Climatic Research Unit : Papers

CRUST: Software for the implementation of Regional Chronology Standardisation: Part 1. Signal-Free RCS

Thomas M. Melvin and Keith R. Briffa
Dendrochronologia (2014) 32, 7-20.
doi: http://dx.doi.org/10.1016/j.dendro.2013.06.002

Abstract

This is the first of a two-part description of a new software tool CRUST (Climatic Research Unit Standardisation of Tree-ring data). This program has been designed primarily to allow the convenient, routine application of "Signal-Free Regional Chronology Standardisation" (SF RCS) to different types of tree-ring data. The program also enables the use of other popular standardisation methods. A series of experiments is described in which the ability of simple RCS and SF RCS to recover known tree-growth forcing signals is tested. In the comparatively rare situation where many sub-fossil data are distributed over a wide time range and there is no slope in the overall common-growth forcing signal, simple RCS is satisfactory. Simple RCS produces distortion in all other examples explored here. SF RCS is superior to simple RCS and in all cases examined. SF RCS works well except when the span of starting dates of sample trees is too narrow, a situation for which a test is available. Based on the results of the tests explored here, we conclude that Signal-Free RCS should be used as the standard method of RCS processing.

Citation: Melvin T. M. and Briffa K.R. (2013) CRUST: Software for the implementation of Regional Chronology Standardisation: Part 1. Signal-Free RCS. Dendrochronologia 32, 7-20, doi: 10.1016/j.dendro.2013.06.002

Paper and Supplementary Material

The paper, supplementary material, data, and software (source code as well as executables) are provided (in this zip file) to document in detail the tree-ring data and the multiple stages of data processing and analysis.

Data Files and Source Code

We have created a reduced-functionality version of the CRUST software that is specific to the RCS Part 1 paper (i.e. it does the specific processing necessary to construct the tree-ring chronologies, undertake the various analyses reported in the paper, and create the figures shown in the paper). This RCS part 1 version of CRUST is available in the zip file linked to above. It contains all the raw data, together with executable versions for Linux and Windows. It also includes the Fortran source code, from which it can be compiled. We are not able to offer any technical support, but it does include a "makefile" to assist with compiling the software (though we recommend using the pre-compiled, executable versions if they work on your computer system). The zip file contains the TRW measurement data and pith offsets files used in the paper.

The full-functionality version of CRUST is available from the CRUST software page.

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