Evaluation of satellite-derived objective potential index for oceanic cloud system during the Mei-Yu period

Many mesoscale convective systems (MCSs) accompanied by heavy rainfall are frequently observed over the Taiwan Strait along the Mei-Yu front. An objective potential index of air-sea interaction was proposed by employing satellite data for pointing out areas where oceanic convective clouds may occur and develop into MCSs [11]. The aim of present research is to evaluate that index through the data of 2001 and 2002. The results show that a greater objective potential index is correlated with a larger probability of colder infrared brightness temperature. In addition, the analysis of serial correlation for these two discrete parameters (objective potential index and GMS-5 IR1 brightness temperature) showed that the correlation coefficient is bigger in the South areas than in the North areas. Also, the leading time is larger in the Southareas. That may imply the air-sea interaction play a more important role and the oceanic convective clouds are more possible to start-up due to the effect of air-sea interaction in the South areas. Since the synoptic scale environmental condition does also play an important role in oceanic convective systems' development, an improved objective potential index with the information of air conditional instability is under the investigation and it will be proposed in the near future.