Fall — Surface layer cooling reduces the strength of the negative gradient in the 

 upper layer during the fall. About 75 percent of the observations indicate a positive grad- 

 ient in the upper layer. A majority of the profiles classified as non-positive were observed 

 during October or early November. Most of these profiles have a surface duct indicating the 

 advent of seasonal mixing and layer deepening which characterizes this transition season. A 

 weak sound speed minimum near 50-75 m is observed sometimes for profiles at locations 

 where the shelf depth exceeds 100 m. The T-S diagram indicates the complexity and 

 weakening of vertical stability in some of the profiles, in comparison to the summer profiles. 

 Both gradient statistical tables indicate that the large percentage of positive profiles is 

 produced by positive gradients in the upper 50 m. Overall gradients from the surface to 

 depths below 50 m are primarily negative. It would be difficult to represent the entire fall 

 season with a single profile. 



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