Tucson format

Tucson format or decadal format or rwl format is one of the most common formats for ring width data storing. 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 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 letters or digits), year of the oldest measurement of the line (4 digits) ring width data, up to ten rings per line. Measurement data is either given with 3 or 4 digits according to resolution. Except the first and last line of each core there are measurements for one decade per line. After the youngest ring there is a "999" as 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 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.