Climate variability

(i) Primary objectives

The goal of this research group is to understand the variability of the climate of the Antarctic Peninsula and adjacent sea areas for the period of the last 50 years and to gain insight into the mechanisms behind the observed changes. Both interannual variability and longer term changes are far greater in this region than those seen elsewhere in Antarctica. The climate of the Peninsula region is determined by a complex interaction between the atmospheric and oceanic circulations and the seasonally varying sea ice cover. Investigations will examine the role of each of these elements using a variety of tools. The surface meteorological observations, which have been collected since the late 1940s, will provide the basic record of the main surface variables over the Peninsula. Further work will be carried out to understand the warming trend and the increase in the number of precipitation events observed over the last 40 years. Numerical analyses provides by the Australian Bureau of Meteorology are available since the early 1970s and will be used to study atmospheric circulation changes over the last 20 years and to investigate the links between the main climatic cycles of the Southern Hemisphere and the observed changes over the Peninsula. Fields of sea ice cover are also available for about 20 years from satellite passive microwave measurements and these data will be used in conjunction with the atmospheric data to study sea ice-atmospheric links. Complementary modelling work will also take place in conjunction with the UK Meteorological Office on the performance of GCMs at high southern latitudes.

(ii) Strengths and achievements

In recent years there has been a major effort to assemble computer data sets of atmospheric data as an aid to climate studies of the Antarctic. The meteorological data collected at the research stations has been progessively entered into an Oracle data base and most of the observations since the 1950s are now loaded and quality controlled. The Australian daily surface and upper air analyses are also available for access in numerical form along with monthly mean fields. High resolution satellite imagery from the ARIES receiver is also available since early 1993 allowing the circulation over selected period to be monitored.

Some of the main achievements of the last five years are:

(iii) Future strategy

Work will concentrate on investigation of the reasons for change in the climate of the Peninsula and understanding the role of the Antarctic in the global climate system. There will be close cooperation with the ice core analysts and an important element of the work will be to try and link the conventional meteorological data and the climate records observed in the ice data. The dual approachs of observational and modelling activities will be central to the work with one of the main goals being to improve the representation of the climate of the Antarctic in GCMs.