Water Chemistry, Currents and Climate and Why do we study

the Ocean?

Salinity refers to the amount of dissolved salt in a volume of water.

On average, the salinity of water is 3.5% There are many different salts in the ocean, but sodium chloride (NaCl) is the most prevalent(table salt).

You have less salt near the mouth of a river.

You have more salt in tropic climates.

The Salty Ocean

Marine organisms use gases dissolved in water. Two gases found in ocean water that are

necessary for living things are oxygen and carbon dioxide.

Oxygen in seawater comes from the atmosphere and from algae in the ocean and produced through photosynthesis.

Carbon dioxide is about 60 times as plentiful in the oceans as in the atmosphere. It is produced by respiration.

Gases in the Ocean

The broad surface of the ocean absorbs energy form the sun.

Because warm water is less dense than cold water, this warm water stays on top.

The water temperature affects the amount of dissolved oxygen in the water.

Cold water has more dissolved oxygen and warm water has less dissolved oxygen.

The Temperature of Ocean Water

Surface Currents A current is a large stream of moving

water that flows through the ocean. Currents carry water from one place to

another and can carry water great distances.

Some move water at the surface others move water the deep water.

Surface currents, which affect water to a depth of several hundred meters, are driven mainly by winds.

How Surface Currents Affect Climate

The largest and most powerful surface current in North Atlantic is the Gulf Stream.

Climate is the pattern of temperature and precipitation typical of an area over a long period of time.

Currents affect climate by moving cold and warm water around the globe.

Surface Currents Continued

A surface current warms or cools the air above it, influencing the climate of the land near the coast.

In general, currents carry warm water from the tropics toward the poles and bring cold water back toward the equator.

 

El Nino Changes in winds and currents can greatly

impact the oceans and the neighboring lands. El Nino is an abnormal climate event that occurs

every 2 to 7 years in the Pacific Ocean. El Nino begins when an unusual pattern of winds

forms over the western Pacific. This causes a vast sheet of warm water to move

eastward toward the South American coast. El Nino conditions can last for one to two years

before the usual winds and currents return.

Scientists are able to conduct habitat studies and research the ocean floor using research submersibles and Remotely Operated Vehicles – ROV’s for short.

ROV’s are able to collect data and collect samples Drawbacks for the ROV Expensive Limited to length of tether Limited viewing area to that of camera Submersibles carry people Independent (no tether), pilot operated (instead of

computer) Drawbacks for submersibles- # of people they can carry Depth of travel and length of trip

Studying the Ocean