Understanding El Nino and La Nina

1. Understanding El Nino and La Nina Aim: To understand the what this weather phenomena is and what conditions it brings (A.K.A – To understand a bloody difficult part of atmospheric physics!!)

2. Aim: To understand the what this weather phenomena is and what conditions it brings 3 Steps to success • Define the terms La Nina and El Nino and be able to distinguish between them both • To describe the phenomena with reference to atmospheric dynamics • To explain the impacts of the phenomena

3. Aim: To understand the what this weather phenomena is and what conditions it brings Brain Warm-Up • What are El Nino and La Nina • What types of conditions do they bring? • What are the impacts of this weather phenomena?

4. Aim: To understand the what this weather phenomena is and what conditions it brings Step 1 – La Nina • A cooling of the surface water of the eastern and central Pacific Ocean, occurring somewhat less frequently than El Niño events but causing similar, generally opposite disruptions to global weather patterns. La Niña conditions occur when the Pacific trade winds blow more strongly than usual, pushing the sun-warmed surface water farther west and increasing the upwelling of cold water in the eastern regions. Together with the atmospheric effects of the related southern oscillation, the cooler water brings drought to western South America and heavy rains to eastern Australia and Indonesia.

5. Aim: To understand the what this weather phenomena is and what conditions it brings Step 1 – El Nino • A warming of the surface water of the eastern and central Pacific Ocean, occurring every 4 to 12 years and causing unusual global weather patterns. An El Niño is said to occur when the trade winds that usually push warm surface water westward weaken, allowing the warm water to pool as far eastward as the western coast of South America. When this happens, the typical pattern of coastal upwelling that carries nutrients from the cold depths to the ocean surface is disrupted, and fish and plankton die off in large numbers. El Niño warming is associated with the atmospheric phenomenon known as the southern oscillation, and their combined effect brings heavy rain to western South American and drought to eastern Australia and Indonesia. El Niño also affects the weather in the United States, but not as predictably.

6. El Nino – Typical surface ocean circulation

7. El Niño conditions • Normal • El Niño – strong counter-current

8. El Niño conditions • Normal • El nino – strong countercurrent

9. http://esminfo.prenhall.com/science/geoanimations/animations/26_NinoNina.htmlhttp://esminfo.prenhall.com/science/geoanimations/animations/26_NinoNina.html

10. Prediction of El Nino • Satellites • provide data on tropical rainfall, wind, and ocean temperature patterns, as well as changes in conditions for hurricane formation. • Ocean buoys • help to monitor sea-surface and upper ocean temperatures. • Radiosondes • balloon-borne instrument platforms with radio transmitting capabilities, help to monitor global weather and climate patterns • Super computers • gather all of the weather data around the world and put it into useful formats used by scientists. • Run models for future change