Going the Extra Mile: The Unsung Heroes of the GLAD Experiment

Figure 1: Screen capture of the GLAD drifter animation (Courtesy of: Dr. Bruce Lipphardt)

Months of planning and preparation, the construction of more than 300 custom drifters ‘on the fly’, behind the scenes calculations 24 hours a day, harrowing drifter chases on the wild seas, this summer a team of researchers carried out the largest scientific experiment of its kind in the Gulf of Mexico.

For three weeks, from July 17-August 3, the Grand Lagrangian Deployment (GLAD) an at-sea experiment, was conducted in northern Gulf of Mexico. Funded by the Gulf of Mexico Research Initiative (GoMRI) in the aftermath of the Deepwater Horizon incident, the Consortium for Advanced Research on Transport of Hydrocarbon in the Environment (CARTHE) GLAD science team was made up of a modeling support group on shore, as well as a deployment crew aboard the University of Miami’s R/V Walton Smith. The GLAD team focused on the release of more than 300 near-surface drifters in the vicinity of the DwH region using deployment patterns scientifically selected to understand the unique oceanic motion in the region. The observation of these upper ocean transport processes is a critical step for the evaluation and improvement of predictive models in case of oil spills.

“Even after months of planning for the GLAD experiment, we knew we were taking a chance on this project”, said CARTHE Director Dr. Tamay Özgökmen. “It was such a large scale deployment in such a precisely-engineered, complex manner, no one had ever attempted it before. We knew we were taking on a major challenge and whether or not we’d be able to pull it off was uncertain. As we faced enormous time constraints not only in building the 300 drifters at RSMAS, but also to deploy them under the ever changing, sometimes dangerous conditions in the Gulf, it made for quite an adventure.”

The sheer number of drifters simultaneously sampling the DwH region makes GLAD the largest upper-ocean dispersion experiment of its kind ever conducted. To convey the scale of the experiment, for the first time ever the team released an animated video of the GLAD drifters released in the Gulf. It can be viewed at this link: (Figure 1 & movie credit: Bruce Lipphardt, University of Delaware).

“Similar to space telescopes or supercolliders that extend our senses, the GLAD observation system has allowed us to see the ocean as never before” said Dr. Gregg Jacobs, the head of Naval Research Laboratory’s (NRL) Modeling of Prediction Branch and a CARTHE researcher. “Every day the system reveals more of the ocean, how it evolves and how it affects surface transport. Many of the oceanographers watching the data coming in have decades of experience through in situ experiments and model forecasts.  As experienced researchers we are amazed with the wealth of new data that comes in every day and what it allows us to see and understand about the ocean. Thus GLAD has allowed CARTHE researchers to see the ocean in ways that have never been previously possible.”

Dr. Özgökmen and the other GLAD team leads believe it was a great drifter design by AMP technician Mike Rebozo, the heroic efforts by daring AMP graduate students Nathan Laxague, Conor Smith, Matt Gough, MPO postdoc Guillaume Novelli and marine technician Mark Graham that led to the success of the deployment. This great scientific synergy was facilitated by RSMAS faculty members Dr. Brian Haus (GLAD Chief Scientist), Dr. Josefina Olascoaga, and Dr. Ad Reniers on the vessel. The drifter design was based on a prototype generously provided by Dr. Bret Webb (University of South Alabama) and Dr. Arnoldo Valle-Levinson (University of Florida).

Figure 2: GLAD drifters in the path of Tropical Storm Isaac in the Gulf of Mexico, August 27, 2012. (Courtesy of: Dr. Tamay Özgökmen

“It truly was an incredible opportunity to be a part of GLAD. It isn’t every day that you’re out at sea involved in oceanography's single-largest drifter deployment operation,” said student Nathan Laxague. “That was my GLAD experience — the exhilaration of research surrounded by the ocean’s vastness, coupled with the knowledge that said work would yield groundbreaking results on the physics of upper-ocean transport.”

In addition, the GLAD crew aboard the ship received outstanding daily data management support from senior research associate Edward Ryan and Warner Baringer (CCS). MPO students Falko Judt and Milan Curcic from Dr. Shuyi Chen’s group operated a coupled air-sea-wave model to provide weather and wave predictions, essential for timing the deployments. In addition, state-of-the-art data-assimilative model outputs were made available by a large team at NRL. Post-analyses of model output were communicated to the ship by CARTHE investigators Dr. Angelique Haza and Dr. Javier Beron-Vera.

CARTHE Program Manager Julie Hollenbeck ensured that GLAD crew received all the components needed to conduct the cruise, while working with Ocean Leadership to organize a press event at Gulfport, Mississippi. After a number of the drifters were inadvertently picked up by fishermen who mistook them for lost research equipment, Dr. Arthur Mariano launched a successful outreach campaign to educate fisherman about leaving the drifters in the Gulf in water.

It was seamless team effort that seems to be paying off in unexpected ways. As Hurricane Isaac moves through the Gulf the team is on high alert, poised to collect some of the most exciting, never before-seen-data from those very same drifters who are directly in the path of the hurricane (Figure 2).  This unique data will shed light on how hurricanes affect ocean surface currents and disperse pollutants in the Gulf of Mexico.

Address questions on GLAD to CARTHE Director Tamay Özgökmen.

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