Waters of the Mona Passage separate the islands of Puerto Rico and Hispaniola and are under the influence of various mesoscale phenomena including internal wave generation, eddy passage and the spreading of buoyant river plumes. These processes are believed to closely modulate microbial processes in the water column and the optical character of near-surface waters. The UPRM and Rutgers research groups are involved in several projects sponsored by ONR, NOAA and the Department of Energy with the goals of characterizing optical and microbial modulation by internal waves and tropical river plumes. Recently, the scientific groups began a collaboration using autonomous underwater vehicles operated by the Rutgers Coastal Ocean Observing Laboratory (COOL) to assay microbial activity and dynamics in an effort to better understand carbon flux in tropical marine environments. In October of 2007, an expedition aboard the Oceanic Research Vessel, BOLD was initiated to monitor river plume dispersion and its modulation by internal waves using COOL’s fleet of autonomous underwater vehicles (gliders).

This UPRM/Rutgers experiment provided an opportunity to jumpstart collaborations between MACOORA and CaRA. Targeted interactions included the first autonomous underwater glider deployment in the Caribbean, initial site surveys for the CaRA HF Radar network starting on the west coast of Puerto Rico, a high interest region for homeland security purposes, plans for the CaRA Operations Center, and discussions of lessons learned from the MACOORA experience of setting up a Regional Association. During the visit by MACOORA leadership, Glider RU16 was deployed during a short boat trip off the UPRM field station at Magueyes Island near La Pagara. RU16 circled around the southwest corner of Puerto Rico and turned north into the Mona Passage between Puerto Rico and the Dominican Republic, transmitting temperature, salinity and optical data to shore through the Coastal Ocean Observation Lab at Rutgers University. Real-time data displays were used to plan shipboard operations during the R/V Bold cruise and to obtain discrete adaptive samples. The glider’s success demonstrated the ability to document:

• The vertical and horizontal displacement of the tidally- generated internal wave known to occur at the site locally known as “El Pichincho”.
• Establish the optical and microbial modulation brought about by the internal wave.
• Visualize the impingement of the wave on the shelf edge at Mona Island.

Finally, this ability to obtain real time data from gliders was paramount for the adaptive sampling requirements of 21st century studies in ocean dynamics and biology.

Fig. 1 First CaRA Glider Deployment Lajas, Puerto Rico - October 19, 2007.

Fig. 2 Initial data from glider RU 16 demonstrating internal waves and impact on chlA levels.

Fig 3. Temperature profiles along the southern coast of Puerto Rico from RU 16

Fig 4. Chlorphyll profiles along the southern coast of Puerto Rico from RU 16

Fig 5. Glider recovery