Project: Carbon Flux Explorer Development

NSF Award Abstract:

The PIs request funding to complete the development of the Carbon Flux Explorer (CFE), a fully autonomous and free robotic system designed to measure and relay in real time via Iridium satellite link the hourly/diurnal variations of particulate organic carbon (POC) and particulate inorganic carbon (PIC) flux at various depths in the upper kilometer of the ocean for seasons to year-long time scales. CFEs are the successful integration of the Sounding Oceanographic Lagrangian Observer (SOLO) float (developed at Scripps) and LBNL/UC Berkeley?s imaging Optical Sediment Trap (OST). The first prototype CFE was successfully tested at sea for 2 days to 800 m in June 2007.

The proposed new work will refine and challenge the CFE design with successively longer deployments in coastal and California Current waters to evaluate and address real world issues such as biofouling and animal invasions. At the same time, engineering refinements will improve power budget and solve multiple minor system issues. On-board image processing/data reduction software will be fully established. Calibration samples (POC and PIC flux) will be obtained concurrently with CFE testing using a buoy tethered twinned OST system operating at similar depths. At the end of this project, three fully developed Carbon Flux Explorers (CFEs) will be deployed (and recovered if possible) in the open ocean for at least 3-6 months in the subarctic N Pacific.

Carbon sedimentation via the bio-carbon pump of the ocean is important to the regulation of atmospheric CO2. Due to limitations of current observational methodology (moorings/ships), carbon export (or sedimentation) is poorly observed in space and time and therefore is poorly understood and parameterized in carbon cycle simulations. CFE deployments in the world?s ocean have the potential to lead to fundamentally new insights into the biology/biogeochemistry of carbon sedimentation.

Broader Impacts:

The potential benefits to society due to the proposed activities are important. These actives will help improve confidence in future carbon cycle predictions. The results could maybe a key to helping society deal with the potentially economically and environmentally hazardous consequences due to climate change. Through education, the proposed activities and technologies developed will make the ocean more accessible to the public in general. An improved understanding of the ocean by the public will help protect the ocean's environment. The real-time observations offered by the proposed activities will help bring about such an understanding and diminish the perceived remoteness of the ocean. The proposed activities will advance ocean related scientific teaching and education. The technology in development will help enliven the ocean in the classroom, moving from textbook knowledge to real-time interactions. The proposed activities will allow students to become more connected to the global environment. The technology will help educate the public in manner needed if society is to overcome the environmental problems humanity currently faces.