1. Michele Prestifilippo
UPNV: Unità di Progetto Nubi Vulcaniche
Mauro Coltelli, Michele Prestifilippo, Simona Scollo, Gaetano Spata

2. 20 July
22 July
23 July
2001
Etna Eruption
24 July
Scollo et all. 2007

3. 58 days of continuous fallout
Merged
Pulsating
2002
Etna Eruption
58 days of continuous fallout
Sustained
Diluite
Andronico et all. in press JGR

4. 2002 Etna Eruption – Fallout problems
Catania
Via Etnea
Catania
Vincenzo Bellini International Airport

5. Main typologies of explosive eruptions at Etna volcano
Short-lasting eruptions
Duration from minutes to a few hours
Magnitude from violent strombolian to subplinian (from 4 to 15 km high eruptive plumes)
One plinian eruption in historical time (26 km high plume)
Occurrence more then 150 in the last 25 years
Frequency up to several tens in a few months
Long-lasting eruptions
Duration from days to a few months
Magnitude violent strombolian (low-troposphere plumes)
Occurrence only two in the last century but at least 8 occurred in the last four century

6. Bonadonna et Philips 2003

7. Tephra Dispersal Models Three dimensional Models
Lagrangian Models
PUFF (Searcy et al. 1998)
HYSPLIT (Draxler and Taylor 1982)
VOLCALPUFF (Barsotti et al. 2008)
Three dimensional Models
Numerically airborne particles are hypothetical :
Advected
Dispersed
Gravitationally settled through the atmosphere.

8. Tephra Dispersal Models
Gaussian Models
HAZMAP (Macedonio et al. 2005)
TEPHRA (Bonadonna et al. 2005)
Advection-Diffusion Models
Mass conservation equation
Constant Diffusion Coefficients
Vertical wind and diffusion negligible
Isotropic atmospheric diffusion in the plane (x,y)
Total mass ejected at t=0

9. Tephra Dispersal Models Three dimensional Models
Eulerian Models
FALL3D (Costa et al. 2006)
Three dimensional Models
Buoyant plume theory
Wind data from local models
Time dependent

10. Volcano Input Parameters
Meteorological Input Parameters
Wind distribution
Temperature
Pression
Humidity
Volcano Input Parameters
Erupted Mass
Topography
Column Height
Eruption Column Model
Total Grain-size Distribution
Particle Shape Factor

11. Meteorological Input Parameters
Meteorological data of ARPA/CINECA
EUMETSAT MSG

12. Volcano Input Parameters
Andronico et all. in press JGR

13. There are the following problems
Acquire meteorological data. (and validate it!)
Define in the most precision way the volcano input parameters values. (and validate it!)
Make a prediction of volcanic ash distribution on ground and on air. (and validate it!)

14. UPNV activities

15. Why is the parallelization required?
Ash forecasting is made everyday using 4 different tephra dispersal models and simulating 2 possible eruptive scenarios:
Eruptive scenarious
Eruption Time
Mass flow[kg/s]
Column height [km]
Grain-size [F]
Sigma
Test case
Weak Plumes
continua
5.E+04
3.5
0.5
1.5
Eruption
Strong Plumes
5 min
1.E+06 8
-0.5
22 July Eruption
The output produced is relative to 2 days with a time resolution of 3 hours and spatial resolution of 171x171x10 km.
In this way we obtain the result after the days of interest.
All the simulation codes are parallelized and scheduled hierarchically by a decentralized-supervisor scheduler allocated in the “Server UPNV”. The produced outputs are elaborated by the central server and are published in the web and sent to the Civil Protection Department (DPC).
Everyday the INGV receives the meteorological data at 06:00 GMT and the processing is complete at 10:30 GMT (4.5h << 64h).
The DPC receives the elaborated outputs at 07:30 GMT.

16. The scheduler
Supervised cluster

17. Volcanic ash forecasting

18. Volcanic Ash forecasting

19. Volcanic Ash forecasting

20. Volcanic Ash forecasting

21. The PUFF model
The output of the lagrangian PUFF modelis a collection of particles so the output is only qualitative but one simulation require few seconds.
We have worked to make a quantitative PUFF.
The new simulations require about 4 millions of particles and the new elaboration time is about 12 minutes so we have also parallelized the PUFF model.

22. Results
Reliable warning of 24/11/2006

23. Results
Reliable warning of 4/09/2007

24. Why is the validation/calibration required?
The real eruption can be notably different from the scenarios assumed.
The mismatch between field and simulated data can be due:
uncertainty of input parameters (calibration)
choice of the tephra dispersal model (validation)
Calibration and validation of models require data measurement and hundred or thousand simulations to verify the matching between field and simulated data, so the parallelization code is necessary to obtain a result within an acceptable time.
Computed data (kg/m2)
Field data (kg/m2)

25. Details about the hardware structure of the system will be explained in the following presentation.
Thanks