Comparing the vertical distribution of iron in the eastern and western North Pacific Ocean

Labile dissolved Fe (< 0.22 mu m) in the western (165 degrees E) and eastern (165 degrees W) North Pacific Ocean had nutrient- and apparent oxygen utilization (AOU)- like profiles characterized by surface depletion and deep enrichment ( 5 - 3000 m depth). Dissolved Fe concentrations in the deep-water column at the mid-latitudes were approximately one-half lower in the eastern region (0.5 - 0.8 nM) than in the western region ( 0.8 - 1.3 nM) although the dissolved Fe concentrations in the surface mixed layer in both regions were extremely depleted to 0.1 - 0.2 nM. Surprisingly, the labile particulate Fe concentrations (<=similar to 0.1 nM, total dissolvable Fe minus labile dissolved Fe) throughout the water column at low latitudes in the eastern region were extremely lower than those (similar to 0.5 - 1 nM) in the western region. It is suggested that the low Fe levels in the eastern mid-latitude oceanic region are primarily due to the lower atmospheric Fe supply in the eastern region.