WHOI Funding and Awards --> Cecil H. and Ida M. Green Technology Innovation Awards --> 2002 Abstracts

Abstracts of 2002 Cecil H. and Ida M. Green Technology Innovation Awards

Automated Sampling System for In Situ Measurements of Acoustic Properties of ZooPlankton (APOP)
Dezhang Chu, Kenneth Doherty and Terry Hammar
Applied Ocean Physics & Engineering Department
and
Peter Wiebe
Biology Department

We propose to build a prototype of a towed Acoustic Properties Of zooPlankton (APOP) system. This in-situ APOP system will be based on a previous version of the APOP system, but will be able to collect live zooplankton and perform measurements on the collected animals automatically. If this approach proves to be successful, the system can be easily extended to a more sophisticated system that can conduct independent sampling at different depths in a single deployment. Such measurements of the material properties of live zooplankton have never been possible. The knowledge resulting from such measurements would significantly enhance our ability to correctly estimate abundance and/or biomass of zooplankton from acoustic survey data. Given the potential applications of this automated sampling APOP system, positive results from this proposed feasibility study would greatly strengthen our chance to seek external funding support for building the more sophisticated APOP system.

A Long-Term Monitoring Mooring for the Arctic
Daniel Frye and Lee Freitag
Applied Ocean Physics & Engineering Department
and
Robert Pickart
Physical Oceanography Department

An important component of climate change research is the need for long-term, sustained measurements. In order to make these measurements economically in harsh and remote environments oceanographers need to deploy instruments for up to 5 years without any maintenance requirement. This proposal is aimed at developing an acoustic sensor for detecting ice cover that will allow periodic data telemetry from these moored systems in the southern Arctic and other areas that have substantial seasonal ice cover. The acoustic ice detector is intended be to be used in conjunction with expendable data capsules that are released during periods of open water and transfer their stored data via satellite.

A New Instrument for Measurements of Carbon Monoxide (CO) from Remote Platforms and Ocean Buoys
Eric Hintsa
Marine Chemistry & Geochemistry Department
and
Calvert Eck
Applied Ocean Physics & Engineering Department

In order to study chemistry and transport in the marine atmosphere, we propose to purchase and evaluate a new carbon monoxide (CO) sensor. This instrument is based on a low-power solid-state detector, which could be ideal for long-term measurements from ocean buoys or other remote platforms. Currently, the marine atmosphere is vastly under-sampled compared to what is needed by atmospheric scientists to understand long-range transport, hydrocarbon oxidation, and ozone formation and destruction processes in the lower troposphere. Time-series data of ozone (using sensors which we are already developing) and CO from buoys could be used to measure regional and intercontinental transport of atmospheric pollution, provide new understanding of chemical cycling anywhere over the ocean, and help to constrain regional and global models of atmospheric chemistry.

An Ice-tethered Instrument for Sustained Observation of the Arctic Ocean
Richard A. Krishfield
Geology & Geophysics Department
Kenneth W. Doherty
Applied Ocean Physics & Engineering Department
and
John M. Toole and Andrey Proshutinsky
Physical Oceanography Department

Pack ice presents a significant impediment to the sustained observation of the Arctic Ocean. Arctic field operations are largely restricted to summer, and the more difficult and thus expensive logistics of ice-capable ships and aircraft, severely limit manned sampling. Furthermore, perennial sea ice precludes the use of most modern automated observational instruments, such as the ARGO and RAFOS floats. As a result, the Arctic Ocean under the ice pack remains very poorly sampled in comparison to the temperate seas. This observational gap represents a critical shortcoming of the envisioned ocean observing system as the Arctic may be the source of major fresh water anomalies that intermittently appear in the subpolar North Atlantic and cause profound changes in deep convection, water mass modification, and possibly the meridional overturning circulation.

But on the other hand, the sea ice represents a natural support platform for ocean sampling systems. For example, ice-tethered drifters with discrete subsurface instrumentation, including the SALARGOS, IOEB and J-CAD buoys, have been successfully fielded in the Arctic in recent years, demonstrating that automated buoys are a viable means of acquiring long-term, in-situ data from beneath the ice pack. However, the vertical resolution of the temperature and salinity observations from these systems has typically been limited to only a few depths due to the costs associated with outfitting multiple sensors on a single package. Even with limited sensors, total system costs has meant that only a small number of such devices have been fielded at any one time. Building on the successful Moored Profiler technology, we propose to initiate development of an automated, long-lived, ice-tethered buoy capable of returning daily high-vertical-resolution profiles of upper ocean temperature and salinity in the Arctic Ocean during all seasons over several years. The buoy will transmit all data in near-real time and be low-cost, allowing systems to be considered expendable (thus alleviating the need for expensive recovery operations). Ultimately, we envision a loose array of these ice-tethered profilers being maintained throughout the Arctic Ocean to observe the annual and inter-annual variations of the upper ocean: the Arctic extension of the international ocean observing system.

Airborne LIDAR Dye Mapping for Upper Ocean Mixing and Dispersion Studies
James R. Ledwell, Eugene A. Terray, and Miles Sundermeyer
Applied Ocean Physics & Engineering Department

We propose to adapt an existing airborne laser ranging system to measure the evolution in three dimensions of patches of fluorescent dye released in the upper ocean. We expect that the enhancement of ship-based measurements with the rapid, nearly synoptic, surveys possible from the air will enable great progress to be made in the study of upper ocean processes such as Langmuir circulations and lateral dispersion in the upper thermocline. Our strategy is to collaborate with the primary group in the U.S. that uses scanning airborne LIDAR (Light Detection and Ranging) to map coastal bathymetry. The expensive technology, the aircraft, crew and engineers, are all in place for this operation. We propose here to make the necessary optical and electronic modifications to convert the system to sense fluorescent dye, and to demonstrate the approach by means of a small field experiment, validated by in-situ measurements.

Development of a High Sample Rate Seafloor Geodetic System for Monitoring Oceanic Faults and Magmatic Systems
J. McGuire, W. Witzell, and M. Gould
Marine Chemistry & Geochemistry Department

The majority of plate boundary deformation occurs beneath the oceans through aseismic processes (i.e., without earthquakes) such as silent fault-slip, viscous mantle flow, and magma intrusion. Seafloor geodetic instrumentation potentially capable of sub cm level accuracy over baselines of a few km has recently become available and is poised to revolutionize the study of seafloor deformation. To date, seafloor geodetic measurements have been done in a "campaign" mode where the instruments are only activated when a ship is interrogating them. While campaign style measurements are sufficient for studying broad scale plate motion, they are unable to capture the temporal evolution of the seafloor's major dynamical systems during an event such as an aseismic slip transient, dyke intrusion, or hydrothermal event. We are requesting funds to test an initial system of a high-sample rate, seafloor based, acoustic extensometer system that should be capable of capturing the temporal evolution of all of the major types of seafloor deformation events.

Analyzing the Radiocarbon Content of Very Small Samples at the National Ocean Sciences Accelerator Mass Spectrometry Facility
Ann P. McNichol and John Hayes
Geology & Geophysics Department
and
Tim Eglinton and Chris Reddy
Marine Chemistry & Geochemistry Department

Measurement of radiocarbon in natural samples provides a powerful tool for understanding the earth's carbon cycle, in the present and over the past 45,000 yr. The advent of accelerator mass spectrometry (AMS) almost two decades ago revolutionized the use radiocarbon as a tool to study the earth by reducing both the size of the sample required for analysis from grams to milligrams, and the time required for analysis from days to minutes. Paleoceanographers can now use foraminifera to obtain the age of sediment horizons while other researchers use the "bomb" signal to trace to transfer of carbon from one pool to another.

At the National Ocean Sciences AMS (NOSAMS) Facility, we provide routine radiocarbon analyses on samples containing from 100-1000 µg C. We have worked hard to reduce the size of the samples that can be analyzed on the accelerator even further and it is now possible to analyze samples containing as little as 20 µg C at NOSAMS reliably. We are considered one of the best laboratories in the world at which to analyze very small samples and other AMS labs have referred researchers to us. There still remain research areas, however, to which radiocarbon could bring valuable insights if it were possible to analyze even smaller samples. We propose here to develop and test a system that would allow us to expand the range of our analyses to include samples containing as little as 1 µg C. Successful development of a method to analyze such small samples would open new areas of research, such as dating of ice core materials, studying black carbon and rock varnish, and studying atmospheric particles, to radiocarbon and expand existing ones, such as compound specific radiocarbon analysis (CSRA).

A Long-Term Monitoring Mooring for the Arctic
Eugene A. Terray and Brian Ward
Applied Ocean Physics & Engineering Department

This proposal is focused on evaluating new technology, based on recent advances in Micro-ElectroMechanical Systems (MEMS), for measuring turbulence in ocean boundary layers. We are primarily interested in two systems: an optical time-of-flight sensor, and a shear stress sensor based on laser technology. These sensors are manufactured by the Viosense Corporation, with whom we will be working closely during this project. Our goal is to determine the expected performance of these sensors as a function of environmental conditions. We will test both sensors in a laboratory flume, acquiring data in shear flows of varying intensities. Error models for each sensor will be calibrated by comparison with the observations, and the resulting model used to predict the likely performance under various ocean conditions.