ARGUS ISLAND is located 22 miles southwest of Bermuda on Plan- 

 tagenet Bank at 31 o 56 , 55"N,65 o 10 ,i J-5"W. Plantagenet Bank is a seamount 

 rising to within a nearly uniform 60 meters of the surface. - The dimen- 

 sions of the Bank are 5 km in the east-west direction and 8 km in the 

 north- south direction. ARGUS ISLAND is located approximately 2 km 

 within the southern edge of the Bank in 58.5 meters of water (Pickett 

 and Beckner, 1966). The tower has oceanographic and meteorological 

 sensors. Oceanographic data are obtained by lowering sensors on instru- 

 ment guide cables to desired depths. 



Sensors 



Wave Staff: A wave staff manufactured by Atlantic Research 

 Corp. consists of a nichrome wire (resistance 3*3 ohms/m) stretched 

 under 18 million dynes of tension along the axis of a 15-meter long 

 cylindrical monel tube. The tube is slotted every 10 cm along its 

 length to allow sea water access to the wire. The staff is normal 

 to the sea surface and half submerged. The nichrome wire is electri- 

 cally shorted to the tube as sea water passes through the slots. Waves 

 up to 15 meters in height register as a change of resistance. A sea 

 surface profile accurate to +15 cm is obtained (Pickett, I96U) . 



Thermistor Chain : The thermistor chain temperature-measur- 

 ing system consists of a vertically submerged electrical cable. Therm- 

 istors are located at intervals of 3 meters. The resistance of each 

 thermistor is inversely proportional to the water temperature. Output 

 is measured with an accuracy of +0.05°C and recorded on magnetic tape. 

 Each thermistor is recorded once a minute. 



Anemometer : A Bendix-Friez anemometer, located ^3 meters 

 above the sea surface, records wind velocity continuously on strip- 

 chart recorders located at several positions on the tower. 



Solar Radiometers : Solar radiation measurements for deter- 

 mining heat budget are obtained with Eppley pyrheliometers and a 

 Thornthwaite net radiometer. These sensors are mounted on a 6-meter- 

 long beam extended from the tower over the water. 



The pyrheliometer measures incoming and reflected solar radiation 

 (0.3- to 2.5-microns wavelength) and consists of a thermopile mounted 

 beneath thin black-and-white concentric rings. White rings are coated 

 with magnesium oxide which has a high reflectance and black rings are 

 coated with Parson's Optical Black, which has a high absorption nature. 

 A temperature differential proportional to the intensity of radiation 

 generates a voltage difference across the thermopile. 



The net radiometer measures the difference between total incoming 

 radiation and total reflected radiation. A protected thermopile is 

 also used in this sensor. Both the upper and lower surfaces are fin- 

 ished with flat black paint to permit uniform absorption of long- and 

 short-wave radiation. The temperature difference between the upper 

 and lower surfaces is proportional to the difference between incoming 

 and reflected solar radiation. 



