Quotation marks, also called 'inverted commas', are of two types: single and double. British practice is normally to enclose quoted matter between single quotation marks, and to use double quotation marks for a quotation within a quotation:
The oceans absorb the sun's heat, transferring it to the atmosphere and distributing it around the world via the ever-moving ocean currents. This drives global weather patterns and acts as a heater in the winter and an air conditioner in the summer.
Downwelling and upwelling currents are important components of the deep ocean conveyor belt and are important in physcially transporting carbon compounds to different parts of the oceans. 1  Watch the NASA video below that animates ocean currents. 2  Next, examine the image below of the Ocean's Conveyor Belt of Deep Ocean and Surface Currents..