Artificial cloud test confirms volcanic ash detection using infrared spectral imaging

作者：Prata A J^*; Dezitter F; Davies I; Weber K; Birnfeld M; Moriano D; Bernardo C; Vogel A; Prata G S; Mather T A; Thomas H E; Cammas J; Weber M

来源：Scientific Reports, 2016, 6(1): 25620.

DOI：10.1038/srep25620

Airborne volcanic ash particles are a known hazard to aviation. Currently, there are no means available to detect ash in flight as the particles are too fine (radii < 30 mu m) for on-board radar detection and, even in good visibility, ash clouds are difficult or impossible to detect by eye. The economic cost and societal impact of the April/May 2010 Icelandic eruption of Eyjafjallajokull generated renewed interest in finding ways to identify airborne volcanic ash in order to keep airspace open and avoid aircraft groundings. We have designed and built a bi-spectral, fast-sampling, uncooled infrared camera device (AVOID) to examine its ability to detect volcanic ash from commercial jet aircraft at distances of more than 50 km ahead. Here we report results of an experiment conducted over the Atlantic Ocean, off the coast of France, confirming the ability of the device to detect and quantify volcanic ash in an artificial ash cloud created by dispersal of volcanic ash from a second aircraft. A third aircraft was used to measure the ash in situ using optical particle counters. The cloud was composed of very fine ash (mean radii similar to 10 mu m) collected from Iceland immediately after the Eyjafjallajokull eruption and had a vertical thickness of similar to 200 m, a width of similar to 2 km and length of between 2 and 12 km. Concentrations of similar to 200 mu g m(-3) were identified by AVOID at distances from similar to 20 km to similar to 70 km. For the first time, airborne remote detection of volcanic ash has been successfully demonstrated from a long-range flight test aircraft.

• 出版日期2016-5-9