This project will investigate the low-frequency variability of the tropical atmosphere and oceans. Research activities fall into three broad areas. First, predictability of intraseasonal variability accompanying the Asian monsoon. Earlier work suggests variations in monsoon rainfall which can cause severe flooding and substantial agricultural impacts in South Asia may be predictable, and work under this grant will construct and test forecasting methods for this intraseasonal variability. Second, the thermodynamic and dynamic processes which determine the size of the western Pacific warm pool, the region of largest sea surface temperature (SST) in the Pacific ocean, which is characterized by large-scale atmospheric convection and precipitation. The area of the warm pool has increased dramatically over the last 30 years, yet the area of large-scale convection has remained constant. Work conducted here seeks to determine the factors which control the size of the warm pool and convecting region and determine their year-to-year variability and long-term secular change. Third, the underlying dynamics of the year-to-year variability of the Asian monsoon. The work will focus on the possibility that years of extremely deficient and extremely excessive monsoon rainfall in India may be predictable.
The broader impacts of the work go beyond the scientific goals of understanding tropical climate dynamics, since fluctuations in monsoon rainfall have severe effects on the populations of South and Southeast Asia. The research has a strong emphasis on developing forecast methodologies which could be of considerable practical value. In addition, research funds will provide training, education, and support for two graduate students and two postdoctoral scholars.
