Global Warming
1. (15 points) Explore the website https://www.pmel.noaa.gov/elnino/ (and use your textbook) to answer the following questions about El Niño/La Niña:
What changes from “normal” conditions in the tropical Pacific Ocean (in terms of winds and distribution of ocean temperatures) occur during El Niño years?
How is La Niña characterized?
Describe the impacts of El Niño on climate and weather for both the western Pacific (such as Indonesia and Australia) and the eastern Pacific (such as Peru and Ecuador). What impacts can El Niño have on the west coast of the U.S.?
2. (10 points) In the space below make a sketch of a cross section of the ocean from the surface to 500 m depth extending from the western Pacific (coast of Australia) to the eastern Pacific (coast of South America)during a “normal” year and an El Niño year. Draw arrows (and label them) to illustrate (1) the direction of the prevailing winds, (2) the direction of movement of the surface water that would create upwelling off the coast of Peru, (3) the relative thickness of the well-mixed surface water layer across the basin, and (4) the slope/shape of the thermocline.
3. (10 points) The TAO/TRITON buoys are used to survey conditions in the equatorial Pacific Ocean. Open the following website: https://www.pmel.noaa.gov/gtmba/pmel-theme/pacific-ocean-tao. Explore the website to find out what range of latitudes and longitudes is covered by the TAO mooring array.
Latitudes:
Longitudes:
Click Moorings under the Technical Information heading. Scroll down on the moorings page. What is the range of depths where temperature measurements are made on each mooring in the Pacific?
4. Study the plots below, generated at https://www.pmel.noaa.gov/tao/drupal/disdel/ , and answer the following questions.
a) (10 points)
b)
Are there currently any significant (>+/- 1°C) temperature anomalies (lower panel) below the ocean surface in the tropical Pacific Ocean? If so, describe where (give approximate range of latitude/longitude and depths):
d) (15 points)Now we will examine how the tropical Pacific has varied over the past 29 years.
View this plot carefully and think about what it is showing. Over this time period, how many individual El Niño events can you identify and what years did they occur in? How many La Niña events can you identify and what years did they occur in? (Hint: Remember to refer to the “Anomalies” to get a sense of the deviation from normal conditions. Assume that anomalies of greater than ~+/-1° C are significant).
El Niño events (years):
La Niña events (years):
Put an asterisk (*) next to the year of the strongest El Niño and La Niña events.
5. (10 points) Visit the website https://www.ncdc.noaa.gov/teleconnections/pdo/ to explore the Pacific Decadal Oscillation (PDO). What does the PDO have in common with ENSO, and what are the differences between the two?
What is the current status of the PDO?
6. (10 points) Now visit the website https://www.ncdc.noaa.gov/teleconnections/nao/ to explore the North Atlantic Oscillation (NAO). How is the NAO index defined (what does positive vs. negative mean)? What are the associated temperature anomalies in the eastern US?
What is the current status of the NAO?