{"id":896,"date":"2008-03-17T10:42:00","date_gmt":"2008-03-17T09:42:00","guid":{"rendered":"https:\/\/kids.esa.int\/a_swirling_atmospheric_sink_on_venus\/"},"modified":"2026-10-08T00:33:30","modified_gmt":"2026-10-07T22:33:30","slug":"a_swirling_atmospheric_sink_on_venus","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/a_swirling_atmospheric_sink_on_venus\/","title":{"rendered":"Py\u00f6rteinen ilmakeh\u00e4n painuma Venuksessa"},"content":{"rendered":"
\n

Kuvittele planeetta, jolla on kaksi imuaukkoa, yksi pohjoisessa ja toinen etel\u00e4ss\u00e4. Kummassakin imuaukossa py\u00f6rii py\u00f6rre ilmakeh\u00e4n kaasuja, jotka py\u00f6riv\u00e4t suurella nopeudella sy\u00f6ksyess\u00e4\u00e4n kohti pintaa. N\u00e4in n\u00e4ytt\u00e4\u00e4 tapahtuvan Maan sisarplaneetalla Venuksella, ESA:n Venus Express -avaruusluotaimen havaintojen mukaan.<\/p>\n<\/div>\n

Euroopan robottitutkimusluotain on kiert\u00e4nyt Aurinkoa toiseksi l\u00e4himp\u00e4n\u00e4 olevaa planeettaa 11. huhtikuuta 2006 l\u00e4htien. Sen varhaisimmissa havainnoissa n\u00e4kyi etel\u00e4navan yl\u00e4puolella tumma, hurrikaanin kaltainen ilmi\u00f6 (jota kutsutaan py\u00f6rteeksi). Samanlainen pilvirakenne oli jo aiemmin havaittu pohjoisnavan yl\u00e4puolella.<\/p>\n

\"The
Hurrikaanin silm\u00e4<\/figcaption><\/figure>\n

Siit\u00e4 l\u00e4htien Venus Express on havainnoinut jatkuvasti Venuksen etel\u00e4napaa, ja \u201cpy\u00f6rteen\u201d keskusta on osoittautunut yll\u00e4tt\u00e4v\u00e4n vaihtelevaksi. 26. helmikuuta 2007 se oli tiimalasin muotoinen. 24 tuntia aiemmin se oli l\u00e4hes py\u00f6re\u00e4. Toisinaan se n\u00e4ytt\u00e4\u00e4 soikealta (munanmuotoiselta). Ilmeisesti t\u00e4m\u00e4 ilmi\u00f6 muuttaa muotoaan varsin nopeasti.<\/p>\n

Mik\u00e4 aiheuttaa t\u00e4m\u00e4n 2000 km leve\u00e4n py\u00f6rteen? Venus Express -luotain on osoittanut, ett\u00e4 sen keskusta on l\u00e4mpim\u00e4mpi kuin sen ymp\u00e4rist\u00f6. Aivan kuten hurrikaanin silm\u00e4, t\u00e4m\u00e4 kuumempi alue merkitsee kohtaa, jossa ilmakeh\u00e4n kaasut liikkuvat alasp\u00e4in, muodostaen painauman pilvien yl\u00e4puolelle.<\/p>\n

\u201cT\u00e4m\u00e4 valtava py\u00f6rre muistuttaa sit\u00e4, mit\u00e4 voi n\u00e4hd\u00e4 kylpyammeessa, kun tulppa on vedetty pois\u201d, sanoo Venus Express -tutkimusprojektin tutkija Giuseppe Piccioni.<\/p>\n

Tutkijat uskovat, ett\u00e4 auringon l\u00e4mp\u00f6 l\u00e4mmitt\u00e4\u00e4 hiilidioksidipitoista ilmakeh\u00e4\u00e4 p\u00e4iv\u00e4ntasaajalla. Kaasu nousee yl\u00f6sp\u00e4in ja liikkuu sitten kohti napaa. Napa-alueilla se laskeutuu muodostaen ilmakeh\u00e4n \u201cpoistovirtauksen\u201d.<\/p>","protected":false},"excerpt":{"rendered":"

Imagine a planet with two drains, one in the north and the other in the south. Each drain features a whirlpool of atmospheric gases which are swirling around at high […]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"esa_banner_image":"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2008\/03\/venus_s_polar_vortex2\/18246846-2-eng-GB\/Venus_s_polar_vortex.jpg","esa_banner_description":"Venus's polar vortex","esa_banner_credit":"ESA\/VIRTIS\/INAF-IASF\/Obs. de Paris-LESIA\/Univ. of Oxford","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2008\/03\/Venus_s_polar_vortex2","esa_external_url":"","esa_external_new_window":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"categories":[10,11,12],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-896","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-planets-and-moons"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/896","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/comments?post=896"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/896\/revisions"}],"predecessor-version":[{"id":4726,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/896\/revisions\/4726"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=896"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=896"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=896"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=896"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=896"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=896"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=896"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=896"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=896"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=896"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}