PISTON stands for the Propagation of Intra-Seasonal Tropical OscillatioNs. While numerous tropical intra-seasonal oscillations exist, PISTON will primarily target the Boreal Summer Intraseasonal Oscillation (BSISO). The BSISO defines the northward and eastward movement of the Asian monsoon during northern-hemispheric (boreal) summertime. This oscillation has been observed to impact weather across the Maritime Continent and into the southeastern portions of continental Asia, and even weather within the United States. The BSISO is rather complex, and PISTON is therefore an extensive field campaign, involving both intensive numerical modeling and observational activities. Namely, the PISTON campaign emphasizes two scientific questions:

1. How do localized features such as island orography and individual thunderstorms influence tropical intraseasonal oscillations?
2. How does variability in large-scale atmospheric circulations over the South China Sea influence the diurnal cycle, synoptic systems, and interactions between the atmosphere and ocean within the Maritime Continent?

PISTON Field Campaign website