Mooring C (Fig. 14; Table 4) is designed primarily to support long-term ESP experiments, but also to accommodate other instruments critical to the success of the OOI-BGF program. Deployment of the ESP at 20 m is proposed as optimal in terms minimizing physical stresses while capturing surface ocean microbial community structure, and yielding information complementary to that emanating from the ISP experiments. Because the ESP contains electro-mechanical robotics and precision micro-fluidic mechanisms (Scholin et al., 2007) it is critical that excessive motion (e.g., by surface wave action) is avoided. New Autonomous Depth Adjuster (ADA) mooring technology developed at WHOI can overcome this problem whereby the surface instrumented buoy is connected to the “underwater-mass” a steel buoy via a highly stretchable (max. 175%) electro-mechanical hose. An ESP is hung from this steel buoy, and the entire mooring system is tethered to the anchor (and acoustic release) via low-stretch steel wire. Prior deployments have demonstrated that this method effectively damps any movement caused by waves up to 9 m in amplitude.
Since an ESP consumes much more energy compared to conventional oceanographic instruments, we propose to deploy a so-called Micro-Grid Power Buoy (MGPB) (Fig. 14). The onboard wind generator and photovoltaic cell combination generates up to the 60 w/hr of electricity on average, which is used to replenish a 200A storage battery installed at the base of the MGPB. In this way, ample electricity can be supplied for quasi-permanent operation of the ESP, contextual underwater and in-air sensors, global broadcasting of resulting data, and for maintenance of a local data network between Mooring C and Moorings B/D. The performance and cost of satellite data transmission is improving at a rapid pace, and there will likely be much greater band-width and flexibility in data transfer by the time that the Global OOI program is fully commissioned. These data will be submitted to data centers and distributed to the research community according to OOI protocols.