Coverage bias in the HadCRUT4 temperature record

Kevin Cowtan and Robert Way

Methods and Data

This page provides code and data required to reproduce all the calculations from the paper. A unix-like system is required (Linux or Mac), although a Windows system with MinGW may also do. Python 2.6/7 is required along with the numpy/scipy and matplotlib libraries. Shell scripts require csh/tcsh. A rudimentary knowledge of the Unix command line is assumed.

Temperature data are files contain 3 columns: Fractional date, Temperature, Standard uncertainty due to coverage only (1σ). Map data are in a similar format to the ascii files provided by Hadley or NCDC, i.e. 1 line with year and month followed by 36 lines of 72 values.