An optical method for measuring temperature in laboratory models of mantleplumes

We present a method for measuring radiat temperature profiles in laboratory thermal plumes using the deflection of a laser beam that passes through th e fluid. Plumes are created by injecting hot corn syrup into a column of co ld syrup at a well-defined rate. Every second a new radial temperature prof ile can be taken, which makes the method suitable for monitoring time-depen dent phenomena. we compare the thermal structure of stationary plume condui ts and of propagating solitary waves with numerical results obtained with a 2-D axisymmetric convection code. The agreement is excellent and shows tha t accurate high-resolution temperature profiles can be obtained without per turbing the flow.