The past few decades of serious drought in the southwestern corner of Australia may be highly unusual compared with the past 750 years, suggests a study published online this week in Nature Geoscience. The report reveals a close association between drought in southwestern Australia and high amounts of snowfall at Law Dome, East Antarctica, as a result of a pattern of atmospheric circulation that brings dry, cool air to Australia, while transporting warm, moist air to East Antarctica.
Tas van Ommen and colleague compared records of precipitation at Law Dome, Antarctica and in southwestern Australia, and found a strong inverse relationship. Ice-core data from Law Dome show that the recent snowfall anomaly at Law Dome is highly unusual relative to the variability throughout the full 750-year record, and suggest that the same may hold for the Australian drought.
The researchers point out that the airflow responsible for both southwest Australian drought and high East Antarctic snowfall is consistent with some projections for circulation changes associated with human-induced climate change.