Balloon-based SO2 measurements of the Hunga Tonga-Hunga Ha'apai eruption plume

摘要: The SO2 sonde was deployed to the Maïdo Observatory in La Réunion as part of the Tonga volcano Rapid Response Experiment (TR2Ex). During 21-25 January 2022, the SO2 sonde measured SO2 in the stratospheric Hunga Tonga-Hunga Ha'apai volcanic plume during four free-release balloon flights. One additional sounding did not pass through the plume. On all five of those launches, an SO2 sonde was paired with a Particle Optical Particle Spectrometer (POPS), measuring the aerosol size distribution. Two soundings (21-22 January) that passed through the plume had ozonesondes on the same payload. In each case, there was a notch (depletion) in the ozone profile at the plume, suggesting some ozone was destroyed. SO2 interference in the electrochemical cells (ECC) accounted for less than 10% of the notches at the plume in those two ozonesonde profiles. Thus, over 90% of the missing ozone in those …