{"id":14714,"date":"2021-01-03T08:20:59","date_gmt":"2021-01-03T07:20:59","guid":{"rendered":"http:\/\/www.on4cn.be\/blog_radio\/?p=14714"},"modified":"2021-01-03T08:20:59","modified_gmt":"2021-01-03T07:20:59","slug":"nuages-noctilucents-pour-en-savoir","status":"publish","type":"post","link":"http:\/\/www.on4cn.be\/blog_radio\/2021\/01\/03\/nuages-noctilucents-pour-en-savoir\/","title":{"rendered":"NUAGES NOCTILUCENTS Pour en savoir"},"content":{"rendered":"
\n
NOCTILUCENT CLOUDS Let\u2019s know a bit more<\/span><\/strong><\/center><\/p>\n

Forwarded by our friend Dr. Volket Stracke DL8JDX<\/strong>, this new issue guides us through a very interesting world.<\/p>\n

Something strange is happening 50 miles above Antarctica<\/strong>. Or rather, not<\/em> happening. Noctilucent clouds (NLCs), which normally blanket the Frozen Continent<\/strong> in December, are almost completely missing. These images from NASA’s AIM spacecraft compare Christmas Eve 2019 with Christmas Eve 2020.\"\"<\/p>\n

“The comparison really is astounding<\/em>,” says Cora Randall<\/em> of the University of Colorado’s Laboratory for Atmospheric and Space Physics. “Noctilucent cloud frequencies are close to zero this year<\/em>.”<\/p>\n

NLCs are Earth’s highest clouds. They form when summertime wisps of water vapor rise up from the poles to the edge of space. Water crystallizing around specks of meteor dust 83 km (~50 miles) above Earth’s surface creates beautiful electric-blue structures<\/a>, typically visible from November to February in the South, and May to August in the North.<\/p>\n

“The southern hemisphere stratosphere is very unusual this year<\/em>” says Randall. “The ozone hole is exceptionally large, until recently zonal winds have been blowing in the wrong direction, and overall the stratosphere is much more ‘winter-like’ than it should be in December<\/em>”<\/p>\n

Hours after publication of this news item, NASA’s AIM satellite reported an uptick of NLC activity<\/a> over Antarctica<\/strong>. “It’s still nowhere as many clouds as last year, but it makes sense given the recent steep drop in zonal wind speed and ozone hole area<\/em>” notes Randall. “The atmosphere definitely has a mind of its own this season!<\/em>“\"\"<\/p>\n

Thanks and credit to:<\/strong> http:\/\/www.spaceweather.com<\/a> and to Volker DL8JDX<\/strong><\/p>\n

Pic aside (Photographer<\/strong>: Jorgelina Alvarez<\/a>) shows a noctilucent cloud s as viewed from Base Marambio<\/a> (WAP ARG-21) in Antarctica<\/strong>.<\/p>\n

Raltime <\/strong>Noctilucent Cloud Photo Gallery can be seen at: <\/strong> https:\/\/spaceweathergallery.com\/nlc_gallery.html<\/a><\/p>\n

<\/p>\n

Version traduite en Fran\u00e7ais via Google Translate<\/span><\/b><\/center>
\n
NUAGES NOCTILUCENTS Pour en savoir un peu plus<\/span><\/b><\/center><\/p>\n

Transmis par notre ami Dr. Volket Stracke DL8JDX <\/strong>, ce nouveau num\u00e9ro nous guide \u00e0 travers un monde tr\u00e8s int\u00e9ressant.<\/p>\n

Quelque chose d’\u00e9trange se passe \u00e0 50 miles au-dessus de l ‘ Antarctique <\/strong>. Ou plut\u00f4t, pas <\/em>. Nuages \u200b\u200bNoctilucent (NLC), qui recouvrent normalement le Frozen
\nContinent <\/strong> en d\u00e9cembre, sont presque compl\u00e8tement absents. Ces images du vaisseau spatial AIM de la NASA comparent la veille de No\u00ebl 2019 avec la veille de No\u00ebl 2020.
\n\"\"<\/p>\n

\u00ab La comparaison est vraiment stup\u00e9fiante <\/em>\u00bb, d\u00e9clare Cora Randall <\/em> du Laboratoire de physique atmosph\u00e9rique et spatiale de l\u2019Universit\u00e9 du Colorado. ‘
\n La fr\u00e9quence des nuages \u200b\u200bnocturnes est proche de z\u00e9ro cette ann\u00e9e <\/em>. ‘<\/p>\n

Les NLC sont les nuages \u200b\u200bles plus hauts de la Terre. Ils se forment lorsque des m\u00e8ches d’\u00e9t\u00e9 de vapeur d’eau montent des p\u00f4les au bord de l’espace. L’eau cristallise autour de grains de poussi\u00e8re de m\u00e9t\u00e9ore 83
\nkm (~ 50 miles) au-dessus de la surface de la Terre cr\u00e9e de belles structures bleu \u00e9lectrique<\/a>,
\ng\u00e9n\u00e9ralement visible de novembre \u00e0 f\u00e9vrier dans le sud et de mai \u00e0 ao\u00fbt dans le nord.<\/p>\n

\u00ab La stratosph\u00e8re de l’h\u00e9misph\u00e8re sud est tr\u00e8s inhabituelle cette ann\u00e9e <\/em>\u00bb, d\u00e9clare Randall. ‘ Le trou d’ozone est exceptionnellement grand, jusqu’\u00e0 r\u00e9cemment, les vents zonaux ont
\nsoufflait dans la mauvaise direction, et dans l\u2019ensemble, la stratosph\u00e8re ressemble beaucoup plus \u00e0 l\u2019hiver qu\u2019elle ne devrait l\u2019\u00eatre en d\u00e9cembre <\/em> ‘<\/p>\n

Quelques heures apr\u00e8s la publication de cet article, le satellite AIM de la NASA a signal\u00e9
\nune augmentation de l’activit\u00e9 NLC<\/a> sur Antarctica<\/strong>. ‘ Il n’y a toujours pas autant de nuages \u200b\u200bque l’ann\u00e9e derni\u00e8re, mais cela a du sens \u00e9tant donn\u00e9 la r\u00e9cente forte baisse
\ndans la vitesse du vent zonale et la zone du trou d’ozone <\/em> \u00bb, note Randall. ‘L’atmosph\u00e8re a d\u00e9finitivement son propre esprit cette saison! <\/em>‘
\n\"\"<\/p>\n

Merci et cr\u00e9dit \u00e0:<\/strong> http:\/\/www.spaceweather.com<\/a> et \u00e0 Volker DL8JDX<\/strong><\/p>\n

Photo de c\u00f4t\u00e9 (Photographer<\/strong>: Jorgelina Alvarez<\/a>) montre un nuage nocturne comme vu de la base Marambio <\/a> (WAP ARG-21) en Antarctique <\/strong>.<\/p>\n

Raltime <\/strong>Noctilucent Cloud Photo Gallery can be seen at: <\/strong> https:\/\/spaceweathergallery.com\/nlc_gallery.html<\/a><\/p>\n

Info de la Source Publi\u00e9 * ICI<\/span><\/b><\/a><\/p>\n<\/article>\n","protected":false},"excerpt":{"rendered":"

NOCTILUCENT CLOUDS Let\u2019s know a bit more 2 Gennaio 2021 Forwarded by our friend Dr. Volket Stracke DL8JDX, this new issue guides us through a very interesting world. Something strange is happening 50 miles above Antarctica. Or rather, not happening. Noctilucent clouds (NLCs), which normally blanket the Frozen Continent in December, are almost completely missing. … Continuer la lecture de « NUAGES NOCTILUCENTS Pour en savoir »<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35,24,25],"tags":[],"class_list":["post-14714","post","type-post","status-publish","format-standard","hentry","category-info","category-trafic-radio","category-trafic-radioamatuer"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t