CSIRO Marine and Atmospheric Research
Past Seminars

Wednesday 25 February 2003, 11.30 am (Tas time)

CSIRO Auditorium, Hobart

Dr Christian Jakob
Bureau of Meteorology Research Centre

The major Tropical Western Pacific cloud regimes and their cloud and radiative characteristics

Data collected at and around the Tropical Western Pacific (TWP) Atmospheric Radiation Measurement Program (ARM) sites is used to characterise the four major TWP cloud regimes identified objectively from International Satellite Cloud Climatology Project (ISCCP) data. The radiative properties of the regimes are derived from both ground and TOA measurements. Cloud “macrophysical” properties are investigated using a cloud boundary product derived from ground-based active remote sensors. Finally, radiosonde soundings and microwave radiometer measurements are used to describe the thermodynamic conditions under which each of the regimes is likely to occur.

Several conclusions can be drawn. First, while the cloud regimes have been derived for the entire TWP region, data at the ARM sites only can be used to consistently characterise the regime properties. This indicates that the ARM sites are representative sites to measure the key features encountered in TWP cloud systems. This result is of further significance, since it might enable the use of measurements only obtainable at those sites (e.g., vertical profiles of cloud fraction) to characterize cloud properties over the entire TWP. The potential benefit of cloud regime dependent analysis of model errors for the development of parameterisations in GCMs will also be highlighted.

Followed by

The Tropical Warm Pool International Cloud Experiment (TWP-ICE) in Darwin 2006

A major international field experiment focusing on the role of clouds, in particular convectively generated cirrus during the Australian monsoon, will be conducted in Darwin in January/February 2006. A brief overview of the different components of the experiment will be given with some focus on the potential role of the RV Southern Surveyor. The current status of planning of the experiment will be summarised.