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Ash Concentration Forecast at VAAC Buenos Aires

Soledad Osores 1, Eliana Vazquez1, Micaela Maurizi2, Leonardo Mingari3, Arnau Folch3, Juan Augusto Díaz1, Michael Pavolonis4, Justin Sieglaff5

  • Affiliations: 1Servicio Meteorológico Nacional, Argentina; 2Universidad de Buenos Aires, Argentina; 3GeoBarceona, Spain; 4NOAA/NESDIS, United States of America; 5Univ. Wisconsin, United States of America 

  • Presentation type: Talk [Invited]

  • Presentation time: Thursday 09:30 - 09:45, Room R280

  • Programme No: 6.4.5

  • Theme 6 > Session 4

Abstract

In the coming years, Volcanic Ash Advisory Centers (VAAC) will have to provide a new product called Quantitative Volcanic Ash Information (QVA) to optimize the use of airspace in the presence of ash in the atmosphere. The QVA consists of numerical ash concentration forecasts that provide deterministic and probabilistic information taking into account established thresholds of danger for aircraft, which correspond to low, medium, high, and very high concentrations. In this context, the Buenos Aires VAAC is developing an ensemble-based ash concentration forecast system using the FALL3D dispersal model.   Preliminary model sensitivity studies determined that the input parameters whose uncertainty generates the greatest impact on model outputs are the height of the eruptive column, the shape of the emission profile, and the meteorological field. Based on this, ensemble-based simulations are generated by slightly changing these critical parameters, which allows quantifying the uncertainty in the transport and dispersion of the ash and giving the range of possible affected areas according to the different concentration thresholds. The simulations are verified with the detection and quantification of ash mass load retrieved from satellite observations. Trying to improve the ensemble by weighting the simulation that presents the best performance to the satellite data. This work continues to be developed in parallel with the standardization best practices shared among the 9 VAACs within the framework of International Civil Aviation Organisation (ICAO) and the collaboration across VAAC's modelers groups within the World Meteorological Organization's Advisory Group on Volcanic Ash Science.