Beschreibung:
<jats:p>Volcanic gas from an inaccessible fumarole at Aso volcano, Japan, was recently measured with a Fourier Transform InfraRed (FT‐IR) spectral radiometer. Absorption features of CO, COS, CO<jats:sub>2</jats:sub>, SO<jats:sub>2</jats:sub>, and HCl were identified in the volcanic plume spectra. This is the first time the five volcanic gas components are detected simultaneously by a remote technique. Based on the measured CO/CO<jats:sub>2</jats:sub> ratio of 2.6 × 10<jats:sup>−3</jats:sup>, the equilibrium temperature of the volcanic gas is estimated to be 750° ± 120°C.</jats:p>