GEOS 595e (ENSO: Past, Present, Future) Spring 2006
Data Exercise II: Teleconnections associated with ENSO
(last updated 10 February 2006)

To be discussed Feb 15th in class.  Questions? Send email or make an appointment to come see me. 

Hand in your summary and a paper copy of any figures you have made for discussion.

Purpose:

To examine the effects of this year's tropical ocean-atmosphere anomalies on the Northern Hemisphere atmospheric circulation, and to understand them in terms of the equatorial ocean-global atmosphere teleconnections (observations and theory) we've been discussing.

Assignment:

Write a summary (1-2 paragraphs) answering the question below, using examples drawn from your responses to the questions below.  Note any questions you have about other features you've observed, which you'd like to discuss in class.  Bring an electronic copy (ppt, pdf) of any figures you'd like to discuss in class on a jump drive, or email them to Mike by 1pm Feb 15th.  Be prepared to discuss this exercise in class Feb. 19th along with the Tribbia (1991) book chapter.

Tools:

You'll need a networked computer with fast (e.g. University) Internet connection, and the largest display you can find.  A UNIX workstation with java-enabled browser would be my preferred system.  Let me know if I can set you up on a workstation here at the  Tree Ring Lab.

Tasks:
  1. First, based on your reading of Tribbia (see also Rasmusson and Wallace, 1983, Horel and Wallace, 1981, and results from last week's data exercise), predict what you expect to see and why in the following data sets: 
    1. Northern Hemisphere outgoing longwave radiation (OLR)
    2. Northern Hemisphere geopotential height anomalies
    3. Honolulu, HI (158W, 21N, 2m) rainfall anomaly
    4. Edmonton, Alberta (114W, 53N, 715m) air temperature anomaly
    5. Jacksonville, FL (82W, 31N, 9m) rainfall anomaly
  2. Now let's look at the observations.  Be sure you understand what is plotted in each figure, as you go, because the plots can get pretty complex.   Start by looking at the current animation of weekly SST and OLR anomalies, and then the latest three month average map for SST,  and the latest equatorially-averaged time-longitude map of OLR.  Do these data suggest an atmospheric teleconnection response over North America should be observed?  Why? 
  3. Examine the 90-day averages of operational 500mb geopotential height anomalies.  Is this picture consistent with the SST and OLR analyses, and with our teleconnection theory?  Why?
  4. Examine the 90-day averages of operational surface wind anomalies. Is the picture consistent with results reviewed by Tribbia (cf. especially Fig. 9.5)?  How and why/why not?  
  5. Examine the 90-day averages of operational surface temperature anomalies.  Is this consistent with Tribbia, and with Horel and Wallace's expectation for Edmonton, Alberta?
  6. Now look at seasonal precipitation data for Honolulu and Jacksonville.  Go to the Climate Prediction Center's Precipitation and Temperature Monitoring Center and click on Precipitation Plots for Selected Cities.  Choose southeastern 1/4 of US, 90 day accumulated precipitation, and click on the dot representing Jacksonville, FL. What is the plot telling you?  Now do the same for Honolulu, Hawaii 90-day precipitation  accumulations.  Does this winter's data for Jacksonville and Honolulu show you what you expected to see?  Why?  
  7. The Southwest US is thought to have a wintertime rainfall teleconnection with ENSO activity (see Redmond and Koch (1991) for the basic idea).  Now examine the 90-day average precipitation accumulations for Tucson from the CPC.  Does this year's data show what you expected to see?  Why/why not?
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