particules charg\u00e9es et des radiations issues du rayonnement solaire. Ce bouclier est produit par la g\u00e9odynamo : des mouvements rapides d'\u00e9normes quantit\u00e9s d'alliage de fer liquide dans le noyau externe de la plan\u00e8te. Pour maintenir ce champ magn\u00e9tique jusqu'\u00e0 aujourd'hui, le\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/lune.jpg?fit=1040%2C1050&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/lune.jpg?fit=1040%2C1050&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/lune.jpg?fit=1040%2C1050&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/lune.jpg?fit=1040%2C1050&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":14868,"url":"https:\/\/www.laterredufutur.com\/accueil\/et-si-mars-devenait-habitable-grace-a-un-champ-magnetique-cree-de-toute-piece\/","url_meta":{"origin":15488,"position":2},"title":"Et si Mars devenait habitable gr\u00e2ce \u00e0 un champ magn\u00e9tique cr\u00e9\u00e9 de toute pi\u00e8ce","author":"Admin","date":"10 mars 2017","format":false,"excerpt":"Lors d'un r\u00e9cent colloque de la Nasa, des chercheurs ont propos\u00e9 une id\u00e9e ing\u00e9nieuse pour terraformer Mars : cr\u00e9er un bouclier magn\u00e9tique artificiel pour supprimer l'\u00e9rosion de son atmosph\u00e8re. Bien que situ\u00e9e dans la zone d'habitabilit\u00e9 du Soleil, Mars est diff\u00e9rente de la Terre. La pression de son atmosph\u00e8re est\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/03\/mars-magnetisme.jpg?fit=630%2C329&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/03\/mars-magnetisme.jpg?fit=630%2C329&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/03\/mars-magnetisme.jpg?fit=630%2C329&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":2126,"url":"https:\/\/www.laterredufutur.com\/accueil\/le-champ-magnetique-terrestre-saffaiblit-plus-vite-que-prevu\/","url_meta":{"origin":15488,"position":3},"title":"Le champ magn\u00e9tique terrestre s&rsquo;affaiblit plus vite que pr\u00e9vu","author":"Admin","date":"3 ao\u00fbt 2014","format":false,"excerpt":"Gr\u00e2ce \u00e0 des satellites lanc\u00e9s en novembre 2013, l'Agence spatiale europ\u00e9enne a pu enregistrer des donn\u00e9es pr\u00e9cises concernant les variations du champ magn\u00e9tique terrestre. Selon les premiers r\u00e9sultats, ce dernier s'affaiblirait bien plus rapidement que pr\u00e9vu. Le champ magn\u00e9tique terrestre s\u2019affaiblit bien plus rapidement que pr\u00e9vu : c\u2019est le constat\u2026","rel":"","context":"Dans &quot;Divers&quot;","block_context":{"text":"Divers","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/divers\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":12218,"url":"https:\/\/www.laterredufutur.com\/accueil\/une-nouvelle-etude-nous-demontre-que-le-champ-magnetique-terrestre-est-en-train-de-changer-rapidement\/","url_meta":{"origin":15488,"position":4},"title":"Une nouvelle \u00e9tude nous d\u00e9montre que le champ magn\u00e9tique terrestre est en train de changer rapidement","author":"Admin","date":"13 mai 2016","format":false,"excerpt":"De nouvelles recherches ont montr\u00e9 en d\u00e9tail comment le champ magn\u00e9tique de la Terre est en train de se modifier rapidement. Il agit comme un bouclier pour nous prot\u00e9ger des vents solaires et du rayonnement cosmique - il est en train de changer, il s'affaiblit sur certaines parties du monde,\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/05\/champ-magnetique.jpg?fit=623%2C415&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/05\/champ-magnetique.jpg?fit=623%2C415&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/05\/champ-magnetique.jpg?fit=623%2C415&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":4685,"url":"https:\/\/www.laterredufutur.com\/accueil\/lintensite-des-vents-solaires-au-plus-bas\/","url_meta":{"origin":15488,"position":5},"title":"L&rsquo;intensit\u00e9 des vents solaires au plus bas","author":"Admin","date":"3 d\u00e9cembre 2008","format":false,"excerpt":"L'intensit\u00e9 des vents solaires form\u00e9s de particules \u00e9ject\u00e9es de la couronne du soleil dans l'espace est au plus bas en un demi-si\u00e8cle. Ce ph\u00e9nom\u00e8ne pourrait r\u00e9duire le bouclier naturel prot\u00e9geant contre une partie des rayons cosmiques. L'intensit\u00e9 des vents solaires form\u00e9s de particules \u00e9ject\u00e9es de la couronne du soleil dans\u2026","rel":"","context":"Dans &quot;Soleil&quot;","block_context":{"text":"Soleil","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/soleil\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/vent-solaire.jpg?fit=792%2C612&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/vent-solaire.jpg?fit=792%2C612&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/vent-solaire.jpg?fit=792%2C612&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/vent-solaire.jpg?fit=792%2C612&ssl=1&resize=700%2C400 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/15488","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/comments?post=15488"}],"version-history":[{"count":1,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/15488\/revisions"}],"predecessor-version":[{"id":15490,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/15488\/revisions\/15490"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media\/15489"}],"wp:attachment":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media?parent=15488"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/categories?post=15488"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/tags?post=15488"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}