Hazard from volcanic ash

Prata, A. J.; Barton, I. J.; Johnson, R. W.; Kamo, Kosuke; Kingwell, Jeff

doi:10.1038/354025a0

Cited by 22 publications

(9 citation statements)

References 3 publications

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“…Safe air travel activity requires clean flight corridors 1 . But in Earth's atmosphere, particles (sand from desert storms, incinerated residues lofted into clouds and volcanic ash erupted at volcanoes) are often present and their concentrations must be carefully monitored through initiatives such as the International Airways Volcano Watch created by the International Civil Aviation Organization 2 3 4 . Particles present in the atmosphere, whether volcanic ash, dust or sand, may present a critical risk to aviation safety 5 6 .…”

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confidence: 99%

Volcanic ash melting under conditions relevant to ash turbine interactions

et al. 2016

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The ingestion of volcanic ash by jet engines is widely recognized as a potentially fatal hazard for aircraft operation. The high temperatures (1,200–2,000 °C) typical of jet engines exacerbate the impact of ash by provoking its melting and sticking to turbine parts. Estimation of this potential hazard is complicated by the fact that chemical composition, which affects the temperature at which volcanic ash becomes liquid, can vary widely amongst volcanoes. Here, based on experiments, we parameterize ash behaviour and develop a model to predict melting and sticking conditions for its global compositional range. The results of our experiments confirm that the common use of sand or dust proxy is wholly inadequate for the prediction of the behaviour of volcanic ash, leading to overestimates of sticking temperature and thus severe underestimates of the thermal hazard. Our model can be used to assess the deposition probability of volcanic ash in jet engines.

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confidence: 99%

Volcanic ash melting under conditions relevant to ash turbine interactions

et al. 2016

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“…However, if the eruption goes unnoticed because the volcano is in a remote location, the weather conditions are unfavourable for satellite detection, or the satellite overpass misses it, several hours might pass before the thread is recognized and warning can be given. Thus already Prata et al (1991) proposed an instrument on board aircraft to sense volcanic ash by its IR emission signature. A portable camera applicable for this purpose was presented in Prata and Bernardo (2009).…”

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confidence: 99%

Early in-flight detection of SO<sub>2</sub> via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes

et al. 2011

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Abstract. Volcanic ash constitutes a risk to aviation, mainly due to its ability to cause jet engines to fail. Other risks include the possibility of abrasion of windshields and potentially serious damage to avionic systems. These hazards have been widely recognized since the early 1980s, when volcanic ash provoked several incidents of engine failure in commercial aircraft. In addition to volcanic ash, volcanic gases also pose a threat. Prolonged and/or cumulative exposure to sulphur dioxide (SO 2 ) or sulphuric acid (H 2 SO 4 ) aerosols potentially affects e.g. windows, air frame and may cause permanent damage to engines. SO 2 receives most attention among the gas species commonly found in volcanic plumes because its presence above the lower troposphere is a clear proxy for a volcanic cloud and indicates that fine ash could also be present.Up to now, remote sensing of SO 2 via Differential Optical Absorption Spectroscopy (DOAS) in the ultraviolet spectral region has been used to measure volcanic clouds from ground based, airborne and satellite platforms. Attention has been given to volcanic emission strength, chemistry inside volcanic clouds and measurement procedures were adapted accordingly. Here we present a set of experimental and model results, highlighting the feasibility of DOAS to be used as an airborne early detection system of SO 2 in two spatial dimensions. In order to prove our new concept, simultaneous airborne and ground-based measurements of the plume of Popocatépetl volcano, Mexico, were conducted Correspondence to: L. Vogel (leif.vogel@iup.uni-heidelberg.de) in April 2010. The plume extended at an altitude around 5250 m above sea level and was approached and traversed at the same altitude with several forward looking DOAS systems aboard an airplane. These DOAS systems measured SO 2 in the flight direction and at ±40 mrad (2.3 • ) angles relative to it in both, horizontal and vertical directions. The approaches started at up to 25 km distance to the plume and SO 2 was measured at all times well above the detection limit. In combination with radiative transfer studies, this study indicates that an extended volcanic cloud with a concentration of 10 12 molecules cm −3 at typical flight levels of 10 km can be detected unambiguously at distances of up to 80 km away. This range provides enough time (approx. 5 min) for pilots to take action to avoid entering a volcanic cloud in the flight path, suggesting that this technique can be used as an effective aid to prevent dangerous aircraft encounters with potentially ash rich volcanic clouds.

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“…The spectral basis for identification lies in the spectral reflectance/ emissivity differences between volcanic cloud and meteorological water/ice cloud. Based on studies of the thermal infrared channels 4 and 5 on AVHRR(full-width-half-maximum band passes of 10.3-11.3 and 11.5-12.5um, respectively) Prata et al suggested that meteorological cloud could be characterized by T4-T5,whereas volcanic cloud typically indicated T4<T5 [13] [14] .Influenced by atmospheric water vapor content, therefore Split window channel threshold method is more suitable for the dry season [15] .…”

Section: Principles and Methodsmentioning

confidence: 97%

Study on the volcanic ash cloud with Feng Yun-3 meteorological satellite data

Gong

Jiang

et al. 2013

SPIE Proceedings

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Volcano eruption can produce a mass of volcanic ash floating in the air for a long period, which will seriously threaten the aerial planes safety, and cause the air pollution, it could do harm to people's living environment and their health. Take the Iceland Eyjafjallajokull volcano as an example which erupted in April to May 2010, the volcano ash cloud were derived with the visible and infrared scanning radiometer of FengYun-3(FY-3 VIRR) meteorological satellite data. The medium wave infrared (MWIR) and the thermal infrared split windows (THIR-SW) data were used separately. the MODIS THIR-SW data were also be used to retrieve ash cloud to test the results derived from FY-3 VIRR data. It showed that the MWIR was more applicable for the ash cloud retrieving than the THIR-SW with FY-3 VIRR data, and the threshold value should be adjusted to around negative 1 rather than 0 for VIRR THIR-SW data. And the threshold should be adjusted with the THIR-SW of FY-3. The ash cloud radiation and bright temperature(BT), spatial distribution characteristics were also analyzed quantitatively with the two channels data. The study could provide parameters for the prediction of volcanic ash cloud dispersion simulate. When the real temperature of lava flow were high enough, the sensor will show a false bright temperature, how to retrieve the real temperature of the higher lava flow is a problem need to be studied in the future.Key words： Volcanic ash cloud，FengYun-3 VIRR, Medium wave infrared，Thermal infrared split windows GONG Cai-lan (1974~):

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Hazard from volcanic ash

Cited by 22 publications

References 3 publications

Volcanic ash melting under conditions relevant to ash turbine interactions

Volcanic ash melting under conditions relevant to ash turbine interactions

Early in-flight detection of SO<sub>2</sub> via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes

Study on the volcanic ash cloud with Feng Yun-3 meteorological satellite data

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Hazard from volcanic ash

Cited by 22 publications

References 3 publications

Volcanic ash melting under conditions relevant to ash turbine interactions

Volcanic ash melting under conditions relevant to ash turbine interactions

Early in-flight detection of SO&lt;sub&gt;2&lt;/sub&gt; via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes

Study on the volcanic ash cloud with Feng Yun-3 meteorological satellite data

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Early in-flight detection of SO<sub>2</sub> via Differential Optical Absorption Spectroscopy: a feasible aviation safety measure to prevent potential encounters with volcanic plumes