Tag Archives: gliders

Skidaway grad students participate on glider team cruise 

From May 31st to June 5th, Skidaway Institute graduate students Kun Ma and Lixin Zhu joined a science cruise on the R/V Savannah off Cape Hatteras, N.C. The cruise was led by Jeffrey Book from the U.S. Naval Research Laboratory (NRL). The main objective of this cruise was to test and demonstrate the use of gliders together in teams and assimilate the data into ocean forecast models. The cruise was 22 days in total, divided into 3 legs. Kun and Lixin were part of the third leg.

Kun Ma cocks Niskin bottles on the CTD.

Kun is a new Ph.D. student at Skidway, working mainly on the MoDIE project with Jay Brandes and Aron Stubbins. This was her first science cruise and she collected some particular organic matter and dissolved inorganic carbon samples. She also helped Skidaway Institute researcher Bill Savidge by collecting some chlorophyll samples in order to calibrate the chlorophyll sensor on the CTD instrument.

Lixin Zhu in immersion suit during safety trainning

Lixin is a visiting Ph.D. student in Aron Stubbins’ lab. He collected filtered water samples on the cruise. He will analyze the color/fluorescence dissolved organic matter, and dissolved black carbon concentrations. In addition, Lixin performed solid phase extraction aboard and collected high-resolution real-time CDOM data using a S::CAN sensor coupled with the underway SCS system on the ship. Eventually, he will combine these data with other field data collected in the South Atlantic Bight area to see the overall dynamics of dissolved black carbon.

Four of the six gliders

“I really appreciate Dr. Jeff Book for having us on this amazing cruise,” Lixin said. “I am glad that we overcame seasickness, and it’s really cool to see that the glider team controlled six gliders at the same time aboard.

(l-r) Pierre-Yves Passaggia from UNC, Ian Martens, Ana Rice, Silvia Beatriz Gremes and Jeffery Book from NRL, Lixin Zhu, Santiago Carrizosa from the Navy, and Kun Ma

“Furthermore, their working approach and decision making process, based on real-time data, modeling and satellite results, impressed me a lot. Getting some samples from such a dynamic area definitely made me really excited.”

 

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Georgia Tech-UGA Skidaway Institute grad student defends dissertation

OLYMPUS DIGITAL CAMERACatherine Edwards’ Ph.D. student, Dongsik Chang, successfully defended his dissertation July 11th in the Department of Electrical and Computer Engineering at Georgia Tech. His dissertation was titled “Motion Tomography Performed by Underwater Mobile Sensor Networks.” He was co-advised by Catherine and Fumin Zhang of Georgia Tech.

Dongsik started his Ph.D. work in 2010 at the Georgia Tech Savannah campus, and began work with Catherine in 2011 for the NSF-funded Long Bay project. He developed the GENIoS (Glider Environment Networked Information System), which optimizes navigation of gliders based on information from real time model and observational data streams like HF radar, satellites, and operational ocean models. Dongsik’s dissertation defense focused on the concept of “motion tomography” pioneered by the Skidaway Institute/Georgia Tech glider lab. Similar to medical CT, which reconstructs 3-D images of objects, glider motion tomography uses the displacement of a glider by currents to reconstruct features of the flow field.

“His work bridging oceanography and engineering has been demonstrated to improve the quality of the data that can be collected by gliders, and has major implications for generalized fleets of autonomous underwater vehicles,” Catherine said. “Congratulations, Dongsik!”

Regional glider network project receives funding

Catherine Edwards is leading a team that has received a five-year, $750,000 grant from the Southeast Coastal Ocean Observing Regional Association (SECOORA) to establish a regional glider network.

The team will work collaboratively to operate regular glider missions in the South Atlantic Bight, providing valuable information for data assimilation and ocean modeling, as well as to fisheries and other stakeholders. This will include regular maps of temperature, salinity, density and other measurements. In addition to regular coordinated experiments with multiple gliders and maximum regional coverage, the project will leverage opportunities to develop regular transects in areas where glider data may be of interest.

Catherine Edwards (r) explains the workings of the glider to Mare Timmons (l) and Mary Sweeney Reeves.

Catherine Edwards (r) explains the workings of the glider to Mare Timmons (l) and Mary Sweeney Reeves.

“This glider observatory is the first time regular glider efforts have been funded in the South Atlantic Bight and is complementary to larger SECOORA efforts in observing and modeling,” Catherine said. “The work is highly leveraged by contributions from each of the PIs and partnerships with fisheries and observing groups at NOAA and NASA.”

Co-PIs include Chad Lembke from the University of South Florida, Ruoying He from North Carolina State University, Harvey Seim from the University of North Carolina and Fumin Zhang from Georgia Tech.

Other partners/stakeholders include state Departments of Natural Resources and the South Atlantic Fisheries Management Council. Gliders will be outfitted with passive and active acoustics data that fisheries managers can use to better understand key species. Data will be shared freely and made available in near-real time through SECOORA and the National Data Buoy Center.

“We’re sending all of the glider data to the National Glider Data Assembly Center in near-real time so that it can be assimilated into the Navy’s operational models to improve their forecasts,” Catherine said.