Water Currents Notes: Student Handout

Label the World’s Ocean Currents on the Map below. Use a red marker to draw currents that move warm water and use a blue marker to draw currents that move cold water. Make sure you write the names of ALL of the currents.

I. Water Currents: _______________________________________________________________________________________________________________ A. Types of Water Currents:

1. ______________________________________2. ______________________________________

II. Gyres: ______________________________________________________________________________________________________________________ A. Formed by:

1. _____________________________________2. _____________________________________3. _____________________________________

B. Gyres include both ________________________ and ____________________ ocean currents.

III. Surface Currents A. Surface Currents are generally ________________________ currents that are driven by __________________. They are located in the top _____________ meters of ocean water and occur in ______% of ocean water (the rest are deep water currents). B. Wind patterns move in _______________ directions in the _______________ hemisphere vs. the ___________________ hemisphere causing Earth’s gyres to circle in opposite directions in those hemispheres.

IV. Surface Currents and the Ekman Spiral A. An Ekman spiral occurs when water _________________ the surface flows in a __________________ direction that the surface current. B. The top later movement is driven by ___________________. C. The deeper layers are set in ________________ by ______________________, ___________________ or_______________________.

V. Deep Ocean Currents A. Deep ocean currents are driven by __________________ and __________________ gradients (differences).

1. ________________________________, also known as the ocean’s conveyor belt, refers to ___________ ocean ______________-driven currents.

2. These currents, which flow __________________ the surface of the ocean and are hidden from immediate detection are called ____________________ ___________________.

B. ________________________ and _____________________ areas in the oceans are areas where significant ___________________ movement of ocean water is observed.

VI. Thermohaline Currents (Thermo relates to temperature and haline refers to salinity) A. Thermohaline currents can be caused by:

1. Differences in ___________________ and __________________: Cold water and water with a __________________ salinity is more dense and will ________________ causing a current.

2. Precipitation and _____________________ (freshwater) entering the ocean pushes more dense water downward.

3. _____________________ and freezing of ocean water (frozen water is typically _______________________) causes the ocean water to be more ________________ and sink.

VII. Upwelling A. Upwelling occurs when _____________________ water moves from the lower levels of the ocean toward the ______________________.

B. Formed by the ___________________ blowing _______________________ to the surface of the water. C. Upwelling brings ________________________ and ________________________ to the _____________________ from the bottom of the ocean. Warm water at the surface of the ocean tends to nutrient and oxygen poor.

VIII. Global Conveyor Belt A. ____________ can flow for very long distances and together they form the __________________ ____________________________ _____________.

1. The Global Conveyor Belt plays a major role in determining most the __________________ in most of Earth’s regions.

2. The _________________ ___________________ brings warmer water from the equator towards ____________________ causing the climate in Europe to be more _____________________ (warmer) than the rest of the countries at the same latitude.

3. ________, _________ is much ___________________ than the surrounding tropical area due to the cold water brought in by the _______________________ and _____________ currents.IX. Longshore Currents (Surface currents) A. Flow ____________________ to the beach. B. Transport _____________ C. Can cause __________________________.X. Rip Currents (Surface Currents)

A. Flow from the __________________ straight outward towards the _____________________.

B. Carries ____________________ out to seas (the water looks a __________________ color). C. Strongest at the _________________ of the current.