The distribution of dissolved copper in the Pacific

The general form of Cu-depth profiles is unique. In the central North Pacific, values decrease from a surface maximum of about 3 nmol/kg to 1.5 nmol/kg in the upper thermocline. Below about 750 m there is an increase to over 6 nmol/kg in the bottom waters with no mid-depth extremum. The profiles in the boundary regions are similar in the deep water but do not have the surface maximum. This unique elemental distribution is maintained by aeolean input to the surface waters comparable in magnitude to the fluvial component, ubiquitous scavenging in the subsurface and deep water, and a strong bottom source. Apparently the scavenging agent, presumably sinking particles, loses its Cu-binding capacity during early diagenesis. The half-life with respect to scavenging is about 1100 years and the overall residence time with respect to input or final removal about 5000 years.