Poster Presentation AMOS Annual Meeting and International Conference on Tropical Meteorology and Oceanography

Using an event perspective to investigate heatwave dynamics (#1030)

Malcolm J King 1 , Michael Reeder 1
  1. ARC Centre of Excellence for Climate Extremes and School of Earth, Atmosphere and Environment, Monash University, Clayton, VIC, Australia

There a range of heatwave measurements and definitions, but these are often defined with regards to a single location, which limits the ability to investigate the spatial movement and extent of heat extremes. However, by combining these heatwave definitions with a spatial connection constraint, it is possible to define and examine individual heatwave events.

We utilise this approach upon ERA-Interim reanalysis data to examine the evolution and dynamics of Australian heatwaves and find that, contrary to common perception, heatwaves over south-eastern Australia do not emanate from anomalously hot conditions in inland Australia but rather tend to follow heat extremes over south-western Australia and the Great Australian Bight. The mechanisms behind the anomalous heat during these events is investigated using back-trajectory analysis, and are consistent with heating coming predominately from compression during descent of air through the troposphere.

The event framework will also be used to investigate differences in the evolution and extent of heatwaves that feature greater compressive heating from those that feature greater heating through diabatic processes; preferred pathways/directions of heatwave development, and differences in heatwave dynamics between the beginning and end of a heatwave event.