Scientists Decode Trajectories in Plume (image) University of Washington Caption A plume of dust and hitchhiking microbes reached the West Coast and was detected at the Mount Bachelor observatory in April, 2011. It traveled from several Asian locations and at various levels in the troposphere (red and yellow being highest), according to scientists using models to determine the back trajectories. Credit U of Washington Usage Restrictions Credit required Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.