Fall AGU Session announcement - V055: Volcanic Ash Dynamics 2: Aggregation and Deposition
From: Alexa Van Eaton <alexa.vaneaton@xxxxxxxxx>
****************************************************************************************
Dear Colleagues,
We draw your attention and invite submissions to the following session at Fall AGU: Volcanic Ash Dynamics 2: Aggregation and Deposition.
Particle
aggregation reduces the atmospheric lifetime of fine grained ash
particles generated by explosive volcanism. Ash cloud dispersion
forecast models generally do not include this process due to gaps in our
understanding of aggregation mechanisms and governing factors. This
omission means that model forecasts tend to underestimate proximal fine
ash fallout and overestimate airborne ash concentrations 100s to 1000s
km from the volcano. This can have substantial impacts when models are
used both for long-term land-use planning and in operational settings
for hazard mitigation. For example, during the 2010 and 2011 Icelandic
volcanic ash cloud crises, large regions of airspace were closed based
on model predictions of high fine grained ash concentrations over Europe
even though available
observations indicated that the amount of ash in the atmosphere was
much lower.
Key
aggregate formation processes and basic classification are topics of
ongoing debate. Several questions remain unanswered: Is aggregation
driven primarily by hydrometeor formation? How does
aggregation vary in time and space? What is the role of electrostatic
charge and 'secondary minerals'? How do instabilities (e.g., mammatus)
change deposition rates? What proportion of fine grained ash ends up in
aggregates? Where does particle aggregation mainly occur (e.g.,
vertical plume, horizontal cloud, during atmospheric sedimentation)?
This
session welcomes (1) field observations and classification; (2) remote
sensing observations; (3) field and laboratory experiments; and (4)
numerical modeling to address these key issues.
We particularly encourage interdisciplinary submissions from
atmospheric physics, and preliminary results on any aspect of
aggregation in volcanic clouds.
Conveners:
Costanza Bonadonna, University of Geneva, Switzerland
Adam Durant, Norwegian Institute for Air Research, Norway
Jennie Gilbert, Lancaster University, UK
Alexa Van Eaton, Victoria University of Wellington, New Zealand
---------------------------------------------------------------
Alexa R. Van Eaton
PhD Candidate, Volcanology
Victoria University of Wellington
PO Box 600 Wellington, New Zealand
Office: +64 4 463 5233 x8197
Victoria University of Wellington
PO Box 600 Wellington, New Zealand
Office: +64 4 463 5233 x8197
Mobile: +64 21 129 9695
==============================================================
Volcano Listserv is a collaborative venture among Arizona State University (ASU), Portland State University (PSU), the Global Volcanism Program (GVP) of the Smithsonian Institution's National Museum of Natural History, and the International Association for Volcanology and Chemistry of the Earth's Interior (IAVCEI).
ASU - http://www.asu.edu/ PSU - http://pdx.edu/ GVP - http://www.volcano.si.edu/ IAVCEI - http://www.iavcei.org/
To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxx.
To contribute to the volcano list, send your message to: volcano@xxxxxxx. Please do not send attachments.
==============================================================
