An unmanned aerial vehicle may be used to monitor and/or track airborne material in a plume. The unmanned aerial vehicle may be configured to eject a tracer material into the plume. The unmanned aerial vehicle may include a sensor for detecting the tracer material. The sensor may detect the position, the velocity, the concentration, amount reacted, etc. of the tracer material. The unmanned aerial vehicle and/or a remote vehicle or facility may include an electromagnetic radiation emitter to irradiate the tracer material. The sensor may measure the interactions of the electromagnetic radiation with the tracer material. The unmanned aerial vehicle and/or a remote system may determine characteristics of the plume and/or a substance of interest based on measurements by the sensor.