1. During normal conditions, a ______ pressure zone forms over Indonesia, causing wind to blow _____________. A.High; Peru to Indonesia B.High; Indonesia to Peru C.Low; Peru to Indonesia D.Low; Indonesia to Peru

Indonesia is on the equator- Low Pressure Zone Peru is in trade wind zone 30 S to Equator- southeasterly winds- (towards the northwest )

2. During a normal conditions, there is an upwelling of water from the deeper ocean along the coast of ____. A.Indonesia B.Peru C.Both D.Neither

With the wind blowing towards Indonesia, water piles up on the west side of the Pacific. With the winds blowing away from Peru, water from below can move upwards in an upwelling.

3. An upwelling of water from the deeper ocean brings water that is _______ and _______ in nutrients A.warmer; lower B.warmer; higher C.colder; lower D.colder; higher

This deeper ocean water is colder and it is also nutrient rich since the nutrients from above accumulate and there is low nutrient uptake due to the slower metabolic rate of organisms.

4. In an El Niño (ENSO) year, the normal trade winds_____. The water temperature off the coast of Peru ___. A.intensify; warms B.intensify; cool C.weaken or even reverse; warms D.weaken or even reverse; cools

5. Which of the following is the sign of an El Niño year? A.An increase in air pressure over Indonesia B.A decrease in air pressure over Indonesia C.An upwelling along the coast of Peru D.A and C E.B and C

6. An El Niño year causes droughts in ____ and increased rainfall and flooding in ___ A.Indonesia and Australia; Peru B.Peru; Indonesia and Australia C.Droughts on both sides of South Pacific D.Heavy rain on both sides of the South Pacific

7. During an El Niño year, there is a(n) _______ in the primary productivity (amount of algae etc.) off the coast of Peru. A.Increase B.Decrease C.No change

With a decrease in the upwelling due to changes in the wind pattern, the water off the coast of Peru is less nutrient rich and is less productive, which affects the whole food chain, decreasing fish populations as well. Fig. 3 Concentration of chlorophyll-a (a pigment in phytoplankton needed for photosynthesis) observed by OCTS in (A) December 1996, before the occurrence of El Niño; and (B) June 1997 during the development stage of El Niño. Refer to the scale bar at the bottom of the diagram for the concentration value (mg/m3). There is a decrease in chlorophyll concentration off the coast of Peru and in the equatorial region 160°E- 160°W.

8. Which of the following correctly describes what a La Niña year is. A.An exaggeration of the el niño conditions. B.An oscillation in the northern hemisphere C.An exaggeration of the normal conditions D.A year with an unusually high number of female births

1.C 2.B 3.D 4.C 5.A 6.A 7.B 8.C