John Adams took his 10-year old son, John Quincy Adams, with him on his first trip across the Atlantic Ocean during the winter of 1777. They were headed to France. In those days, trips across the Atlantic Ocean were not easy. Planes hadn’t been invented yet, not even steamboats. The only available transportation to any part of Europe was a frigate—a very large sailboat that depends on wind power. The wind that powers sailboats also affects the behavior of the ocean. Winds create wind-driven currents, which can either reduce the travel time or lengthen it, depending on which way the current is flowing. These currents determine both how quickly a boat can get across the ocean and the path the boat will take.

While winds can help speed travel, they can also cause problems for captains and their passengers, especially when they blow too hard and cause storms. In his journal, John Adams described one of the storms the ship he was on encountered in the North Atlantic Ocean:

Today people rarely use ships to travel from one continent to another. However, ships are still used to transport materials that, because of their size or quantity, are not easily transported by air. Sometimes these ships encounter large storms at sea. Since a lot of cargo is stored on the decks, a big wave or strong wind can send a container and its contents overboard. While this may mean an economic loss for a company and increase the amount of trash in the oceans, lost cargo has helped oceanographers chart ocean currents. While the vast majority of what we have learned about ocean currents has come from carefully planned oceanographic expeditions over the past century, oceanographers have been able to add to their understanding by looking at the pathways that lost cargo takes in the open sea.

In the last activity you investigated density-driven currents. In this activity, you will examine wind-driven currents, paying special attention to two of the factors that affect the direction of these currents: global winds and landmasses.

Goals

• You will map the path of four different ocean currents.
• You will be able to explain the connection between wind direction and ocean current direction.
• You will observe how landmasses and wind help create circular patterns in the ocean called gyres.