The implementation and evaluation of a black carbon aerosol sampler used on an unmanned aircraft during the prescribed fire experiment RxCADRE

Abstract

Black carbon (BC) aerosols impact the earth's climate by absorbing solar radiation in the atmosphere and depositing on ice surfaces and lowering the albedo of those surfaces. Black carbon aerosols have been widely studied; however, using small unmanned aircraft systems (UAS) for the airborne study of the vertical and horizontal concentrations of BC is an emerging field. Using UAS to study BC poses some challenges due to size and weight restrictions of the aircraft, as well as issues that arise when adapting ground based instrumentation for use on different aircraft. University of Alaska Fairbanks researchers successfully integrated and flew a microAeth AE-51 on a Boeing ScanEagle to measure the concentration of BC and other absorbing and scattering particles in the smoke plume from a prescribed fire experiment, RxCADRE, conducted at Eglin AFB, FL, during October and November 2012. The ScanEaglemounted microAeth successfully collected black carbon aerosols in the smoke plume. The optical particle sizing and mass loadings from an optical particle counter disagreed with the results from the microAeth, which measures absorbing aerosols. The microAeth was tested in the laboratory-using two optical particle sizers to verify the sizes and concentrations of laboratory-generated aerosols entering the instrument and determine the capabilities and limits of the instrument. The optical particle counters were used in other applications as well showing the versatility of the instruments in extreme conditions.