It is increasingly recognized that the Arctic is a bellwether for climate change. As the Arctic region responds to climate forcings, monitoring how aerosol distributions respond and modify their impact on radiative transfer will become increasingly important in refining climate models and predictions. NASA, along with other agencies, has launched several programs such as ARCTAS to increase observations of the region and incorporate findings into large scale climate models. In order to supplement satellite observations and given the difficulty of ground-based observations in the Arctic, instrumented Unmanned Aircraft Systems (UASs) represent one means to efficiently monitor large areas. Measurement of the vertical profile of atmospheric aerosol optical properties can provide new data crucial to understanding climate change in the Arctic. New instrumentation is required to enable routine, widespread measurements with good precision from unmanned aircraft. These new observations will have important implications for global climate change modeling and, ultimately, international energy policy making. In the Phase I program, we will develop a complete conceptual design for a flight-worthy, compact, eye safe lidar that will enable vertical profiling of aerosol optical extinction and scattering and that will be deployable on a compact unmanned aircraft system like the SIERRA or ScanEagle. In the Phase II program, we will fabricate, test, and field demonstrate a prototype sensor.