According to the studies of cyclones with increasing CO2, there is a reduction of baroclinicity at lower troposphere but an increase of that at upper troposphere. Given these changes, it is expected that the level of vertical organization of tropospheric cyclones would change.

We have examined the features and changes of the vertical consistency over surface cyclone centres with the NCEP-DOE reanalysis 2 and CSIRO MarkII atmosphere-ocean coupled GCM increasing CO2 experiments data, focusing on the SH cyclones. We have searched and tracked cyclones at six vertical levels (mean sea level, Z950, Z850, Z700, Z600, and Z500) with the Melbourne University cyclone finding and tracking scheme. For each cyclone we have developed indices quantifying the degree to which surface features are reflected at upper levels.

Statistics on the upper level cyclone characteristics such as frequency, intensity, scale, and depth are found. On top of this, the vertical organization and degree of tilting are examined. The variability of these results over the last two decades is presented.

Based on the climatology, the changes in cyclone characteristics and the vertical features under greenhouse warming are examined and discussed at this talk.