Leader of Fukushima Study: “Intense exposure” headed toward US west coast; Plume traveling very fast via oceanic jet — “High concentrations” to impact California coastal areas; Prolonged period of radioactive upwelling expected

Pacific Northwest

• Slide at 49:30 in — Northern shelves: jet-like advection of the surface plume explain the short but intense exposure.
• 42:20 in — You can see that it is not a homogenous advection, you’ve got this jet here. This jet was consistent across the ensembles, and it’s been observed also in other studies. It advected the plume faster, at about 40°N [latitude].
• 49:30 in — The surface plume is traveling very fast toward the coast of the US.
• 50:45 in — The northern shelf, we have the jet-like convection that creates the first impact with elevated concentrations.

California

 

• Slide at 49:30 in — Strong Ekman divergence delay the arrival of the surface plume. but mode water formation and subsurface 3D pathways explained the prolonged moderated exposure.
• 50:00 in — [Subsurface] water created between 2011 and 2014, that will travel and reemerge later off the coast of California… in 2021… We can see this color here of high concentration… Persistent upwelling… sources its water exactly at this [subsurface plume's] depth… this upwelling will source this water from the contaminated water and release this water into the shelf area for a while, for the longer term… They will have longer exposure because of this sinking contaminated water that went  across… and then comes up about 10 years later.
• 58:30 in — I averaged the concentration over the shelf… It doesn’t mean you’d measure it right on the coast, on the beach. I took 150 kilometers along the coast. Southern California for instance it might have already reached the coastal area, essentially because of the upwelling, it might have already reached the outer shelf. I don’t know if they’re doing any kind of measurement.