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Liquid Robotics announces PacX Challenge grand prize winner

Dr. Villareal and Dr. Cara Wilson pose in front of Wave Glider Benjamin. (Photo courtesy of Liquid Robotics)

Dr. Villareal and Dr. Cara Wilson pose in front of Wave Glider Benjamin. (Photo courtesy of Liquid Robotics)

Karin Stanton | Hawaii 24/7 Editor

A Texas professor of marine science helped pull two worlds together and won $50,000 for his efforts, plus access to some of the most advanced ocean data.

Named the Liquid Robotics PacX Challenge grand prize winner, Dr. Tracy Villareal compared ocean data collected from satellites with surface data collected by the four PacX Wave Gliders. His work was able to take the broad images taken from space – which may show ocean surface anomalies – and then use the Wave Glider data to explore and explain those satellite peculiarities.

Villareal’s winning project was announced by Liquid Robotics, the ocean data service provider and developer of the Wave Glider, at the recent Oceans’13 MTS/IEEE scientific conference in California.

His winning research focused on a comparison of scientific spatial data collected from U.S. satellite streams to surface data collected by the four PacX Wave Gliders.

Villareal studied the detection and behavior of large phytoplankton species critical to removing carbon from the ocean’s surface and a major food source for the deep sea.

His findings provide the scientific community valuable surface validation of satellite measurements across a variety of oceanographic data (turbidity, weather, hydrographic, chlorophyll fluorescence) which is instrumental to gaining insight to the effects of global climate change on our oceans’ ecosystems.

Additionally, he noted the autonomous surface vehicles ability to track rapidly developing ocean phenomena – adaptive sampling in real time – providing spatial and temporal variability that can’t be measured by satellites today.

Liquid Robotics Vice President Graham Hine said the PacX Challenge aimed to encourage scientists and students to make use of the Wave Glider data in interesting, productive, or innovative ways.

“We’re so excited to see this happen. All the finalists submitted interesting papers,” he said. “This is tremendous. It’s a tremendous revelation for us. These scientists are saying this is a great tool in our arsenal. It really validates the work we’ve done in the past seven years.”

Two years ago, Liquid Robotics – which has a base in Kawaihae -sent four Wave Gliders on an unprecedented scientific mission to navigate and collect data across the Pacific Ocean. The mission was a success, garnering the company a Guinness World Record for the longest journey of an unmanned autonomous surface vehicle.

The PacX challenge drew 27 proposals from around the world, with the top four evaluated by an independent PacX Science Board comprised of industry and academic experts.

For his achievement, Dr. Villareal received a $50,000 research grant from BP and six months of Wave Glider data services valued more than $300,000.

The PacX scientists conducted research into some of the world’s most challenging ocean issues ranging from measuring the ocean’s health and respiration to studying the ocean’s biomass – the most fundamental organisms critical to ocean life.

Liquid Robotics encourages all ocean explorers and scientists to access and explore the PacX Challenge data set (more than 5.5 million discrete data points). This data set is available free to anyone who registers on

Grand Prize Winner:

* Tracy Villareal, University of Texas at Austin, Texas
Phytoplankton Bloom detection and satellite/in-situ validation of oceanic conditions: “A comparison of the PacX trans-Pacific Wave Glider data (MODIS, Aquarius, TRMM and VIIRS)”

Tracy Villareal

Tracy Villareal

Dr. Tracy Villareal
Marine Science Department, University of Texas at Austin

Tracy Villareal is a professor in the Department of Marine Science at The University of Texas, Austin. He pursues his interests in biological oceanography and phytoplankton ecology at the Marine Science Institute in Port Aransas, Texas located on Mustang Island.

After receiving a B.S. and M.S from Texas A&M University, he got his Ph.D. in Oceanography from the University of Rhode Island’s Graduate School of Oceanography working with Prof. T. J. Smayda.

He has received the Harold C. Bold and Luigi Provosoli Awards from the Phycological Society of America, and the Darbaker Prize from the Botanical Society of America.

A collaborative ship-based teacher training program with Dr. N. Hanegan of BYU, was awarded a Eisenhower National Clearinghouse Digital Dozen Award for the STEAMER website.

His first love in oceanography has always been blue water phytoplankton, particularly the unusual, very large diatoms that inhibit the open sea.

In recent years, he has returned to his work on nitrogen-fixing symbiotic associations in these diatoms. This work focuses on the Pacific Ocean, hence his interest in the Wave Glider and the PacX challenge.


* J. Michael Beman, University of California Merced, Merced, Calif.
Ocean Respiration: “Ocean-scale patterns in community respiration rates along continuous transects across the Pacific Ocean”

* Nicole Goebel, University of California Santa Cruz, Santa Cruz, Calif.
Phytoplankton ecology: “Using Replicate Wave Glider Sampling to Improve Estimates of Ocean Phytoplankton Biomass”

* Elise Ralph, Independent Oceanographer, Boston, Mass.
FSLE Predictive Nature: “In Situ Observations of Finite Size Lyapunov Exponent Ridges in the Surface Pacific”

“A comparison of the PacX trans-Pacific Wave Glider data (MODIS, Aquarius, TRMM and VIIRS)” Summary

Dr. Tracy Villareal | University of Texas at Austin

Four wave-propelled autonomous vehicles (Wave Gliders) instrumented with a variety of oceanographic and meteorological sensors were launched from San Francisco, Calif. in November 2011 for a trans-Pacific (PacX) voyage to test platform endurance.

Two arrived in Australia, one in Dec 2012 and one in February 2013, while the two destined for Japan both ran into technical difficulties and did not arrive at their destination.

The gliders were all equipped with sensors to measure temperature, salinity, turbidity, oxygen, chlorophyll and oil fluorescence, meteorological, and wave data.

Our interest was in using the data set to look at whether it could detect how certain large phytoplankton species (small floating plants) bloom, aggregate into large flocs, and eventually sink. This is an important step in removing carbon from the surface ocean and is a major food source for the deep sea. It happens quickly and is difficult to study with ships but is know to occur in the open Pacific Ocean.

The Wave Gliders were equipped with instruments (chlorophyll and turbidity sensors) that have been used successfully from ships to document aggregates, thus providing a real opportunity to look for them at scales never before attempted. To do this, we first had to conduct an initial assessment of the data set looking for artifacts and systematic problems with sensors during this very long deployment.

We conducted a comparison of the PacX dataset to equivalent, or near-equivalent, satellite measurements. Sea surface temperature and salinity compared well to satellite measurements. Chlorophyll fluorescence, a proxy for plant biomass, was poorly correlated with the satellite measurements and there was substantial variability between gliders. Both turbidity and oil CDOM (colored dissolved organic material) sensors were compromised to some degree by interfering processes.

However, the gliders did document the well-known diel cycle in chlorophyll fluorescence over the entire basin, observations that show great potential for using these gliders to study phytoplankton physiology. The gliders captured the Pacific Ocean’s major oceanographic features including the increased chlorophyll biomass of the California Current and equatorial upwelling.

A comparison of satellite sea surface salinity from the Aquarius satellite and glider-measured salinity revealed thin low salinity lenses in the southwestern Pacific Ocean caused by regional rainfall patterns. One glider survived a direct passage through a tropical cyclone.

After all this preliminary assessment, we determined that two gliders traversed an open ocean phytoplankton bloom in the western Pacific.

One glider’s data (Fontaine Maru) was compromised beyond use, but extensive spiking in the chlorophyll fluorescence data from the other (Piccard Maru) was consistent with phytoplankton aggregation. It occurred at the interface of two ocean eddies, exactly as has been predicted in recent research.

To us, this indicates that there is a great potential for future use of these gliders to study aggregation by phytoplankton. However, on long missions, redundant instrumentation is really necessary for interpreting unusual data streams.

In addition, the gliders need a means to periodically image the sensor heads to determine if biofouling (or wandering fish) are interfering with the data, and some sensors need to be placed where bubbles will not interfere with the readings.

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