Preliminary 234Th activities are quantified at-sea. There is often a sharp gradient observed in 234Th between the coast, where export is high and total 234Th activities are lowest, and sites further offshore sites where net particulate export through the 100m horizon is small. Using these 234Th data and site and time specific measurements of the POC to 234Th ratio on particles, we can predict the POC export rates for the entire study region. There is some evidence of a localized high export event off-shore along the northern transect during the intermonsoon period. We find that our fluxes at 100m are significantly elevated over those obtained via deeper moored traps and are in general agreement regarding the delayed timing of particle export relative to the onset of strong winds during the monsoon.
Enhanced export appears to be associated with biological communities that are dominated by diatoms.
Vertical data in the upper 100m also suggest that there is considerable remineralization in the POC export flux between the upper euphotic zone and the 100m horizon.