Question

The north-Atlantic deep-water is associated with ____________.

• A. Low temperature and low salinity
• B. High temperature and high salinity
• C. High temperature and low salinity
• D. Low temperature and high salinity

Hint:

Deep water formation = \textbf{thermohaline circulation}. Always look for the combination that increases density: low temperature + high salinity.

Answer 1

The Correct Option is B, D

Step 1: What forms deep water?
Deep water masses form by convection where surface water becomes dense enough to sink. Density increases with low temperature and high salinity.

Step 2: North Atlantic Deep Water (NADW).
In the North Atlantic, especially near the Labrador and Greenland Seas, cold surface temperatures and brine rejection from sea ice formation create very dense water.

Step 3: Exclude wrong options.
- (A) Low T + Low S → not dense enough.
- (B) High T + High S → warm, less dense.
- (C) High T + Low S → least dense of all.
- (D) Low T + High S → very dense, sinks to form NADW.
Final Answer:
\[ \boxed{\text{Low temperature and high salinity}} \]