Why do natural archives (proxy climate records) apparently respond to the ENSO phenomenon?

The diagram in the paper handout shows correlations between the Southern Oscillation Index and 10 natural and historical records. All but 3 show moderate to high correlations. The locations to which they refer are shown in the map, and details of each record follow here. In each case, explain the correlations, or lack of them, between the proxy record and the SOI. Do this in terms of both warm and cold ENSO events, wherever possible. The crucial stage of the explanation will be the connection between the large-scale features of ENSO phenomenon and the regional climate where the proxy was derived. For information, use the lecture handouts, the knowledge of regional climatology you have gained in Katie Hirschboeck's class, and any relevant information you can find on the World Wide Web. A good place to start looking is the El Niņo theme page:

http://www.pmel.noaa.gov/toga-tao/el-nino/impacts.html

Once you have worked out explanations for all 10, please e-mail them to me at mhughes@ltrr.arizona.edu, by April 25

Potential proxy records of ENSO.

  1. This is a tree-ring index from drought-sensitive trees over a large region of the west centered on Arizona. These trees respond primarily to precipitation in the winter half-year before the growing season.
    2. .
  2. As for 1, but for tree rings centered on Arkansas. These trees respond more strongly to precipitation during the spring before the growing season.
  3. As for 1. and 2. , with the timing of the response to moisture somewhat intermediate.
  4. Temperature-sensitive oxygen isotope ratios in coral from the Galapagos islands - an annual record.
  5. Teak tree rings in Java. - Small rings are formed when the dry season is long.
  6. The ratio of oxygen isotopes in ice on Quelccaya, Peru (over 6000m elevation). Thought to be a measure of temperature at which the precipitation was formed.
  7. Accumulation rate of snow on Quelccaya
  8. An index derived from historical documents recording El Niņo events in coastal Peru and southern Ecuador.
    9. .
  9. Winter precipitation at Santiago de Chile reconstructed from tree rings.
  10. . Summer temperature in Patagonia reconstructed from tree rings