Topic 4B: Sensors for Sustained, Autonomous Meaturement of Chemical or Biological Parameters in the Ocean

Commercialization of Autonomous Sensor Systems for Quantifying pCO2 and Total Inorganic Carbon

Lead PI: Dr. Michael DeGrandpre, University of Montana

NOPP Topic 4B provides an ideal opportunity for the oceanographic community to be proactive in the commercialization of chemical sensor technology required to advance ocean science. We will use NOPP funding to promote commercialization of one such technology, the SAMI-CO2, a sensor developed for autonomous measurements of the partial pressure of CO2 (pCO2). The SAMI-CO2 was commercialized in 1999 through an exclusive license from the University of Montana to Sunburst Sensors, a company in Missoula, Montana (see sunburstsensors.com). Field deployments by DeGrandpre and others have demonstrated the excellent long-term stability predicted by the SAMIs’ well-understood theoretical response. The design, however, is complex and prone to failures, especially by customers who are not trained to operate the SAMI. Incremental changes in the design have improved reliability, but a full redesign is required to implement modern electronic and manufacturing technology. The new design will allow individual investigators to make pCO2 measurements reliably over long time periods in widespread ocean locations on many different ocean platforms. It will focus on improving the reliability, ease of operation and platform flexibility while reducing the size, cost and power requirements.

The specific work involves 8 tasks: 1) reagent and blank flushing, 2) electronic drift, 3) optical cell complexity and performance, 4) calibration complexity, 5) software, 6) documentation, 7) optimization of size, power, and manufacturing costs, and 8) environmental testing. Within ~1.5-2 years of NOPP funding, prototype designs will be available for testing by the oceanographic community. Feedback from these tests will be implemented and a final design will be widely marketed by Sunburst Sensors during Year 3.

Number of Years: 3

Requested Funds: $879,024

Partners:

Scripps Institution of Oceanography
University of California at San Diego
Woods Hole Oceanographic Institution
Sunburst Sensors

Development of Fluorescent Induction and Relaxation Systems for the Measurement of Biomass and Primary Productivity on Webb Sloccum Gliders

Lead PI: Dr. Oscar Schofield, Rutgers University

Despite their relatively small area, continental shelves are disproportionately important in biogeochemical cycles. Quantifying the transport and transformation of organic matter on continental shelves, however, is difficult due to the numerous processes operating over a wide range of space (meters to 100s of kilometers) and time (hours to years) scales. Traditional sampling strategies are hard pressed to sample the relevant scales. Autonomous underwater vehicles (AUVs), though, have advanced to the point that they now allow scientists to maintain a continuous presence in the sea. Over the last decade, the pump-and-probe and Fast Repetition Rate Fluorometers (FRRF) have provided unprecedented insight into the factors controlling phytoplankton physiology and primary production in the ocean. The use of fluorescence kinetics is increasingly becoming an integral part of many oceanographic field programs, but its broad community use is limited by the complexity and high cost of the available instrumentation. These systems are limited to just a few labs even though these measurements are becoming increasingly central to field work and have been commercially available for almost a decade.

To overcome these problems, we have designed and built a new instrument, called Fluorescence Induction and Relaxation (FIRe) System, to measure a comprehensive suite of photosynthetic characteristics in phytoplankton and benthic organisms. This NOPP partnership will develop a miniaturized cost-effective biological sensor capable of measuring the concentration, physiological state, and productivity of phytoplankton. Specifically, we will miniaturize a new compact FIRe system which will be combined with Aanderaa 3835 oxygen electrodes. This sensor will be combined with a miniaturized optical Satlantic nitrate sensor. These sensor suites will be integrated into Webb Slocum Gliders. They will complement existing backscatter-attenuation-absorption Glider sensor packages, to provide a complete particle productivity sensing capability on long duration autonomous AUVs. We will demonstrate the utility of this system by collecting measurements in an existing AUV shelf-wide time series focused on defining the physical forcing on particle dynamics of the Mid-Atlantic Bight (MAB). We propose to use the FIRe-O2 sensor suite to study how shelf-wide processes drive summer upwelling and the associated phytoplankton blooms, and to determine the linkage to low bottom water DO in the MAB.

Our goals for these deployments are to: Map the seasonal spatial extent of the MAB cold pool; Map the health, productivity and concentration of phytoplankton associated with the Cold Pool as it flows southward on the MAB; Relate the health, productivity and concentration of phytoplankton to the availability of nitrogen on the MAB; and Assess the coupling of the shelf O2 levels to the health and concentrations of the phytoplankton on the shelf.

This project will directly benefit several ongoing education efforts. It will provide data and field opportunities for Ph.D., masters, and undergraduate students. The K-12 outreach will be facilitated through the Mid-Atlantic Center for Ocean Science Education Excellence (COSEE) here at Rutgers.

Number of Years: 3

Requested Funds: $410,000

Partners:

Rutgers University
Webb Research Corporation
Satlantic Incorporated

Transitioning Submersible Chemical Analyzer Technologies for Sustained, Autonomous Observations from Profiling Moorings, Gliders and other AUVs

Lead PI: Dr. Alfred Hanson, SubChem Systems Inc. and University of Rhode Island

We plan to transition our existing prototype autonomous profiling nutrient analyzers (APNA) into a commercial product that can be readily deployed on autonomous profiling moorings, coastal gliders and propeller-driven unmanned underwater vehicles and used for sustained, autonomous ocean observations of chemical distributions and variability. Field tests of the APNA prototype deployed on the University of Rhode Island’s profiling mooring and the REMUS AUV have demonstrated its capability to autonomously profile nutrient concentrations in real-time and provide the in situ self-calibration data needed to verify in situ performance. At the same time, these field tests have identified a series of issues that need to be addressed to convert the nutrient analyzer into a commercial unit that can be widely used by the community for sustained and accurate, stable, autonomous operation in the ocean. These issues are: (1) a more compact size, (2) reduced reagent and power consumption, (3) enhanced biofouling suppression, (4) ease of use by non-chemists, and (5) documented performance when deployed on different platforms.

We will address these issues by using recent advances in micro-fluidics and optical detectors (new SubChem and WET Labs technologies) to (1) reduce sample flow rates and volumes and thus reagent and power consumption; (2) extend the length of field deployments by periodically isolating sensitive components so that back-flushing and chemical techniques can be used to suppress bio-fouling, (3) increase the ease of use by simplifying operation, pre-packaging reagents and outputting the data in engineering units, and (4) document thoroughly the performance by conducting a demonstration experiment at a field site that has strong vertical and horizontal nutrient gradients and episodic phytoplankton blooms.

We plan to achieve these objectives through a partnership between industry, university, and government. During this project, the industry partners will take the lead in developing the commercial version of the nutrient analyzers while the university and government partners will take the lead in establishing the initial performance criteria for the nutrient analyzer and in providing the deployment platforms and conducting the field testing and demonstration experiments. These partners have extensive experience in working together to develop and test new sensing and deployment systems and then collaborating through SBIR and NOPP programs to commercialize those technologies for use by the broader community. We will undertake this project using the collaborative management and experimental techniques that evolved during earlier successful instrument development, testing and commercialization efforts.

Number of Years: 3

Requested Funds: $1,317,732

Partners:

SubChem Systems, Inc.
University of Rhode Island
WET Labs, Inc.
SPAWAR Systems Center – San Diego

Development of a Mass Spectrometer for Deployment on Moorings and Cabled Observatories for Long-Term Unattended Observation of Low-Molecular Weight Chemicals in the Water Column

Lead PI: Dr. Jean Whelan, Woods Hole Oceanographic Institution

The goals of this project are to address the need for advanced chemical sensing in the ocean environment through development of a new mass spectrometer for long-term unattended deployment. The mass spectrometer is based on Monitor Instruments’ miniature cycloidal mass analyzer technology and oceanographic components developed by WHOI. Testing and trial deployments will be carried out by WHOI at its Deep Submergence Laboratory and Martha’s Vineyard Coastal Observatory (MVCO). Monitor Instruments will carry out commercialization of this instrument, which will be known as TETHYS (TETHered Yearlong Spectrometer).

We are performing a multi-year development of the TETHYS instrument. TETHYS will be optimized for long-term measurement of low molecular weight dissolved biogenic, atmospheric, and noble gases as well as light hydrocarbon compounds from 2 to 100 AMU. This instrument will have minimum limits of detection on the order of parts-per-billion and be capable of shallow water to full ocean depth deployment. It will utilize techniques currently under development at WHOI to enable automated re-calibration in-situ and will also include measures for anti-fouling, an essential consideration for long-term deployment. TETHYS is being designed for production in significant quantity, through the use of low cost components that can be rapidly produced and is designed to operate without moving parts or high-frequency electronics. Without the need for mechanical pumping and high-frequency electronics, the instrument will better avoid mechanical wear and subsequent failure, and will not generate vibration or EM field fluctuations. These modes of noise are potential sources of interference to other instrumentation attached to a given mooring or cable node (i.e. hydrophones, seismometers, electromagnetic sub-bottom profilers, magnetometers). The instrument will also be capable of carrying an onboard battery for operation on moorings or in the case of power disruption to the node.

TETHYS is designed to be extremely durable, with service intervals on the scale of weeks to months, with modularity allowing for periodic maintenance and component upgrade. Its physical configuration will enable initial deployment and maintenance by scuba divers from the R/V Tioga at the MVCO. This configuration will also accommodate later deployment and maintenance with ROVs in deeper environments.

Number of Years: 3

Requested Funds: $942,991

Partners: