REFIR- A multi-parameter system for near real-time estimates of plume-height and mass eruption rate during explosive eruptions

Abstract

Meaningful forecasting of the atmospheric concentration and ground accumulation of volcanic ash during explo-sive eruptions requires detailed knowledge of the eruption source parameters. However, due to the large uncer-tainties in observations and limitations of current models used to make inferences from these, monitoring anongoing eruption and quantifying the mass eruption rate in real-time is a considerable challenge. Within theEU supersite project“FutureVolc”, an integrated approach has been applied to develop a quasi-autonomousmulti-parameter system, denoted“REFIR”, for monitoring volcanic eruptions in Iceland and assessing the erup-tion massflow rate by inverting the plume height information and taking account of these uncertainties. REFIRhas the capability to ingest and process streaming plume-height data provided by a multitude of ground basedsensors, including C–and X-band radars and web-cam based plume height tracking systems. These observationaldata are used with a suite of plume models that also consider the current wind and other atmospheric conditions,providing statistically assessed best estimates of plume height and mass eruption rate. Provided instrumentaldata is available, near real-time estimates are obtained (the delay corresponding to the scan rate of data-providing instruments, presently of the order of minutes). Using the Hekla 2000, and Eyjafjallajökull 2010 erup-tions in Iceland, the potential of REFIR is demonstrated and discussed through application to three scenarios. Thesystem has been developed to provide maximumflexibility. A setup script assists the user in adapting to localconditions, allowing implementation of REFIR for any volcanic eruption site worldwide. REFIR is designed to beeasily upgradable, allowing future extension of monitoring networks, learning from new events, and incorpora-tion of new technologies and model improvements. This article gives an overview of the basic structure, modelsimplemented, functionalities and the computational techniques of REFIR.