Publication Date:
2021-05-17
Description:
During AprileMay 2010 volcanic ash clouds from the Icelandic Eyjafjallajökull volcano reached Europe
causing an unprecedented disruption of the EUR/NAT region airspace. Civil aviation authorities banned
all flight operations because of the threat posed by volcanic ash to modern turbine aircraft. New
quantitative airborne ash mass concentration thresholds, still under discussion, were adopted for
discerning regions contaminated by ash. This has implications for ash dispersal models routinely used to
forecast the evolution of ash clouds. In this new context, quantitative model validation and assessment of
the accuracies of current state-of-the-art models is of paramount importance. The passage of volcanic
ash clouds over central Europe, a territory hosting a dense network of meteorological and air quality
observatories, generated a quantity of observations unusual for volcanic clouds. From the ground, the
cloud was observed by aerosol lidars, lidar ceilometers, sun photometers, other remote-sensing instruments
and in-situ collectors. From the air, sondes and multiple aircraft measurements also took
extremely valuable in-situ and remote-sensing measurements. These measurements constitute an
excellent database for model validation. Here we validate the FALL3D ash dispersal model by comparing
model results with ground and airplane-based measurements obtained during the initial 14e23 April
2010 Eyjafjallajökull explosive phase. We run the model at high spatial resolution using as input hourlyaveraged
observed heights of the eruption column and the total grain size distribution reconstructed
from field observations. Model results are then compared against remote ground-based and in-situ
aircraft-based measurements, including lidar ceilometers from the German Meteorological Service,
aerosol lidars and sun photometers from EARLINET and AERONET networks, and flight missions of the
German DLR Falcon aircraft. We find good quantitative agreement, with an error similar to the spread in
the observations (however depending on the method used to estimate mass eruption rate) for both
airborne and ground mass concentration. Such verification results help us understand and constrain the
accuracy and reliability of ash transport models and it is of enormous relevance for designing future
operational mitigation strategies at Volcanic Ash Advisory Centers.
Description:
Published
Description:
165-183
Description:
4.3. TTC - Scenari di pericolosità vulcanica
Description:
JCR Journal
Description:
restricted
Keywords:
Volcanic ash dispersion
;
Numerical model
;
Model validation
;
2010 Eyjafjallajökull eruption
;
04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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