Pressure Change from Tonga Eruption

These readings from the Maunakea weather tower show a pressure change (middle plot, in orange) related to the volcanic eruption near Tonga in the South Pacific. This signal was first pointed out to us by Michitoshi Yoshida, Director of the Subaru Telescope. Note the average pressure — just over 0.6 bar (600 mb) or 60% average atmospheric pressure — reflecting the high altitude of the Maunakea site.