Climate Variability and Weather Extremes
How will the key science questions be addressed?
Can we improve dynamical understanding of the El Nino/Southern Oscillation (ENSO) and use this understanding to investigate and correct errors in the representation (including parameterisation) of physical processes in dynamical models?
Observations from the Argo array, Indonesian Throughflow (ITF) current time series and improved satellite data-streams (from surface validation) will lead to an improved understanding of ENSO. Data assimilated into models will enable realistic mechanisms to be determined. Ongoing projects will lead into the above questions. Analysis and interpretation of the observations will be supported by CAWCR modelling activities in POAMA and ACCESS.
Are we able to improve dynamical understanding of the Indian Ocean Dipole (IOD). How do decadal periods of high IOD activity depend on the depth of the thermocline off Sumat
era as a pre-condition?
These questions require long-term datasets provided by Argo, satellite platforms, research cruises and improved ocean and coupled models. The ITF array will provide long-term measurements of the strength of this inflow – vital to understanding the climate influences of the Pacific-Indian Ocean connection. Researchers at UNSW have recently taken the lead in IOD research and some activity is ongoing in CAWCR. Modelling at both institutions supports analysis and interpretation. A new UNSW collaboration with a leading ocean-climate modelling group in Kiel, Germany will address the above questions.
How could the Madden Julian Oscillation (MJO) be used to predict climate (e.g. rainfall patterns) at intraseasonal to interannual timescales?
How does the MJO interact with other recurrent climate processes, such as ENSO, IOD and the Australian monsoon?
How does intraseasonal variability interact with the upper ocean off northwest Australia?
How can the observed correlation of interannual tropical cyclone activity to seasonal SST be incorporated into dynamical prediction models?
Improved understanding and modelling of seasonal and intraseasonal climate and severe weather hinges on better resolving and simulating ocean-atmosphere fluxes and upper ocean responses. The SOOP SST, flux measurements and the next stage RAMA (Research Moored Array for African–Asian–Australian Monsoon Analysis and Prediction) buoy will provide improved resolution of near-surface diurnal cycles and surface fluxes. This research is carried out primarily at CAWCR, in close coordination with ENSO research.
How do interactions between the atmosphere and the ocean surface layer, e.g. the exchange of heat and moisture, affect climate processes?
Identify the mechanisms that control SST in different climate modes at different times through heat budget studies?
Observations from the flux moorings, underway measurements (flux, SST) and Argo will provide important contributions to this question. In particular the Southern Ocean surface flux mooring will determine the magnitude and variability of air-sea heat, freshwater and carbon exchange for the Southern Ocean and waters around Australia.
Are we able to improve the data assimilation and initialisation systems in POAMA (Predictive Ocean Atmosphere Model for Australia)?
Improvements in both assimilation and initialisation of POAMA is centrally related to both the quantity and quality of observations of temperature, salinity and surface height available from both in situ and satellite sources. The IMOS contributions to the Argo array, XBT lines, support for satellite calibration-validation are of major importance.