TM No. 377 



The mean winds at the BBEI£ are typical of the east coast in the north 

 temperate zone. In the warmer months, during periods of fair weather, pre™ 

 vailing winds are from the west to southwest. East and northeast winds, 

 and generally foul weather, occur during passage of low pressure cyclones 

 moving to the northeast off the New England coast. In the winter months, 

 the semi -permanent Canadian polar high tends to impress a strong north- 

 westerly wind component in this area. During the periods of wave measurements, 

 the spring and summer of 1964 and 1965, tiie prevailing winds were generally 

 from the west and west-southwest. 



Starting in April and continuing through the summer months (in fair 

 weather periods), a sea breeze effect occurs at about 1200=1300 hours, 

 intensifying the southwesterly component of the wind vector. 3y mid- 

 afternoon, there is a very predictable southwest wind from 6»>9 '& sec" 1 . 

 This wind dies down by sunset, and on occasion gives way to a slight land 

 breeze effect. 



Waves passing the station are usually a combination of ground swells, 

 which almost always travel from the south or south-southeast, and of 

 ambient local wind waves, which generally move in the same direction as 

 the local wind field. 



Gross Environmental Studies Made at B3ELS 



In measuring any time variable oceanographical or meteorological 

 phenomenon, one must have at least a cursory knowledge of ambient con- 

 ditions, of the so-called background environment. The purpose of the 

 present experiment was to study the actions of surface waves having a 

 frequency range from 50 to 2500 mc sec - and a wave number { 2.TT t"') 

 range from 0.6 to 20 m" 1 . It is clear that the open ocean environment 

 has components of motion other than those associated with surface 

 gravity waves. Thus, in measurements of two-dimensional wave motions 

 in a vertical plane, the observed horizontal velocity record will 

 certainly have components associated with tidal currents and other 

 phenomena, which may or may not appear as a mean current over the 

 period of wave measurement. Specifically, the wave record may have 

 a component of horizontal flow which occurs as a monatonic variation 

 (a trend) in the horizontal u record. Or horizontal eddying motions 

 could produce several fluctuations during the wave record. This low 

 frequency motion can be described by a modification of equation (lli>12)s 



Wit) = H +Wvt + W c (17-1) 



where l4=Uw+ul Ihe.ttil is the time variable oscillatory motion caused by 

 the waves; and 1f£ is any ether time variable fluctuation in the horizontal 

 motion,; which would be of somewhat lower frequency than U^ . The lie 

 component might be caused by a horizontal meandering motion such as that 

 observed on or near the continental shelf, where the interaction of local 



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