1. In comparison to the neutral phase of ENSO (i.e., in comparison to normal conditions), what are the conditions in the South Pacific during the El Nitio phase of ENSO, in terms of the pressure patterns, relative strength and direction of the trade winds, upwelling along the west coast of South America, sea surface temperatures, and rain patterns?

2. In comparison to the neutral phase of ENSO (i.e., in comparison to normal conditions), what are the conditions in the south Pacific during the La Nitia phase of ENSO, in terms of the pressure patterns, relative strength and direction of the trade winds, upwelling along the west coast of South America, sea surface temperatures, and rain patterns?

3. Changes in weather associated with ENSO are due to its effect on the jet stream. Explain, in general terms, how ENSO affects the pattern of the jet stream and how that, in turn, affects global weather patterns.

4. Summarize the changes from a normal winter (December-February) in air temperature and precipitation patterns in the United States during an El Nth° phase of ENSO (hint: see the summary graphic in the Weather Impacts section — for example: the typical changes from a normal winter in air temperature and precipitation patterns in the south-central and southeast United States, during an El Nifio phase of the ENSO cycle, are wetter and cooler than normal.).

5. Summarize the changes from a normal winter (December February) in air temperature and precipitation patters in the United States during a La Nina phase of ENSO.