Mount Hope Bay Cruise, August 18-19, 2005
SMAST researchers have developed a model of Mount Hope Bay that simulates major circulation patterns in the bay. On 18-19 August aboard the R/V Lucky Lady, a team from SMAST made an intensive survey of Mount Hope Bay to validate that model. The objectives of the survey were to examine (1) the current separation and eddy formation due to tidal flushing in the deep channel connecting Mount Hope Bay with Narragansett Bay and (2) the structure of the thermal plume caused by the hot water injected from the Fall River power plant.
The survey was organized and led by SMAST scientist Dr. Liuzhi Zhao, who has had a major role in developing the circulation model of Mount Hope Bay. Other participants included Profs. Changsheng Chen and Dan MacDonald, research scientist Dr. Geoff Cowles, research associate Qichun Xu, and graduate students Song Hu and Fei Chen. Woods Hole Oceanographic Institution scientists Jim Churchill and Tim Fristedt participated in the first day of the cruise and deployed two GPS-tracked drifters to trace the water movement at flood tide. They also trained the scientists and graduate students of SMAST in the use of drifters. A towed CTD/ADCP instrument—which measures conductivity, temperature, depth, and current velocity, and provides researchers with the means to determine salinity—was set up by Dr. Zhao and Fei Chen. Prof. MacDonald was on the boat for the first day to check the CTD/ADCP setup and to teach Dr. Zhao and Song Hu how to configure and operate the instrument. Prof. Chen was on the boat both days to help Dr. Zhao adjust the measurement design to best realize the cruise objectives.
During the first day of the cruise, which was focused on the current separation, towed CTD/ADCP measurements were made repeatedly along transects covering the eastern region of Mount Hope Bay where the eddy was detected from the model simulation. Two drifters were deployed at 3:00 PM around the maximum flood tidal current near the Mount Hope Bridge. The trajectories of the drifters raised many interesting questions that need to be addressed in the future modeling experiment.
During the second day of the cruise, which focused on the structure of the thermal plume, toyo-CTD measurements were made repeatedly across the plume offshore of the power plant during the ebb and flood tides. Under the direction of Dr. Cowles, two drifters were released near the outflow channel of the hot water injection. This was the first cruise involving all the scientists and graduate students of the Mount Hope Bay Natural Laboratory, both modelers and observationalists, in a single project.
Photos: At top, Prof. Changsheng Chen and in the background Fei Chen and Liuzhi Zhao. Bottom, Liuzhi Zhao and Geoff Cowles.TOP