Jul 26, 2012

Trends and low frequency variability of extra-tropical cyclone activity in the ensemble of twentieth century reanalysis

Xiaolan L. Wang • Y. Feng, G. P. Compo, V. R. Swail, F. W. Zwiers, R. J. Allan, P. D. Sardeshmukh
Climate Dynamics
  • Applies an objective cyclone tracking algorithm to twentieth century reanalysis (20CR) 6-hourly mean sea level pressure fields for the period 1871–2010 to infer historical trends and variability in extra-tropical cyclone activity
  • Applies the tracking algorithm both to the ensemble-mean analyses and to each of the 56 ensemble members individually
  • Finds the ensemble-mean analyses are unsuitable for accurately determining cyclone statistics
  • Finds pooled cyclone statistics obtained by averaging statistics from individual members generally agree well with statistics from the NCEP-NCAR reanalyses for 1951–2010
  • Finds both reanalyses show similar cyclone trend patterns in the northern hemisphere (NH) over 1951–2010
  • Analyzes homogenized pooled cyclone statistics for trends and variability