Successful Completion to the Department of Energy’s International Polar Year (IPY) Study

Summary

Office of Science’s Atmospheric Radiation Measurement (ARM) International Polar Year study, Indirect and Semi-Direct Aerosol Campaign (ISDAC), ended its month-long mission on April 30, 2008. All of the campaign’s objectives were met and will help answer some of the key scientific questions about Arctic cloud and aerosol interactions. Results from the ISDAC study will be presented at the 4^th PAN-Global Water and Energy Experiment (GEWEX) Cloud System Study meeting, June 2-6, 2008, in Toulouse, France. The study involved the use of research aircraft containing state-of-the-art instruments that measured cloud microphysics, aerosol chemistry and optical properties, particularly for ice and mixed-phase clouds, which are key regulators of Arctic climate. The suite of instruments used included the Single Particle Laser Ablation Time-of-flight mass spectrometer (SPLAT) which measures in-situ the size and composition of individual aerosols. SPLAT-II was designed, constructed and operated by EMSL. Cooperation across BER programs enabled SPLATT-II to be compatible with an airborne platform (weight, size and power consumption reductions; and shock absorbance). Measurements collected during the ISDAC study included layers of organic and black carbon from Siberian fires, dust from China, and sulfate from fossil fuel combustion. Sampling was also conducted of low level ice/mixed phase and water clouds, and high level cirrus clouds.