Project Proposed: This project, acquiring a networked instrument composed of two complementary Autonomous Underwater Vehicles (AUVs), supports an extensive program of research in robotics, underwater acoustic communication and networking, marine biology, oceanography, and biogeochemistry at the Center for Integrated Networked Aquatic PlatformS (CINAPS). These two AUVs add capability to those already in use by CINAPS. The work addresses two current key limitations: limited depth (depth no greater than 200m) and limited communication (only supports communication through the air, i.e., when the vehicles are not below the surface.) These instruments impact agendas in two main fields: research in the Southern California coastal marine ecosystem (in physical oceanography, geobiological oceanography, and microbial ecology), and research in robotics, communication, and networking. The instrumentation consists of a Slocum Electric Glider and an EcoMapper-EP (Expandable Payload) Autonomous Underwater Vehicle. The Slocum glider, for use up to 1000m, was developed by in the early 1990's, and has become an integral tool of ocean science in this decade. It is driven entirely by a variable buoyancy system rather than active propulsion. The glider's wings convert the buoyancy-dependent vertical motion into forward velocity. Slocum gliders are truly autonomous, requiring a surface vessel only for deployment and recovery. On-board communications capabilities include a two-way RF modem, Iridium satellite and an ARGOS locator. With its onboard instrumentation, combined with its mobility and long-range capabilities, the glider provides continuous, near-real-time information, about the physics and biogeochemistry of the ocean. Designed specifically for water quality and bathymetry mapping applications, the Ecomapper for shallow use (up to 200m) is a unique AUV. Easily deployed by one person, it is able to perform a wide-area survey without a surface workboat or associated personnel. The EP class EcoMapper allows for additional ports for customized sensor integration and space for a second low-power CPU to support the additional sensors and software. This additional CPU enables mission adaptations to occur on-the-fly based on real-time sensor readings that are necessary when trying to detect and track dynamically changing oceanic features a range of important processes and associated questions can only be studied with the coupling of deep AUV operations (up to 1000m) with shallow (up to 200m). These include (a) the toxic effect of harmful algal blooms at greater depth, (b) the temporal and spatial variations of the low oxygen interface (deep basins can become hypoxic or anoxic due to isolation), and (c) fluxes of particulate material from urban runoff to the deeper sea that are discontinuous in both time and space; the spatial extent of which can be best resolved with autonomous vehicles that can maintain a presence over several events. To enable these studies, new algorithms for multi-AUV communication and control are necessary. The ability to coordinate vehicle trajectories and missions while submerged presents a current limitation. This is of particular concern in the Southern California Bight, the study site, a region with high maritime traffic where surfacing of the AUVs needs to be minimized. Used as a field instrument deployed in the Southern California Bight (SCB), the instrument is programmed and bench-tested in the Robotic Embedded Systems Laboratory on the USC main campus in LA. The instrument manager is supported by the PI;s grants. USC covers all operational and maintenance costs. Broader Impacts: The instrumentation impacts faculty research and student education, contributing to enable new science in diverse research projects and impacting the ongoing instruction at the institution and serves as a learning tool to develop student scientific proficiency (through existing courses and participation in faculty-led research). This acquisition plays an important role in the Southern California Bight Study planned for Spring 2010, coordinated by the Southern California Coastal Water Research Project (SCCWRP), a public agency focusing on the coastal ecosystems of Southern California. The PIs have close collaborative ties to this agency. Moreover, the networked and adaptive sensor systems provide important data relating to the climate and health of Southern California coastal ocean. Undergraduate students are involved through REU site awards at USC. Since the PI runs the USC Computer Science department REU site for research in various areas of computer science, students in his lab often assist with data analysis and programming for the robotic boats. The EcoMapper vehicle, which is designed to be portable and deployable in shallow water, is particularly suitable for the next generation of REU students. Other PIs participate as faculty mentors in USC biochemistry REU site encouraging similar participation from undergraduate students in biology.
PI: Gaurav Sukhatme, University of Southern California Autonomous Underwater Vehicles (AUVs) and the instruments they carry play a major role in the collection of oceanographic data. This enhances our understanding of a range of ocean processes: physical (e.g., tidal mixing), chemical (e.g., nutrient upwelling), geological (e.g., hydrothermal vents), and biological (e.g., harmful algal blooms). This grant was written to acquire an AUV and associated sensors (both for accurate navigation and for measuring nutrients in the ocean). The resulting infrastructure supports an extensive program of research in robotics, marine biology, and oceanography at the University of Southern California (USC). We acquired the following instruments under this grant. An EcoMapper-EP (Expandable Payload) Autonomous Underwater Vehicle: Designed specifically for water quality and bathymetry mapping applications by YSI Integrated Systems & Services in Marion, MA. Underwater acoustic modem S2CR 12/24: This type of underwater acoustic modem made by Evologics is very well suited for long range operations, allowing the EcoMapper AUV to communicate with the surface while performing a mission underwater. The Satlantic SUNA V2 (Submersible Ultraviolet Nitrate Analyzer) provides a long term, cost effective solution to nitrate monitoring. Nitrate can contribute significantly to algal bloom development and data of this type is an essential component of routine water quality monitoring. This instrument is currently being integrated into the EcoMapper AUV. The Cycle PO4 sensor is an in situ phosphate analyzer from Wet Labs that is designed for unattended, long-term deployment. Concurrent deployment of the Cycle PO4 sensor with the SUNA nitrate sensor provides the ability to simultaneously monitor multiple nutrient species. These instruments are being used to develop new algorithms for underwater vehicle autonomy and for observational studies of the coastal ocean. On Tuesday, March 8, 2011, King Harbor in the City of Redondo Beach experienced a massive fish kill (Figure, 170 tons of Pacific sardines; approximately 2 million fish). The event received global attention. Our research group was able to react immediately to the event. Deployment of the EcoMapper during and following the event provided vital information for properly interpreting the cause of the fish kill. Environmental parameters (temperature, salinity, dissolved oxygen, and chlorophyll fluorescence) were recorded prior to and during the event, and indicated a precipitous drop in dissolved oxygen coincident with the mortality event. Based on this information, we concluded that depletion of dissolved oxygen was unquestionably the immediate cause of the mortality event. These findings were conveyed in repeated meetings with the City Council and the Harbor Commission of the City of Redondo Beach in an effort to aid the City in future policy and actions. A major component of the research supported by this grant has been coordinated with a NOAA-funded project (EcoHAB: Ecology of Harmful Algal Blooms) conducted off southern California during Fall 2012. The project involved monitoring and experimental studies to examine the potential impact of a diversion of effluent from the Orange County Sanitation District, from their pipe that discharges secondarily treated effluent 5 miles offshore, through their older 1-mile pipe while repairs to the 5-mile pipe were enacted. This diversion was responsible for the discharge of effluent into the near-coast ecosystem off Newport Beach containing high concentrations of nitrogen (primarily ammonium) and phosphate. Our efforts focused on response of the phytoplankton community to the diversion event. The event, and the observational activities of the group, received considerable publicity in the local press (Figure).
