Sakurajima and Colima: two candidates for our next field campaign
Lab experiments and theoretical consideration will never be enough to catch the complexity of a natural system. Fieldcampaigns are absolutely necessary to observe lightning in its natural environment. Although volcanic lightning has beenobserved in many explosive volcanoes, the selection of a volcano for a field campaign is not so easy. First of all, explosiveevents must be frequent enough, and flashes large enough to be catch by our instruments. Second, observation spots mustallow to observe the crater in complete safety. Although we are attuned to any report of new eruptions, we scrutinize inparticular two volcanoes, Sakurajima and Colima, whose electric activity we know to be high.
Sakurajima volcano, in Kyūshū island (Japan), has always been considered as one of the best volcanoes to observelightning. Its frequent explosions (a few per day), the frequent occurrence of lightning as well as the presence of a welldeveloped monitoring network run by the Sakurajima Volcano Observatory (SVO) enabled four successful fieldcampaigns in 2013 and 2015. Unfortunately, since the end of 2015, its activity has become less regular.
On the graph below (from SVO last report), the explosions are represented by the red triangles while the daily maximumheight of the emitted ash plume is represented in black. After a first pause between November 2015 and January 2016, thevolcanic activity had resumed. But at the end of June 2016, the activity stopped again. But we will definitively stay tunedto spot any activity resume.
The Volcán de Colima in central-west Mexico is our plan B. It would be an excellent alternative, since it is eruptingcontinuously since January 2013. Even last week, several ash clouds have been spotted by the Washington Volcanic Ash Advisory Center (VAAC). Logistically, this volcano is harder to reach and to observe than Sakurajima, and field trips willrequire more preparation.
