{"id":3929,"date":"2007-04-01T18:54:36","date_gmt":"2007-04-01T16:54:36","guid":{"rendered":"http:\/\/www.laterredufutur.com\/accueil1\/?p=3929"},"modified":"2015-04-11T18:57:34","modified_gmt":"2015-04-11T16:57:34","slug":"dossier-n-1-les-courants-marins","status":"publish","type":"post","link":"https:\/\/www.laterredufutur.com\/accueil\/dossier-n-1-les-courants-marins\/","title":{"rendered":"Dossier N\u00b0 1 : Les Courants Marins"},"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>dossier, en\u00a04 parties qui seront publi\u00e9es sur la Terre du Futur, transmis par Fifi321fth (Thomas)<a href=\"http:\/\/www.laterredufutur.com\/html\/modules.php?name=Forums&amp;file=profile&amp;mode=viewprofile&amp;u=10\">, <\/a>pass\u00e9 au lyc\u00e9e Sacr\u00e9-Coeur \u00e0 Reims.<\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Thomas <span style=\"font-size: small;\"><span style=\"color: #2b2bff; font-family: ComicSansMS-Bold;\">L., <\/span><\/span>Enguerran D., <\/span><span style=\"font-family: ComicSansMS-Bold; font-size: small;\"><span style=\"color: #2b2bff;\">Juliette M.<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Dossier Exclusif sur les Courants Marins et de ce qui en r\u00e9sulte&#8230;<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #ffffff;\">Ici\u00a01 ere partie..<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-family: ComicSansMS-Bold; font-size: small;\">SOMMAIRE des\u00a04 parties qui seront publi\u00e9es en\u00a04 articles :<\/span><\/p>\n<p align=\"justify\">INTRODUCTION<\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">I. Localisation et fonctionnement des courants<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">marins.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">1\u00b0) Localisation des courants marins<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">2\u00b0) Les m\u00e9canismes du fonctionnement des courants<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">marins.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">a) Le soleil<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">b) Le vent<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">c) La force de Coriolis<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">d) Les diff\u00e9rences de densit\u00e9 (salinit\u00e9)<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">e) La diff\u00e9rence de hauteur d&rsquo;eau (SSH)<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">f) Des influences animales marines ?<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">II. L&rsquo;influence des courants marins.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">1\u00b0) Les influences thermiques et pluviom\u00e9triques des<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">courants marins permanents.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">2\u00b0) Les influences des courants temporaires<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">a) El Nino<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">b) La Nina<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">3\u00b0) Les autres influences des courants marins<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">III. Des perspectives d&rsquo;avenir.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">1\u00b0) Le contexte du r\u00e9chauffement climatique<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">2\u00b0) Quels risques pour les courants marins ?<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">3\u00b0) Des signes avant-coureurs ?<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">CONCLUSION<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-family: TimesNewRomanPSMT; font-size: small;\">\u00a0<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">INTRODUCTION :<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Il a \u00e9t\u00e9 observ\u00e9 durant ces deux derniers si\u00e8cles, et notamment durant <\/span><span style=\"color: #2b2bff; font-size: small;\">ces deux derni\u00e8res d\u00e9cennies, des changements climatiques. Les <\/span><span style=\"color: #2b2bff; font-size: small;\">scientifiques se sont donc interrog\u00e9s sur les origines de ces changements.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Ils ont alors remarqu\u00e9 que les courants marins, dont ils avaient <\/span><span style=\"color: #2b2bff; font-size: small;\">conjectur\u00e9 un effet possible sur les climats \u00e0 plus ou moins grande <\/span><span style=\"color: #2b2bff; font-size: small;\">\u00e9chelle, avaient en fait une r\u00e9elle incidence sur ce ph\u00e9nom\u00e8ne.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Les courants marins ont-ils vraiment un effet sur le climat ?<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Si oui lequel ?<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Un courant marin est un d\u00e9placement d&rsquo;eau de mer caract\u00e9ris\u00e9 par sa <\/span><span style=\"color: #2b2bff; font-size: small;\">direction, sa vitesse et son d\u00e9bit. Il repose sur des notions <\/span><span style=\"color: #2b2bff; font-size: small;\">fondamentales physiques, c&rsquo;est-\u00e0-dire qu&rsquo;il a un fonctionnement connu. <\/span><span style=\"color: #2b2bff; font-size: small;\">Gr\u00e2ce \u00e0 ce fonctionnement, et au fait qu&rsquo;\u00e0 New York qui est \u00e0 la latitude <\/span><span style=\"color: #2b2bff; font-size: small;\">de Milan il fasse bien plus froid, on en d\u00e9duit des influences pr\u00e9cises qui <\/span><span style=\"color: #2b2bff; font-size: small;\">r\u00e9gissent le climat mondial d\u00fb \u00e0 la grande inertie thermique (calorifique) <\/span><span style=\"color: #2b2bff; font-size: small;\">des oc\u00e9ans.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Ce sont donc les oc\u00e9ans qui sont les acteurs pr\u00e9pond\u00e9rants de notre <\/span><span style=\"color: #2b2bff; font-size: small;\">temps d&rsquo;aujourd&rsquo;hui et de demain.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">I. Localisation et fonctionnement des courants marins.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff;\">1\u00b0) Localisation des courants marins<\/span><\/p>\n<p align=\"center\"><span style=\"color: #2b2bff;\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant1.jpg?resize=477%2C267\" alt=\"\" width=\"477\" height=\"267\" \/><\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Courants froids : &gt; Permanents : Californie, Humblot, Labrador, Canaris, <\/span><span style=\"color: #2b2bff; font-size: small;\">Benguela, courant circumpolaire Antarctique, Oya Shivo<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">&gt; Temporaires : La Ni\u00f1a.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Courants chauds : &gt; Permanents : Kouro Shivo, CCE, CSE, CHE, Gulf<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Stream, Br\u00e9sil, Aiguille Mascareigne, Australie Ort.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">&gt; Temporaires : El Ni\u00f1o.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">2\u00b0) Les m\u00e9canismes du fonctionnement des courants <\/span><span style=\"color: #2b2bff; font-size: small;\">marins.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">a) Le soleil<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Le soleil est une \u00e9toile comme il en existe des milliards de milliards <\/span><span style=\"color: #2b2bff; font-size: small;\">dans l&rsquo;univers, c&rsquo;est celle de notre syst\u00e8me solaire compos\u00e9 de quatre <\/span><span style=\"color: #2b2bff; font-size: small;\">plan\u00e8tes telluriques (= rocheuses (pr\u00e9sence de sillice)), qui sont Mercure, <\/span><span style=\"color: #2b2bff; font-size: small;\">V\u00e9nus, la Terre et Mars ; et de quatre plan\u00e8tes gazeuses (g\u00e9antes <\/span><span style=\"color: #2b2bff; font-size: small;\">gazeuses), qui sont Jupiter, Saturne, Uranus et Neptune.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Le soleil est la source d&rsquo;\u00e9nergie qui r\u00e8gle les mouvements de l&rsquo;oc\u00e9an <\/span><span style=\"color: #2b2bff; font-size: small;\">et de l&rsquo;atmosph\u00e8re et donc notre climat.<\/span><\/p>\n<p align=\"center\"><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff;\"><img data-recalc-dims=\"1\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant2.jpg\" alt=\"\" \/><\/span><\/span><\/p>\n<p align=\"justify\">Ensoleillement (en Watt\/m\u00b2)<\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Comme on peut le voir sur cette carte, qui repr\u00e9sente la dose <\/span><span style=\"color: #2b2bff; font-size: small;\">d&rsquo;infrarouges re\u00e7ue par le sol, l&rsquo;\u00e9quateur re\u00e7oit beaucoup plus de rayons <\/span><span style=\"color: #2b2bff; font-size: small;\">solaires (environ 500 W\/m\u00b2) que les p\u00f4les, ou les moyennes latitudes (100 <\/span><span style=\"color: #2b2bff; font-size: small;\">\u00e0 300W\/m\u00b2). Cela est simplement d\u00fb \u00e0 l&rsquo;inclinaison de l&rsquo;\u00e9cliptique de <\/span><span style=\"color: #2b2bff; font-size: small;\">notre plan\u00e8te (23\u00b0), ainsi qu&rsquo;\u00e0 la variation de son orbite autour du soleil.<\/span><\/p>\n<p align=\"center\"><span style=\"color: #2b2bff;\"><img data-recalc-dims=\"1\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant3.jpg\" alt=\"\" \/><\/span><\/p>\n<p align=\"justify\">b) Le vent<\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS-Bold;\"><span style=\"color: #2b2bff; font-size: small;\">Le principal moteur des courants de surfaces est le vent. <\/span><\/span><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">Les <\/span><span style=\"color: #2b2bff; font-size: small;\">vents sont r\u00e9gis par une alternance de basses et de hautes pressions <\/span><span style=\"color: #2b2bff; font-size: small;\">selon la latitude. A l&rsquo;\u00e9quateur, nous observons comme une \u00e9norme mar\u00e9e <\/span><span style=\"color: #2b2bff; font-size: small;\">barom\u00e9trique, c&rsquo;est-a-dire que c&rsquo;est une grande zone caract\u00e9ris\u00e9e par <\/span><span style=\"color: #2b2bff; font-size: small;\">des pressions d&rsquo;environ 1015 Hpa. La chaleur et la forte \u00e9vaporation \u00e0 <\/span><span style=\"color: #2b2bff; font-size: small;\">l&rsquo;\u00e9quateur cr\u00e9ent des mouvements de convection.<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">On distingue donc dans la circulation atmosph\u00e9rique g\u00e9n\u00e9rale trois <\/span><span style=\"color: #2b2bff; font-size: small;\">parties qui composent la surface de la terre, sym\u00e9triques par rapport \u00e0 <\/span><span style=\"color: #2b2bff; font-size: small;\">l&rsquo;\u00e9quateur:<\/span><\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">&gt; Les cellules de Hadley (anticyclones)<\/span><\/span><\/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 align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">&gt; Les cellules de Ferrel (d\u00e9pressions)<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">&gt; Les vortex polaire et austral (d\u00e9pressions)<\/span><\/p>\n<p align=\"center\"><span style=\"color: #2b2bff;\"><img data-recalc-dims=\"1\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant4_1.jpg\" alt=\"\" \/><\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Entre les cellules de Hadley, \u00e0 l&rsquo;\u00e9quateur donc, soufflent les aliz\u00e9s <\/span><span style=\"color: #2b2bff; font-size: small;\">d&rsquo;Est en Ouest. <\/span><span style=\"color: #2b2bff; font-size: small;\">Entre les cellules de Hadley et de Ferrel soufflent les Westerlies <\/span><span style=\"color: #2b2bff; font-size: small;\">d&rsquo;Ouest en Est dans l&rsquo;HN (h\u00e9misph\u00e8re nord), et dans l&rsquo;HS c&rsquo;est pareil, le <\/span><span style=\"color: #2b2bff; font-size: small;\">sens est le m\u00eame d&rsquo;Ouest en Est, par contre les sens de rotation des <\/span><span style=\"color: #2b2bff; font-size: small;\">anticyclones et depressions sont invers\u00e9s.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">HN: les anticyclones tournent dans le sens des aiguilles d&rsquo;une montre et <\/span><span style=\"color: #2b2bff; font-size: small;\">les d\u00e9pressions en sens inverse des aiguilles d&rsquo;une montre.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">HS: les anticyclones tournent en sens inverse des aiguilles d&rsquo;une montre <\/span><span style=\"color: #2b2bff; font-size: small;\">et les d\u00e9pressions dans le sens des aiguilles d&rsquo;une montre.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff;\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant5_1.jpg?resize=375%2C429\" alt=\"\" width=\"375\" height=\"429\" align=\"right\" \/><\/span><\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS-Bold;\"><span style=\"color: #2b2bff; font-size: small;\">Les jet-streams subtropicaux qui circulent parall\u00e8lement aux latitudes (selon <\/span><span style=\"color: #2b2bff; font-size: small;\">les fl\u00e8ches vertes) alimentent les aliz\u00e9s, qui reviennent vers l\u2019\u00e9quateur (selon <\/span><span style=\"color: #2b2bff; font-size: small;\">les fl\u00e8ches bleues), bouclant la cellule de Hadley. Ils alimentent aussi des <\/span><span style=\"color: #2b2bff; font-size: small;\">vents qui se dirigent vers les p\u00f4les et qui font partie de la cellule de Ferrel.<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">La circulation atmosph\u00e9rique globale comprend plusieurs \u00abcellules\u00bb ou boucles <\/span><span style=\"color: #2b2bff; font-size: small;\">de vent juxtapos\u00e9es. Lors d\u2019un \u00e9v\u00e9nement El Ni\u00f1o, qui modifie la cellule de <\/span><span style=\"color: #2b2bff; font-size: small;\">Walker (parall\u00e8le \u00e0 l\u2019\u00e9quateur) et la cellule de Hadley, les cellules voisines <\/span><span style=\"color: #2b2bff; font-size: small;\">sont \u00e9galement modifi\u00e9s, ainsi que leurs voisines&#8230; ce qui explique pourquoi El <\/span><span style=\"color: #2b2bff; font-size: small;\">Ni\u00f1o a des r\u00e9percutions sur l\u2019ensemble du globe.<\/span><\/p>\n<p align=\"justify\">c) La force de Coriolis<\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">Dans un syst\u00e8me de r\u00e9f\u00e9rence (r\u00e9f\u00e9rentiel) en rotation uniforme, <\/span><span style=\"color: #2b2bff; font-size: small;\">les corps en mouvement, tels que vus par un observateur partageant le <\/span><span style=\"color: #2b2bff; font-size: small;\">m\u00eame r\u00e9f\u00e9rentiel, apparaissent sujets \u00e0 une force d&rsquo;inertie <\/span><span style=\"color: #2b2bff; font-size: small;\">perpendiculaire \u00e0 la direction de leur mouvement. Cette force est appel\u00e9e<\/span><span style=\"color: #2b2bff; font-size: small;\">force de Coriolis en l&rsquo;honneur de l&rsquo;ing\u00e9nieur fran\u00e7ais Gaspard-Gustave <\/span><span style=\"color: #2b2bff; font-size: small;\">Coriolis.<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">La force de Coriolis permet l&rsquo;interpr\u00e9tation de beaucoup de <\/span><span style=\"color: #2b2bff; font-size: small;\">ph\u00e9nom\u00e8nes \u00e0 la surface de la terre. <\/span><span style=\"color: #2b2bff; font-size: small;\">La vitesse de rotation de la <\/span><\/span><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">terre \u00e0 la surface est maximale \u00e0 <\/span><span style=\"color: #2b2bff; font-size: small;\">l&rsquo;\u00e9quateur et d\u00e9croit vers les p\u00f4les.<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">Tout objet qui se dirige vers les p\u00f4les est donc sous l&rsquo;effet d&rsquo;une <\/span><span style=\"color: #2b2bff; font-size: small;\">acc\u00e9l\u00e9ration qui l&rsquo;entraine vers l&rsquo;est. <\/span><span style=\"color: #2b2bff; font-size: small;\">C&rsquo;est la <\/span><\/span><span style=\"font-family: ComicSansMS-Bold;\"><span style=\"color: #2b2bff; font-size: small;\">Force de Coriolis.<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Cette force peut \u00eatre mod\u00e9lis\u00e9e par de l&rsquo;eau s&rsquo;\u00e9coulant dans un \u00e9vier, en <\/span><span style=\"color: #2b2bff; font-size: small;\">effet, l&rsquo;eau qui s&rsquo;\u00e9coule tourne dans un sens \u00e0 l&rsquo;h\u00e9misph\u00e8re Nord, et dans <\/span><span style=\"color: #2b2bff; font-size: small;\">le sens oppos\u00e9 \u00e0 l&rsquo;h\u00e9misph\u00e8re sud, comme c&rsquo;est le cas pour la rotation <\/span><span style=\"color: #2b2bff; font-size: small;\">des masses d&rsquo;air.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant6.jpg?resize=250%2C217\" alt=\"\" width=\"250\" height=\"217\" align=\"left\" \/>Cependant, la Terre tourne et en utilisant la d\u00e9finition de la force <\/span><span style=\"color: #2b2bff; font-size: small;\">de Coriolis dans <\/span><\/span><span style=\"font-family: ComicSansMS-Bold;\"><span style=\"color: #2b2bff; font-size: small;\">un r\u00e9f\u00e9rentiel en rotation<\/span><\/span><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">, on voit que cette derni\u00e8re<\/span><span style=\"color: #2b2bff; font-size: small;\">augmente \u00e0 mesure que la vitesse obtenue par le gradient de pression<\/span><span style=\"color: #2b2bff; font-size: small;\">augmente mais dans la direction perpendiculaire. Ainsi la circulation de <\/span><span style=\"color: #2b2bff; font-size: small;\">l&rsquo;air sera anti-horaire autour d&rsquo;une d\u00e9pression et horaire autour d&rsquo;un <\/span><span style=\"color: #2b2bff; font-size: small;\">anticyclone (h\u00e9misph\u00e8re nord).<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-size: small;\">Le sens de rotation de cette basse pression <\/span><span style=\"color: #2b2bff; font-size: small;\">tournant au large de l&rsquo;Islande dans le sens <\/span><span style=\"color: #2b2bff; font-size: small;\">contraire des aiguilles d&rsquo;une montre est d\u00fb aux <\/span><span style=\"color: #2b2bff; font-size: small;\">effets combin\u00e9s de la force de Coriolis et du <\/span><span style=\"color: #2b2bff; font-size: small;\">gradient de pression.<\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff; font-family: ComicSansMS; font-size: small;\">Les d\u00e9pressions ne peuvent pas se former pr\u00e8s de l&rsquo;\u00e9quateur o\u00f9 la <\/span><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">composante horizontale de la force de Coriolis est nulle. La variation de la <\/span><span style=\"color: #2b2bff; font-size: small;\">force de Coriolis donne donc diff\u00e9rents r\u00e9gimes de circulation <\/span><span style=\"color: #2b2bff; font-size: small;\">atmosph\u00e9rique selon la latitude.<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS;\"><span style=\"color: #2b2bff; font-size: small;\">Dans la figure, on voit comment cela se produit e<img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant7.jpg?resize=256%2C256\" alt=\"\" width=\"256\" height=\"256\" align=\"right\" \/>n prenant les quatre <\/span><span style=\"color: #2b2bff; font-size: small;\">points cardinaux comme d\u00e9but de l&rsquo;interaction des forces. Le gradient de <\/span><span style=\"color: #2b2bff; font-size: small;\">pression (fl\u00e8ches bleues) amorce le d\u00e9placement de l&rsquo;air mais la force de <\/span><span style=\"color: #2b2bff; font-size: small;\">Coriolis (fl\u00e8ches rouges) le fait d\u00e9vier vers la droite (fl\u00e8ches noires). Le <\/span><span style=\"color: #2b2bff; font-size: small;\">gradient de pression s&rsquo;ajuste en direction avec ce changement ainsi que <\/span><span style=\"color: #2b2bff; font-size: small;\">la force de Coriolis ce qui fait changer continuellement la direction de <\/span><span style=\"color: #2b2bff; font-size: small;\">notre parcelle.<\/span><\/span><\/p>\n<p align=\"justify\"><span style=\"color: #2b2bff;\">d) les diff\u00e9rences de densit\u00e9 (salinit\u00e9)<\/span><\/p>\n<p align=\"justify\"><span style=\"font-family: ComicSansMS; font-size: small;\"><span style=\"color: #2b2bff;\">\u00e0 suivre au prochain volet de ce dossier<\/span><\/span><\/p>\n<p align=\"justify\">La Terre du Futur<\/p>\n<p align=\"left\"><span style=\"font-size: small;\">sources\u00a0:<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; http:\/\/flynetweb.free.fr\/index.htm<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; http:\/\/fr.wikipedia.org\/wiki\/courant-marin.<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; http:\/\/fr.wikipedia.org\/wiki\/force-de-coriolis<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; http:\/\/www.ens-lyon.fr\/Planet-Terre\/Infosciences\/Climats\/Dynam-atmos\/courscoriolis<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; http:\/\/www.ifremer.fr\/aei2006\/presentation\/T1S3\/aei2006_16_58.pdf<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; http:\/\/www.mercator-ocean.fr\/html\/<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; http:\/\/la.climatologie.free.fr\/sommaire.htm<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; http:\/\/laterredufutur.com\/html<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">LIVRES :<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; Petit atlas du climat, Laure Ch\u00e9mery<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; Plan\u00e8te oc\u00e9ane (pp 47-55)<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">Dictionnaires :<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; Le Petit Larousse illustr\u00e9, \u00e9dition 2007<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; Le Robert, \u00e9dition 2007<\/span><\/p>\n<p align=\"left\"><span style=\"font-size: small;\">&gt; Encyclop\u00e9die Universalis, \u00e9dition 2000<\/span><\/p>\n<p>&nbsp;<\/p>\n<p class=\"bawpvc-ajax-counter\" data-id=\"3929\">(1193)<\/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>dossier, en\u00a04 parties qui seront publi\u00e9es sur la Terre du Futur, transmis par Fifi321fth (Thomas), pass\u00e9 au lyc\u00e9e Sacr\u00e9-Coeur \u00e0&#8230;<\/p>\n","protected":false},"author":1,"featured_media":3930,"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_post_was_ever_published":false,"_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":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[20,23],"tags":[41,2434,430,396,1523],"class_list":["post-3929","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-climat","category-circulation-oceanique","tag-climat","tag-dossier","tag-etude","tag-gulf-stream","tag-rapport","wpcat-20-id","wpcat-23-id"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/Courants-Marins.gif?fit=250%2C172&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p631RN-11n","jetpack-related-posts":[{"id":3949,"url":"https:\/\/www.laterredufutur.com\/accueil\/dossier-n4-les-courants-marins\/","url_meta":{"origin":3929,"position":0},"title":"Dossier N\u00b04 : Les Courants Marins","author":"Admin","date":"15 avril 2007","format":false,"excerpt":"Voici un dossier, en\u00a04 parties qui seront publi\u00e9es sur la Terre du Futur, transmis par Fifi321fth (Thomas), pass\u00e9 au lyc\u00e9e Sacr\u00e9-Coeur \u00e0 Reims. Thomas L., Enguerran D., Juliette M. Dossier Exclusif sur les Courants Marins et de ce qui en r\u00e9sulte. Ici\u00a04 eme partie... Sch\u00e9mas de la salinit\u00e9 de diff\u00e9rents\u2026","rel":"","context":"Dans &quot;Climat&quot;","block_context":{"text":"Climat","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/climat\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant19.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant19.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant19.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":3942,"url":"https:\/\/www.laterredufutur.com\/accueil\/dossier-n3-les-courants-marins\/","url_meta":{"origin":3929,"position":1},"title":"Dossier N\u00b03 : Les Courants Marins","author":"Admin","date":"10 avril 2007","format":false,"excerpt":"Voici un dossier, en\u00a04 parties qui seront publi\u00e9es sur la Terre du Futur, transmis par Fifi321fth (Thomas), pass\u00e9 au lyc\u00e9e Sacr\u00e9-Coeur \u00e0 Reims. Thomas L., Enguerran D., Juliette M. Dossier Exclusif sur les Courants Marins et de ce qui en r\u00e9sulte. Ici 3 eme partie. Des mesures satellitaires ont r\u00e9v\u00e9l\u00e9\u2026","rel":"","context":"Dans &quot;Climat&quot;","block_context":{"text":"Climat","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/climat\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant15.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant15.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant15.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":3936,"url":"https:\/\/www.laterredufutur.com\/accueil\/dossier-n-2-les-courants-marins\/","url_meta":{"origin":3929,"position":2},"title":"Dossier N\u00b0 2 : Les Courants Marins","author":"Admin","date":"5 avril 2007","format":false,"excerpt":"Voici un dossier, en\u00a04 parties qui seront publi\u00e9es sur la Terre du Futur, transmis par Fifi321fth (Thomas), pass\u00e9 au lyc\u00e9e Sacr\u00e9-Coeur \u00e0 Reims. Thomas L., Enguerran D., Juliette M. Dossier Exclusif sur les Courants Marins et de ce qui en r\u00e9sulte. Ici 2 eme partie... d) les diff\u00e9rences de densit\u00e9\u2026","rel":"","context":"Dans &quot;Climat&quot;","block_context":{"text":"Climat","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/climat\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/laterredufutur.com\/spaw\/images\/courant7.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":14657,"url":"https:\/\/www.laterredufutur.com\/accueil\/le-sahara-etait-vert-il-y-a-plus-de-6000-ans-et-avait-10-fois-plus-de-pluie-quaujourdhui\/","url_meta":{"origin":3929,"position":3},"title":"Le Sahara \u00e9tait \u00abvert\u00bb il y a plus de 6000 ans et avait 10 fois plus de pluie qu&rsquo;aujourd&rsquo;hui","author":"Admin","date":"6 f\u00e9vrier 2017","format":false,"excerpt":"Selon une nouvelle \u00e9tude publi\u00e9e r\u00e9cemment dans la revue Advances Sciencemag, il est prouv\u00e9 que les humains occupaient une grande partie du Sahara au cours de la \u00abp\u00e9riode humide\u00bb d'il y a environ 8000 ans. Gr\u00e2ce \u00e0 une analyse des s\u00e9diments marins, des chercheurs de l'Universit\u00e9 de l'Arizona ont \u00e9tabli\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\/2017\/01\/vert-sahara-sphinx.jpg?fit=620%2C419&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/01\/vert-sahara-sphinx.jpg?fit=620%2C419&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/01\/vert-sahara-sphinx.jpg?fit=620%2C419&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":2640,"url":"https:\/\/www.laterredufutur.com\/accueil\/dossier-legende-1\/","url_meta":{"origin":3929,"position":4},"title":"Dossier L\u00e9gende 1","author":"Admin","date":"6 janvier 2005","format":false,"excerpt":"Voici un nouveau dossier en 4 parties concernant l'une des plus grandes l\u00e9gendes qui nous a jamais \u00e9t\u00e9 cont\u00e9e : L'Atlantide. Qu'une civilisation grandiose ait pu exister et dispara\u00eetre subitement, voil\u00e0 qui a de quoi fasciner. Un nom, l'Atlantide, r\u00e9sume cette histoire ou ce r\u00eave. Le mot \u00e9voque une \u00eele\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\/spaw\/images\/picho_gruta_1.jpeg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":11332,"url":"https:\/\/www.laterredufutur.com\/accueil\/les-oceans-captent-plus-de-chaleur\/","url_meta":{"origin":3929,"position":5},"title":"Les oc\u00e9ans captent plus de chaleur","author":"Admin","date":"6 mars 2016","format":false,"excerpt":"Selon une nouvelle \u00e9tude publi\u00e9e dans la revue \"Nature climate change\", les oc\u00e9ans, qui captent 90 % de la chaleur suppl\u00e9mentaire g\u00e9n\u00e9r\u00e9e par le r\u00e9chauffement de la plan\u00e8te, en ont absorb\u00e9 autant au cours des deux derni\u00e8res d\u00e9cennies que depuis 1865. \"Nous avons calcul\u00e9 que la moiti\u00e9 de la chaleur\u2026","rel":"","context":"Dans &quot;Climat&quot;","block_context":{"text":"Climat","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/climat\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/05\/ocean.jpg?fit=820%2C420&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/05\/ocean.jpg?fit=820%2C420&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/05\/ocean.jpg?fit=820%2C420&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/05\/ocean.jpg?fit=820%2C420&ssl=1&resize=700%2C400 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/3929","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=3929"}],"version-history":[{"count":1,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/3929\/revisions"}],"predecessor-version":[{"id":3931,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/3929\/revisions\/3931"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media\/3930"}],"wp:attachment":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media?parent=3929"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/categories?post=3929"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/tags?post=3929"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}