Tucson format

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Tucson format or decadal format or rwl format is one of the most common formats for storing ring width data. It is the standard format for ITRDB. It is a text file format. Different extensions are used, such as .rwl, .crn, .tuc and .dec. (.crn is used for derivate chronologies). The name comes from the city of Tucson in Arizona.

A Tucson file consists of three lines of meta data followed by an undefined number of data lines (and cores). A data line consist of the core identity (max 8 alphanumeric characters, i.e. letters or digits), the year of the oldest measurement of the line (4 digits)[1] ring width data, up to ten rings per line. Measurement data is either given with 3 or 4 digits according to resolution. Except for the first and last lines of each core there are measurements for one decade per line. After the youngest ring there is a "999" as a stop mark. Missing data mark is -999.

PMkr12b 1781   120    87    69   122   108    85   125   114    77
PMkr12b 1790   134   131   114    97   117    49    69   100   123    89
PMkr12b 1800   137    89  -999    79    44    38    62    99    68    26
PMkr12b 1810    27    43    51    57    36   999

An example of a three digit resolution sample which covers the timespan AD 1781-1814, with a missing ring for AD 1802 (-999). The width of AD 1781 (the first year) annual ring is 1.20 mm and for 1782 AD 0.87 mm.

CDendro interpretation

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See also CDendro naming standard

Limitations of the Tucson format

Notes

  1. If 5 digits are needed for the year, i.e. older than -999, the identity cannot be more than 7 alphanumeric characters.