The latitude of the subtropical ridge over eastern Australia:: The L index revisited

Recent research has suggested that the position of the subtropical ridge in mean sea-level pressure over eastern Australia, referred to as the L index, has undergone a substantial poleward shift over the past century. These findings are not supported by calculations of the L index based on daily National Centers for Environmental Prediction reanalysis from 1948 to 2002, and on monthly mean Australian pressure data from 1890 to 2003. Reasons for these differences are discussed, together with the relationship between the L index and Australian rainfall. Copyright (c) 2005 Royal Meteorological Society.