Dynamics of the Boreal Summer Intraseasonal Oscillation: Multiscale Interactions

University Of Hawaii, Honolulu

Investigators

Abstract

This project examines the Boreal Summer Intraseasonal Oscillation (BSISO), a tropical mode of variation in precipitation, cloudiness, and winds of large spatial extent. The work examines the impact of the BSISO on the Asian summer monsoon and the extent to which this impact is predictable. The research also considers the relationship between the BSISO and the Quasi-Biweekly (QBW) Oscillation, which is of interest because the combined activity of the BSISO and QBW oscillation is associated with droughts and floods over northern India. The BSISO can be regarded as a large and slow moving envelope of cloud systems and precipitation, and a specific focus of the work is the extent to which upscale transports of heat and momentum from the cloud systems within the BSISO are responsible for its development and propagation. The research will be conducted using a combination of statistical diagnostic analysis, experiments with a global cloud resolving model, and a coupled ocean-atmosphere general circulation model. The BSISO is thought to be important for determining the active and break periods of the Asian monsoon and may thus be of great agricultural importance for a large and densely populated region of the earth. A better understanding of the BSISO may lead to improvements in forecasts of precipitation, floods, and droughts for South and Southeast Asia. in addition, the project provides support and training for a postdoctoral researcher, thereby providing for the development of the scientific work force in this area.