Simulations of Australian extreme rainfall and circulation during the January 2011 La Nina

Abstract

We examine the synoptics and the role of different classes of dynamical disturbances, from both observations and ensemble simulations, during of one of Australia's most severe flooding events in January 2011. We analyse ensemble simulations using the CSIRO M3L general circulation spectral model. Using wavenumber extraction techniques and dynamical mode analyses, we note the collision and convective coupling of Kelvin waves and the Madden--Julian oscillation in the Australian monsoonal region. Model simulations and the dynamical analyses are consistent with the synoptic situation, and provide a more complete explanation for the extensive precipitation impacts over Australia during January 2011. References

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