El Niño Subtitle

What you need today: Pencil Bellringer sheet Binder Everything else on the counter. Bellringer # 1 What have you heard about El Niño? Has El Niño affected you? Recall: How does the ocean affect climate?

Today’s Objectives Students will be able to: Describe how conditions in the Pacific Ocean differ during El Niño. Explain how the ocean affects climate. Identify the source cause of El Niño.

Today’s Science Practice Today you will be engaging in constructing explanations. Science and Engineering Practices 1.Asking questions and defining problems. 2.Developing and using models. 3.Planning and carrying out investigations. 4.Analyzing and interpreting data. 5.Using mathematics and computational thinking. 6.Constructing explanations. 7.Engaging in argument from evidence. 8.Obtaining, evaluating, and communicating information.

Trade Winds  Close to the equator, the trade winds blow from east to west.  These steady winds push warm surface water in the Pacific Ocean away from the western coast of South America.  This allows upwelling to occur. Cold water rushes upward from below.  The air above the upwelling water cools and sinks, creating a high pressure area.  On the other side of the pacific ocean air rises over warm waters, creating a low- pressure area.  What does the difference in air pressures across the Pacific Ocean do?

Normal Conditions

El Niño What happens when the trade winds weaken? The normal patterns of high and low pressures across the Pacific Ocean reverse. Warm water surges back toward South America. What would this prevent? This phenonmenon is called El Niño.

El Niño  The El Niño/Southern Oscillation (ENSO) causes another type of short-term climate change.  During ENSO, the trade winds weaken and warm water surges back toward South America.

El Niño Conditions

El Niño  A complete ENSO cycle occurs every three to eight years, with the following effects:  lots of precipitation along the western coast of South America.  droughts in normally wet regions.  increased number of violent storms in California and southern U.S.