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Meteorology and Volcanology - areas of cooperation

 

In the last week of March 2010, a workshop convened by the World Meteorological Organisation, in collaboration with the International Civil Aviation Organisation, discussed scientific issues related to volcanic clouds and aviation safety. The volcano observatories represented included USGS,  Istituto Nazionale di Geofisica e Vulcanologia (Italy),  OVSICORI-UNA (Costa Rica) , and New Zealand Geological & Nuclear Sciences, and Servicio Nacional de Geología y Minería de Chile. 

 

One of the break-out sessions at the workshop discussed relationships betwen volcano observatories and meterological agencies, and how they could work together better (and even where the two are combined, they may exist in quite separate divisions).  Given the interest in the current eruption at Eyjafjallajokull and the very important cooperation between meteorologists and volcanologists, the summary text of the session may be worth sharing.  Any comment to Andrew Tupper (andrewcraigtupper at gmail.com). 

 

 5th International Workshop on Volcanic Ash, Santiago, Chile 22-26 March 2010 - extract from draft report

 

a) Data-sharing for the International Airways Volcano Watch 

Given the good representation of volcano observatories at the Workshop, the opportunity was taken to have discussions on scientific data-sharing needs and related issues required for the purposes of the IAVW.

The group considered that:

·     the scientific data that should be shared should be that which helps each agency reach a professional and consistent analysis of the situation,

·     data analysis should be performed by the agency with the appropriate expertise (for example, seismic station data by the Volcano Observatory (VO), and

 ·     documented data-sharing arrangements between VOs, National Meteorological and Hydrological Services (NMHSs) , and Volcanic Ash Advisory Centres (VAACs) should ideally be agreed in advance of a volcanic crisis.

Observatories have been requested to use the Volcano Observatory Notice for Aviation (VONA) format for their analysis of volcanic activity for aviation purposes, including for the critical role of eruption prediction. In general the data contained in this or equivalent communications should suffice for operational purposes, although there may be occasions where other information might be usefully added by mutual agreement or individual initiative.

An example of this last point might be for information about possible ‘remobilised ash’, where dry ash can be blown off a deposit for many decades after an event.  These clouds can be seen in remote sensing and pose an aviation hazard, but the events also bear much in common with sandstorms despite the lower melting point of ash and the associated explicit aviation hazard.

In order to produce the analysis contained in a VONA, the data needs of the Volcano Observatories from other IAVW participants will vary according to local arrangements, but may include:

·     Pilot, ship, and ground-based meteorological observer observations of volcanic activity, including cloud height

·     Radar observations of a volcanic plume

·     Lightning data indicating the possibility of eruptions at a volcano

·     Satellite-based analysis of volcanic plumes

·     Satellite-derived ‘hot spot’ observations (noting that many NMHSs and all  VAACs are in receipt of meteorological satellite data including ‘hot spot’ channels in real-time)

·     Archived VAAs for post analysis

·        Post event analysis results, including that information sent to the Smithsonian Institution.

Where a volcanic eruption has no ground-based monitoring in place, the above observations tend to take on particular importance, but even with instrumental monitoring, multiple sources of information are often required to establish volcanic plume height, which can significantly affect volcanological assessment of the scale of an eruption as well as the scale of plume dispersion.

 

b) Data-sharing for general disaster risk reduction

 

The Handbook on the International Airways Volcano Watch, ICAO Doc 9766-AN/968, which sets out communications between Selected State Observatories and other parties for the purposes of aviation safety, suggests that, consistent with the Hyogo Framework for Action 2005-2015,  “in order to enhance stronger linkages, coherence and integration with States' disaster risk reduction units, Contracting States are encouraged to send back to States' volcano observatories any relevant information regarding volcanic ash to the extent and in a form agreed between the VAAC and the VO concerned”.

Further to this, the group noted informally that a number of volcanic hazards are closely related to atmospheric processes, and that close cooperation between VO, VAACs and NMHSs would indeed be useful in providing a comprehensive and consistent natural hazards warning system in the States concerned.  Areas of interest include:

1)      Ashfall modelling and dispersion modelling.  Volcano observatories are becoming increasingly interested and proficient in modelling ashfall using real-time numerical model data and combined dispersion models such as Fall3d & VOL-CALPUFF.  Ashfall is an important volcanic hazard because of the immediate risk to life and property close to the source, as well as a disruption to life and to industries such as agriculture further away from the source.  Ashfall on airports has caused considerable disruption during many eruptions, and this can have the further effect of inhibiting airborne relief efforts.

Ashfall modelling and long-term dispersion modelling for airborne volcanic cloud warnings are typically conducted on different scales and at different model resolutions (with terrain a particular consideration for mesoscale ashfall patterns), but it would nevertheless be useful to ensure consistent input meteorology to the extent possible, and that, regardless of which agency takes formal responsibility for ashfall, NMHSs, VOs, and VAACs closely coordinate for efficiency of effort, ensure the best possible meteorological and volcanological input, and possibly seek assistance from a WMO Regional Specialised Meteorological Centre in obtaining suitable numerical weather prediction data.

The group also noted that quantitative estimates of ash depth are an important factor in ashfall prediction.  Currently, ash concentration is more qualitative for VAAC dispersion modelling, since there is no defined ‘safe’ concentration, but this may change in the future.  The group also noted the potential importance of an ensemble approach in future work.

2)      Rainfall-triggered volcanic hazards.  Lahars (volcanic mudflows) are a common, highly destructive, and frequently fatal volcanic hazard and are generally rainfall triggered.  Rainfall is also known to trigger lava dome collapses in some situations, causing highly dangerous pyroclastic flows.  Rainfall intensity and duration forecasting by NMHSs can be highly useful for assisting VOs and disaster mitigation agencies in mitigating these hazards.

3)      Volcanic landslides, ashfall, submarine eruptions and pyroclastic flows, into the sea pose shipping hazards. Landslides and volcanic eruptions may cause localised tsunami, and major volcanic eruptions or collapses may cause basin or ocean-wide tsunami.  Incorporation of warnings and eruption analysis from VOs will be important in the further development of global tsunami warning systems.