Description: 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.

Benefits: The proposed airborne lidar will enable measurements of aerosol optical extinction on a wider scale and at higher frequencies than are possible now. This is especially important in monitoring climate change in the Arctic. The larger database from more frequent studies will directly benefit the goals of NASA's climate change research efforts. One future NASA program that might benefit from the proposed airborne lidar is the GEOstationary Coastal and Air Pollution Events (GEO-CAPE) mission. Although a satellite-based program, the program might benefit from airborne corroborative observations of aerosol optical depth and aerosol absorption optical depth, much as was done for the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) program by manned aircraft. The basic sensor platform will be adaptable to applications requiring measurement of aerosols where sensor robustness and size are critical to performance, such as monitoring networks for boundary layer meteorology, as well as hazardous volcanic ash clouds.

The proposed airborne lidar will enable measurements of aerosol optical extinction on a wider scale and at higher frequencies than are possible now. Non-NASA commercial applications are likely to include many ground-based applications such as CBRNE detection, visibility and Asian dust monitoring, hazardous volcanic ash cloud monitoring, regional air quality and human health assessments. Introduction of the proposed lidar into newly emerging networks for boundary layer meteorology may also be possible.