Ragged bands and patches of a surface slick give the sea around the tower a glassy 

 appearance. Covering as much as 10 percent of the surface, slicks usually orient them- 

 selves in lines parallel to the shore. The time of the slick's arrival at the tower is 

 noted and correlated with recordings of the thermal structure and other phenomena. 



ON-SHORE WIND 



The slick film collected from the tower appears oily 

 and frequently contains pieces of seaweed, foam, and 

 other debris. 



Surface pressure across slicks was studied by 

 dropping various concentrations of oil and alcohol on 

 the surface and noting the spreading effect. In this 

 example the greatest surface pressure is skewed in 

 the upwind direction toward the trailing edge of the 

 slick. 



41 



