The Impact of COSMIC GPS RO Data on the Analysis and Prediction of Tropical Cyclogenesis

Tropical cyclonesis remains as one of the most challenging problems in atmospheric sciences, and is still subject to lively debate. Some argue that the tropical cyclogenesis is mostly controlled by large-scale circulations, and therefore, possesses a high degree of predictability. Others argue that the large-scale circulations only provides a favorable environment, the actual cyclogenesis is significantly affected by small-scale processes (in particular, organized convection). As a result, it is essentially a stochastic process, with low predictability. The study of tropical cyclogenesis is greatly hindered by the lack of observational data over tropical oceans. In particular, the lack of reliable moisture observations presents significant challenge for the analysis and prediction of tropical cyclogenesis. Over the past decade, radio occultation (RO) technique making use of signals transmitted by Global Positioning System (GPS) has emerged as one of the most promising global observing system. In particular, GPS RO observation has been shown to be of high accuracy and high vertical resolution, and it is not affected by clouds and prediction. This makes it ideally suited for the study of tropical cyclogenesis. With the launch of the six-satellite constellation COSMIC mission, approximately 2,000 GPS RO soundings per day are routinely available, uniformly distributed around the globe. This presents an exciting new opportunity to study the impact of GPS RO data on tropical cyclogenesis.