{"id":6703,"date":"2016-04-02T11:55:59","date_gmt":"2016-04-02T10:55:59","guid":{"rendered":"http:\/\/www.grandesterresbio.com\/?p=6703"},"modified":"2016-04-02T11:55:59","modified_gmt":"2016-04-02T10:55:59","slug":"dou-vient-la-rosee-printaniere","status":"publish","type":"post","link":"https:\/\/claire-jannot.com\/?p=6703","title":{"rendered":"D’o\u00f9 vient la ros\u00e9e printani\u00e8re ?"},"content":{"rendered":"
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Parce que la m\u00e9t\u00e9o \u00e0 cette saison y est propice, que ce soit \u00e0 la tomb\u00e9e de la nuit ou au petit matin. Plusieurs conditions doivent \u00eatre r\u00e9unies pour que des gouttelettes viennent emperler l\u2019herbe ou les arbustes\u2009: le sol doit \u00eatre froid et l\u2019air proche de lui charg\u00e9 d\u2019une certaine humidit\u00e9. Plus en hauteur, l\u2019air doit \u00eatre plus sec.<\/h2>\n<\/header>\n
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Guttation sur une pr\u00eale des eaux (Equisetum fluviatile)<\/p><\/div>\n

Pr\u00e9cis\u00e9ment, la temp\u00e9rature du sol doit descendre en dessous du\u00ab\u00a0point de ros\u00e9e\u00a0\u00bb, une donn\u00e9e thermodynamique qui d\u00e9pend de la pression et de l\u2019humidit\u00e9 ambiantes.<\/strong> Par exemple, lorsque l\u2019air est \u00e0 10\u00a0\u00b0C et 60\u00a0% d\u2019humidit\u00e9, le point de ros\u00e9e vaut 2,5\u00a0\u00b0C environ.<\/span><\/p>\n

Les fra\u00eeches nuits printani\u00e8res favorisent la ros\u00e9e.\u00a0<\/strong>Alors, au contact d\u2019une plante ou tout autre surface se trouvant en dessous de cette temp\u00e9rature, les mol\u00e9cules d\u2019eau contenues dans l\u2019air se condensent et la recouvrent de mille gouttelettes.<\/p>\n

Un ph\u00e9nom\u00e8ne favoris\u00e9 par les fra\u00eeches nuits printani\u00e8res o\u00f9 le ciel est d\u00e9gag\u00e9 et le vent de moins de 5\u00a0km\/h.<\/strong> L\u2019\u00e9t\u00e9, l\u2019humidit\u00e9 est souvent insuffisante et la temp\u00e9rature trop \u00e9lev\u00e9e\u2009; l\u2019automne, le vent souffle souvent trop fort\u2009; tandis que l\u2019hiver, l\u2019air est parfois si froid qu\u2019\u00e0 la place de la ros\u00e9e se forme la \u201cgel\u00e9e blanche\u201d, compos\u00e9e de mol\u00e9cules d\u2019eau givr\u00e9e.<\/span><\/p>\n

Source : Fiorenza Gracci –\u00a0D\u2019apr\u00e8s S&V Questions-R\u00e9ponses n\u00b015<\/em><\/span><\/h6>\n
Cr\u00e9dit photo :\u00a0I, Luc Viatour [GFDL (http:\/\/www.gnu.org\/copyleft\/fdl.html), CC-BY-SA-3.0 (http:\/\/creativecommons.org\/licenses\/by-sa\/3.0\/) ou CC BY-SA 2.5-2.0-1.0 (http:\/\/creativecommons.org\/licenses\/by-sa\/2.5-2.0-1.0)], via Wikimedia Commons<\/span><\/h6>\n<\/div>\n

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Parce que la m\u00e9t\u00e9o \u00e0 cette saison y est propice, que ce soit \u00e0 la tomb\u00e9e de la nuit ou au petit matin. Plusieurs conditions doivent \u00eatre r\u00e9unies pour que des gouttelettes viennent emperler l\u2019herbe ou les arbustes\u2009: le sol … Continuer la lecture →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"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":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[2],"tags":[39,4,27,21],"class_list":["post-6703","post","type-post","status-publish","format-standard","hentry","category-ecologie","tag-eau","tag-ecologie2","tag-insolite","tag-jardin"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5jjt5-1K7","_links":{"self":[{"href":"https:\/\/claire-jannot.com\/index.php?rest_route=\/wp\/v2\/posts\/6703","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/claire-jannot.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/claire-jannot.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/claire-jannot.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/claire-jannot.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6703"}],"version-history":[{"count":2,"href":"https:\/\/claire-jannot.com\/index.php?rest_route=\/wp\/v2\/posts\/6703\/revisions"}],"predecessor-version":[{"id":6706,"href":"https:\/\/claire-jannot.com\/index.php?rest_route=\/wp\/v2\/posts\/6703\/revisions\/6706"}],"wp:attachment":[{"href":"https:\/\/claire-jannot.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6703"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/claire-jannot.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6703"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/claire-jannot.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6703"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}