The Radiative and Cloud Characteristics of the Major TWP Cloud Regimes

Jakob, C., Bureau of Meteorology Research Centre

It has been shown that the cloud distributions encountered in the TWP region can be grouped into a small number of recurring typical regimes by means of cluster analysis. The current work uses data collected at and around the TWP ARM sites to characterize the four major TWP cloud regimes identified in a previous study from ISCCP data. The radiative properties of the regimes are derived from both ground and TOA measurements. Cloud macrophysical properties are investigated using the ARSCL cloud boundary product. Finally, radiosonde soundings and MWR measurements are used to describe the thermodynamic regimes 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 characterize 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 benefits of cloud regime dependent analysis of model errors for the development of parameterizations in GCMs will also be highlighted.

Note: This is the poster abstract presented at the meeting; an extended version was not provided by the author(s).