Why can deep water form in the North Atlantic but not in the North Pacific?

Warren (1983) first noted that the difference in salinity between the North Pacific and the North Atlantic (Figure 1) was the principal reason deep water formation occurs today only in the North Atlantic. Salty water, when cooled, achieves a higher density and is thus able to sink to greater depth in the water column.

What happens when North Atlantic deep water NADW and Aabw meet?

NADW moves south through the western Atlantic before meeting the AABW north of the Weddell Sea. Together these water masses move eastwards into the Indian and Pacific Oceans. By this time the NADW and AABW have started mixing, to create what is called Common Water.

How does the North Atlantic deep water change as it travels from its region of formation towards Antarctica?

Water flowing northward becomes modified through evaporation and mixing with other water masses, leading to increased salinity. When this water reaches the North Atlantic it cools and sinks through convection, due to its decreased temperature and increased salinity resulting in increased density.

How is the Antarctic Bottom Water formed?

Formation and circulation. Antarctic bottom water is created in part due to the major overturning of ocean water. Antarctic bottom water is formed in the Weddell and Ross Seas, off the Adélie Coast and by Cape Darnley from surface water cooling in polynyas and below the ice shelf.

How are deep and bottom waters formed?

Deep waters are “formed” where the air temperatures are cold and where the salinity of the surface waters are relatively high. The combinations of salinity and cold temperatures make the water denser and cause it to sink to the bottom. Places where the water is cold enough and salty enough to form bottom water.

How does the deep Atlantic water change as it travels to the deep Pacific ocean?

While surface currents are driven mainly by wind, deep water circulation is driven by gravity. Cold and salty ocean surface water in the North Atlantic and elsewhere will slowly sink downward until it reaches a level of equal density. The water then flows past Antarctica and into the Pacific and Indian Oceans.

How does the cold and denser water masses sink to the depths of ocean *?

How does the cold and denser water masses sink to the depths of ocean? Explanation: The cold and denser water masses formed by surface water sink to the depths of the ocean by thermohaline circulation. This occurs because the upwelling of cold water from the deep ocean is replaced by downwelling of surface waters. 7.

How does the deep Atlantic water change as it travels to the deep Pacific Ocean?

What is at the bottom of the North Atlantic ocean?

There is at the bottom of the sea between Cape Race and Newfoundland and Cape Clear in Irelanu, a remarkable steppe, which is already known as the ” telegraphic plateau.” The great circle distance between these two shore lines is sixteen hundred miles, and the sea along this route is probably nowhere more than ten …

What is bottom water formation?

Bottom waters are formed in the high latitudes of both hemispheres. In the Northern Hemisphere the densest waters are formed in the North Atlantic Ocean, in the Labrador and Greenland seas. The Mertz Glacier polynya is a very important location for the production of the dense salty waters.

Why does North Atlantic Deep Water and Antarctic Intermediate Water override Antarctic Bottom Water?

density of water and the formation of deepwater masses. slightly warmer and less dense North Atlantic Deep Water. Antarctic Intermediate Water is still warmer and less dense, and thus it overrides the other two deepwater masses.

Where is the ocean bottom deep water generated?

Deep water formation takes place in a few localized areas: the Greenland–Norwegian Sea, the Labrador Sea, the Mediterranean Sea, the Weddell Sea, and the Ross Sea.

Where does deep water form in the North Atlantic Ocean?

Similar processes in the North Atlantic produce the North Atlantic Deep Water (NADW) in the Greenland Sea (Figure 9.8.1). Figure 9.8.1 The primary sites of deep water formation; Antarctic Bottom Water is formed int he Weddell Sea, and North Atlantic Deep water is formed in the Greenland Sea (PW).

How is bottom water formed in Antarctica?

Formation of Antarctic Bottom Water Antarctic Bottom Water is formed at a few sites along the continental margin of Antarctica during the winter months (Figure 2). The shelf dense water slips across the shelf break to descend to the deep ocean, perhaps within the confines of incised canyons on the continental slope.

What is the difference between offshore and onshore flow in Antarctica?

The offshore water is warmer than the dense shelf water, with temperatures closer to +1.0°C. Once on the shelf this water cools to renew the reservoir of freezing point shelf water. The onshore flow is drawn from deep water of the world ocean that slowly flows southward and upward, crossing the Antarctic Circumpolar Current.

How can the density of seawater be increased?

The main processes that increase seawater density are cooling, evaporation, and ice formation. Evaporation and ice formation cause an increase in density by removing fresh water, leaving the remaining seawater with greater salinity (see section 5.3 ).