September 2013
Name: Sophie Chu
Department: Oceanography/Applied Ocean Science and Engineering
School: Massachusetts Institute of Technology/Woods Hole Oceanographic Institute
Project: Developing New Technologies for High-Resolution Measurements of Marine CO2 System Parameters
Research Advisor: Dr. Zhou Hui “Aleck” Wang
Sophie received her Bachelor of Science in Chemical Engineering at Columbia University. During her undergraduate education, she developed an interest in research that involves studying the effects of human activities on the environment. She began her research in the realm of atmospheric chemistry and moved into the field of chemical oceanography when she started her Ph.D. in the MIT/WHOI Joint Program in Oceanography/Applied Ocean Science and Engineering. Sophie was quickly immersed in the world of marine carbonate chemistry. The seawater CO2 system regulates CO2 exchange between the ocean and atmosphere. To capture the dynamics of the marine CO2 system, there is a strong need for in situ sensors. In situ sensors can provide spatiotemporally resolved carbon data at lower costs than traditional bottle sampling and enable a better assessment of inorganic carbon fluxes, which allows for a better prediction of future changes under anthropogenic forcing such as ocean acidification.
The marine CO2 system is defined primarily by four parameters: pH, TA, DIC and fugacity or partial pressure of CO2 (fCO2 or pCO2). It is necessary to have at least two of the parameters to define the system. Sophie’s Link project will allow her to continue working on two projects to develop technologies that measure seawater total dissolved inorganic carbon (DIC), pH and total alkalinity (TA). The projects involve: 1) deployment of a new in situ, spectrophotometric DIC-pH sensor package and 2) development of a new continuous, spectrophotometric TA method suitable for in situ measurements to study the carbon cycle and ocean acidification in coastal oceans. A sensor for simultaneous measurements of seawater DIC and pH allows for full characterization of the CO2 system with relatively small error. Instead of calculating TA with the other CO2 parameters, directly measuring TA improves accuracy by accounting for undefined alkalinity, such as organic alkalinity, which is often found in highly productive coastal oceans. High quality measurements of the seawater CO2 system at a broad range of spatiotemporal scales will allow assessments of carbon fluxes at scales appropriate to the processes being studied.
Name: Levi DeVries
Department: Department of Aerospace Engineering
School: University of Maryland at College Park
Project: Bio-Inspired Flow Sensing for Underwater Guidance and Navigation
Research Advisor: Professor Derek Paley
Levi graduated from Concordia College in Moorhead, Minnesota, double majoring in physics and mathematics. While attending Concordia College, Levi completed an internship through NASAs Minnesota Space Grant Consortium where he conducted research on the effect of hypervelocity dust particle impacts on thin film coatings. It was this research that sparked his interest in the field of aerospace engineering. He joined the Department of Aerospace Engineering at the University of Maryland after completing his Bachelor’s degree and is currently a member of the Collective Dynamics and Control Laboratory under the advisement of the laboratory's director, Dr. Derek Paley. Levi's research focuses on the control and coordination of distributed multi-agent sensing systems for environmental sampling in the presence of strong flowfields.
For his Link Foundation research project, Levi will assimilate bio-inspired sensing modalities to improve the guidance and navigation of underwater vehicles. Stream-dwelling fish have an innate ability to navigate through often-tumultuous environments with impressive precision, which is a highly desirable trait for underwater vehicle applications. For example, fish can use their lateral line to sense vortices shed by an upstream obstacle and slalom between the vortices to reduce energy expenditure compared to free-stream swimming. Recent developments in materials science have produced sensors whose measurements emulate those provided by a fish's lateral line and integration of this sensing modality may enhance the navigation abilities of underwater vehicles beyond traditional means.
This project will derive theoretically justified estimation algorithms allowing an underwater vehicle to estimate the position and size of obstacles based on properties of the wake it produces. The theoretical objectives are twofold and consist of 1) deriving a nonlinear estimation model that uses flow measurements taken near the surface of the vehicle to detect and estimate “hydrodynamic-level” quantities such as the position and strength of varying numbers of vortices shed from the obstacle, and 2) assimilating the “hydrodynamic-level” estimates and their associated statistics to estimate environment-level quantities such as the position and size of the object shedding the vortices. The theoretical results will be experimentally validated in an obstacle laden flow tank by outfitting an underwater vehicle with an array of bio-inspired sensors.
Name: Firat Eren
Department: Mechanical Engineering
School: University of New Hampshire
Project: Dynamic Positioning Between Unmanned Underwater Vehicles (UUVs) Utilizing Optical Sensory Feedback
Research Advisor: Professor May-Win Thein
Firat Eren is currently a Ph.D. student at the University of New Hampshire (UNH). He received the B.S. degree in Mechatronics Engineering from Sabanci University in Istanbul, Turkey in 2008 and the M.S. degree from the Department of Mechanical Engineering at UNH in 2011. During his time at UNH, Firat has been helping to foster undergraduate interest in the world of ocean engineering. Over the past three years, he was the graduate student advisor for the UNH Remotely Operated Vehicle (ROV) team that included design and construction of ROVs for the annual MATE International ROV Competition. In January 2013, Firat participated in the Ocean Engineering course offered at UNH, (“ROV Science and Applications”). This course also included researchers from the Center for Coastal and Ocean Mapping and UNH faculty along with NOAA researchers from the Ocean Exploration Research (OER). With the support from Link Foundation, Firat is working to develop an optical communication system for use in the control of a “leader-follower” type formation between a team of Unmanned Underwater Vehicles (UUVs).
UUVs are used to perform survey operations that are not suitable for divers, such as underwater pipeline inspection, bathymetry exploration and military operations. Some underwater operations require the surveying of large areas. A single UUV is not suitable for such surveys because of the costs associated with operating UUVs for long periods of time. One approach to reduce operation time is the deployment of multiple UUVs that can perform tasks in a formation. A key requirement for a group of UUVs to move in a formation is a communication link between the UUVs. In addition to UUV operation in controlled formation, an underwater communication link can also be used for UUV docking or data transfer from an operating UUV to a data storage platform. The two latter applications allow UUVs to operate underwater for longer periods of time. Firat is now developing and researching different optical detector array designs that can be mounted on a UUV. Using image processing techniques, these array designs are to provide the position and orientation of the follower UUV. This information is to be used as feedback for autonomous control algorithms that Firat will also be developing as a part of his Ph.D. research.