 The eruption of the Hungatonga-Hungahapai, HTVH, volcano on January 15, 2022 injected large amounts of water vapor, H2O, directly into the stratosphere. This caused significant changes in the atmosphere's refractive index, which can be measured using radio occultation, RO. By comparing these measurements with temperature data from the microwave limb sounder, MLS, researchers were able to identify the presence of H2O in the stratosphere. They found that the amount of H2O was between 110 and 140 TG, or about 8% of the global average for stratospheric H2O. The H2O was also found to have descended at a rate of minus 1 kilometer per day for the first few days after the eruption, before slowing down to minus 200 meters per day over the next week as it spread out. This article was authored by William J. Randall, Benjamin R. Johnston, John J. Braun, and others. We are article.tv, links in the description below.