The field experiment on landfalling tropical cyclone program with acronym of CLATEX (China Landfalling Typhoon Experiment) was implemented in July-August 2002. The main scientific objective of the experiment is to get better understanding of the impact of land topography and environmental flow on the structure and intensity change, track turning, wind and rainfall distribution of the landfalling typhoons. Advanced instruments such as doppler radar, wind-profiler, ultra sonic anemometer, optical rain gauge, radio sonde, satellite observation, automatic weather stations, tower gradient observation etc were employed.

The Severe tropical storm Vongfong (0214) was selected as a target typhoon in the experiment. The asymmetric distribution of winds, rainfall and the thermal structure of Vongfong were analyzed based on the assimilation of the data from different sources of TRMM, TBB, doppler radar, wind-profiler and AWS etc. Vongfong got intensification in a short period right before landfall. The analysis also showed that the intensification had a close relation with the latent heat flux transfer in the boundary layer and the weak cold air intrusion from the higher latitude. The SNR (signal to noise ratio) data from the wind-profiler demonstrate the variation of the boundary layer thickness around the period of Vongfong landfall.

CLATEX is a part of the Typhoon Landfall Research Program and it would like to develop an international cooperation with other coastal tropical cyclone programs around the world.