Added 7/05:  the fortran (77) source code ("multiproxy.f") used by Mann et al 
(1998) for implementing the temperature reconstruction methodology described 
therein. An independent implemenation of the algorithm in open-source ("R") 
software, and reproduction of the published results, can be found at the 
National Center for Atmospheric Research (NCAR):
http://www.cgd.ucar.edu/ccr/ammann/millennium/MBH_reevaluation.html

We note here a few additional minor details of the MBH98 methodology
that were not explicitly discussed in MBH98 due to space
constraints.
A brief listing of these is provided below, while a more detailed
enhanced description of the Methods used by MBH98 is provided in the file
"AlgorithmDescription.txt" in this directory.


1. The number of PCs retained in various proxy sub-networks were determined 
for each independent interval of the stepwise reconstruction based on a 
combination of objective criteria (modified Preisendorfer rule N and scree 
test)

2. Reconstructed Principal Components (RPCs) were scaled to have same variance 
as the annual mean instrumental PCs over the calibration period (1902-1980).

3. Proxy data and instrumental data were normalized by their detrended variance.

An additional, independent application of the methodology of MBH98 can be found 
in the following publication:

Zorita, E., F. Gonzalez-Rouco, and S. Legutke, 2003: Testing the Mann et al. 
(1998) approach to paleoclimate reconstructions in the context of a 1000-yr 
control simulation with the ECHO-G Coupled Climate Model, J. Climate, 16, 
1378-1390.