super(2) super(1) super(0) Po, an atmospheric tracer of long-range transport of volcanic plumes

With the aim of testing the ability of super(2) super(1) super(0) Po to be a tracer of volcanic aerosol plumes, we collected air samples during an oceanographic cruise around the Indonesian arc and measured the radioactivity of super(2) super(1) super(0) Po. Owing to the atmospheric circulation pattern and geographical distribution of super(2) super(1) super(0) Po sources around the sampling site, the origin of super(2) super(1) super(0) Po of the samples could be determined by calculating 5-day backward air mass trajectories. It is shown that the signature of super(2) super(1) super(0) Po originating from volcanic emissions is distinct from that of super(2) super(2) super(2) Rn decay, even though these processes are the 2 major sources of atmospheric super(2) super(1) super(0) Po. Moreover, the proportion of super(2) super(1) super(0) Po in a given air parcel is conservative during the transport: as other aerosols, super(2) super(1) super(0) Po aerosols are very sensitive to the atmospheric removal processes and the production and the loss of super(2) super(1) super(0) Po by radio decay within an air parcel is negligible. Our results confirm that super(2) super(1) super(0) Po is a good tracer for aerosols emitted by volcanoes.