376 



UNDERWATER WEATHER STATION 



LOWERING POSITION 



DIVER TOWING POSITION 



INSTALLED 



TUBES 

 INFLATED 



Fig. 141. Schematic diagram of the Sealabll Underwater Weather Station in lowering posi- 

 tion, diver-towing position, and installed position. Numbers indicate sensors: (1) upper 

 current speed, Savonius rotor, (3) compass, (4) upper thermistor, (5) lower current speed, 

 Savonius rotor, (6) lower current direction vane, (7) pressure sensor, Vibrotron, (8) lower 

 thermistor, (9) ambient light 



Two days were required to install sensors on both the upper and lower weather station. 

 Conductors were run to the station, and underwater weather was recorded in the habitat. Two 

 trips were made daily to service instruments and check sensors. Recorders inside the habitat 

 were checked, and comparisons with observed weather conditions from the 24-inch ports were 

 made. 



RESULTS 



Data were recorded in analog form in Sealab 11 and in benthic control center. Also, all 

 data transmitted over the benthic lab cables were routinely sampled, digitized, and then stored 

 on the telemetry system's magnetic tape recorder. Unfortunately, an erratic fluctuation of the 

 time -identification channel made much of this magnetic tape data unintelligible. 



The routine analog recording through the long lines of benthic lab had high levels of back- 

 ground noise, as well as long-period, quasi- systematic fluctuations that partially obscured the 

 data signals. Therefore, it was not practical to make a systematic reduction of all of the ana- 

 log data. Rather, the approach was to (a) analyze those records that presented synoptic infor- 

 mation from a number of stations, such as the underwater weather station, the 150-ft station, 

 and the pier end (Figs. 142 and 143) and (b) make detailed analysis during times of unusual 

 phenomena, such as high waves (Figs. 140 and 144). Detailed analysis was facilitated by the 

 use of a high-speed data acquisition system, DAS, which stored data of finite length for future 

 spectral and cross-spectral analysis. 



Presentation of Data 



Seven days of synoptic measurements of currents at the Sealab II underwater weather sta- 

 tion and at the 150 ft deep station in the head of Scripps Submarine Canyon were made (Sept. 

 22-26 and Sept. 29-Oct. 1, 1965). Comparison of currents from both localities during two days 

 when the currents were most active are shown in Figs. 142 and 144, together with measure- 

 ments of tide and wind from the Scripps Pier. 



