Environmental Measurements and Observations in Support of the Naval Research Laboratory's High Frequency Acoustic Coherence Experiments, Panama City 1995.

From 30 March to 19 April 1995, the Naval Research Laboratory conducted a series of high frequency acoustic coherence measurements in the shallow-water (6-12 m) coastal environment off Panama City Beach, FL. This report contains descriptions of the equipment used to collect the data, the data quantity and quality, plots and tabulations, and an analysis of the oceanographic environment in which the acoustic data were collected. From 30 March to 22 April, wind speed and direction, air temperature, barometric pressure, and solar irradiation were collected every 15 min. Oceanographic measurements were taken as sea conditions permitted from 5 April to 19 April. A total of 29 CTD profiles and two CTD time series of 2 and 4 days each were collected. Wave spectra and small scale temperature variations were also collected during each acoustic run. Weather and oceanographic conditions were typical of the northeastern Gulf of Mexico during spring. In general, air and sea temperatures rose over the course of the experiment except during the passage of cold fronts. Water column temperatures were close to isothermal and had not developed the typical late spring, mid-depth thermocline. However, changes in the water mass produced by effluence from St. Andrews Bay during falling tides were evident on calm days in the temperature, salinity, and sound speed time series. On at least three occasions, internal wave activity was also associated with these water mass changes.