Response to “Comments on ‘Failures in detecting volcanic ash from a satellite-based technique’”

Simpson, Joseph; Hufford, Gary L.; Pieri, David C.; Berg, Jared S.

doi:10.1016/s0034-4257(01)00230-9

Cited by 26 publications

(25 citation statements)

References 13 publications

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“…Recent discussion in the literature , Simpson et al, 2001 has, however, highlighted the need for improved communication between the 'operational' and 'research' communities regionally and worldwide.…”

Section: The Iavw In the Western 'Ring Of Fire'mentioning

confidence: 99%

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

Tupper

Carn

Davey

et al. 2004

Remote Sensing of Environment

108

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We examined recent volcanic cloud events in the Western Pacific and Indonesian area, to validate the performance of remote sensing techniques used to support the International Airways Volcano Watch (IAVW). Five events were considered, during which eruptions from eight volcanoes injected ash into the upper troposphere or lower stratosphere. For one of the eruptions, at Miyakejima, Japan, at least five aircraft encountered volcanic ash clouds, and the cost to three operators alone exceeded US $12,000,000 in aircraft repairs, diversions, and lost operating time. We performed 'reverse' absorption and 'pattern analysis' using GMS-5/VISSR, MODIS and AVHRR data, and we examined TOMS SO 2 and Aerosol Index data, surface-based observations, pilot reports, and dispersion model output. Our results verify that the introduction of 'reverse' absorption using the geostationary GMS-5 platform significantly enhanced our capacity to monitor volcanic ash clouds in the region. In one case, we tracked an eruption cloud for approximately 80 hours. The primary impediment to remote monitoring is the presence of overlying cloud, or substantial amounts of ice within the volcanic clouds. TOMS data showed success in identifying volcanic clouds during these conditions, but was limited by the infrequency of observations. More effective future operation of the IAVW relies on developing complementary methods of volcanic cloud remote sensing, and greatly increasing the amount and quality of available surface and air observations, including observations of precursor activity. An understanding of the likely future limitations of remote sensing techniques will aid in the refining of IAVW procedures.

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Section: The Iavw In the Western 'Ring Of Fire'mentioning

confidence: 99%

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

Tupper

Carn

Davey

et al. 2004

Remote Sensing of Environment

108

View full text Add to dashboard Cite

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“…Class separation, however, is especially difficult as ⌬T approaches zero . In fact, volcanoes with low levels of silicate in their plumes [e.g., Soufriere Hills (Montserrat), Bogoslof (Alaska), or White Island (New Zealand)] are especially difficult to differentiate from meteorological clouds (Simpson et al 2001). Other factors [atmospheric water vapor, ice, chemical composition and particle size distribution, particle shape (departure from spherical), errors in radiometric calibration, surface emissivity, groundwater and juvenile water in the magma, optically active coatings (e.g., sulfuric acid)] also may compromise accurate detection using the split-window technique (also see Simpson et al 2000Simpson et al , 2001Pieri et al 2002, and the references contained therein).…”

Section: Satellite-based Retrievals a Split-window Detection Of Airbmentioning

confidence: 99%

“…There is currently no requirement for the VAACs to issue such advisories. Other factors (e.g., total precipitable water vapor or ice coating of the particles) may further complicate interpretation of the T 4 Ϫ T 5 signal (Simpson et al 2000). Therefore, care should be exercised by VAACs to consider these problems.…”

Section: Volume 18 W E a T H E R A N D F O R E C A S T I N Gmentioning

confidence: 99%

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Airborne Asian Dust: Case Study of Long-Range Transport and Implications for the Detection of Volcanic Ash

Simpson¹,

Hufford²,

Servranckx³

et al. 2003

Wea. Forecasting

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The transport of fine-grained Asian dust from its source (e.g., the Gobi Desert, Mongolia) to North America is a common springtime phenomenon. Because of its chemical composition (silicon, iron, aluminum, and calcium) and its particle size distribution (mean aerodynamic diameter 2-4 m), Asian dust produces a negative signal in the split-window T 4 Ϫ T 5 algorithm, as does airborne volcanic ash. The split-window algorithm is commonly used by operational volcanic ash advisory centers. Thus, it is important to find ways to differentiate between airborne Asian dust and airborne volcanic ash. Use of Total Ozone Mapping Spectrometer aerosol and sulfur dioxide indices, in conjunction with the split-window method, can mitigate the possibility of a false airborne volcanic ash alarm. Asian dust also is important for other reasons. Thus, meteorological agencies should monitor it because 1) it can be transported thousands of kilometers from its source region and thus is of global interest (e.g., effects on radiative forcing) and 2) fine-grain particles pose a potentially serious public health hazard.

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“…However, these traditional satellite techniques, although performing quite well under specific conditions (e.g. low water vapour or ice concentration inside the plume, suitable temperature contrast between surface background and ash clouds), generally show unstable behaviour, with performances depending on local conditions as well as on the nature and features of erupted ash clouds (Ellrod and Connel 1999, Simpson et al 2000, Prata et al 2001, Simpson et al 2001, Ellrod et al 2003.…”

Section: Introductionmentioning

confidence: 99%

Assessment and validation in time domain of a Robust Satellite Technique (RST_ASH) for ash cloud detection

Marchese

Filizzola

Mazzeo

et al. 2011

Geomatics, Natural Hazards and Risk

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The Robust Satellite Technique (RST) approach is a general scheme of satellite data analysis used to study several natural and environmental hazards. In this paper, the results of a long-term time domain analysis, performed on its RST ASH configuration, specifically tailored to detect and track volcanic ash clouds, are presented. One year of satellite sub-scenes provided by the Advanced Very High Resolution Radiometer (AVHRR), covering an area of about 90 000 km 2 around Mt Etna volcano (Italy), was analysed in order to assess RST ASH performances in periods of ash emissions, as well as during unperturbed conditions (i.e. no ash events). The results and limits of such an approach are discussed, together with possible further improvements achievable by its implementation to different satellite sensor data, e.g. EOS-MODIS and MSG-SEVIRI.

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Response to “Comments on ‘Failures in detecting volcanic ash from a satellite-based technique’”

Cited by 26 publications

References 13 publications

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

Airborne Asian Dust: Case Study of Long-Range Transport and Implications for the Detection of Volcanic Ash

Assessment and validation in time domain of a Robust Satellite Technique (RST_ASH) for ash cloud detection

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Response to “Comments on ‘Failures in detecting volcanic ash from a satellite-based technique’”

Cited by 26 publications

References 13 publications

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western ‘Ring of Fire’

Airborne Asian Dust: Case Study of Long-Range Transport and Implications for the Detection of Volcanic Ash

Assessment and validation in time domain of a Robust Satellite Technique (RSTASH) for ash cloud detection

Contact Info

Product

Resources

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Assessment and validation in time domain of a Robust Satellite Technique (RST_ASH) for ash cloud detection