exNGT is an R software project to analyze the new NGT-2012 stable oxygen isotope stack time series covering the last millennium up to the year 2011 CE, which is built from an extended North Greenland Traverse (NGT) firn core dataset. This project includes the compilation and the processing of all relevant data as well as all analyses related to the new NGT-2012 stack, including the comparison with other climate datasets for the Arctic region.

The software project is a supplement to the journal article Modern temperatures in central–north Greenland warmest in past millennium by Hörhold, M., Münch, T., Weißbach, S. et al., published in Nature, 613, 503–507 (2023).