Contrast density variations with depth in the high and low ...

[dalyningkenk]

Contrast density variations with depth in the high and low latitudes. Why do high-latitude waters generally lack a pycnocline?
 
  What will be an ideal response?

Question 2

What two factors influence seawater density? Which one has the greater influence on surface seawater density?
 
  What will be an ideal response?

[aham8f]

Answer to Question 1

Tropical lower-latitude surface waters are lower density than high-latitude surface waters. As you go deeper in the water column, density increases, so there is a pycnocline in low-latitude waters, while high-latitude deep water is only marginally denser than the water at surface, so there is no pycnocline.

Answer to Question 2

Density is influenced by temperature and salinity. Temperature has the greatest influence on surface seawater density because variations in surface seawater temperature are greater than salinity variations.