This award is for support of a two year project to continue measurements of dust concentration along the Summit ice core using the 90o Laser-Light-Scattering (LLS) instrument developed under the previous grant (DPP-8922042). As part of this instrument there is a special heater that melts ice in increments along the core and sucks the meltwater at 90o is measured by a photomultiplier tube and the output, which is proportional to the mass of suspended particulate matter in the meltwater, is recorded by a computer. Preliminary measurements of laser light scattering on unmelted ice using a similar technique have been made and the initial results are promising. More work on the technique of laser light scattering on unmelted ice will be pursued in this study.
