Autonomous Shortwave Spectroradiometer for Retrieval of Cloud Properties from Marine Platforms

Marine regions are important to climate but are highly under sampled due to the expense of ship-borne field campaigns. Deploying instruments on commercial ships provides a unique opportunity for expanding observations of marine regions but creates significant challenges for measurements. A recent DOE Biological and Environmental Research workshop discussed high priority shipborne measurements as well as challenges in unattended autonomous shipborne operations. Included in the measurements of interest are cloud optical depth (COD) and liquid water path (LWP). We propose to adapt our Three Wavelength Spectrally Agile Technique Cloud Properties Sensor (TWST-CPS), which provides 1 second derived data products for microphysical properties including COD and LWP, to autonomously operate from a marine platform. The TWST-CPS system is a robust hyperspectral radiometer recently developed under a DOE SBIR for ground-based measurements of cloud properties and fully characterized under the ARM TASZERS study. By adapting this commercial product to operate autonomously under marine specific conditions, including sea spray, constant tilt and motion, and lack of personnel to check on equipment, we address a stated DOE need and increase the commercialization potential of our sensor package. The Phase 1 effort will entail proof-of-principle testing and assessing designs to (1) automatically keep the window free of condensation, precipitation, and contamination; (2) add a position/attitude sensor for determination of solar position and pitch/roll and upgrade our algorithms to account for these changes; and (3) integrate an internal computer with data storage and remote communication capability so all of the electronics are in the same environmental enclosure. In Phase 2, we will build one or more prototype instruments incorporating the Phase 1 improvements. The prototype(s) will be tested at Aerodyne and then deployed on marine platforms for testing in an operational environment. We intend to collaborate with the DOE national laboratory conducting a pilot study observing marine clouds and aerosols from ships. The proposed work will significantly enhance the capabilities and applications of our TWST-CPS system, increasing the acceptance across both DOE-supported monitoring networks and among atmospheric, marine, and climate researchers. This new application builds upon and will expand the commercial success of our TWST technology.