H81 Department
            Wasser-Atmosphäre-Umwelt H81 Department Water, Atmosphere and Environment  H814 Institute of Meteorology Environmental Meteorology SAVAA Project

SAVAA - Support for Volcanic Ash Advisories

Staff: Petra Seibert

Project partners:


Volcanic eruptions can inject large quantities of volcanic ash and gases into the atmosphere at heights that range from the summit of the volcano to as high as 50 km. Winds can transport the ash and gases rapidly depending on the wind speed and the wind direction changing with height. The ash can cause extensive damage to aircraft. Volcanic gases, specifically SO2 may also pose a hazard to aircraft. The remoteness of volcanoes, the sporadic timings of eruptions and the ability of the upper atmosphere winds to quickly spread ash and gas, make satellite remote sensing a key tool for developing hazard warning systems. Volcanic Ash Advisory Centres (VAACs) are the principle authority for collecting and disseminating information related to volcanic ash and aviation. Volcanic ash advisories (VAAs) are issued to the aviation industry by the VAACs and in turn the VAACs rely on a complex system of data collection which includes weather observations, volcano observatory observations, satellite data information, “eye-witness” reports, pilot reports and invariably news reports.

A system will be developed to support VAACs. Two solutions are proposed:

  1. a webportal which allows VAACs to access data products and services developed through this project, and
  2. a system (VAS) which demonstrates how real-time satellite data can be ingested, processed and then used with FLEXVOL to deliver timely volcanic data analyses and forecasts.

Some features of VAS are its ability to include data and services from pre-existing sources (e.g. SACS or the new OMI system) and also its flexibility to permit use of other dispersion models. For example, FLEXVOL utilises FLEXPART at its core for providing atmospheric dispersion information, but this could be replaced with HYSPLIT, PUFF, NAME etc. The emphasis is on the systems integration of satellite products, dispersion and inverse modelling tailored to the needs of the VAACs.

Project is financed by ESA. ESA


Inverse modelling of the eruption at Kasatochi in August 2008:

- paper in the JGR Special Issue on Okmok and Kasatochi (see below)
- poster at EGU 2010 (link to pdf see below)
- paper in Geomatics, Natural Hazards and Risk EGU 2010 Special issue, sensitivity study for inverse modelling of Kasatochi SO2

Eyjafjall eruption April/May 2010

- Eyja eruption scientific background information
- Participation in the ESA-ESRIN Volcanic Ash workshop, May 2010 (see also publications below)
- Inverse modelling of ash paper in ACP and presentation in EGU 2011 (see below)

Related Links:

SAVAA home page (at NILU)
SAVAA entry at BOKU research information system (FIS)
Volcanic Ash Advisory Centers
Volcanic ash article on Wikipedia


Kristiansen, N. I., A. Stohl, A. J. Prata, A. Richter, S. Eckhardt, P. Seibert, A. Hoffmann, C. Ritter, L. Bitar, T. J. Duck, and K. Stebel (2010), Remote sensing and inverse transport modeling of the Kasatochi eruption sulfur dioxide cloud, in JGR, Special Issue "The 2008 Eruptions of Okmok and Kasatochi Volcanoes, Alaska", doi:10.1029/2009JD013286

C. Zähner (ed.): Monitoring volcanic ash from space - ESA-EUMETSAT workshop on the 14 April to 23 May 2010 eruption at the Eyjafjoll volcano, South Iceland. ESA-ESRIN, 26-27 May 2010, Publication: ESA STM-280 July 2010, ISBN: 978-92-9221-901-7, ISSN: 0379-4067, DOI: doi:10.5270/atmch-10-01, PDF

Stohl, A., Prata, A. J., Eckhardt, S., Clarisse, L., Durant, A., Henne, S., Kristiansen, N. I., Minikin, A., Schumann, U., Seibert, P., Stebel, K., Thomas, H. E., Thorsteinsson, T., Torseth, K., Weinzierl, B. (2011): Determination of time- and height-resolved volcanic ash emissions and their use for quantitative ash dispersion modeling: the 2010 Eyjafjallajökull eruption. Atmos. Chem. Phys., 11, 5541-5588,, in: Special Issue: Atmospheric implications of the volcanic eruptions of Eyjafjallajökull, Iceland 2010

Seibert Petra, Nina I. Kristiansen, Andreas Richter, Sabine Eckhardt, Alfred J. Prata & Andreas Stohl (2011): Uncertainties in the inverse modelling of sulphur dioxide eruption
profiles. Geomatics, Natural Hazards and Risk, 2, 201-216,
Note that there is a correction to this paper ( The content is that in Eq. 7, the term containing the a priori uncertainties of the source has to be removed. Results and conclusions of the paper are not affected.

N. I. Kristiansen, A. Stohl, A. J. Prata, N. Bukowiecki, H. Dacre, S. Eckhardt, S. Henne, M. C. Hort, B. T. Johnson, F. Marenco, B. Neininger, O. Reitebuch, P. Seibert, D. J. Thomson, H. N. Webster, B. Weinzierl (2012): Performance assessment of a volcanic ash transport model mini-ensemble used for inverse modeling of the 2010 Eyjafjallajökull eruption. J. Geoph. Res., 117, D00U11, doi:10.1029/2011JD016844.