Lightning Mapping Observations of the 2006 Eruption of Augustine Volcano, Alaska

In January of 2006 Mt. Augustine erupted explosively producing ash plumes that often exceeded 9 km in altitude. A small Lightning Mapping Array was deployed east of Mt. Augustine in Alaska and was in operation for the eruption on January 28, 2006. Our observations show a lightning sequence in the volcanic plume (called the plume phase), which began approximately ten minutes following the onset of the eruption, and extended to distances up to 22 km from Augustine's vent. Though only two stations were deployed for this eruption, one station functioned as a sea-surface interferometer. This has enabled us to determine some altitudes of the VHF sources. Using interferometry techniques combined with time-of-arrival analysis, the lightning sequence on January 28, 2006 has been analyzed. We will present details of the temporal evolution of the lightning activity that developed in the volcanic plume as it drifted southward. In addition, we will compare and contrast our observations of volcanic plume lightning with thunderstorm lightning.