Twentieth Century Reanalysis (V2): Opportunities for Improvement

  1. 7 July 2011: For the days of 6 June 1886, 1 January 1952, 7 July 2004, and 24 January 2007, ensemble mean and spread values derived from every-member 20CRv2 data at the NERSC Science Gateway http://portal.nersc.gov/project/20C_Reanalysis/ will differ from those obtained from here at NOAA ESRL http://www.esrl.noaa.gov/psd/data/gridded/data.20thC_ReanV2.html and NCAR ds131.1 http://dss.ucar.edu/datasets/ds131.1/. The every-member data at the NERSC portal are prior to re-runs to correct problems with the data archiving for these periods. The data online here and at NCAR are derived from the re-run fields.
  2. (originally posted 1/20/2010; updated 7/8/2010) Sea Ice concentration used by the data assimilation system is lower than the specified HadISST1.1 in many coastal regions of the Arctic and Antarctic. This appears to have resulted in a warm bias in the lowest parts of the troposphere of both poles near the land areas, particularly during the non-summer seasons.