2-2-2-2-2-2-2-2-2-2-2-2-2 From: David Jessop <d.jessop@xxxxxxx> Dear colleagues, As the abstract deadline for the 2023 IAVCEI conference approaches, we would like to invite you to submit an abstract to our session entitled "*Dynamics of explosive eruption columns and clouds*", in the "*Using field data, geophysics, geochemistry, statistics and modelling to probe volcanic and plutonic systems <https://urldefense.com/v3/__https://confer.eventsair.com/iavcei2023/scientific-symposia__;!!IKRxdwAv5BmarQ!fXvGj8dcZTufvXSgjNqYyb4hni1wydQ5rzjcs8fmY6RZzJhXNGfay1yzBTf0_MBq2CCZ7PLvTfhb-vFh$>*" symposium. *Session Outline* Explosive volcanic eruptions are driven by rapid degassing of viscous magmas rising in the conduit and often produce substantial and sustained eruption columns (plumes). While stable plumes may reach heights of several tens of kilometres into the atmosphere where they spread laterally as a gravity current, unstable plumes partially or entirely collapse to produce ground-hugging pyroclastic density currents. The spectrum of plume behaviours exert a fundamental control on the volcanic risk and impacts on environment and society. For example, stable plumes are associated with reduced proximal risks but increased risk of shutdown of major aviation routes, and when the plume reaches the stratosphere, seasonal to multi-decadal impacts on climate. The particle size distribution is initially determined by fragmentation processes in the conduit and then modulated by ash aggregation and reactions between ash particles, and volcanic and atmospheric gases entrained into the plume. The stability and longevity of volcanic plumes is governed by a range of complex dynamics including the evolution of the size distribution of particles in the erupted mixture and also, crucially, the turbulent entrainment of atmosphere into the eruptive column which may itself be strongly affected by the particle size distribution. These complex interactions and feedbacks have a fundamental role in: i) determining plume stability, ii) determining proximal to medial tephra fall out, iii) serving as the starting conditions for pyroclastic density currents derived from plume collapse, and iv) determining the composition, phase and vertical distribution of gases and particulate injected by the column into the atmosphere. We invite contributions on recent advances on the topics identified above, whether these be in the form of analogue or theoretical (numerical) modelling, field-based, remote-sensing studies or any combination of these. Abstract submission <https://urldefense.com/v3/__https://confer.eventsair.com/iavcei2023/scientific-symposia__;!!IKRxdwAv5BmarQ!fXvGj8dcZTufvXSgjNqYyb4hni1wydQ5rzjcs8fmY6RZzJhXNGfay1yzBTf0_MBq2CCZ7PLvTfhb-vFh$> deadline is September 2, 2022 We look forward to receiving your abstracts and to seeing you in New Zealand! David Jessop, Thomas Aubry, Thomas Giachetti, Julia Eychenne, Elena Maters and Eric Breard 2-2-2-2-2-2-2-2-2-2-2-2-2 ------------------------------
