I have prepared a high-capacity disk with two programs and the corresponding data sets, and they form the basis of my forthcoming text "Reconstructing Large-Scale Climatic Patterns from Tree-Ring data: A Diagnostic Analysis". The mapping programs can be used on several types of printer.
One program maps average values of up to 102 chronologies for time periods you can select. Differences can be calculated between two time periods, or individually selected groups of years to perform tests of hypotheses you may make. The other program does the same thing using the annual and seasonal temperature and precipitation reconstructions from 1602-1960. For example. 1) Plot years of large volcanic eruption and subtract them from years of no known eruption. 2) Years of forest fires versus years of no known fire. 3) El Nino years, etc. All of these have provided very instructive results. Read the DOC files for instructions on uncrunching the disks. You will need a hard drive with at least 6 MEG of free space for all of the data on this disk.
The manuscript text describes the annual temperature, precipitation, and pressure reconstructions which appear to be the most reliable results. Use the seasonal data on the disks with caution. They have large error terms, because of the effects of other seasons and variables on the annual ring growth. I would not try to interpret values for single seasons or even single years; but if you average a number of years of similar characteristics, the error may be sufficiently reduced to provide meaningful results. This varying reliability is discussed in the text. Temperature is more reliable than precipitation, annual values more reliable than seasonal values, and the reconstructions near the tree-ring grid more reliable than those more distant from the tree-ring grid. Don't trust the reconstructions for Eastern North America or for the Gulf Coast. The annual temperature reconstructions for the central part of the U.S. have some reliability but not the precipitation estimates. Please keep these limitations in mind if you use the disk.
Harold C. Fritts, Laboratory of Tree-ring Research, University of Arizona, Tucson, Arizona 85721, U.S.A.