{"id":632,"date":"2024-02-25T16:18:38","date_gmt":"2024-02-25T15:18:38","guid":{"rendered":"http:\/\/vandiepenbeeck.org\/?p=632"},"modified":"2024-02-25T16:27:57","modified_gmt":"2024-02-25T15:27:57","slug":"du-vent-mais-de-quelle-force-echelle-de-beaufort","status":"publish","type":"post","link":"http:\/\/vandiepenbeeck.org\/?p=632","title":{"rendered":"Du vent ? Mais, de quelle force ? \u00c9chelle de Beaufort"},"content":{"rendered":"\n<p>L\u2019\u00e9chelle de Beaufort est une \u00e9chelle qui permet d\u2019estimer la vitesse <strong><em>moyenne<\/em><\/strong> du vent. Elle a \u00e9t\u00e9 \u00e9tablie par l\u2019amiral britannique Francis Beaufort (1774-1857), \u00e0 une \u00e9poque o\u00f9 les bateaux ne poss\u00e9daient pas d\u2019instruments de mesure du vent. Elle est compos\u00e9e de crit\u00e8res permettant d\u2019avoir une id\u00e9e de la force du vent.<\/p>\n\n\n\n<p>Cette \u00e9chelle est compos\u00e9e de degr\u00e9 variant de 0 \u00e0 12. Les crit\u00e8res \u00e9taient bas\u00e9s sur des \u00e9l\u00e9ments visibles d\u2019un navire&nbsp;: l\u2019\u00e9tat de la mer, la pr\u00e9sence de moutons (sommet de vagues blanch\u00e2tres), train\u00e9es d\u2019embrun, amplitude des vagues. Ces degr\u00e9s sont utiles au temps de la marine \u00e0 voile. Il fallait savoir quand r\u00e9duire la voilure pour \u00e9viter des d\u00e9m\u00e2tages entre autres.<\/p>\n\n\n\n<p>Par la suite, on a ajout\u00e9 des crit\u00e8res pour estimer la force du vent sur Terre. Ces crit\u00e8res sont bas\u00e9s sur le comportement des fum\u00e9es, des mouvements du feuillage, du soul\u00e8vement des poussi\u00e8res, de l\u2019agitation des drapeaux, du comportement des branches et du tronc d\u2019arbres, l\u2019apparition de d\u00e9g\u00e2ts (voir figure 1).<\/p>\n\n\n\n<p>Remarque, on ne peut pas attribuer un degr\u00e9 Beaufort (unit\u00e9 Bf) aux rafales.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"469\" src=\"http:\/\/vandiepenbeeck.org\/wp-content\/uploads\/2024\/02\/576_310.jpg\" alt=\"\" class=\"wp-image-633\" srcset=\"http:\/\/vandiepenbeeck.org\/wp-content\/uploads\/2024\/02\/576_310.jpg 800w, http:\/\/vandiepenbeeck.org\/wp-content\/uploads\/2024\/02\/576_310-300x176.jpg 300w, http:\/\/vandiepenbeeck.org\/wp-content\/uploads\/2024\/02\/576_310-768x450.jpg 768w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><\/figure>\n\n\n\n<p>\u00c9chelle de Beaufort (source : https:\/\/otake.frenchboard.com\/t1223-echelle-de-beaufort)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>L\u2019\u00e9chelle de Beaufort est une \u00e9chelle qui permet d\u2019estimer la vitesse moyenne du vent. Elle a \u00e9t\u00e9 \u00e9tablie par l\u2019amiral britannique Francis Beaufort (1774-1857), \u00e0 une \u00e9poque o\u00f9 les bateaux ne poss\u00e9daient pas d\u2019instruments de mesure du vent. Elle est compos\u00e9e de crit\u00e8res permettant d\u2019avoir une id\u00e9e de la force du vent. Cette \u00e9chelle est [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-632","post","type-post","status-publish","format-standard","hentry","category-meteo"],"_links":{"self":[{"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=\/wp\/v2\/posts\/632"}],"collection":[{"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=632"}],"version-history":[{"count":2,"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=\/wp\/v2\/posts\/632\/revisions"}],"predecessor-version":[{"id":635,"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=\/wp\/v2\/posts\/632\/revisions\/635"}],"wp:attachment":[{"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=632"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/vandiepenbeeck.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}