{"id":6919,"date":"2023-01-12T10:11:26","date_gmt":"2023-01-12T09:11:26","guid":{"rendered":"https:\/\/www.mio.osupytheas.fr\/fr\/impact-des-cendres-de-leruption-volcanique-de-tonga-en-2022-sur-les-signatures-satellitaires-de-la-couleur-de-locean\/"},"modified":"2023-01-12T10:11:26","modified_gmt":"2023-01-12T09:11:26","slug":"impact-of-ash-from-the-tonga-volcanic-eruption-in-2022-on-satellite-colour-signatures-of-locean","status":"publish","type":"post","link":"https:\/\/www.mio.osupytheas.fr\/en\/impact-des-cendres-de-leruption-volcanique-de-tonga-en-2022-sur-les-signatures-satellitaires-de-la-couleur-de-locean\/","title":{"rendered":"Impact of ash from the Tonga volcanic eruption in 2022 on satellite signatures of ocean colour"},"content":{"rendered":"<div id=\"basic-page-content\" class=\"page-content\">    <div class=\"content\">    <div class=\"container\">      <div class=\"row\">        <div class=\"col-xs-12\">                      <div class=\"container clearfix\">              <div class=\"row\">                <div class=\"col-xs-12\">                                  <\/div>              <\/div>            <\/div>                                <div class=\"body\">              <div class=\"field field-name-body field-type-text-with-summary field-label-hidden\"><div class=\"field-items\"><div class=\"field-item even\" property=\"content:encoded\"><p>An article by Andra Whiteside (MIO), C\u00e9cile Dupouy (MIO) Awnesh Singh, Philipson Bani, Jing Tan and Robert Frouinpublished in January 2023 in Frontiers in Marine Science<\/p><p>A powerful eruption from the Hunga Tonga-Hunga Ha'apai (HTHH) volcano in the Kingdom of Tonga occurred on 15 January 2022.<br>The volcanic explosion was enormous, leading many scientists to investigate the impact and scale of the event via satellite observations.<br>This study describes a new ocean colour signature based on a discoloured water spot created by the HTHH eruption.<br>\u00a0The high concentration of chlorophyll-a at the surface, ranging from 0.15 to 2.7 mg.m-3, was not associated with a<br>to the growth of phytoplankton, but to the basaltic and andesitic ash expelled by the volcano and into the ocean.<br>volcano and in the ocean, leading to erroneous estimates of Chl-a.<br>The gradual reduction in light attenuation or the diffuse attenuation coefficient.<br>for downwelling radiation at 490 nm, Kd(490), was interpreted as being due to the ash sinking into the ocean.<br>due to the sinking of ash particles over time. It is suggested that due to the high<br>high porosity of 30-40%, a density close to that of seawater, the ash particles remain in the water.<br>suspended in the water column for more than 10 days with sustained high values of chlorine content derived by satellite.<br>high values of satellite-derived Chl-a, Kd(490), and the particle backscatter coefficient at 443 nm.<br>particles at 443 nm. This is due to the strong attenuation of the light caused by the ash, which reduces the depth of penetration to less than 10 metres.<br>penetration depth of less than 10 metres during the first period after the eruption<br>the eruption may have had implications for ecological processes and the<br>biogeochemical cycles in Tongan waters.<\/p><h4><a href=\"https:\/\/www.researchgate.net\/publication\/366883902_Impact_of_ashes_from_the_2022_Tonga_volcanic_eruption_on_satellite_ocean_color_signatures\" target=\"_blank\" rel=\"noopener\">More information<\/a><\/h4><p>\u00a0<\/p><\/div><\/div><\/div>            <\/div>                            <\/div>      <\/div>    <\/div>  <\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>Un article d&#8217;Andra Whiteside (MIO), C\u00e9cile Dupouy (MIO) Awnesh Singh, Philipson Bani, Jing Tan and Robert Frouinparu paru en janvier 2023 dans Frontiers in Marine ScienceUne puissante \u00e9ruption au sein [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":4489,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-6919","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-actualites"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/posts\/6919","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/comments?post=6919"}],"version-history":[{"count":0,"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/posts\/6919\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/media\/4489"}],"wp:attachment":[{"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/media?parent=6919"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/categories?post=6919"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mio.osupytheas.fr\/en\/wp-json\/wp\/v2\/tags?post=6919"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}