{"id":4816,"date":"2012-06-27T07:35:00","date_gmt":"2012-06-27T07:35:00","guid":{"rendered":"https:\/\/nilu.gnist.dev\/2012\/06\/gode-askedata-berget-flytrafikken\/"},"modified":"2012-06-27T07:35:00","modified_gmt":"2012-06-27T07:35:00","slug":"good-volcanic-ash-data-saves-european-air-traffic","status":"publish","type":"post","link":"https:\/\/nilu.gnist.dev\/en\/2012\/06\/good-volcanic-ash-data-saves-european-air-traffic\/","title":{"rendered":"Good volcanic ash data saves European air traffic"},"content":{"rendered":"

By Bjarne R\u00f8sj\u00f8<\/p>\n

\"Kjetil
\u201cIt was primarily observational data from satellites that enabled us to have good enough estimates of the ash concentrations from the eruption,\u201d says Kjetil T\u00f8rseth, director of the Department for Atmospheric and Climate Research at NILU. Photo: Ingar N\u00e6ss<\/figcaption><\/figure>\n

When Iceland\u2019s Eyjafjallaj\u00f6kull volcano erupted in April and May 2010, hurling vast quantities of ash into the atmosphere, both Norwegian and international aviation authorities were poorly prepared. It had been a long time since anything like this had happened in Europe, and the ash cloud from Eyjafjallaj\u00f6kull grounded more planes than any previous volcanic eruption. Millions of airline passengers remained \u201ctrapped by volcanic ash\u201d, and the airlines lost huge amounts of money.<\/p>\n

But when Iceland\u2019s Grimsv\u00f6tn volcano in Iceland erupted a year later, on 21 May 2011, both the Norwegian and international aviation authorities were far better prepared. On Tuesday 24 May, the London Volcanic Ash Advisory Centre (VAAC), based at the UK Met Office, warned that the airspace above Haugesund, Stavanger and Kristiansand forecast high enough concentrations of ash so that it would be inadvisable to fly, and making it likely that thousands of passengers would be stranded starting at 14.00 that day.<\/p>\n

An emergency meeting<\/strong><\/h2>\n

In spite of these warnings, Norwegian air traffic was able to continue as normal because the country\u2019s aviation authorities had entered into a unique collaboration with a number of Norwegian research institutions. Experience from the Eyjafjallaj\u00f6kull eruption led the Civil Aviation Authority to established Agency Volcanic Ash Group (EVA), with representatives and experts from the Civil Aviation Authority, Avinor, the Norwegian Meteorological Institute and the Norwegian Institute for Air Research (NILU).<\/p>\n

When the Grimsv\u00f6tn volcano erupted, EVA members were called into an emergency meeting, where scientists were able to present reliable satellite data on the probability that the airspace over the southwestern part of Norway would not be subject to high concentrations of ash.<\/p>\n

This was a historic decision: Norway was the first country in Europe that chose to rely on its national expertise instead of warnings from the VAAC, and the Civil Aviation Authority allowed air traffic to proceed normally in an area where the VAAC had warned that ash concentrations would be unacceptably high. This decision resulted in savings for airlines and prevented a great number of travellers from suffering the inconvenience of being unnecessarily grounded.<\/p>\n

\"\"
The ash cloud that ascended into the atmosphere right after the eruption of Grimsv\u00f6tn in May 2011 Photo: Wikimedia commons, Calistemon<\/figcaption><\/figure>\n

The Agency Group\u2019s decision was sent to the airlines just minutes before air traffic over large parts of southern Norway would have been paralyzed. The EVA subsequently had daily meetings until the volcano\u2019s eruptions calmed down, and it turned out that the Norwegian forecasts were accurate. Norwegian airlines thus avoided significant economic losses from rescheduling several hundred flights, while air traffic over Iceland, northern Sweden, Denmark, Germany and Scotland was hit hard.<\/p>\n

Satellite data kept the air space open<\/strong><\/h2>\n

\u201cIt was primarily observational data from satellites that enabled us to have good enough estimates of the ash concentrations from the eruption. EVA is a concrete example of how good working relationship between the research community and regulatory agencies can provide results that benefit society,\u201d says Kjetil T\u00f8rseth, director of NILU\u2019s Department of Atmospheric and Climate Research.<\/p>\n

NILU has studied the spread and detection of volcanic ash clouds for a number of years, and has monitored the spread of ash clouds with the aid of satellite-borne instruments that were originally designed to detect radiation and clouds. \u201cResearchers at NILU have developed methods that make it possible to use data from these instruments to determine whether there is ash in the atmosphere. These algorithms proved their worth when the Grimsv\u00f6tn volcano erupted in May 2011,\u201d T\u00f8rseth says.<\/p>\n

The Eyjafjallaj\u00f6kull eruption in 2010 led to several changes in international aviation authority regulations. \u201cWhen Eyjafjallaj\u00f6kull erupted, regulations were issued that prohibited commercial flights if there was any ash whatsoever in the air. But this was too restrictive, so threshold levels were established that would allow planes to fly in low levels of ash if certain procedures were followed. In May 2011, the VAAC in London forecasted that these threshold limits could be exceeded in southern Norway, while our satellite data showed lower ash concentrations than the limits,\u201d T\u00f8rseth said.<\/p>\n

Although the Norwegian government chose to ignore the VAAC advice to close the air space, it does not mean that the watchdogs in London did a bad job. Providing forecasts of ash concentrations is actually a very difficult task.<\/p>\n

\u201cBringing in national, in addition to international expertise, provided an improved basis for decision-making. In addition, this made it possible to take advantage of local knowledge and made for closer proximity to the important decisions that had to be taken,\u201d T\u00f8rseth said.<\/p>\n","protected":false},"excerpt":{"rendered":"

Tre dager etter et vulkanutbrudd på Island i mai 2011, advarte Met Office i London om at aske i luftrommet over store deler av Sør-Norge kunne representere en fare for flytrafikken. Men norske eksperter hadde egne modeller og gode satellittdata, og konkluderte med at flytrafikken kunne gå som normalt.<\/p>\n","protected":false},"author":1,"featured_media":3524,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_searchwp_excluded":"","footnotes":""},"categories":[21],"tags":[],"class_list":["post-4816","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-newsarchive"],"acf":[],"_links":{"self":[{"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/posts\/4816","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/comments?post=4816"}],"version-history":[{"count":2,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/posts\/4816\/revisions"}],"predecessor-version":[{"id":4818,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/posts\/4816\/revisions\/4818"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/media\/3524"}],"wp:attachment":[{"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/media?parent=4816"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/categories?post=4816"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nilu.gnist.dev\/en\/wp-json\/wp\/v2\/tags?post=4816"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}