Assessing RAT (Robust AVHRR Techniques) performances for volcanic ash cloud detection and monitoring in near real-time : The 2002 eruption of Mt. Etna (Italy)

Abstract Performances of the recently proposed RAT (Robust AVHRR Techniques) approach in detecting and monitoring eruptive ash clouds by satellite have been assessed. The Mt. Etna (Sicily, Italy) eruption of 2002, producing intense ash emissions has been used as a study case. Potentialities and limitations of two different RAT configuration schemes (i.e. two and three channel based) have been investigated, both in terms of reliability (i.e. accurate detection) and sensitivity (detailed ash cloud properties description) and tested for several days after the eruption onset, also in different observational conditions. The main outcomes of this assessment study are: i) the more complete, three-channel scheme seems to offer accurate ash detection and discrimination from meteorological clouds with a high level of reliability, better than traditional satellite schemes; ii) on the other hand, the simplified RAT configuration performs well in ash cloud monitoring and tracking, providing a better description of cloud characteristics and properties (e.g. size, shape, direction, etc.). Consequently, a specific protocol has been suggested and experimented, with both the two configuration schemes applied in cascade; it provides a first, accurate and reliable ash detection and discrimination and, afterwards, a more detailed description of the previously identified eruptive cloud, also in terms of its internal structure and density. Preliminary, qualitative validations of the derived ash cloud ‘structure’, performed by comparison with some independent satellite observations, have also been briefly presented.

[1]  C. Bertrand,et al.  Estimation of the 2002 Mount Etna eruption cloud radiative forcing from Meteosat-7 data , 2003 .

[2]  Vincenzo Cuomo,et al.  Assessing the potential of thermal infrared satellite surveys for monitoring seismically active areas: The case of Kocaeli (İzmit) earthquake, August 17, 1999 , 2005 .

[3]  Alfred J Prata,et al.  Infrared radiative transfer calculations for volcanic ash clouds , 1989 .

[4]  Valerio Tramutoli,et al.  Two years of operational use of Subpixel Automatic Navigation of AVHRR scheme: accuracy assessment and validation , 2003 .

[5]  Fred Prata,et al.  An evaluation of volcanic cloud detection techniques during recent significant eruptions in the western 'Ring of Fire' , 2004 .

[6]  Frank W. Burcham,et al.  EVEN MINOR VOLCANIC ASH ENCOUNTERS CAN CAUSE MAJOR DAMAGE TO AIRCRAFT. , 2002 .

[7]  Arlin J. Krueger,et al.  The February-March 2000 eruption of Hekla, Iceland from a satellite perspective , 2013 .

[8]  Teodosio Lacava,et al.  Improving volcanic ash cloud detection by a robust satellite technique , 2004 .

[9]  T. Casadevall,et al.  The 1989–1990 eruption of Redoubt Volcano, Alaska: impacts on aircraft operations , 1994 .

[10]  David C. Pieri,et al.  Analyses of in‐situ airborne volcanic ash from the February 2000 eruption of Hekla Volcano, Iceland , 2002 .

[11]  Valerio Tramutoli,et al.  SANA: Sub-pixel automatic navigation of AVHRR imagery , 2000 .

[12]  J. Simpson,et al.  Response to “Comments on ‘Failures in detecting volcanic ash from a satellite-based technique’” , 2001 .

[13]  Valerio Tramutoli,et al.  Robust AVHRR techniques (RAT) for environmental monitoring: theory and applications , 1998, Remote Sensing.

[14]  David J. Schneider,et al.  Satellite images offer aircraft protection from volcanic ash clouds , 1996 .

[15]  David C. Pieri,et al.  Operational implications of airborne volcanic ash , 2000 .

[16]  Arlin J. Krueger,et al.  Comparison of TOMS and AVHRR volcanic ash retrievals from the August 1992 eruption of Mt. Spurr , 1999 .

[17]  William I. Rose,et al.  Integrating retrievals of volcanic cloud characteristics from satellite remote sensors: a summary , 2000, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[18]  Alfred J Prata,et al.  Observations of volcanic ash clouds in the 10-12 μm window using AVHRR/2 data , 1989 .

[19]  Jay R. Herman,et al.  Detection of volcanic ash clouds from Nimbus 7/total ozone mapping spectrometer , 1997 .

[20]  David C. Pieri,et al.  Failures in detecting volcanic ash from a satellite-based technique , 2000 .

[21]  V. Tramutoli,et al.  AVHRR automated detection of volcanic clouds , 2005 .

[22]  Teodosio Lacava,et al.  Robust satellite techniques for volcanicand seismic hazards monitoring , 2004 .

[23]  Frank W. Burcham,et al.  ENGINE DAMAGE TO A NASA DC-8-72 AIRPLANE FROM A HIGH-ALTITUDE ENCOUNTER WITH A DIFFUSE VOLCANIC ASH CLOUD , 2003 .

[24]  Donald W. Hillger,et al.  Improved detection of airborne volcanic ash using multispectral infrared satellite data , 2003 .

[25]  David C. Pieri,et al.  The February 2001 Eruption of Mount Cleveland, Alaska: Case Study of an Aviation Hazard , 2002 .

[26]  William I. Rose,et al.  Retrieval of sizes and total masses of particles in volcanic clouds using AVHRR bands 4 and 5 , 1994 .

[27]  Fred Prata,et al.  Comments on "Failures in detecting volcanic ash from a satellite-based technique" , 2001 .

[28]  Stefano Natali,et al.  Terminal settling velocity measurements of volcanic ash during the 2002–2003 Etna eruption by an X‐band microwave rain gauge disdrometer , 2005 .

[29]  Clive Oppenheimer,et al.  Review article: Volcanological applications of meteorological satellites , 1998 .

[30]  David J. Schneider,et al.  Observations of Volcanic Clouds in Their First Few Days of Atmospheric Residence: The 1992 Eruptions of Crater Peak, Mount Spurr Volcano, Alaska , 2001, The Journal of Geology.

[31]  David J. Schneider,et al.  Tracking of 1992 eruption clouds from Crater Peak vent of Mount Spurr Volcano, Alaska, using AVHRR , 1995 .

[32]  Scott E. Hannon,et al.  Quantifying tropospheric volcanic emissions with AIRS: The 2002 eruption of Mt. Etna (Italy) , 2005 .

[33]  L. Mona,et al.  Raman lidar observations of aerosol emitted during the 2002 Etna eruption , 2004 .