Summary
Comparison of ice core records from Law Dome, East Antarctica and meteorological records shows that periods of strengthened atmospheric zonal wave three (ZW3) circulation drive enhanced meridional transport of moisture and tend to produce higher snowfall at Law Dome. This enhanced meridional circulation is accompanied by transport of cold, dry air]masses to the southwest of Western Australia which has been linked with drought over recent decades. In this paper, this link is examined and some of the wider implications of ZW3 circulation are discussed. The ZW3 pattern has been shown to modulate sea]ice extent and also proposed as an important factor in decadal]scale variability at mid]latitudes. Strengthening of the ZW3 pattern as a result of ozone and possibly greenhouse gas changes has been suggested and changes consistent with this are seen in meridional wind stress in some AR4 model runs. Work from the Law Dome ice core record of precipitation shows a stronger sensitivity to the ZW3 structure in the Australian sector than to the full hemispheric pattern. This makes sense because Law Dome is within this sector, but suggests that asymmetries within the ZW3 pattern are important as well as variations in the overall pattern itself.