But not all sulfur is of anthropogenic origin. For instance, there are numerous active volcanoes along the Chilean Andes (> 100!!!!) which can put substantial amounts of SOx in the troposphere and the stratosphere. We are studying the dispersion and deposition of SOx emitted in connection with fumarolic and eruptive activity of the Láscar volcano. One of the few volcanoes in Chile that have been somewhat characterized with respect to emissions. This is also functional to a better understanding of the circulation over the high Andes, and issue that is also very fascinating.