These findings suggest that there are two sources of low ∆ 14C waters that
upwell at the Galapagos, Subantarctic Mode Water and shallow overturning water from the subpolar North Pacific.
«This is particularly important
at the Antarctic Polar Front (red boxed area in the scheme, the area where the «old», CO2 - rich waters described in the article
upwell to the surface and release CO2 to the atmosphere), where an enormous amount of biological production takes place in late spring / summer.