EL NIÑO & THE SOUTHERN OSCILLATION: MONITORING A GLOBAL PHENOMENON WITH LOCAL DATA

Purpose

This activity will address the effects of El Nino and the Southern Oscillation (ENSO) across spatial scales, with particular attention directed to the influence of this phenomenon in the southern Appalachian Mountains.

Learning Outcomes

• Distinguish the differences between El Niño and La Niña indicators • Gain familiarity with the website: http://www.noaa.gov?• Accurately interpret data presented in figures, tables, and graphs?• Recognize relationships between ENSO and weather in our region • Consider the biological impacts of the abiotic ENSO phenomenon

Background on ENSO

El Niño (EN) is characterized by unusually warm ocean temperatures in the Equatorial Pacific, as opposed to La Niña, which characterized by unusually cold ocean temperatures in the Equatorial Pacific. El Niño is an oscillation of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe. These phenomena are often analyzed in conjunction with the Southern Oscillation (SO), a comparison of atmospheric pressures in the southwestern Pacific Ocean to those in the southeastern Pacific Ocean.
ENSO news reports often focus on the phenomenon's impact on South American weather, wildlife, and commerce. While it is important to remember that El Niño brings Peru rain, mudslides, and poor fishing (while La Niña produces the opposite), scientific research suggests broader meteorological impacts. What impacts the atmosphere, ultimately affects the biosphere.

Part I: A National Perspective

The figures below show "winter" snowfall values for the contiguous United States for the years 1948-2006.

The top map shows mean snowfall amounts based on the 38 "neutral years" (i.e., neither El Niño nor La Niña years). The map on the lower left shows the average departure from that mean during the ten El Niño years, while the map on the lower right shows average departures for the eleven La Niña years. All values are in inches.

Maps available at: www.noaa.gov

1. Snowfall amounts in the Pacific Northwest and Northern Rockies were greater than the "neutral year mean" during El Niño / La Niña years between 1948 and 2006. (Circle One)

2. What topographic feature along the border of North Carolina and Tennessee is responsible for the relatively high snowfall amounts this area receives compared to other locations within the Southeast?

3. Virginia and western North Carolina received less snowfall during El Niño / La Niña years between 1948 and 2006. (Circle One)

4. How could land managers and wildland firefighters use this information to prepare for the location and intensity of summer fires?

Part II: Access Local Data

Go to the website: http://www.noaa.gov. Spend a moment looking at the home page of this site.

5. The acronym NOAA (pronounced, "Noah") is short for the National _________ _________ Administration.

6. NOAA is a division of the United States Department of ___________.

The NOAA website allows access to information about dozens of research topics including weather, climate, ecology, and hydrology.

You will investigate local ENSO effects by accessing data from an affiliate of NOAA called the National Operational Hydrologic Remote Sensing Center.?Go to their snow analysis website: http://www.nohrsc.noaa.gov/nsa/

7. Today's date is ______________. Looking at the "Automated Model Discussion," you notice that ________% of the sample area is covered by snow.

8. Scroll through selection fields titled "Select Region and Date." Data for the "National" region is available back to what year?

Data from this site will allow you to compare snow conditions for the Southern Appalachian Mountains during the El Niño winter of 2009-2010 and the La Niña winter two years (2007-2008) earlier. Under the selection field titled "Region," select: "Southern Appalachia".

9. What percent of the Southern Appalachia region was covered by snow on February 1, 2010? ___________ What was the average snow depth?

10. What percent of the Southern Appalachia region was covered by snow on February 1, 2008? __________ What was the average snow depth?

11. A. Why is it difficult to contrast El Nino vs. La Niña snow conditions in Southern Appalachia based solely on these two observations?

B. How would you use this website to formulate a testable hypothesis?

12. Choose two organisms that are native to Southern Appalachia. Write a paragraph about each organism that addresses how local snowfall variability, which is partially influenced by ENSO, could affect their habitats and the health and reproduction of the organisms.

Example organisms are the spruce-fir moss spider, northern flying squirrel, Frasier fir, eastern hemlock, black bear, rabbit, deer, wild turkey, or wild brook or speckled trout. Look up their scientific names online.

Organism A _____________ Scientific Name ____________

Organism B _____________ Scientific Name ___________