Sep 7, 2007

Interdecadal trend and ENSO-related interannual variability in Southern Hemisphere blocking

by
Li Dong, Timothy J. Vogelsang, and Stephen J. Colucci
,
American Meteorological Society
  • Analyzes the interdecadal trend and ENSO-related interannual variability in the frequency and intensity of atmospheric blocking in the Southern Hemisphere using a statistical model that takes account of serial correlation in the datasets
  • Results suggest that an autoregressive process AR(1) fits the error term of the Southern Hemisphere blocking occurrence series, and a white-noise process AR(0) fits the error term of the Southern Hemisphere blocking intensity series reasonably well
  • Finds that the Southern Hemisphere blocking days have decreased over the past 52 yr (1948–99) but with an enhanced intensity
  • Finds that the Southern Hemisphere atmospheric blocking occurs more frequently in the warm phase of ENSO cycles, whereas the intensity of the Southern Hemisphere atmospheric blocking does not appear to be affected by ENSO cycles