Please read about a potential issue if you acquired daily 2m air temperature files between 8/14/2014 and 11/7/2014.
We have transitioned the data files from netCDF3 to netCDF4-classic format (transition date: Aug 14th).

20th Century Reanalysis

Referencing plots produced at NOAA/ESRL PSD

We ask that you acknowledge the Physical Sciences Division of NOAA/ESRL in your publication/talk/presentation. For example, "Image provided by the NOAA-ESRL Physical Sciences Division, Boulder Colorado from their Web site at http://www.esrl.noaa.gov/psd/".

You should also reference the dataset. Papers using the Twentieth Century Reanalysis Project dataset are requested to include the following text in their acknowledgments: "Support for the Twentieth Century Reanalysis Project dataset is provided by the U.S. Department of Energy, Office of Science Innovative and Novel Computational Impact on Theory and Experiment (DOE INCITE) program, and Office of Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Office."