Australian Climate Maps - Map information

About these maps: These maps showing broadscale atmospheric circulation patterns are monthly mean and anomaly maps, showing analyses derived from the Bureau of Meteorology's GASP and ACCESS models. [Data up to May 2010 are from the GASP model, data from June 2010 are from the ACCESS model.] The 00Z analyses for each day in the month are used to generate the monthly fields. The monthly maps are typically generated in the first few days of the following month.

Some fields and anomalies are not shown over regions of elevated topography. 200 hPa velocity potential and divergent winds data are only available up to May 2010.

For maps of Outgoing Longwave Radiation (OLR), the underlying daily data are obtained from the United States of America NOAA Climate Prediction Center (external site).

Climatology: The climatology in use up until the end of 2003 for generation of the anomalies was based on ECMWF analyses for the period 1979-1989. For 2004 onwards, the climatology in use is based on the United States of America's National Centers for Environmental Prediction NCEP2 re-analyses for the period 1979-2000.

For OLR data, anomalies are calculated as the difference from the 1979 to 1998 mean after removing the annual cycle.

Map Projections: The maps are presented in five projections: (a) global maps in the cylindrical equidistant projection, (b) southern hemispheric maps in the polar stereographic projection, (c) the South Pacific, in the Mercator projection, (d) the Asia/Pacific tropics, in the Mercator projection, and (e) Australian region maps in a Lambert Conformal projection with standard parallels 10°S and 40°S.

This page last modified 30 June 2010.